text: #include "node.h"
  #include "node_buffer.h"
  #include "node_constants.h"
  #include "node_file.h"
  #include "node_http_parser.h"
  #include "node_javascript.h"
  #include "node_version.h"
  #include "node_v8_platform.h"
  
  #if defined HAVE_PERFCTR
  #include "node_counters.h"
  #endif
  
  #if HAVE_OPENSSL
  #include "node_crypto.h"
  #endif
  
  #if defined(NODE_HAVE_I18N_SUPPORT)
  #include "node_i18n.h"
  #endif
  
  #if defined HAVE_DTRACE || defined HAVE_ETW
  #include "node_dtrace.h"
  #endif
  
  #include "ares.h"
  #include "async-wrap.h"
  #include "async-wrap-inl.h"
  #include "env.h"
  #include "env-inl.h"
  #include "handle_wrap.h"
  #include "req_wrap.h"
  #include "string_bytes.h"
  #include "util.h"
  #include "uv.h"
  #include "v8-debug.h"
  #include "v8-profiler.h"
  #include "zlib.h"
  
  #include <errno.h>
  #include <limits.h>  // PATH_MAX
  #include <locale.h>
  #include <signal.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <sys/types.h>
  
  #if defined(_MSC_VER)
  #include <direct.h>
  #include <io.h>
  #include <process.h>
  #define strcasecmp _stricmp
  #define getpid _getpid
  #define umask _umask
  typedef int mode_t;
  #else
  #include <sys/resource.h>  // getrlimit, setrlimit
  #include <unistd.h>  // setuid, getuid
  #endif
  
  #if defined(__POSIX__) && !defined(__ANDROID__)
  #include <pwd.h>  // getpwnam()
  #include <grp.h>  // getgrnam()
  #endif
  
  #ifdef __APPLE__
  #include <crt_externs.h>
  #define environ (*_NSGetEnviron())
  #elif !defined(_MSC_VER)
  extern char **environ;
  #endif
  
  namespace node {
  
  using v8::Array;
  using v8::ArrayBuffer;
  using v8::Boolean;
  using v8::Context;
  using v8::EscapableHandleScope;
  using v8::Exception;
  using v8::Function;
  using v8::FunctionCallbackInfo;
  using v8::FunctionTemplate;
  using v8::Handle;
  using v8::HandleScope;
  using v8::HeapStatistics;
  using v8::Integer;
  using v8::Isolate;
  using v8::Local;
  using v8::Locker;
  using v8::Message;
  using v8::Number;
  using v8::Object;
  using v8::ObjectTemplate;
  using v8::PropertyCallbackInfo;
  using v8::String;
  using v8::TryCatch;
  using v8::Uint32;
  using v8::V8;
  using v8::Value;
  using v8::kExternalUint32Array;
  
  static bool print_eval = false;
  static bool force_repl = false;
  static bool trace_deprecation = false;
  static bool throw_deprecation = false;
  static const char* eval_string = nullptr;
  static bool use_debug_agent = false;
  static bool debug_wait_connect = false;
  static int debug_port = 5858;
  static bool v8_is_profiling = false;
  static bool node_is_initialized = false;
  static node_module* modpending;
  static node_module* modlist_builtin;
  static node_module* modlist_linked;
  static node_module* modlist_addon;
  
  #if defined(NODE_HAVE_I18N_SUPPORT)
  // Path to ICU data (for i18n / Intl)
  static const char* icu_data_dir = nullptr;
  #endif
  
  // used by C++ modules as well
  bool no_deprecation = false;
  
  // process-relative uptime base, initialized at start-up
  static double prog_start_time;
  static bool debugger_running;
  static uv_async_t dispatch_debug_messages_async;
  
  static Isolate* node_isolate = nullptr;
  
  int WRITE_UTF8_FLAGS = v8::String::HINT_MANY_WRITES_EXPECTED |
                         v8::String::NO_NULL_TERMINATION;
  
  class ArrayBufferAllocator : public ArrayBuffer::Allocator {
   public:
    // Impose an upper limit to avoid out of memory errors that bring down
    // the process.
    static const size_t kMaxLength = 0x3fffffff;
    static ArrayBufferAllocator the_singleton;
    virtual ~ArrayBufferAllocator() = default;
    virtual void* Allocate(size_t length) override;
    virtual void* AllocateUninitialized(size_t length) override;
    virtual void Free(void* data, size_t length) override;
   private:
    ArrayBufferAllocator() = default;
    DISALLOW_COPY_AND_ASSIGN(ArrayBufferAllocator);
  };
  
  ArrayBufferAllocator ArrayBufferAllocator::the_singleton;
  
  
  void* ArrayBufferAllocator::Allocate(size_t length) {
    if (length > kMaxLength)
      return nullptr;
    char* data = new char[length];
    memset(data, 0, length);
    return data;
  }
  
  
  void* ArrayBufferAllocator::AllocateUninitialized(size_t length) {
    if (length > kMaxLength)
      return nullptr;
    return new char[length];
  }
  
  
  void ArrayBufferAllocator::Free(void* data, size_t length) {
    delete[] static_cast<char*>(data);
  }
  
  
  static void CheckImmediate(uv_check_t* handle) {
    Environment* env = Environment::from_immediate_check_handle(handle);
    HandleScope scope(env->isolate());
    Context::Scope context_scope(env->context());
    MakeCallback(env, env->process_object(), env->immediate_callback_string());
  }
  
  
  static void IdleImmediateDummy(uv_idle_t* handle) {
    // Do nothing. Only for maintaining event loop.
    // TODO(bnoordhuis) Maybe make libuv accept nullptr idle callbacks.
  }
  
  
  static inline const char *errno_string(int errorno) {
  #define ERRNO_CASE(e)  case e: return #e;
    switch (errorno) {
  #ifdef EACCES
    ERRNO_CASE(EACCES);
  #endif
  
  #ifdef EADDRINUSE
    ERRNO_CASE(EADDRINUSE);
  #endif
  
  #ifdef EADDRNOTAVAIL
    ERRNO_CASE(EADDRNOTAVAIL);
  #endif
  
  #ifdef EAFNOSUPPORT
    ERRNO_CASE(EAFNOSUPPORT);
  #endif
  
  #ifdef EAGAIN
    ERRNO_CASE(EAGAIN);
  #endif
  
  #ifdef EWOULDBLOCK
  # if EAGAIN != EWOULDBLOCK
    ERRNO_CASE(EWOULDBLOCK);
  # endif
  #endif
  
  #ifdef EALREADY
    ERRNO_CASE(EALREADY);
  #endif
  
  #ifdef EBADF
    ERRNO_CASE(EBADF);
  #endif
  
  #ifdef EBADMSG
    ERRNO_CASE(EBADMSG);
  #endif
  
  #ifdef EBUSY
    ERRNO_CASE(EBUSY);
  #endif
  
  #ifdef ECANCELED
    ERRNO_CASE(ECANCELED);
  #endif
  
  #ifdef ECHILD
    ERRNO_CASE(ECHILD);
  #endif
  
  #ifdef ECONNABORTED
    ERRNO_CASE(ECONNABORTED);
  #endif
  
  #ifdef ECONNREFUSED
    ERRNO_CASE(ECONNREFUSED);
  #endif
  
  #ifdef ECONNRESET
    ERRNO_CASE(ECONNRESET);
  #endif
  
  #ifdef EDEADLK
    ERRNO_CASE(EDEADLK);
  #endif
  
  #ifdef EDESTADDRREQ
    ERRNO_CASE(EDESTADDRREQ);
  #endif
  
  #ifdef EDOM
    ERRNO_CASE(EDOM);
  #endif
  
  #ifdef EDQUOT
    ERRNO_CASE(EDQUOT);
  #endif
  
  #ifdef EEXIST
    ERRNO_CASE(EEXIST);
  #endif
  
  #ifdef EFAULT
    ERRNO_CASE(EFAULT);
  #endif
  
  #ifdef EFBIG
    ERRNO_CASE(EFBIG);
  #endif
  
  #ifdef EHOSTUNREACH
    ERRNO_CASE(EHOSTUNREACH);
  #endif
  
  #ifdef EIDRM
    ERRNO_CASE(EIDRM);
  #endif
  
  #ifdef EILSEQ
    ERRNO_CASE(EILSEQ);
  #endif
  
  #ifdef EINPROGRESS
    ERRNO_CASE(EINPROGRESS);
  #endif
  
  #ifdef EINTR
    ERRNO_CASE(EINTR);
  #endif
  
  #ifdef EINVAL
    ERRNO_CASE(EINVAL);
  #endif
  
  #ifdef EIO
    ERRNO_CASE(EIO);
  #endif
  
  #ifdef EISCONN
    ERRNO_CASE(EISCONN);
  #endif
  
  #ifdef EISDIR
    ERRNO_CASE(EISDIR);
  #endif
  
  #ifdef ELOOP
    ERRNO_CASE(ELOOP);
  #endif
  
  #ifdef EMFILE
    ERRNO_CASE(EMFILE);
  #endif
  
  #ifdef EMLINK
    ERRNO_CASE(EMLINK);
  #endif
  
  #ifdef EMSGSIZE
    ERRNO_CASE(EMSGSIZE);
  #endif
  
  #ifdef EMULTIHOP
    ERRNO_CASE(EMULTIHOP);
  #endif
  
  #ifdef ENAMETOOLONG
    ERRNO_CASE(ENAMETOOLONG);
  #endif
  
  #ifdef ENETDOWN
    ERRNO_CASE(ENETDOWN);
  #endif
  
  #ifdef ENETRESET
    ERRNO_CASE(ENETRESET);
  #endif
  
  #ifdef ENETUNREACH
    ERRNO_CASE(ENETUNREACH);
  #endif
  
  #ifdef ENFILE
    ERRNO_CASE(ENFILE);
  #endif
  
  #ifdef ENOBUFS
    ERRNO_CASE(ENOBUFS);
  #endif
  
  #ifdef ENODATA
    ERRNO_CASE(ENODATA);
  #endif
  
  #ifdef ENODEV
    ERRNO_CASE(ENODEV);
  #endif
  
  #ifdef ENOENT
    ERRNO_CASE(ENOENT);
  #endif
  
  #ifdef ENOEXEC
    ERRNO_CASE(ENOEXEC);
  #endif
  
  #ifdef ENOLINK
    ERRNO_CASE(ENOLINK);
  #endif
  
  #ifdef ENOLCK
  # if ENOLINK != ENOLCK
    ERRNO_CASE(ENOLCK);
  # endif
  #endif
  
  #ifdef ENOMEM
    ERRNO_CASE(ENOMEM);
  #endif
  
  #ifdef ENOMSG
    ERRNO_CASE(ENOMSG);
  #endif
  
  #ifdef ENOPROTOOPT
    ERRNO_CASE(ENOPROTOOPT);
  #endif
  
  #ifdef ENOSPC
    ERRNO_CASE(ENOSPC);
  #endif
  
  #ifdef ENOSR
    ERRNO_CASE(ENOSR);
  #endif
  
  #ifdef ENOSTR
    ERRNO_CASE(ENOSTR);
  #endif
  
  #ifdef ENOSYS
    ERRNO_CASE(ENOSYS);
  #endif
  
  #ifdef ENOTCONN
    ERRNO_CASE(ENOTCONN);
  #endif
  
  #ifdef ENOTDIR
    ERRNO_CASE(ENOTDIR);
  #endif
  
  #ifdef ENOTEMPTY
    ERRNO_CASE(ENOTEMPTY);
  #endif
  
  #ifdef ENOTSOCK
    ERRNO_CASE(ENOTSOCK);
  #endif
  
  #ifdef ENOTSUP
    ERRNO_CASE(ENOTSUP);
  #else
  # ifdef EOPNOTSUPP
    ERRNO_CASE(EOPNOTSUPP);
  # endif
  #endif
  
  #ifdef ENOTTY
    ERRNO_CASE(ENOTTY);
  #endif
  
  #ifdef ENXIO
    ERRNO_CASE(ENXIO);
  #endif
  
  
  #ifdef EOVERFLOW
    ERRNO_CASE(EOVERFLOW);
  #endif
  
  #ifdef EPERM
    ERRNO_CASE(EPERM);
  #endif
  
  #ifdef EPIPE
    ERRNO_CASE(EPIPE);
  #endif
  
  #ifdef EPROTO
    ERRNO_CASE(EPROTO);
  #endif
  
  #ifdef EPROTONOSUPPORT
    ERRNO_CASE(EPROTONOSUPPORT);
  #endif
  
  #ifdef EPROTOTYPE
    ERRNO_CASE(EPROTOTYPE);
  #endif
  
  #ifdef ERANGE
    ERRNO_CASE(ERANGE);
  #endif
  
  #ifdef EROFS
    ERRNO_CASE(EROFS);
  #endif
  
  #ifdef ESPIPE
    ERRNO_CASE(ESPIPE);
  #endif
  
  #ifdef ESRCH
    ERRNO_CASE(ESRCH);
  #endif
  
  #ifdef ESTALE
    ERRNO_CASE(ESTALE);
  #endif
  
  #ifdef ETIME
    ERRNO_CASE(ETIME);
  #endif
  
  #ifdef ETIMEDOUT
    ERRNO_CASE(ETIMEDOUT);
  #endif
  
  #ifdef ETXTBSY
    ERRNO_CASE(ETXTBSY);
  #endif
  
  #ifdef EXDEV
    ERRNO_CASE(EXDEV);
  #endif
  
    default: return "";
    }
  }
  
  const char *signo_string(int signo) {
  #define SIGNO_CASE(e)  case e: return #e;
    switch (signo) {
  #ifdef SIGHUP
    SIGNO_CASE(SIGHUP);
  #endif
  
  #ifdef SIGINT
    SIGNO_CASE(SIGINT);
  #endif
  
  #ifdef SIGQUIT
    SIGNO_CASE(SIGQUIT);
  #endif
  
  #ifdef SIGILL
    SIGNO_CASE(SIGILL);
  #endif
  
  #ifdef SIGTRAP
    SIGNO_CASE(SIGTRAP);
  #endif
  
  #ifdef SIGABRT
    SIGNO_CASE(SIGABRT);
  #endif
  
  #ifdef SIGIOT
  # if SIGABRT != SIGIOT
    SIGNO_CASE(SIGIOT);
  # endif
  #endif
  
  #ifdef SIGBUS
    SIGNO_CASE(SIGBUS);
  #endif
  
  #ifdef SIGFPE
    SIGNO_CASE(SIGFPE);
  #endif
  
  #ifdef SIGKILL
    SIGNO_CASE(SIGKILL);
  #endif
  
  #ifdef SIGUSR1
    SIGNO_CASE(SIGUSR1);
  #endif
  
  #ifdef SIGSEGV
    SIGNO_CASE(SIGSEGV);
  #endif
  
  #ifdef SIGUSR2
    SIGNO_CASE(SIGUSR2);
  #endif
  
  #ifdef SIGPIPE
    SIGNO_CASE(SIGPIPE);
  #endif
  
  #ifdef SIGALRM
    SIGNO_CASE(SIGALRM);
  #endif
  
    SIGNO_CASE(SIGTERM);
  
  #ifdef SIGCHLD
    SIGNO_CASE(SIGCHLD);
  #endif
  
  #ifdef SIGSTKFLT
    SIGNO_CASE(SIGSTKFLT);
  #endif
  
  
  #ifdef SIGCONT
    SIGNO_CASE(SIGCONT);
  #endif
  
  #ifdef SIGSTOP
    SIGNO_CASE(SIGSTOP);
  #endif
  
  #ifdef SIGTSTP
    SIGNO_CASE(SIGTSTP);
  #endif
  
  #ifdef SIGBREAK
    SIGNO_CASE(SIGBREAK);
  #endif
  
  #ifdef SIGTTIN
    SIGNO_CASE(SIGTTIN);
  #endif
  
  #ifdef SIGTTOU
    SIGNO_CASE(SIGTTOU);
  #endif
  
  #ifdef SIGURG
    SIGNO_CASE(SIGURG);
  #endif
  
  #ifdef SIGXCPU
    SIGNO_CASE(SIGXCPU);
  #endif
  
  #ifdef SIGXFSZ
    SIGNO_CASE(SIGXFSZ);
  #endif
  
  #ifdef SIGVTALRM
    SIGNO_CASE(SIGVTALRM);
  #endif
  
  #ifdef SIGPROF
    SIGNO_CASE(SIGPROF);
  #endif
  
  #ifdef SIGWINCH
    SIGNO_CASE(SIGWINCH);
  #endif
  
  #ifdef SIGIO
    SIGNO_CASE(SIGIO);
  #endif
  
  #ifdef SIGPOLL
  # if SIGPOLL != SIGIO
    SIGNO_CASE(SIGPOLL);
  # endif
  #endif
  
  #ifdef SIGLOST
    SIGNO_CASE(SIGLOST);
  #endif
  
  #ifdef SIGPWR
  # if SIGPWR != SIGLOST
    SIGNO_CASE(SIGPWR);
  # endif
  #endif
  
  #ifdef SIGSYS
    SIGNO_CASE(SIGSYS);
  #endif
  
    default: return "";
    }
  }
  
  
  // Convenience methods
  
  
  void ThrowError(v8::Isolate* isolate, const char* errmsg) {
    Environment::GetCurrent(isolate)->ThrowError(errmsg);
  }
  
  
  void ThrowTypeError(v8::Isolate* isolate, const char* errmsg) {
    Environment::GetCurrent(isolate)->ThrowTypeError(errmsg);
  }
  
  
  void ThrowRangeError(v8::Isolate* isolate, const char* errmsg) {
    Environment::GetCurrent(isolate)->ThrowRangeError(errmsg);
  }
  
  
  void ThrowErrnoException(v8::Isolate* isolate,
                           int errorno,
                           const char* syscall,
                           const char* message,
                           const char* path) {
    Environment::GetCurrent(isolate)->ThrowErrnoException(errorno,
                                                          syscall,
                                                          message,
                                                          path);
  }
  
  
  void ThrowUVException(v8::Isolate* isolate,
                        int errorno,
                        const char* syscall,
                        const char* message,
                        const char* path) {
    Environment::GetCurrent(isolate)->ThrowErrnoException(errorno,
                                                          syscall,
                                                          message,
                                                          path);
  }
  
  
  Local<Value> ErrnoException(Isolate* isolate,
                              int errorno,
                              const char *syscall,
                              const char *msg,
                              const char *path) {
    Environment* env = Environment::GetCurrent(isolate);
  
    Local<Value> e;
    Local<String> estring = OneByteString(env->isolate(), errno_string(errorno));
    if (msg == nullptr || msg[0] == '\0') {
      msg = strerror(errorno);
    }
    Local<String> message = OneByteString(env->isolate(), msg);
  
    Local<String> cons1 =
        String::Concat(estring, FIXED_ONE_BYTE_STRING(env->isolate(), ", "));
    Local<String> cons2 = String::Concat(cons1, message);
  
    if (path) {
      Local<String> cons3 =
          String::Concat(cons2, FIXED_ONE_BYTE_STRING(env->isolate(), " '"));
      Local<String> cons4 =
          String::Concat(cons3, String::NewFromUtf8(env->isolate(), path));
      Local<String> cons5 =
          String::Concat(cons4, FIXED_ONE_BYTE_STRING(env->isolate(), "'"));
      e = Exception::Error(cons5);
    } else {
      e = Exception::Error(cons2);
    }
  
    Local<Object> obj = e->ToObject(env->isolate());
    obj->Set(env->errno_string(), Integer::New(env->isolate(), errorno));
    obj->Set(env->code_string(), estring);
  
    if (path != nullptr) {
      obj->Set(env->path_string(), String::NewFromUtf8(env->isolate(), path));
    }
  
    if (syscall != nullptr) {
      obj->Set(env->syscall_string(), OneByteString(env->isolate(), syscall));
    }
  
    return e;
  }
  
  
  // hack alert! copy of ErrnoException, tuned for uv errors
  Local<Value> UVException(Isolate* isolate,
                           int errorno,
                           const char *syscall,
                           const char *msg,
                           const char *path) {
    Environment* env = Environment::GetCurrent(isolate);
  
    if (!msg || !msg[0])
      msg = uv_strerror(errorno);
  
    Local<String> estring = OneByteString(env->isolate(), uv_err_name(errorno));
    Local<String> message = OneByteString(env->isolate(), msg);
    Local<String> cons1 =
        String::Concat(estring, FIXED_ONE_BYTE_STRING(env->isolate(), ", "));
    Local<String> cons2 = String::Concat(cons1, message);
  
    Local<Value> e;
  
    Local<String> path_str;
  
    if (path) {
  #ifdef _WIN32
      if (strncmp(path, "\\\\?\\UNC\\", 8) == 0) {
        path_str = String::Concat(FIXED_ONE_BYTE_STRING(env->isolate(), "\\\\"),
                                  String::NewFromUtf8(env->isolate(), path + 8));
      } else if (strncmp(path, "\\\\?\\", 4) == 0) {
        path_str = String::NewFromUtf8(env->isolate(), path + 4);
      } else {
        path_str = String::NewFromUtf8(env->isolate(), path);
      }
  #else
      path_str = String::NewFromUtf8(env->isolate(), path);
  #endif
  
      Local<String> cons3 =
          String::Concat(cons2, FIXED_ONE_BYTE_STRING(env->isolate(), " '"));
      Local<String> cons4 =
          String::Concat(cons3, path_str);
      Local<String> cons5 =
          String::Concat(cons4, FIXED_ONE_BYTE_STRING(env->isolate(), "'"));
      e = Exception::Error(cons5);
    } else {
      e = Exception::Error(cons2);
    }
  
    Local<Object> obj = e->ToObject(env->isolate());
    // TODO(piscisaureus) errno should probably go
    obj->Set(env->errno_string(), Integer::New(env->isolate(), errorno));
    obj->Set(env->code_string(), estring);
  
    if (path != nullptr) {
      obj->Set(env->path_string(), path_str);
    }
  
    if (syscall != nullptr) {
      obj->Set(env->syscall_string(), OneByteString(env->isolate(), syscall));
    }
  
    return e;
  }
  
  
  // Look up environment variable unless running as setuid root.
  inline const char* secure_getenv(const char* key) {
  #ifndef _WIN32
    if (getuid() != geteuid() || getgid() != getegid())
      return nullptr;
  #endif
    return getenv(key);
  }
  
  
  #ifdef _WIN32
  // Does about the same as strerror(),
  // but supports all windows error messages
  static const char *winapi_strerror(const int errorno, bool* must_free) {
    char *errmsg = nullptr;
  
    FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
        FORMAT_MESSAGE_IGNORE_INSERTS, nullptr, errorno,
        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR)&errmsg, 0, nullptr);
  
    if (errmsg) {
      *must_free = true;
  
      // Remove trailing newlines
      for (int i = strlen(errmsg) - 1;
          i >= 0 && (errmsg[i] == '\n' || errmsg[i] == '\r'); i--) {
        errmsg[i] = '\0';
      }
  
      return errmsg;
    } else {
      // FormatMessage failed
      *must_free = false;
      return "Unknown error";
    }
  }
  
  
  Local<Value> WinapiErrnoException(Isolate* isolate,
                                    int errorno,
                                    const char* syscall,
                                    const char* msg,
                                    const char* path) {
    Environment* env = Environment::GetCurrent(isolate);
    Local<Value> e;
    bool must_free = false;
    if (!msg || !msg[0]) {
      msg = winapi_strerror(errorno, &must_free);
    }
    Local<String> message = OneByteString(env->isolate(), msg);
  
    if (path) {
      Local<String> cons1 =
          String::Concat(message, FIXED_ONE_BYTE_STRING(isolate, " '"));
      Local<String> cons2 =
          String::Concat(cons1, String::NewFromUtf8(isolate, path));
      Local<String> cons3 =
          String::Concat(cons2, FIXED_ONE_BYTE_STRING(isolate, "'"));
      e = Exception::Error(cons3);
    } else {
      e = Exception::Error(message);
    }
  
    Local<Object> obj = e->ToObject(env->isolate());
    obj->Set(env->errno_string(), Integer::New(isolate, errorno));
  
    if (path != nullptr) {
      obj->Set(env->path_string(), String::NewFromUtf8(isolate, path));
    }
  
    if (syscall != nullptr) {
      obj->Set(env->syscall_string(), OneByteString(isolate, syscall));
    }
  
    if (must_free)
      LocalFree((HLOCAL)msg);
  
    return e;
  }
  #endif
  
  
  void SetupDomainUse(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  
    if (env->using_domains())
      return;
    env->set_using_domains(true);
  
    HandleScope scope(env->isolate());
    Local<Object> process_object = env->process_object();
  
    Local<String> tick_callback_function_key = env->tick_domain_cb_string();
    Local<Function> tick_callback_function =
        process_object->Get(tick_callback_function_key).As<Function>();
  
    if (!tick_callback_function->IsFunction()) {
      fprintf(stderr, "process._tickDomainCallback assigned to non-function\n");
      abort();
    }
  
    process_object->Set(env->tick_callback_string(), tick_callback_function);
    env->set_tick_callback_function(tick_callback_function);
  
    CHECK(args[0]->IsArray());
    CHECK(args[1]->IsObject());
  
    env->set_domain_array(args[0].As<Array>());
  
    Local<Object> domain_flag_obj = args[1].As<Object>();
    Environment::DomainFlag* domain_flag = env->domain_flag();
    domain_flag_obj->SetIndexedPropertiesToExternalArrayData(
        domain_flag->fields(),
        kExternalUint32Array,
        domain_flag->fields_count());
  
    // Do a little housekeeping.
    env->process_object()->Delete(
        FIXED_ONE_BYTE_STRING(args.GetIsolate(), "_setupDomainUse"));
  }
  
  void RunMicrotasks(const FunctionCallbackInfo<Value>& args) {
    args.GetIsolate()->RunMicrotasks();
  }
  
  
  void SetupNextTick(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  
    CHECK(args[0]->IsObject());
    CHECK(args[1]->IsFunction());
    CHECK(args[2]->IsObject());
  
    // Values use to cross communicate with processNextTick.
    Local<Object> tick_info_obj = args[0].As<Object>();
    tick_info_obj->SetIndexedPropertiesToExternalArrayData(
        env->tick_info()->fields(),
        kExternalUint32Array,
        env->tick_info()->fields_count());
  
    env->set_tick_callback_function(args[1].As<Function>());
  
    env->SetMethod(args[2].As<Object>(), "runMicrotasks", RunMicrotasks);
  
    // Do a little housekeeping.
    env->process_object()->Delete(
        FIXED_ONE_BYTE_STRING(args.GetIsolate(), "_setupNextTick"));
  }
  
  
  Handle<Value> MakeCallback(Environment* env,
                             Handle<Value> recv,
                             const Handle<Function> callback,
                             int argc,
                             Handle<Value> argv[]) {
    // If you hit this assertion, you forgot to enter the v8::Context first.
    CHECK_EQ(env->context(), env->isolate()->GetCurrentContext());
  
    Local<Object> process = env->process_object();
    Local<Object> object, domain;
    bool has_async_queue = false;
    bool has_domain = false;
  
    if (recv->IsObject()) {
      object = recv.As<Object>();
      Local<Value> async_queue_v = object->Get(env->async_queue_string());
      if (async_queue_v->IsObject())
        has_async_queue = true;
    }
  
    if (env->using_domains()) {
      CHECK(recv->IsObject());
      Local<Value> domain_v = object->Get(env->domain_string());
      has_domain = domain_v->IsObject();
      if (has_domain) {
        domain = domain_v.As<Object>();
        if (domain->Get(env->disposed_string())->IsTrue())
          return Undefined(env->isolate());
      }
    }
  
    TryCatch try_catch;
    try_catch.SetVerbose(true);
  
    if (has_domain) {
      Local<Value> enter_v = domain->Get(env->enter_string());
      if (enter_v->IsFunction()) {
          enter_v.As<Function>()->Call(domain, 0, nullptr);
        if (try_catch.HasCaught())
          return Undefined(env->isolate());
      }
    }
  
    if (has_async_queue) {
      try_catch.SetVerbose(false);
      env->async_hooks_pre_function()->Call(object, 0, nullptr);
      if (try_catch.HasCaught())
        FatalError("node:;MakeCallback", "pre hook threw");
      try_catch.SetVerbose(true);
    }
  
    Local<Value> ret = callback->Call(recv, argc, argv);
  
    if (has_async_queue) {
      try_catch.SetVerbose(false);
      env->async_hooks_post_function()->Call(object, 0, nullptr);
      if (try_catch.HasCaught())
        FatalError("node::MakeCallback", "post hook threw");
      try_catch.SetVerbose(true);
    }
  
    if (has_domain) {
      Local<Value> exit_v = domain->Get(env->exit_string());
      if (exit_v->IsFunction()) {
        exit_v.As<Function>()->Call(domain, 0, nullptr);
        if (try_catch.HasCaught())
          return Undefined(env->isolate());
      }
    }
    env->tick_callback_function()->Call(process, 0, nullptr);
    CHECK_EQ(env->context(), env->isolate()->GetCurrentContext());
  
    if (try_catch.HasCaught()) {
      return Undefined(env->isolate());
    }
  
    Environment::TickInfo* tick_info = env->tick_info();
  
    if (tick_info->in_tick()) {
      return ret;
    }
  
    if (tick_info->length() == 0) {
      env->isolate()->RunMicrotasks();
    }
  
    if (tick_info->length() == 0) {
      tick_info->set_index(0);
      return ret;
    }
  
    tick_info->set_in_tick(true);
  
    // process nextTicks after call
    env->tick_callback_function()->Call(process, 0, nullptr);
  
    tick_info->set_in_tick(false);
  
    if (try_catch.HasCaught()) {
      tick_info->set_last_threw(true);
      return Undefined(env->isolate());
    }
  
    return ret;
  }
  
  
  // Internal only.
  Handle<Value> MakeCallback(Environment* env,
                             Handle<Object> recv,
                             uint32_t index,
                             int argc,
                             Handle<Value> argv[]) {
    Local<Value> cb_v = recv->Get(index);
    CHECK(cb_v->IsFunction());
    return MakeCallback(env, recv.As<Value>(), cb_v.As<Function>(), argc, argv);
  }
  
  
  Handle<Value> MakeCallback(Environment* env,
                             Handle<Object> recv,
                             Handle<String> symbol,
                             int argc,
                             Handle<Value> argv[]) {
    Local<Value> cb_v = recv->Get(symbol);
    CHECK(cb_v->IsFunction());
    return MakeCallback(env, recv.As<Value>(), cb_v.As<Function>(), argc, argv);
  }
  
  
  Handle<Value> MakeCallback(Environment* env,
                             Handle<Object> recv,
                             const char* method,
                             int argc,
                             Handle<Value> argv[]) {
    Local<String> method_string = OneByteString(env->isolate(), method);
    return MakeCallback(env, recv, method_string, argc, argv);
  }
  
  
  Handle<Value> MakeCallback(Isolate* isolate,
                             Handle<Object> recv,
                             const char* method,
                             int argc,
                             Handle<Value> argv[]) {
    EscapableHandleScope handle_scope(isolate);
    Local<Context> context = recv->CreationContext();
    Environment* env = Environment::GetCurrent(context);
    Context::Scope context_scope(context);
    return handle_scope.Escape(
        Local<Value>::New(isolate, MakeCallback(env, recv, method, argc, argv)));
  }
  
  
  Handle<Value> MakeCallback(Isolate* isolate,
                             Handle<Object> recv,
                             Handle<String> symbol,
                             int argc,
                             Handle<Value> argv[]) {
    EscapableHandleScope handle_scope(isolate);
    Local<Context> context = recv->CreationContext();
    Environment* env = Environment::GetCurrent(context);
    Context::Scope context_scope(context);
    return handle_scope.Escape(
        Local<Value>::New(isolate, MakeCallback(env, recv, symbol, argc, argv)));
  }
  
  
  Handle<Value> MakeCallback(Isolate* isolate,
                             Handle<Object> recv,
                             Handle<Function> callback,
                             int argc,
                             Handle<Value> argv[]) {
    EscapableHandleScope handle_scope(isolate);
    Local<Context> context = recv->CreationContext();
    Environment* env = Environment::GetCurrent(context);
    Context::Scope context_scope(context);
    return handle_scope.Escape(Local<Value>::New(
          isolate,
          MakeCallback(env, recv.As<Value>(), callback, argc, argv)));
  }
  
  
  enum encoding ParseEncoding(Isolate* isolate,
                              Handle<Value> encoding_v,
                              enum encoding _default) {
    HandleScope scope(isolate);
  
    if (!encoding_v->IsString())
      return _default;
  
    node::Utf8Value encoding(isolate, encoding_v);
  
    if (strcasecmp(*encoding, "utf8") == 0) {
      return UTF8;
    } else if (strcasecmp(*encoding, "utf-8") == 0) {
      return UTF8;
    } else if (strcasecmp(*encoding, "ascii") == 0) {
      return ASCII;
    } else if (strcasecmp(*encoding, "base64") == 0) {
      return BASE64;
    } else if (strcasecmp(*encoding, "ucs2") == 0) {
      return UCS2;
    } else if (strcasecmp(*encoding, "ucs-2") == 0) {
      return UCS2;
    } else if (strcasecmp(*encoding, "utf16le") == 0) {
      return UCS2;
    } else if (strcasecmp(*encoding, "utf-16le") == 0) {
      return UCS2;
    } else if (strcasecmp(*encoding, "binary") == 0) {
      return BINARY;
    } else if (strcasecmp(*encoding, "buffer") == 0) {
      return BUFFER;
    } else if (strcasecmp(*encoding, "hex") == 0) {
      return HEX;
    } else if (strcasecmp(*encoding, "raw") == 0) {
      if (!no_deprecation) {
        fprintf(stderr, "'raw' (array of integers) has been removed. "
                        "Use 'binary'.\n");
      }
      return BINARY;
    } else if (strcasecmp(*encoding, "raws") == 0) {
      if (!no_deprecation) {
        fprintf(stderr, "'raws' encoding has been renamed to 'binary'. "
                        "Please update your code.\n");
      }
      return BINARY;
    } else {
      return _default;
    }
  }
  
  Local<Value> Encode(Isolate* isolate,
                      const char* buf,
                      size_t len,
                      enum encoding encoding) {
    CHECK_NE(encoding, UCS2);
    return StringBytes::Encode(isolate, buf, len, encoding);
  }
  
  Local<Value> Encode(Isolate* isolate, const uint16_t* buf, size_t len) {
    return StringBytes::Encode(isolate, buf, len);
  }
  
  // Returns -1 if the handle was not valid for decoding
  ssize_t DecodeBytes(Isolate* isolate,
                      Handle<Value> val,
                      enum encoding encoding) {
    HandleScope scope(isolate);
  
    if (val->IsArray()) {
      fprintf(stderr, "'raw' encoding (array of integers) has been removed. "
                      "Use 'binary'.\n");
      UNREACHABLE();
      return -1;
    }
  
    return StringBytes::Size(isolate, val, encoding);
  }
  
  // Returns number of bytes written.
  ssize_t DecodeWrite(Isolate* isolate,
                      char* buf,
                      size_t buflen,
                      Handle<Value> val,
                      enum encoding encoding) {
    return StringBytes::Write(isolate, buf, buflen, val, encoding, nullptr);
  }
  
  void AppendExceptionLine(Environment* env,
                           Handle<Value> er,
                           Handle<Message> message) {
    if (message.IsEmpty())
      return;
  
    HandleScope scope(env->isolate());
    Local<Object> err_obj;
    if (!er.IsEmpty() && er->IsObject()) {
      err_obj = er.As<Object>();
  
      // Do it only once per message
      if (!err_obj->GetHiddenValue(env->processed_string()).IsEmpty())
        return;
      err_obj->SetHiddenValue(env->processed_string(), True(env->isolate()));
    }
  
    char arrow[1024];
  
    // Print (filename):(line number): (message).
    node::Utf8Value filename(env->isolate(), message->GetScriptResourceName());
    const char* filename_string = *filename;
    int linenum = message->GetLineNumber();
    // Print line of source code.
    node::Utf8Value sourceline(env->isolate(), message->GetSourceLine());
    const char* sourceline_string = *sourceline;
  
    // Because of how node modules work, all scripts are wrapped with a
    // "function (module, exports, __filename, ...) {"
    // to provide script local variables.
    //
    // When reporting errors on the first line of a script, this wrapper
    // function is leaked to the user. There used to be a hack here to
    // truncate off the first 62 characters, but it caused numerous other
    // problems when vm.runIn*Context() methods were used for non-module
    // code.
    //
    // If we ever decide to re-instate such a hack, the following steps
    // must be taken:
    //
    // 1. Pass a flag around to say "this code was wrapped"
    // 2. Update the stack frame output so that it is also correct.
    //
    // It would probably be simpler to add a line rather than add some
    // number of characters to the first line, since V8 truncates the
    // sourceline to 78 characters, and we end up not providing very much
    // useful debugging info to the user if we remove 62 characters.
  
    int start = message->GetStartColumn();
    int end = message->GetEndColumn();
  
    int off = snprintf(arrow,
                       sizeof(arrow),
                       "%s:%i\n%s\n",
                       filename_string,
                       linenum,
                       sourceline_string);
    CHECK_GE(off, 0);
  
    // Print wavy underline (GetUnderline is deprecated).
    for (int i = 0; i < start; i++) {
      if (sourceline_string[i] == '\0' ||
          static_cast<size_t>(off) >= sizeof(arrow)) {
        break;
      }
      CHECK_LT(static_cast<size_t>(off), sizeof(arrow));
      arrow[off++] = (sourceline_string[i] == '\t') ? '\t' : ' ';
    }
    for (int i = start; i < end; i++) {
      if (sourceline_string[i] == '\0' ||
          static_cast<size_t>(off) >= sizeof(arrow)) {
        break;
      }
      CHECK_LT(static_cast<size_t>(off), sizeof(arrow));
      arrow[off++] = '^';
    }
    CHECK_LE(static_cast<size_t>(off - 1), sizeof(arrow) - 1);
    arrow[off++] = '\n';
    arrow[off] = '\0';
  
    Local<String> arrow_str = String::NewFromUtf8(env->isolate(), arrow);
    Local<Value> msg;
    Local<Value> stack;
  
    // Allocation failed, just print it out
    if (arrow_str.IsEmpty() || err_obj.IsEmpty() || !err_obj->IsNativeError())
      goto print;
  
    msg = err_obj->Get(env->message_string());
    stack = err_obj->Get(env->stack_string());
  
    if (msg.IsEmpty() || stack.IsEmpty())
      goto print;
  
    err_obj->Set(env->message_string(),
                 String::Concat(arrow_str, msg->ToString(env->isolate())));
    err_obj->Set(env->stack_string(),
                 String::Concat(arrow_str, stack->ToString(env->isolate())));
    return;
  
   print:
    if (env->printed_error())
      return;
    env->set_printed_error(true);
    uv_tty_reset_mode();
    fprintf(stderr, "\n%s", arrow);
  }
  
  
  static void ReportException(Environment* env,
                              Handle<Value> er,
                              Handle<Message> message) {
    HandleScope scope(env->isolate());
  
    AppendExceptionLine(env, er, message);
  
    Local<Value> trace_value;
  
    if (er->IsUndefined() || er->IsNull())
      trace_value = Undefined(env->isolate());
    else
      trace_value = er->ToObject(env->isolate())->Get(env->stack_string());
  
    node::Utf8Value trace(env->isolate(), trace_value);
  
    // range errors have a trace member set to undefined
    if (trace.length() > 0 && !trace_value->IsUndefined()) {
      fprintf(stderr, "%s\n", *trace);
    } else {
      // this really only happens for RangeErrors, since they're the only
      // kind that won't have all this info in the trace, or when non-Error
      // objects are thrown manually.
      Local<Value> message;
      Local<Value> name;
  
      if (er->IsObject()) {
        Local<Object> err_obj = er.As<Object>();
        message = err_obj->Get(env->message_string());
        name = err_obj->Get(FIXED_ONE_BYTE_STRING(env->isolate(), "name"));
      }
  
      if (message.IsEmpty() ||
          message->IsUndefined() ||
          name.IsEmpty() ||
          name->IsUndefined()) {
        // Not an error object. Just print as-is.
        node::Utf8Value message(env->isolate(), er);
        fprintf(stderr, "%s\n", *message);
      } else {
        node::Utf8Value name_string(env->isolate(), name);
        node::Utf8Value message_string(env->isolate(), message);
        fprintf(stderr, "%s: %s\n", *name_string, *message_string);
      }
    }
  
    fflush(stderr);
  }
  
  
  static void ReportException(Environment* env, const TryCatch& try_catch) {
    ReportException(env, try_catch.Exception(), try_catch.Message());
  }
  
  
  // Executes a str within the current v8 context.
  static Local<Value> ExecuteString(Environment* env,
                                    Handle<String> source,
                                    Handle<String> filename) {
    EscapableHandleScope scope(env->isolate());
    TryCatch try_catch;
  
    // try_catch must be nonverbose to disable FatalException() handler,
    // we will handle exceptions ourself.
    try_catch.SetVerbose(false);
  
    Local<v8::Script> script = v8::Script::Compile(source, filename);
    if (script.IsEmpty()) {
      ReportException(env, try_catch);
      exit(3);
    }
  
    Local<Value> result = script->Run();
    if (result.IsEmpty()) {
      ReportException(env, try_catch);
      exit(4);
    }
  
    return scope.Escape(result);
  }
  
  
  static void GetActiveRequests(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  
    Local<Array> ary = Array::New(args.GetIsolate());
    QUEUE* q = nullptr;
    int i = 0;
  
    QUEUE_FOREACH(q, env->req_wrap_queue()) {
      ReqWrap<uv_req_t>* w = ContainerOf(&ReqWrap<uv_req_t>::req_wrap_queue_, q);
      if (w->persistent().IsEmpty())
        continue;
      ary->Set(i++, w->object());
    }
  
    args.GetReturnValue().Set(ary);
  }
  
  
  // Non-static, friend of HandleWrap. Could have been a HandleWrap method but
  // implemented here for consistency with GetActiveRequests().
  void GetActiveHandles(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  
    Local<Array> ary = Array::New(env->isolate());
    QUEUE* q = nullptr;
    int i = 0;
  
    Local<String> owner_sym = env->owner_string();
  
    QUEUE_FOREACH(q, env->handle_wrap_queue()) {
      HandleWrap* w = ContainerOf(&HandleWrap::handle_wrap_queue_, q);
      if (w->persistent().IsEmpty() || (w->flags_ & HandleWrap::kUnref))
        continue;
      Local<Object> object = w->object();
      Local<Value> owner = object->Get(owner_sym);
      if (owner->IsUndefined())
        owner = object;
      ary->Set(i++, owner);
    }
  
    args.GetReturnValue().Set(ary);
  }
  
  
  static void Abort(const FunctionCallbackInfo<Value>& args) {
    abort();
  }
  
  
  static void Chdir(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  
    if (args.Length() != 1 || !args[0]->IsString()) {
      return env->ThrowTypeError("Bad argument.");
    }
  
    node::Utf8Value path(args.GetIsolate(), args[0]);
    int err = uv_chdir(*path);
    if (err) {
      return env->ThrowUVException(err, "uv_chdir");
    }
  }
  
  
  static void Cwd(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  #ifdef _WIN32
    /* MAX_PATH is in characters, not bytes. Make sure we have enough headroom. */
    char buf[MAX_PATH * 4];
  #else
    char buf[PATH_MAX];
  #endif
  
    size_t cwd_len = sizeof(buf);
    int err = uv_cwd(buf, &cwd_len);
    if (err) {
      return env->ThrowUVException(err, "uv_cwd");
    }
  
    Local<String> cwd = String::NewFromUtf8(env->isolate(),
                                            buf,
                                            String::kNormalString,
                                            cwd_len);
    args.GetReturnValue().Set(cwd);
  }
  
  
  static void Umask(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
    uint32_t old;
  
    if (args.Length() < 1 || args[0]->IsUndefined()) {
      old = umask(0);
      umask(static_cast<mode_t>(old));
    } else if (!args[0]->IsInt32() && !args[0]->IsString()) {
      return env->ThrowTypeError("argument must be an integer or octal string.");
    } else {
      int oct;
      if (args[0]->IsInt32()) {
        oct = args[0]->Uint32Value();
      } else {
        oct = 0;
        node::Utf8Value str(env->isolate(), args[0]);
  
        // Parse the octal string.
        for (size_t i = 0; i < str.length(); i++) {
          char c = (*str)[i];
          if (c > '7' || c < '0') {
            return env->ThrowTypeError("invalid octal string");
          }
          oct *= 8;
          oct += c - '0';
        }
      }
      old = umask(static_cast<mode_t>(oct));
    }
  
    args.GetReturnValue().Set(old);
  }
  
  
  #if defined(__POSIX__) && !defined(__ANDROID__)
  
  static const uid_t uid_not_found = static_cast<uid_t>(-1);
  static const gid_t gid_not_found = static_cast<gid_t>(-1);
  
  
  static uid_t uid_by_name(const char* name) {
    struct passwd pwd;
    struct passwd* pp;
    char buf[8192];
  
    errno = 0;
    pp = nullptr;
  
    if (getpwnam_r(name, &pwd, buf, sizeof(buf), &pp) == 0 && pp != nullptr) {
      return pp->pw_uid;
    }
  
    return uid_not_found;
  }
  
  
  static char* name_by_uid(uid_t uid) {
    struct passwd pwd;
    struct passwd* pp;
    char buf[8192];
    int rc;
  
    errno = 0;
    pp = nullptr;
  
    if ((rc = getpwuid_r(uid, &pwd, buf, sizeof(buf), &pp)) == 0 &&
        pp != nullptr) {
      return strdup(pp->pw_name);
    }
  
    if (rc == 0) {
      errno = ENOENT;
    }
  
    return nullptr;
  }
  
  
  static gid_t gid_by_name(const char* name) {
    struct group pwd;
    struct group* pp;
    char buf[8192];
  
    errno = 0;
    pp = nullptr;
  
    if (getgrnam_r(name, &pwd, buf, sizeof(buf), &pp) == 0 && pp != nullptr) {
      return pp->gr_gid;
    }
  
    return gid_not_found;
  }
  
  
  #if 0  // For future use.
  static const char* name_by_gid(gid_t gid) {
    struct group pwd;
    struct group* pp;
    char buf[8192];
    int rc;
  
    errno = 0;
    pp = nullptr;
  
    if ((rc = getgrgid_r(gid, &pwd, buf, sizeof(buf), &pp)) == 0 &&
        pp != nullptr) {
      return strdup(pp->gr_name);
    }
  
    if (rc == 0) {
      errno = ENOENT;
    }
  
    return nullptr;
  }
  #endif
  
  
  static uid_t uid_by_name(Handle<Value> value) {
    if (value->IsUint32()) {
      return static_cast<uid_t>(value->Uint32Value());
    } else {
      // TODO(trevnorris): Fix to not use GetCurrent().
      node::Utf8Value name(Isolate::GetCurrent(), value);
      return uid_by_name(*name);
    }
  }
  
  
  static gid_t gid_by_name(Handle<Value> value) {
    if (value->IsUint32()) {
      return static_cast<gid_t>(value->Uint32Value());
    } else {
      // TODO(trevnorris): Fix to not use GetCurrent().
      node::Utf8Value name(Isolate::GetCurrent(), value);
      return gid_by_name(*name);
    }
  }
  
  
  static void GetUid(const FunctionCallbackInfo<Value>& args) {
    // uid_t is an uint32_t on all supported platforms.
    args.GetReturnValue().Set(static_cast<uint32_t>(getuid()));
  }
  
  
  static void GetGid(const FunctionCallbackInfo<Value>& args) {
    // gid_t is an uint32_t on all supported platforms.
    args.GetReturnValue().Set(static_cast<uint32_t>(getgid()));
  }
  
  
  static void SetGid(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  
    if (!args[0]->IsUint32() && !args[0]->IsString()) {
      return env->ThrowTypeError("setgid argument must be a number or a string");
    }
  
    gid_t gid = gid_by_name(args[0]);
  
    if (gid == gid_not_found) {
      return env->ThrowError("setgid group id does not exist");
    }
  
    if (setgid(gid)) {
      return env->ThrowErrnoException(errno, "setgid");
    }
  }
  
  
  static void SetUid(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  
    if (!args[0]->IsUint32() && !args[0]->IsString()) {
      return env->ThrowTypeError("setuid argument must be a number or a string");
    }
  
    uid_t uid = uid_by_name(args[0]);
  
    if (uid == uid_not_found) {
      return env->ThrowError("setuid user id does not exist");
    }
  
    if (setuid(uid)) {
      return env->ThrowErrnoException(errno, "setuid");
    }
  }
  
  
  static void GetGroups(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  
    int ngroups = getgroups(0, nullptr);
  
    if (ngroups == -1) {
      return env->ThrowErrnoException(errno, "getgroups");
    }
  
    gid_t* groups = new gid_t[ngroups];
  
    ngroups = getgroups(ngroups, groups);
  
    if (ngroups == -1) {
      delete[] groups;
      return env->ThrowErrnoException(errno, "getgroups");
    }
  
    Local<Array> groups_list = Array::New(env->isolate(), ngroups);
    bool seen_egid = false;
    gid_t egid = getegid();
  
    for (int i = 0; i < ngroups; i++) {
      groups_list->Set(i, Integer::New(env->isolate(), groups[i]));
      if (groups[i] == egid)
        seen_egid = true;
    }
  
    delete[] groups;
  
    if (seen_egid == false) {
      groups_list->Set(ngroups, Integer::New(env->isolate(), egid));
    }
  
    args.GetReturnValue().Set(groups_list);
  }
  
  
  static void SetGroups(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  
    if (!args[0]->IsArray()) {
      return env->ThrowTypeError("argument 1 must be an array");
    }
  
    Local<Array> groups_list = args[0].As<Array>();
    size_t size = groups_list->Length();
    gid_t* groups = new gid_t[size];
  
    for (size_t i = 0; i < size; i++) {
      gid_t gid = gid_by_name(groups_list->Get(i));
  
      if (gid == gid_not_found) {
        delete[] groups;
        return env->ThrowError("group name not found");
      }
  
      groups[i] = gid;
    }
  
    int rc = setgroups(size, groups);
    delete[] groups;
  
    if (rc == -1) {
      return env->ThrowErrnoException(errno, "setgroups");
    }
  }
  
  
  static void InitGroups(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  
    if (!args[0]->IsUint32() && !args[0]->IsString()) {
      return env->ThrowTypeError("argument 1 must be a number or a string");
    }
  
    if (!args[1]->IsUint32() && !args[1]->IsString()) {
      return env->ThrowTypeError("argument 2 must be a number or a string");
    }
  
    node::Utf8Value arg0(env->isolate(), args[0]);
    gid_t extra_group;
    bool must_free;
    char* user;
  
    if (args[0]->IsUint32()) {
      user = name_by_uid(args[0]->Uint32Value());
      must_free = true;
    } else {
      user = *arg0;
      must_free = false;
    }
  
    if (user == nullptr) {
      return env->ThrowError("initgroups user not found");
    }
  
    extra_group = gid_by_name(args[1]);
  
    if (extra_group == gid_not_found) {
      if (must_free)
        free(user);
      return env->ThrowError("initgroups extra group not found");
    }
  
    int rc = initgroups(user, extra_group);
  
    if (must_free) {
      free(user);
    }
  
    if (rc) {
      return env->ThrowErrnoException(errno, "initgroups");
    }
  }
  
  #endif  // __POSIX__ && !defined(__ANDROID__)
  
  
  void Exit(const FunctionCallbackInfo<Value>& args) {
    exit(args[0]->Int32Value());
  }
  
  
  static void Uptime(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
    double uptime;
  
    uv_update_time(env->event_loop());
    uptime = uv_now(env->event_loop()) - prog_start_time;
  
    args.GetReturnValue().Set(Number::New(env->isolate(), uptime / 1000));
  }
  
  
  void MemoryUsage(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  
    size_t rss;
    int err = uv_resident_set_memory(&rss);
    if (err) {
      return env->ThrowUVException(err, "uv_resident_set_memory");
    }
  
    // V8 memory usage
    HeapStatistics v8_heap_stats;
    env->isolate()->GetHeapStatistics(&v8_heap_stats);
  
    Local<Integer> heap_total =
        Integer::NewFromUnsigned(env->isolate(), v8_heap_stats.total_heap_size());
    Local<Integer> heap_used =
        Integer::NewFromUnsigned(env->isolate(), v8_heap_stats.used_heap_size());
  
    Local<Object> info = Object::New(env->isolate());
    info->Set(env->rss_string(), Number::New(env->isolate(), rss));
    info->Set(env->heap_total_string(), heap_total);
    info->Set(env->heap_used_string(), heap_used);
  
    args.GetReturnValue().Set(info);
  }
  
  
  void Kill(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  
    if (args.Length() != 2) {
      return env->ThrowError("Bad argument.");
    }
  
    int pid = args[0]->Int32Value();
    int sig = args[1]->Int32Value();
    int err = uv_kill(pid, sig);
    args.GetReturnValue().Set(err);
  }
  
  // used in Hrtime() below
  #define NANOS_PER_SEC 1000000000
  
  // Hrtime exposes libuv's uv_hrtime() high-resolution timer.
  // The value returned by uv_hrtime() is a 64-bit int representing nanoseconds,
  // so this function instead returns an Array with 2 entries representing seconds
  // and nanoseconds, to avoid any integer overflow possibility.
  // Pass in an Array from a previous hrtime() call to instead get a time diff.
  void Hrtime(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  
    uint64_t t = uv_hrtime();
  
    if (args.Length() > 0) {
      // return a time diff tuple
      if (!args[0]->IsArray()) {
        return env->ThrowTypeError(
            "process.hrtime() only accepts an Array tuple.");
      }
      Local<Array> inArray = Local<Array>::Cast(args[0]);
      uint64_t seconds = inArray->Get(0)->Uint32Value();
      uint64_t nanos = inArray->Get(1)->Uint32Value();
      t -= (seconds * NANOS_PER_SEC) + nanos;
    }
  
    Local<Array> tuple = Array::New(env->isolate(), 2);
    tuple->Set(0, Integer::NewFromUnsigned(env->isolate(), t / NANOS_PER_SEC));
    tuple->Set(1, Integer::NewFromUnsigned(env->isolate(), t % NANOS_PER_SEC));
    args.GetReturnValue().Set(tuple);
  }
  
  extern "C" void node_module_register(void* m) {
    struct node_module* mp = reinterpret_cast<struct node_module*>(m);
  
    if (mp->nm_flags & NM_F_BUILTIN) {
      mp->nm_link = modlist_builtin;
      modlist_builtin = mp;
    } else if (!node_is_initialized) {
      // "Linked" modules are included as part of the node project.
      // Like builtins they are registered *before* node::Init runs.
      mp->nm_flags = NM_F_LINKED;
      mp->nm_link = modlist_linked;
      modlist_linked = mp;
    } else {
      modpending = mp;
    }
  }
  
  struct node_module* get_builtin_module(const char* name) {
    struct node_module* mp;
  
    for (mp = modlist_builtin; mp != nullptr; mp = mp->nm_link) {
      if (strcmp(mp->nm_modname, name) == 0)
        break;
    }
  
    CHECK(mp == nullptr || (mp->nm_flags & NM_F_BUILTIN) != 0);
    return (mp);
  }
  
  struct node_module* get_linked_module(const char* name) {
    struct node_module* mp;
  
    for (mp = modlist_linked; mp != nullptr; mp = mp->nm_link) {
      if (strcmp(mp->nm_modname, name) == 0)
        break;
    }
  
    CHECK(mp == nullptr || (mp->nm_flags & NM_F_LINKED) != 0);
    return mp;
  }
  
  typedef void (UV_DYNAMIC* extInit)(Handle<Object> exports);
  
  // DLOpen is process.dlopen(module, filename).
  // Used to load 'module.node' dynamically shared objects.
  //
  // FIXME(bnoordhuis) Not multi-context ready. TBD how to resolve the conflict
  // when two contexts try to load the same shared object. Maybe have a shadow
  // cache that's a plain C list or hash table that's shared across contexts?
  void DLOpen(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
    uv_lib_t lib;
  
    CHECK_EQ(modpending, nullptr);
  
    if (args.Length() < 2) {
      env->ThrowError("process.dlopen takes exactly 2 arguments.");
      return;
    }
  
    Local<Object> module = args[0]->ToObject(env->isolate());  // Cast
    node::Utf8Value filename(env->isolate(), args[1]);  // Cast
    const bool is_dlopen_error = uv_dlopen(*filename, &lib);
  
    // Objects containing v14 or later modules will have registered themselves
    // on the pending list.  Activate all of them now.  At present, only one
    // module per object is supported.
    node_module* const mp = modpending;
    modpending = nullptr;
  
    if (is_dlopen_error) {
      Local<String> errmsg = OneByteString(env->isolate(), uv_dlerror(&lib));
  #ifdef _WIN32
      // Windows needs to add the filename into the error message
      errmsg = String::Concat(errmsg, args[1]->ToString(env->isolate()));
  #endif  // _WIN32
      env->isolate()->ThrowException(Exception::Error(errmsg));
      return;
    }
  
    if (mp == nullptr) {
      env->ThrowError("Module did not self-register.");
      return;
    }
    if (mp->nm_version != NODE_MODULE_VERSION) {
      char errmsg[1024];
      snprintf(errmsg,
               sizeof(errmsg),
               "Module version mismatch. Expected %d, got %d.",
               NODE_MODULE_VERSION, mp->nm_version);
      env->ThrowError(errmsg);
      return;
    }
    if (mp->nm_flags & NM_F_BUILTIN) {
      env->ThrowError("Built-in module self-registered.");
      return;
    }
  
    mp->nm_dso_handle = lib.handle;
    mp->nm_link = modlist_addon;
    modlist_addon = mp;
  
    Local<String> exports_string = env->exports_string();
    Local<Object> exports = module->Get(exports_string)->ToObject(env->isolate());
  
    if (mp->nm_context_register_func != nullptr) {
      mp->nm_context_register_func(exports, module, env->context(), mp->nm_priv);
    } else if (mp->nm_register_func != nullptr) {
      mp->nm_register_func(exports, module, mp->nm_priv);
    } else {
      env->ThrowError("Module has no declared entry point.");
      return;
    }
  
    // Tell coverity that 'handle' should not be freed when we return.
    // coverity[leaked_storage]
  }
  
  
  static void OnFatalError(const char* location, const char* message) {
    if (location) {
      fprintf(stderr, "FATAL ERROR: %s %s\n", location, message);
    } else {
      fprintf(stderr, "FATAL ERROR: %s\n", message);
    }
    fflush(stderr);
    abort();
  }
  
  
  NO_RETURN void FatalError(const char* location, const char* message) {
    OnFatalError(location, message);
    // to supress compiler warning
    abort();
  }
  
  
  void FatalException(Isolate* isolate,
                      Handle<Value> error,
                      Handle<Message> message) {
    HandleScope scope(isolate);
  
    Environment* env = Environment::GetCurrent(isolate);
    Local<Object> process_object = env->process_object();
    Local<String> fatal_exception_string = env->fatal_exception_string();
    Local<Function> fatal_exception_function =
        process_object->Get(fatal_exception_string).As<Function>();
  
    if (!fatal_exception_function->IsFunction()) {
      // failed before the process._fatalException function was added!
      // this is probably pretty bad.  Nothing to do but report and exit.
      ReportException(env, error, message);
      exit(6);
    }
  
    TryCatch fatal_try_catch;
  
    // Do not call FatalException when _fatalException handler throws
    fatal_try_catch.SetVerbose(false);
  
    // this will return true if the JS layer handled it, false otherwise
    Local<Value> caught =
        fatal_exception_function->Call(process_object, 1, &error);
  
    if (fatal_try_catch.HasCaught()) {
      // the fatal exception function threw, so we must exit
      ReportException(env, fatal_try_catch);
      exit(7);
    }
  
    if (false == caught->BooleanValue()) {
      ReportException(env, error, message);
      exit(1);
    }
  }
  
  
  void FatalException(Isolate* isolate, const TryCatch& try_catch) {
    HandleScope scope(isolate);
    // TODO(bajtos) do not call FatalException if try_catch is verbose
    // (requires V8 API to expose getter for try_catch.is_verbose_)
    FatalException(isolate, try_catch.Exception(), try_catch.Message());
  }
  
  
  void OnMessage(Handle<Message> message, Handle<Value> error) {
    // The current version of V8 sends messages for errors only
    // (thus `error` is always set).
    FatalException(Isolate::GetCurrent(), error, message);
  }
  
  
  static void Binding(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  
    Local<String> module = args[0]->ToString(env->isolate());
    node::Utf8Value module_v(env->isolate(), module);
  
    Local<Object> cache = env->binding_cache_object();
    Local<Object> exports;
  
    if (cache->Has(module)) {
      exports = cache->Get(module)->ToObject(env->isolate());
      args.GetReturnValue().Set(exports);
      return;
    }
  
    // Append a string to process.moduleLoadList
    char buf[1024];
    snprintf(buf, sizeof(buf), "Binding %s", *module_v);
  
    Local<Array> modules = env->module_load_list_array();
    uint32_t l = modules->Length();
    modules->Set(l, OneByteString(env->isolate(), buf));
  
    node_module* mod = get_builtin_module(*module_v);
    if (mod != nullptr) {
      exports = Object::New(env->isolate());
      // Internal bindings don't have a "module" object, only exports.
      CHECK_EQ(mod->nm_register_func, nullptr);
      CHECK_NE(mod->nm_context_register_func, nullptr);
      Local<Value> unused = Undefined(env->isolate());
      mod->nm_context_register_func(exports, unused,
        env->context(), mod->nm_priv);
      cache->Set(module, exports);
    } else if (!strcmp(*module_v, "constants")) {
      exports = Object::New(env->isolate());
      DefineConstants(exports);
      cache->Set(module, exports);
    } else if (!strcmp(*module_v, "natives")) {
      exports = Object::New(env->isolate());
      DefineJavaScript(env, exports);
      cache->Set(module, exports);
    } else {
      char errmsg[1024];
      snprintf(errmsg,
               sizeof(errmsg),
               "No such module: %s",
               *module_v);
      return env->ThrowError(errmsg);
    }
  
    args.GetReturnValue().Set(exports);
  }
  
  static void LinkedBinding(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args.GetIsolate());
  
    Local<String> module = args[0]->ToString(env->isolate());
  
    Local<Object> cache = env->binding_cache_object();
    Local<Value> exports_v = cache->Get(module);
  
    if (exports_v->IsObject())
      return args.GetReturnValue().Set(exports_v.As<Object>());
  
    node::Utf8Value module_v(env->isolate(), module);
    node_module* mod = get_linked_module(*module_v);
  
    if (mod == nullptr) {
      char errmsg[1024];
      snprintf(errmsg,
               sizeof(errmsg),
               "No such module was linked: %s",
               *module_v);
      return env->ThrowError(errmsg);
    }
  
    Local<Object> exports = Object::New(env->isolate());
  
    if (mod->nm_context_register_func != nullptr) {
      mod->nm_context_register_func(exports,
                                    module,
                                    env->context(),
                                    mod->nm_priv);
    } else if (mod->nm_register_func != nullptr) {
      mod->nm_register_func(exports, module, mod->nm_priv);
    } else {
      return env->ThrowError("Linked module has no declared entry point.");
    }
  
    cache->Set(module, exports);
  
    args.GetReturnValue().Set(exports);
  }
  
  static void ProcessTitleGetter(Local<String> property,
                                 const PropertyCallbackInfo<Value>& info) {
    Environment* env = Environment::GetCurrent(info.GetIsolate());
    HandleScope scope(env->isolate());
    char buffer[512];
    uv_get_process_title(buffer, sizeof(buffer));
    info.GetReturnValue().Set(String::NewFromUtf8(env->isolate(), buffer));
  }
  
  
  static void ProcessTitleSetter(Local<String> property,
                                 Local<Value> value,
                                 const PropertyCallbackInfo<void>& info) {
    Environment* env = Environment::GetCurrent(info.GetIsolate());
    HandleScope scope(env->isolate());
    node::Utf8Value title(env->isolate(), value);
    // TODO(piscisaureus): protect with a lock
    uv_set_process_title(*title);
  }
  
  
  static void EnvGetter(Local<String> property,
                        const PropertyCallbackInfo<Value>& info) {
    Environment* env = Environment::GetCurrent(info.GetIsolate());
    HandleScope scope(env->isolate());
  #ifdef __POSIX__
    node::Utf8Value key(env->isolate(), property);
    const char* val = getenv(*key);
    if (val) {
      return info.GetReturnValue().Set(String::NewFromUtf8(env->isolate(), val));
    }
  #else  // _WIN32
    String::Value key(property);
    WCHAR buffer[32767];  // The maximum size allowed for environment variables.
    DWORD result = GetEnvironmentVariableW(reinterpret_cast<WCHAR*>(*key),
                                           buffer,
                                           ARRAY_SIZE(buffer));
    // If result >= sizeof buffer the buffer was too small. That should never
    // happen. If result == 0 and result != ERROR_SUCCESS the variable was not
    // not found.
    if ((result > 0 || GetLastError() == ERROR_SUCCESS) &&
        result < ARRAY_SIZE(buffer)) {
      const uint16_t* two_byte_buffer = reinterpret_cast<const uint16_t*>(buffer);
      Local<String> rc = String::NewFromTwoByte(env->isolate(), two_byte_buffer);
      return info.GetReturnValue().Set(rc);
    }
  #endif
    // Not found.  Fetch from prototype.
    info.GetReturnValue().Set(
        info.Data().As<Object>()->Get(property));
  }
  
  
  static void EnvSetter(Local<String> property,
                        Local<Value> value,
                        const PropertyCallbackInfo<Value>& info) {
    Environment* env = Environment::GetCurrent(info.GetIsolate());
    HandleScope scope(env->isolate());
  #ifdef __POSIX__
    node::Utf8Value key(env->isolate(), property);
    node::Utf8Value val(env->isolate(), value);
    setenv(*key, *val, 1);
  #else  // _WIN32
    String::Value key(property);
    String::Value val(value);
    WCHAR* key_ptr = reinterpret_cast<WCHAR*>(*key);
    // Environment variables that start with '=' are read-only.
    if (key_ptr[0] != L'=') {
      SetEnvironmentVariableW(key_ptr, reinterpret_cast<WCHAR*>(*val));
    }
  #endif
    // Whether it worked or not, always return rval.
    info.GetReturnValue().Set(value);
  }
  
  
  static void EnvQuery(Local<String> property,
                       const PropertyCallbackInfo<Integer>& info) {
    Environment* env = Environment::GetCurrent(info.GetIsolate());
    HandleScope scope(env->isolate());
    int32_t rc = -1;  // Not found unless proven otherwise.
  #ifdef __POSIX__
    node::Utf8Value key(env->isolate(), property);
    if (getenv(*key))
      rc = 0;
  #else  // _WIN32
    String::Value key(property);
    WCHAR* key_ptr = reinterpret_cast<WCHAR*>(*key);
    if (GetEnvironmentVariableW(key_ptr, nullptr, 0) > 0 ||
        GetLastError() == ERROR_SUCCESS) {
      rc = 0;
      if (key_ptr[0] == L'=') {
        // Environment variables that start with '=' are hidden and read-only.
        rc = static_cast<int32_t>(v8::ReadOnly) |
             static_cast<int32_t>(v8::DontDelete) |
             static_cast<int32_t>(v8::DontEnum);
      }
    }
  #endif
    if (rc != -1)
      info.GetReturnValue().Set(rc);
  }
  
  
  static void EnvDeleter(Local<String> property,
                         const PropertyCallbackInfo<Boolean>& info) {
    Environment* env = Environment::GetCurrent(info.GetIsolate());
    HandleScope scope(env->isolate());
    bool rc = true;
  #ifdef __POSIX__
    node::Utf8Value key(env->isolate(), property);
    rc = getenv(*key) != nullptr;
    if (rc)
      unsetenv(*key);
  #else
    String::Value key(property);
    WCHAR* key_ptr = reinterpret_cast<WCHAR*>(*key);
    if (key_ptr[0] == L'=' || !SetEnvironmentVariableW(key_ptr, nullptr)) {
      // Deletion failed. Return true if the key wasn't there in the first place,
      // false if it is still there.
      rc = GetEnvironmentVariableW(key_ptr, nullptr, 0) == 0 &&
           GetLastError() != ERROR_SUCCESS;
    }
  #endif
    info.GetReturnValue().Set(rc);
  }
  
  
  static void EnvEnumerator(const PropertyCallbackInfo<Array>& info) {
    Environment* env = Environment::GetCurrent(info.GetIsolate());
    HandleScope scope(env->isolate());
  #ifdef __POSIX__
    int size = 0;
    while (environ[size])
      size++;
  
    Local<Array> envarr = Array::New(env->isolate(), size);
  
    for (int i = 0; i < size; ++i) {
      const char* var = environ[i];
      const char* s = strchr(var, '=');
      const int length = s ? s - var : strlen(var);
      Local<String> name = String::NewFromUtf8(env->isolate(),
                                               var,
                                               String::kNormalString,
                                               length);
      envarr->Set(i, name);
    }
  #else  // _WIN32
    WCHAR* environment = GetEnvironmentStringsW();
    if (environment == nullptr)
      return;  // This should not happen.
    Local<Array> envarr = Array::New(env->isolate());
    WCHAR* p = environment;
    int i = 0;
    while (*p) {
      WCHAR *s;
      if (*p == L'=') {
        // If the key starts with '=' it is a hidden environment variable.
        p += wcslen(p) + 1;
        continue;
      } else {
        s = wcschr(p, L'=');
      }
      if (!s) {
        s = p + wcslen(p);
      }
      const uint16_t* two_byte_buffer = reinterpret_cast<const uint16_t*>(p);
      const size_t two_byte_buffer_len = s - p;
      Local<String> value = String::NewFromTwoByte(env->isolate(),
                                                   two_byte_buffer,
                                                   String::kNormalString,
                                                   two_byte_buffer_len);
      envarr->Set(i++, value);
      p = s + wcslen(s) + 1;
    }
    FreeEnvironmentStringsW(environment);
  #endif
  
    info.GetReturnValue().Set(envarr);
  }
  
  
  static Handle<Object> GetFeatures(Environment* env) {
    EscapableHandleScope scope(env->isolate());
  
    Local<Object> obj = Object::New(env->isolate());
  #if defined(DEBUG) && DEBUG
    Local<Value> debug = True(env->isolate());
  #else
    Local<Value> debug = False(env->isolate());
  #endif  // defined(DEBUG) && DEBUG
  
    obj->Set(env->debug_string(), debug);
  
    obj->Set(env->uv_string(), True(env->isolate()));
    // TODO(bnoordhuis) ping libuv
    obj->Set(env->ipv6_lc_string(), True(env->isolate()));
  
  #ifdef OPENSSL_NPN_NEGOTIATED
    Local<Boolean> tls_npn = True(env->isolate());
  #else
    Local<Boolean> tls_npn = False(env->isolate());
  #endif
    obj->Set(env->tls_npn_string(), tls_npn);
  
  #ifdef SSL_CTRL_SET_TLSEXT_SERVERNAME_CB
    Local<Boolean> tls_sni = True(env->isolate());
  #else
    Local<Boolean> tls_sni = False(env->isolate());
  #endif
    obj->Set(env->tls_sni_string(), tls_sni);
  
  #if !defined(OPENSSL_NO_TLSEXT) && defined(SSL_CTX_set_tlsext_status_cb)
    Local<Boolean> tls_ocsp = True(env->isolate());
  #else
    Local<Boolean> tls_ocsp = False(env->isolate());
  #endif  // !defined(OPENSSL_NO_TLSEXT) && defined(SSL_CTX_set_tlsext_status_cb)
    obj->Set(env->tls_ocsp_string(), tls_ocsp);
  
    obj->Set(env->tls_string(),
             Boolean::New(env->isolate(),
                          get_builtin_module("crypto") != nullptr));
  
    return scope.Escape(obj);
  }
  
  
  static void DebugPortGetter(Local<String> property,
                              const PropertyCallbackInfo<Value>& info) {
    Environment* env = Environment::GetCurrent(info.GetIsolate());
    HandleScope scope(env->isolate());
    info.GetReturnValue().Set(debug_port);
  }
  
  
  static void DebugPortSetter(Local<String> property,
                              Local<Value> value,
                              const PropertyCallbackInfo<void>& info) {
    Environment* env = Environment::GetCurrent(info.GetIsolate());
    HandleScope scope(env->isolate());
    debug_port = value->Int32Value();
  }
  
  
  static void DebugProcess(const FunctionCallbackInfo<Value>& args);
  static void DebugPause(const FunctionCallbackInfo<Value>& args);
  static void DebugEnd(const FunctionCallbackInfo<Value>& args);
  
  
  void NeedImmediateCallbackGetter(Local<String> property,
                                   const PropertyCallbackInfo<Value>& info) {
    Environment* env = Environment::GetCurrent(info.GetIsolate());
    const uv_check_t* immediate_check_handle = env->immediate_check_handle();
    bool active = uv_is_active(
        reinterpret_cast<const uv_handle_t*>(immediate_check_handle));
    info.GetReturnValue().Set(active);
  }
  
  
  static void NeedImmediateCallbackSetter(
      Local<String> property,
      Local<Value> value,
      const PropertyCallbackInfo<void>& info) {
    HandleScope handle_scope(info.GetIsolate());
    Environment* env = Environment::GetCurrent(info.GetIsolate());
  
    uv_check_t* immediate_check_handle = env->immediate_check_handle();
    bool active = uv_is_active(
        reinterpret_cast<const uv_handle_t*>(immediate_check_handle));
  
    if (active == value->BooleanValue())
      return;
  
    uv_idle_t* immediate_idle_handle = env->immediate_idle_handle();
  
    if (active) {
      uv_check_stop(immediate_check_handle);
      uv_idle_stop(immediate_idle_handle);
    } else {
      uv_check_start(immediate_check_handle, CheckImmediate);
      // Idle handle is needed only to stop the event loop from blocking in poll.
      uv_idle_start(immediate_idle_handle, IdleImmediateDummy);
    }
  }
  
  
  void SetIdle(uv_prepare_t* handle) {
    Environment* env = Environment::from_idle_prepare_handle(handle);
    env->isolate()->GetCpuProfiler()->SetIdle(true);
  }
  
  
  void ClearIdle(uv_check_t* handle) {
    Environment* env = Environment::from_idle_check_handle(handle);
    env->isolate()->GetCpuProfiler()->SetIdle(false);
  }
  
  
  void StartProfilerIdleNotifier(Environment* env) {
    uv_prepare_start(env->idle_prepare_handle(), SetIdle);
    uv_check_start(env->idle_check_handle(), ClearIdle);
  }
  
  
  void StopProfilerIdleNotifier(Environment* env) {
    uv_prepare_stop(env->idle_prepare_handle());
    uv_check_stop(env->idle_check_handle());
  }
  
  
  void StartProfilerIdleNotifier(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
    StartProfilerIdleNotifier(env);
  }
  
  
  void StopProfilerIdleNotifier(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
    StopProfilerIdleNotifier(env);
  }
  
  
  #define READONLY_PROPERTY(obj, str, var)                                      \
    do {                                                                        \
      obj->ForceSet(OneByteString(env->isolate(), str), var, v8::ReadOnly);     \
    } while (0)
  
  
  void SetupProcessObject(Environment* env,
                          int argc,
                          const char* const* argv,
                          int exec_argc,
                          const char* const* exec_argv) {
    HandleScope scope(env->isolate());
  
    Local<Object> process = env->process_object();
  
    process->SetAccessor(env->title_string(),
                         ProcessTitleGetter,
                         ProcessTitleSetter);
  
    // process.version
    READONLY_PROPERTY(process,
                      "version",
                      FIXED_ONE_BYTE_STRING(env->isolate(), NODE_VERSION));
  
    // process.moduleLoadList
    READONLY_PROPERTY(process,
                      "moduleLoadList",
                      env->module_load_list_array());
  
    // process.versions
    Local<Object> versions = Object::New(env->isolate());
    READONLY_PROPERTY(process, "versions", versions);
  
    const char http_parser_version[] = NODE_STRINGIFY(HTTP_PARSER_VERSION_MAJOR)
                                       "."
                                       NODE_STRINGIFY(HTTP_PARSER_VERSION_MINOR);
    READONLY_PROPERTY(versions,
                      "http_parser",
                      FIXED_ONE_BYTE_STRING(env->isolate(), http_parser_version));
  
    // +1 to get rid of the leading 'v'
    READONLY_PROPERTY(versions,
                      "node",
                      OneByteString(env->isolate(), NODE_VERSION + 1));
    READONLY_PROPERTY(versions,
                      "v8",
                      OneByteString(env->isolate(), V8::GetVersion()));
    READONLY_PROPERTY(versions,
                      "uv",
                      OneByteString(env->isolate(), uv_version_string()));
    READONLY_PROPERTY(versions,
                      "zlib",
                      FIXED_ONE_BYTE_STRING(env->isolate(), ZLIB_VERSION));
    READONLY_PROPERTY(versions,
                      "ares",
                      FIXED_ONE_BYTE_STRING(env->isolate(), ARES_VERSION_STR));
  
    const char node_modules_version[] = NODE_STRINGIFY(NODE_MODULE_VERSION);
    READONLY_PROPERTY(
        versions,
        "modules",
        FIXED_ONE_BYTE_STRING(env->isolate(), node_modules_version));
  
  #if HAVE_OPENSSL
    // Stupid code to slice out the version string.
    {  // NOLINT(whitespace/braces)
      size_t i, j, k;
      int c;
      for (i = j = 0, k = sizeof(OPENSSL_VERSION_TEXT) - 1; i < k; ++i) {
        c = OPENSSL_VERSION_TEXT[i];
        if ('0' <= c && c <= '9') {
          for (j = i + 1; j < k; ++j) {
            c = OPENSSL_VERSION_TEXT[j];
            if (c == ' ')
              break;
          }
          break;
        }
      }
      READONLY_PROPERTY(
          versions,
          "openssl",
          OneByteString(env->isolate(), &OPENSSL_VERSION_TEXT[i], j - i));
    }
  #endif
  
    // process.arch
    READONLY_PROPERTY(process, "arch", OneByteString(env->isolate(), NODE_ARCH));
  
    // process.platform
    READONLY_PROPERTY(process,
                      "platform",
                      OneByteString(env->isolate(), NODE_PLATFORM));
  
    // process.argv
    Local<Array> arguments = Array::New(env->isolate(), argc);
    for (int i = 0; i < argc; ++i) {
      arguments->Set(i, String::NewFromUtf8(env->isolate(), argv[i]));
    }
    process->Set(env->argv_string(), arguments);
  
    // process.execArgv
    Local<Array> exec_arguments = Array::New(env->isolate(), exec_argc);
    for (int i = 0; i < exec_argc; ++i) {
      exec_arguments->Set(i, String::NewFromUtf8(env->isolate(), exec_argv[i]));
    }
    process->Set(env->exec_argv_string(), exec_arguments);
  
    // create process.env
    Local<ObjectTemplate> process_env_template =
        ObjectTemplate::New(env->isolate());
    process_env_template->SetNamedPropertyHandler(EnvGetter,
                                                  EnvSetter,
                                                  EnvQuery,
                                                  EnvDeleter,
                                                  EnvEnumerator,
                                                  Object::New(env->isolate()));
    Local<Object> process_env = process_env_template->NewInstance();
    process->Set(env->env_string(), process_env);
  
    READONLY_PROPERTY(process, "pid", Integer::New(env->isolate(), getpid()));
    READONLY_PROPERTY(process, "features", GetFeatures(env));
    process->SetAccessor(env->need_imm_cb_string(),
        NeedImmediateCallbackGetter,
        NeedImmediateCallbackSetter);
  
    // -e, --eval
    if (eval_string) {
      READONLY_PROPERTY(process,
                        "_eval",
                        String::NewFromUtf8(env->isolate(), eval_string));
    }
  
    // -p, --print
    if (print_eval) {
      READONLY_PROPERTY(process, "_print_eval", True(env->isolate()));
    }
  
    // -i, --interactive
    if (force_repl) {
      READONLY_PROPERTY(process, "_forceRepl", True(env->isolate()));
    }
  
    // --no-deprecation
    if (no_deprecation) {
      READONLY_PROPERTY(process, "noDeprecation", True(env->isolate()));
    }
  
    // --throw-deprecation
    if (throw_deprecation) {
      READONLY_PROPERTY(process, "throwDeprecation", True(env->isolate()));
    }
  
    // --trace-deprecation
    if (trace_deprecation) {
      READONLY_PROPERTY(process, "traceDeprecation", True(env->isolate()));
    }
  
    size_t exec_path_len = 2 * PATH_MAX;
    char* exec_path = new char[exec_path_len];
    Local<String> exec_path_value;
    if (uv_exepath(exec_path, &exec_path_len) == 0) {
      exec_path_value = String::NewFromUtf8(env->isolate(),
                                            exec_path,
                                            String::kNormalString,
                                            exec_path_len);
    } else {
      exec_path_value = String::NewFromUtf8(env->isolate(), argv[0]);
    }
    process->Set(env->exec_path_string(), exec_path_value);
    delete[] exec_path;
  
    process->SetAccessor(env->debug_port_string(),
                         DebugPortGetter,
                         DebugPortSetter);
  
    // define various internal methods
    env->SetMethod(process,
                   "_startProfilerIdleNotifier",
                   StartProfilerIdleNotifier);
    env->SetMethod(process,
                   "_stopProfilerIdleNotifier",
                   StopProfilerIdleNotifier);
    env->SetMethod(process, "_getActiveRequests", GetActiveRequests);
    env->SetMethod(process, "_getActiveHandles", GetActiveHandles);
    env->SetMethod(process, "reallyExit", Exit);
    env->SetMethod(process, "abort", Abort);
    env->SetMethod(process, "chdir", Chdir);
    env->SetMethod(process, "cwd", Cwd);
  
    env->SetMethod(process, "umask", Umask);
  
  #if defined(__POSIX__) && !defined(__ANDROID__)
    env->SetMethod(process, "getuid", GetUid);
    env->SetMethod(process, "setuid", SetUid);
  
    env->SetMethod(process, "setgid", SetGid);
    env->SetMethod(process, "getgid", GetGid);
  
    env->SetMethod(process, "getgroups", GetGroups);
    env->SetMethod(process, "setgroups", SetGroups);
    env->SetMethod(process, "initgroups", InitGroups);
  #endif  // __POSIX__ && !defined(__ANDROID__)
  
    env->SetMethod(process, "_kill", Kill);
  
    env->SetMethod(process, "_debugProcess", DebugProcess);
    env->SetMethod(process, "_debugPause", DebugPause);
    env->SetMethod(process, "_debugEnd", DebugEnd);
  
    env->SetMethod(process, "hrtime", Hrtime);
  
    env->SetMethod(process, "dlopen", DLOpen);
  
    env->SetMethod(process, "uptime", Uptime);
    env->SetMethod(process, "memoryUsage", MemoryUsage);
  
    env->SetMethod(process, "binding", Binding);
    env->SetMethod(process, "_linkedBinding", LinkedBinding);
  
    env->SetMethod(process, "_setupNextTick", SetupNextTick);
    env->SetMethod(process, "_setupDomainUse", SetupDomainUse);
  
    // pre-set _events object for faster emit checks
    process->Set(env->events_string(), Object::New(env->isolate()));
  }
  
  
  #undef READONLY_PROPERTY
  
  
  static void AtExit() {
    uv_tty_reset_mode();
  }
  
  
  static void SignalExit(int signo) {
    uv_tty_reset_mode();
    raise(signo);
  }
  
  
  // Most of the time, it's best to use `console.error` to write
  // to the process.stderr stream.  However, in some cases, such as
  // when debugging the stream.Writable class or the process.nextTick
  // function, it is useful to bypass JavaScript entirely.
  static void RawDebug(const FunctionCallbackInfo<Value>& args) {
    CHECK(args.Length() == 1 && args[0]->IsString() &&
          "must be called with a single string");
    node::Utf8Value message(args.GetIsolate(), args[0]);
    fprintf(stderr, "%s\n", *message);
    fflush(stderr);
  }
  
  
  void LoadEnvironment(Environment* env) {
    HandleScope handle_scope(env->isolate());
  
    env->isolate()->SetFatalErrorHandler(node::OnFatalError);
    env->isolate()->AddMessageListener(OnMessage);
  
    // Compile, execute the src/node.js file. (Which was included as static C
    // string in node_natives.h. 'natve_node' is the string containing that
    // source code.)
  
    // The node.js file returns a function 'f'
    atexit(AtExit);
  
    TryCatch try_catch;
  
    // Disable verbose mode to stop FatalException() handler from trying
    // to handle the exception. Errors this early in the start-up phase
    // are not safe to ignore.
    try_catch.SetVerbose(false);
  
    Local<String> script_name = FIXED_ONE_BYTE_STRING(env->isolate(), "node.js");
    Local<Value> f_value = ExecuteString(env, MainSource(env), script_name);
    if (try_catch.HasCaught())  {
      ReportException(env, try_catch);
      exit(10);
    }
    CHECK(f_value->IsFunction());
    Local<Function> f = Local<Function>::Cast(f_value);
  
    // Now we call 'f' with the 'process' variable that we've built up with
    // all our bindings. Inside node.js we'll take care of assigning things to
    // their places.
  
    // We start the process this way in order to be more modular. Developers
    // who do not like how 'src/node.js' setups the module system but do like
    // Node's I/O bindings may want to replace 'f' with their own function.
  
    // Add a reference to the global object
    Local<Object> global = env->context()->Global();
  
  #if defined HAVE_DTRACE || defined HAVE_ETW
    InitDTrace(env, global);
  #endif
  
  #if defined HAVE_PERFCTR
    InitPerfCounters(env, global);
  #endif
  
    // Enable handling of uncaught exceptions
    // (FatalException(), break on uncaught exception in debugger)
    //
    // This is not strictly necessary since it's almost impossible
    // to attach the debugger fast enought to break on exception
    // thrown during process startup.
    try_catch.SetVerbose(true);
  
    env->SetMethod(env->process_object(), "_rawDebug", RawDebug);
  
    Local<Value> arg = env->process_object();
    f->Call(global, 1, &arg);
  }
  
  static void PrintHelp();
  
  static bool ParseDebugOpt(const char* arg) {
    const char* port = nullptr;
  
    if (!strcmp(arg, "--debug")) {
      use_debug_agent = true;
    } else if (!strncmp(arg, "--debug=", sizeof("--debug=") - 1)) {
      use_debug_agent = true;
      port = arg + sizeof("--debug=") - 1;
    } else if (!strcmp(arg, "--debug-brk")) {
      use_debug_agent = true;
      debug_wait_connect = true;
    } else if (!strncmp(arg, "--debug-brk=", sizeof("--debug-brk=") - 1)) {
      use_debug_agent = true;
      debug_wait_connect = true;
      port = arg + sizeof("--debug-brk=") - 1;
    } else if (!strncmp(arg, "--debug-port=", sizeof("--debug-port=") - 1)) {
      port = arg + sizeof("--debug-port=") - 1;
    } else {
      return false;
    }
  
    if (port != nullptr) {
      debug_port = atoi(port);
      if (debug_port < 1024 || debug_port > 65535) {
        fprintf(stderr, "Debug port must be in range 1024 to 65535.\n");
        PrintHelp();
        exit(12);
      }
    }
  
    return true;
  }
  
  static void PrintHelp() {
    printf("Usage: node [options] [ -e script | script.js ] [arguments] \n"
           "       node debug script.js [arguments] \n"
           "\n"
           "Options:\n"
           "  -v, --version        print node's version\n"
           "  -e, --eval script    evaluate script\n"
           "  -p, --print          evaluate script and print result\n"
           "  -i, --interactive    always enter the REPL even if stdin\n"
           "                       does not appear to be a terminal\n"
           "  --no-deprecation     silence deprecation warnings\n"
           "  --throw-deprecation  throw an exception anytime a deprecated "
           "function is used\n"
           "  --trace-deprecation  show stack traces on deprecations\n"
           "  --v8-options         print v8 command line options\n"
           "  --max-stack-size=val set max v8 stack size (bytes)\n"
  #if defined(NODE_HAVE_I18N_SUPPORT)
           "  --icu-data-dir=dir   set ICU data load path to dir\n"
           "                         (overrides NODE_ICU_DATA)\n"
  #if !defined(NODE_HAVE_SMALL_ICU)
           "                       Note: linked-in ICU data is\n"
           "                       present.\n"
  #endif
  #endif
           "\n"
           "Environment variables:\n"
  #ifdef _WIN32
           "NODE_PATH              ';'-separated list of directories\n"
  #else
           "NODE_PATH              ':'-separated list of directories\n"
  #endif
           "                       prefixed to the module search path.\n"
           "NODE_MODULE_CONTEXTS   Set to 1 to load modules in their own\n"
           "                       global contexts.\n"
           "NODE_DISABLE_COLORS    Set to 1 to disable colors in the REPL\n"
  #if defined(NODE_HAVE_I18N_SUPPORT)
           "NODE_ICU_DATA          Data path for ICU (Intl object) data\n"
  #if !defined(NODE_HAVE_SMALL_ICU)
           "                       (will extend linked-in data)\n"
  #endif
  #endif
           "\n"
           "Documentation can be found at http://nodejs.org/\n");
  }
  
  
  // Parse command line arguments.
  //
  // argv is modified in place. exec_argv and v8_argv are out arguments that
  // ParseArgs() allocates memory for and stores a pointer to the output
  // vector in.  The caller should free them with delete[].
  //
  // On exit:
  //
  //  * argv contains the arguments with node and V8 options filtered out.
  //  * exec_argv contains both node and V8 options and nothing else.
  //  * v8_argv contains argv[0] plus any V8 options
  static void ParseArgs(int* argc,
                        const char** argv,
                        int* exec_argc,
                        const char*** exec_argv,
                        int* v8_argc,
                        const char*** v8_argv) {
    const unsigned int nargs = static_cast<unsigned int>(*argc);
    const char** new_exec_argv = new const char*[nargs];
    const char** new_v8_argv = new const char*[nargs];
    const char** new_argv = new const char*[nargs];
  
    for (unsigned int i = 0; i < nargs; ++i) {
      new_exec_argv[i] = nullptr;
      new_v8_argv[i] = nullptr;
      new_argv[i] = nullptr;
    }
  
    // exec_argv starts with the first option, the other two start with argv[0].
    unsigned int new_exec_argc = 0;
    unsigned int new_v8_argc = 1;
    unsigned int new_argc = 1;
    new_v8_argv[0] = argv[0];
    new_argv[0] = argv[0];
  
    unsigned int index = 1;
    while (index < nargs && argv[index][0] == '-') {
      const char* const arg = argv[index];
      unsigned int args_consumed = 1;
  
      if (ParseDebugOpt(arg)) {
        // Done, consumed by ParseDebugOpt().
      } else if (strcmp(arg, "--version") == 0 || strcmp(arg, "-v") == 0) {
        printf("%s\n", NODE_VERSION);
        exit(0);
      } else if (strcmp(arg, "--help") == 0 || strcmp(arg, "-h") == 0) {
        PrintHelp();
        exit(0);
      } else if (strcmp(arg, "--eval") == 0 ||
                 strcmp(arg, "-e") == 0 ||
                 strcmp(arg, "--print") == 0 ||
                 strcmp(arg, "-pe") == 0 ||
                 strcmp(arg, "-p") == 0) {
        bool is_eval = strchr(arg, 'e') != nullptr;
        bool is_print = strchr(arg, 'p') != nullptr;
        print_eval = print_eval || is_print;
        // --eval, -e and -pe always require an argument.
        if (is_eval == true) {
          args_consumed += 1;
          eval_string = argv[index + 1];
          if (eval_string == nullptr) {
            fprintf(stderr, "%s: %s requires an argument\n", argv[0], arg);
            exit(9);
          }
        } else if ((index + 1 < nargs) &&
                   argv[index + 1] != nullptr &&
                   argv[index + 1][0] != '-') {
          args_consumed += 1;
          eval_string = argv[index + 1];
          if (strncmp(eval_string, "\\-", 2) == 0) {
            // Starts with "\\-": escaped expression, drop the backslash.
            eval_string += 1;
          }
        }
      } else if (strcmp(arg, "--interactive") == 0 || strcmp(arg, "-i") == 0) {
        force_repl = true;
      } else if (strcmp(arg, "--no-deprecation") == 0) {
        no_deprecation = true;
      } else if (strcmp(arg, "--trace-deprecation") == 0) {
        trace_deprecation = true;
      } else if (strcmp(arg, "--throw-deprecation") == 0) {
        throw_deprecation = true;
      } else if (strcmp(arg, "--v8-options") == 0) {
        new_v8_argv[new_v8_argc] = "--help";
        new_v8_argc += 1;
  #if defined(NODE_HAVE_I18N_SUPPORT)
      } else if (strncmp(arg, "--icu-data-dir=", 15) == 0) {
        icu_data_dir = arg + 15;
  #endif
      } else {
        // V8 option.  Pass through as-is.
        new_v8_argv[new_v8_argc] = arg;
        new_v8_argc += 1;
      }
  
      memcpy(new_exec_argv + new_exec_argc,
             argv + index,
             args_consumed * sizeof(*argv));
  
      new_exec_argc += args_consumed;
      index += args_consumed;
    }
  
    // Copy remaining arguments.
    const unsigned int args_left = nargs - index;
    memcpy(new_argv + new_argc, argv + index, args_left * sizeof(*argv));
    new_argc += args_left;
  
    *exec_argc = new_exec_argc;
    *exec_argv = new_exec_argv;
    *v8_argc = new_v8_argc;
    *v8_argv = new_v8_argv;
  
    // Copy new_argv over argv and update argc.
    memcpy(argv, new_argv, new_argc * sizeof(*argv));
    delete[] new_argv;
    *argc = static_cast<int>(new_argc);
  }
  
  
  // Called from V8 Debug Agent TCP thread.
  static void DispatchMessagesDebugAgentCallback(Environment* env) {
    // TODO(indutny): move async handle to environment
    uv_async_send(&dispatch_debug_messages_async);
  }
  
  
  static void StartDebug(Environment* env, bool wait) {
    CHECK(!debugger_running);
  
    env->debugger_agent()->set_dispatch_handler(
          DispatchMessagesDebugAgentCallback);
    debugger_running = env->debugger_agent()->Start(debug_port, wait);
    if (debugger_running == false) {
      fprintf(stderr, "Starting debugger on port %d failed\n", debug_port);
      fflush(stderr);
      return;
    }
  }
  
  
  // Called from the main thread.
  static void EnableDebug(Environment* env) {
    CHECK(debugger_running);
  
    // Send message to enable debug in workers
    HandleScope handle_scope(env->isolate());
  
    Local<Object> message = Object::New(env->isolate());
    message->Set(FIXED_ONE_BYTE_STRING(env->isolate(), "cmd"),
                 FIXED_ONE_BYTE_STRING(env->isolate(), "NODE_DEBUG_ENABLED"));
    Local<Value> argv[] = {
      FIXED_ONE_BYTE_STRING(env->isolate(), "internalMessage"),
      message
    };
    MakeCallback(env, env->process_object(), "emit", ARRAY_SIZE(argv), argv);
  
    // Enabled debugger, possibly making it wait on a semaphore
    env->debugger_agent()->Enable();
  }
  
  
  // Called from the main thread.
  static void DispatchDebugMessagesAsyncCallback(uv_async_t* handle) {
    if (debugger_running == false) {
      fprintf(stderr, "Starting debugger agent.\n");
  
      Environment* env = Environment::GetCurrent(node_isolate);
      Context::Scope context_scope(env->context());
  
      StartDebug(env, false);
      EnableDebug(env);
    }
    Isolate::Scope isolate_scope(node_isolate);
    v8::Debug::ProcessDebugMessages();
  }
  
  
  #ifdef __POSIX__
  static volatile sig_atomic_t caught_early_debug_signal;
  
  
  static void EarlyDebugSignalHandler(int signo) {
    caught_early_debug_signal = 1;
  }
  
  
  static void InstallEarlyDebugSignalHandler() {
    struct sigaction sa;
    memset(&sa, 0, sizeof(sa));
    sa.sa_handler = EarlyDebugSignalHandler;
    sigaction(SIGUSR1, &sa, nullptr);
  }
  
  
  static void EnableDebugSignalHandler(int signo) {
    // Call only async signal-safe functions here!
    v8::Debug::DebugBreak(*static_cast<Isolate* volatile*>(&node_isolate));
    uv_async_send(&dispatch_debug_messages_async);
  }
  
  
  static void RegisterSignalHandler(int signal,
                                    void (*handler)(int signal),
                                    bool reset_handler = false) {
    struct sigaction sa;
    memset(&sa, 0, sizeof(sa));
    sa.sa_handler = handler;
    sa.sa_flags = reset_handler ? SA_RESETHAND : 0;
    sigfillset(&sa.sa_mask);
    CHECK_EQ(sigaction(signal, &sa, nullptr), 0);
  }
  
  
  void DebugProcess(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
  
    if (args.Length() != 1) {
      return env->ThrowError("Invalid number of arguments.");
    }
  
    pid_t pid;
    int r;
  
    pid = args[0]->IntegerValue();
    r = kill(pid, SIGUSR1);
    if (r != 0) {
      return env->ThrowErrnoException(errno, "kill");
    }
  }
  
  
  static int RegisterDebugSignalHandler() {
    // FIXME(bnoordhuis) Should be per-isolate or per-context, not global.
    RegisterSignalHandler(SIGUSR1, EnableDebugSignalHandler);
    // If we caught a SIGUSR1 during the bootstrap process, re-raise it
    // now that the debugger infrastructure is in place.
    if (caught_early_debug_signal)
      raise(SIGUSR1);
    return 0;
  }
  #endif  // __POSIX__
  
  
  #ifdef _WIN32
  DWORD WINAPI EnableDebugThreadProc(void* arg) {
    v8::Debug::DebugBreak(*static_cast<Isolate* volatile*>(&node_isolate));
    uv_async_send(&dispatch_debug_messages_async);
    return 0;
  }
  
  
  static int GetDebugSignalHandlerMappingName(DWORD pid, wchar_t* buf,
      size_t buf_len) {
    return _snwprintf(buf, buf_len, L"node-debug-handler-%u", pid);
  }
  
  
  static int RegisterDebugSignalHandler() {
    wchar_t mapping_name[32];
    HANDLE mapping_handle;
    DWORD pid;
    LPTHREAD_START_ROUTINE* handler;
  
    pid = GetCurrentProcessId();
  
    if (GetDebugSignalHandlerMappingName(pid,
                                         mapping_name,
                                         ARRAY_SIZE(mapping_name)) < 0) {
      return -1;
    }
  
    mapping_handle = CreateFileMappingW(INVALID_HANDLE_VALUE,
                                        nullptr,
                                        PAGE_READWRITE,
                                        0,
                                        sizeof *handler,
                                        mapping_name);
    if (mapping_handle == nullptr) {
      return -1;
    }
  
    handler = reinterpret_cast<LPTHREAD_START_ROUTINE*>(
        MapViewOfFile(mapping_handle,
                      FILE_MAP_ALL_ACCESS,
                      0,
                      0,
                      sizeof *handler));
    if (handler == nullptr) {
      CloseHandle(mapping_handle);
      return -1;
    }
  
    *handler = EnableDebugThreadProc;
  
    UnmapViewOfFile(static_cast<void*>(handler));
  
    return 0;
  }
  
  
  static void DebugProcess(const FunctionCallbackInfo<Value>& args) {
    Environment* env = Environment::GetCurrent(args);
    Isolate* isolate = args.GetIsolate();
    DWORD pid;
    HANDLE process = nullptr;
    HANDLE thread = nullptr;
    HANDLE mapping = nullptr;
    wchar_t mapping_name[32];
    LPTHREAD_START_ROUTINE* handler = nullptr;
  
    if (args.Length() != 1) {
      env->ThrowError("Invalid number of arguments.");
      goto out;
    }
  
    pid = (DWORD) args[0]->IntegerValue();
  
    process = OpenProcess(PROCESS_CREATE_THREAD | PROCESS_QUERY_INFORMATION |
                              PROCESS_VM_OPERATION | PROCESS_VM_WRITE |
                              PROCESS_VM_READ,
                          FALSE,
                          pid);
    if (process == nullptr) {
      isolate->ThrowException(
          WinapiErrnoException(isolate, GetLastError(), "OpenProcess"));
      goto out;
    }
  
    if (GetDebugSignalHandlerMappingName(pid,
                                         mapping_name,
                                         ARRAY_SIZE(mapping_name)) < 0) {
      env->ThrowErrnoException(errno, "sprintf");
      goto out;
    }
  
    mapping = OpenFileMappingW(FILE_MAP_READ, FALSE, mapping_name);
    if (mapping == nullptr) {
      isolate->ThrowException(WinapiErrnoException(isolate,
                                               GetLastError(),
                                               "OpenFileMappingW"));
      goto out;
    }
  
    handler = reinterpret_cast<LPTHREAD_START_ROUTINE*>(
        MapViewOfFile(mapping,
                      FILE_MAP_READ,
                      0,
                      0,
                      sizeof *handler));
    if (handler == nullptr || *handler == nullptr) {
      isolate->ThrowException(
          WinapiErrnoException(isolate, GetLastError(), "MapViewOfFile"));
      goto out;
    }
  
    thread = CreateRemoteThread(process,
                                nullptr,
                                0,
                                *handler,
                                nullptr,
                                0,
                                nullptr);
    if (thread == nullptr) {
      isolate->ThrowException(WinapiErrnoException(isolate,
                                                   GetLastError(),
                                                   "CreateRemoteThread"));
      goto out;
    }
  
    // Wait for the thread to terminate
    if (WaitForSingleObject(thread, INFINITE) != WAIT_OBJECT_0) {
      isolate->ThrowException(WinapiErrnoException(isolate,
                                                   GetLastError(),
                                                   "WaitForSingleObject"));
      goto out;
    }
  
   out:
    if (process != nullptr)
      CloseHandle(process);
    if (thread != nullptr)
      CloseHandle(thread);
    if (handler != nullptr)
      UnmapViewOfFile(handler);
    if (mapping != nullptr)
      CloseHandle(mapping);
  }
  #endif  // _WIN32
  
  
  static void DebugPause(const FunctionCallbackInfo<Value>& args) {
    v8::Debug::DebugBreak(args.GetIsolate());
  }
  
  
  static void DebugEnd(const FunctionCallbackInfo<Value>& args) {
    if (debugger_running) {
      Environment* env = Environment::GetCurrent(args);
      env->debugger_agent()->Stop();
      debugger_running = false;
    }
  }
  
  
  void Init(int* argc,
            const char** argv,
            int* exec_argc,
            const char*** exec_argv) {
    // Initialize prog_start_time to get relative uptime.
    prog_start_time = static_cast<double>(uv_now(uv_default_loop()));
  
    // Make inherited handles noninheritable.
    uv_disable_stdio_inheritance();
  
    // init async debug messages dispatching
    // FIXME(bnoordhuis) Should be per-isolate or per-context, not global.
    uv_async_init(uv_default_loop(),
                  &dispatch_debug_messages_async,
                  DispatchDebugMessagesAsyncCallback);
    uv_unref(reinterpret_cast<uv_handle_t*>(&dispatch_debug_messages_async));
  
    // TODO(bnoordhuis) V8 3.32 is unshipping Harmony classes for the moment.
    // We're currently at 3.31, disable classes for feature parity.  Remove
    // again when we upgrade.
    V8::SetFlagsFromString("--noharmony_classes",
                           sizeof("--noharmony_classes") - 1);
    V8::SetFlagsFromString("--noharmony_object_literals",
                           sizeof("--noharmony_object_literals") - 1);
  
  #if defined(NODE_V8_OPTIONS)
    // Should come before the call to V8::SetFlagsFromCommandLine()
    // so the user can disable a flag --foo at run-time by passing
    // --no_foo from the command line.
    V8::SetFlagsFromString(NODE_V8_OPTIONS, sizeof(NODE_V8_OPTIONS) - 1);
  #endif
  
    // Parse a few arguments which are specific to Node.
    int v8_argc;
    const char** v8_argv;
    ParseArgs(argc, argv, exec_argc, exec_argv, &v8_argc, &v8_argv);
  
    // TODO(bnoordhuis) Intercept --prof arguments and start the CPU profiler
    // manually?  That would give us a little more control over its runtime
    // behavior but it could also interfere with the user's intentions in ways
    // we fail to anticipate.  Dillema.
    for (int i = 1; i < v8_argc; ++i) {
      if (strncmp(v8_argv[i], "--prof", sizeof("--prof") - 1) == 0) {
        v8_is_profiling = true;
        break;
      }
    }
  
  #if defined(NODE_HAVE_I18N_SUPPORT)
    if (icu_data_dir == nullptr) {
      // if the parameter isn't given, use the env variable.
      icu_data_dir = secure_getenv("NODE_ICU_DATA");
    }
    // Initialize ICU.
    // If icu_data_dir is nullptr here, it will load the 'minimal' data.
    if (!i18n::InitializeICUDirectory(icu_data_dir)) {
      FatalError(nullptr, "Could not initialize ICU "
                       "(check NODE_ICU_DATA or --icu-data-dir parameters)");
    }
  #endif
    // The const_cast doesn't violate conceptual const-ness.  V8 doesn't modify
    // the argv array or the elements it points to.
    V8::SetFlagsFromCommandLine(&v8_argc, const_cast<char**>(v8_argv), true);
  
    // Anything that's still in v8_argv is not a V8 or a node option.
    for (int i = 1; i < v8_argc; i++) {
      fprintf(stderr, "%s: bad option: %s\n", argv[0], v8_argv[i]);
    }
    delete[] v8_argv;
    v8_argv = nullptr;
  
    if (v8_argc > 1) {
      exit(9);
    }
  
    if (debug_wait_connect) {
      const char expose_debug_as[] = "--expose_debug_as=v8debug";
      V8::SetFlagsFromString(expose_debug_as, sizeof(expose_debug_as) - 1);
    }
  
    V8::SetArrayBufferAllocator(&ArrayBufferAllocator::the_singleton);
  
  #ifdef __POSIX__
    // Raise the open file descriptor limit.
    {  // NOLINT (whitespace/braces)
      struct rlimit lim;
      if (getrlimit(RLIMIT_NOFILE, &lim) == 0 && lim.rlim_cur != lim.rlim_max) {
        // Do a binary search for the limit.
        rlim_t min = lim.rlim_cur;
        rlim_t max = 1 << 20;
        // But if there's a defined upper bound, don't search, just set it.
        if (lim.rlim_max != RLIM_INFINITY) {
          min = lim.rlim_max;
          max = lim.rlim_max;
        }
        do {
          lim.rlim_cur = min + (max - min) / 2;
          if (setrlimit(RLIMIT_NOFILE, &lim)) {
            max = lim.rlim_cur;
          } else {
            min = lim.rlim_cur;
          }
        } while (min + 1 < max);
      }
    }
    // Ignore SIGPIPE
    RegisterSignalHandler(SIGPIPE, SIG_IGN);
    RegisterSignalHandler(SIGINT, SignalExit, true);
    RegisterSignalHandler(SIGTERM, SignalExit, true);
  #endif  // __POSIX__
  
    if (!use_debug_agent) {
      RegisterDebugSignalHandler();
    }
  }
  
  
  struct AtExitCallback {
    AtExitCallback* next_;
    void (*cb_)(void* arg);
    void* arg_;
  };
  
  static AtExitCallback* at_exit_functions_;
  
  
  // TODO(bnoordhuis) Turn into per-context event.
  void RunAtExit(Environment* env) {
    AtExitCallback* p = at_exit_functions_;
    at_exit_functions_ = nullptr;
  
    while (p) {
      AtExitCallback* q = p->next_;
      p->cb_(p->arg_);
      delete p;
      p = q;
    }
  }
  
  
  void AtExit(void (*cb)(void* arg), void* arg) {
    AtExitCallback* p = new AtExitCallback;
    p->cb_ = cb;
    p->arg_ = arg;
    p->next_ = at_exit_functions_;
    at_exit_functions_ = p;
  }
  
  
  void EmitBeforeExit(Environment* env) {
    Context::Scope context_scope(env->context());
    HandleScope handle_scope(env->isolate());
    Local<Object> process_object = env->process_object();
    Local<String> exit_code = FIXED_ONE_BYTE_STRING(env->isolate(), "exitCode");
    Local<Value> args[] = {
      FIXED_ONE_BYTE_STRING(env->isolate(), "beforeExit"),
      process_object->Get(exit_code)->ToInteger(env->isolate())
    };
    MakeCallback(env, process_object, "emit", ARRAY_SIZE(args), args);
  }
  
  
  int EmitExit(Environment* env) {
    // process.emit('exit')
    HandleScope handle_scope(env->isolate());
    Context::Scope context_scope(env->context());
    Local<Object> process_object = env->process_object();
    process_object->Set(env->exiting_string(), True(env->isolate()));
  
    Handle<String> exitCode = env->exit_code_string();
    int code = process_object->Get(exitCode)->Int32Value();
  
    Local<Value> args[] = {
      env->exit_string(),
      Integer::New(env->isolate(), code)
    };
  
    MakeCallback(env, process_object, "emit", ARRAY_SIZE(args), args);
  
    // Reload exit code, it may be changed by `emit('exit')`
    return process_object->Get(exitCode)->Int32Value();
  }
  
  
  // Just a convenience method
  Environment* CreateEnvironment(Isolate* isolate,
                                 Handle<Context> context,
                                 int argc,
                                 const char* const* argv,
                                 int exec_argc,
                                 const char* const* exec_argv) {
    Environment* env;
    Context::Scope context_scope(context);
  
    env = CreateEnvironment(isolate,
                            uv_default_loop(),
                            context,
                            argc,
                            argv,
                            exec_argc,
                            exec_argv);
  
    LoadEnvironment(env);
  
    return env;
  }
  
  
  static void HandleCloseCb(uv_handle_t* handle) {
    Environment* env = reinterpret_cast<Environment*>(handle->data);
    env->FinishHandleCleanup(handle);
  }
  
  
  static void HandleCleanup(Environment* env,
                            uv_handle_t* handle,
                            void* arg) {
    handle->data = env;
    uv_close(handle, HandleCloseCb);
  }
  
  
  Environment* CreateEnvironment(Isolate* isolate,
                                 uv_loop_t* loop,
                                 Handle<Context> context,
                                 int argc,
                                 const char* const* argv,
                                 int exec_argc,
                                 const char* const* exec_argv) {
    HandleScope handle_scope(isolate);
  
    Context::Scope context_scope(context);
    Environment* env = Environment::New(context, loop);
  
    isolate->SetAutorunMicrotasks(false);
  
    uv_check_init(env->event_loop(), env->immediate_check_handle());
    uv_unref(
        reinterpret_cast<uv_handle_t*>(env->immediate_check_handle()));
  
    uv_idle_init(env->event_loop(), env->immediate_idle_handle());
  
    // Inform V8's CPU profiler when we're idle.  The profiler is sampling-based
    // but not all samples are created equal; mark the wall clock time spent in
    // epoll_wait() and friends so profiling tools can filter it out.  The samples
    // still end up in v8.log but with state=IDLE rather than state=EXTERNAL.
    // TODO(bnoordhuis) Depends on a libuv implementation detail that we should
    // probably fortify in the API contract, namely that the last started prepare
    // or check watcher runs first.  It's not 100% foolproof; if an add-on starts
    // a prepare or check watcher after us, any samples attributed to its callback
    // will be recorded with state=IDLE.
    uv_prepare_init(env->event_loop(), env->idle_prepare_handle());
    uv_check_init(env->event_loop(), env->idle_check_handle());
    uv_unref(reinterpret_cast<uv_handle_t*>(env->idle_prepare_handle()));
    uv_unref(reinterpret_cast<uv_handle_t*>(env->idle_check_handle()));
  
    // Register handle cleanups
    env->RegisterHandleCleanup(
        reinterpret_cast<uv_handle_t*>(env->immediate_check_handle()),
        HandleCleanup,
        nullptr);
    env->RegisterHandleCleanup(
        reinterpret_cast<uv_handle_t*>(env->immediate_idle_handle()),
        HandleCleanup,
        nullptr);
    env->RegisterHandleCleanup(
        reinterpret_cast<uv_handle_t*>(env->idle_prepare_handle()),
        HandleCleanup,
        nullptr);
    env->RegisterHandleCleanup(
        reinterpret_cast<uv_handle_t*>(env->idle_check_handle()),
        HandleCleanup,
        nullptr);
  
    if (v8_is_profiling) {
      StartProfilerIdleNotifier(env);
    }
  
    Local<FunctionTemplate> process_template = FunctionTemplate::New(isolate);
    process_template->SetClassName(FIXED_ONE_BYTE_STRING(isolate, "process"));
  
    Local<Object> process_object = process_template->GetFunction()->NewInstance();
    env->set_process_object(process_object);
  
    SetupProcessObject(env, argc, argv, exec_argc, exec_argv);
  
    return env;
  }
  
  
  int Start(int argc, char** argv) {
    const char* replaceInvalid = secure_getenv("NODE_INVALID_UTF8");
  
    if (replaceInvalid == nullptr)
      WRITE_UTF8_FLAGS |= String::REPLACE_INVALID_UTF8;
  
  #if !defined(_WIN32)
    // Try hard not to lose SIGUSR1 signals during the bootstrap process.
    InstallEarlyDebugSignalHandler();
  #endif
  
    CHECK_GT(argc, 0);
  
    // Hack around with the argv pointer. Used for process.title = "blah".
    argv = uv_setup_args(argc, argv);
  
    // This needs to run *before* V8::Initialize().  The const_cast is not
    // optional, in case you're wondering.
    int exec_argc;
    const char** exec_argv;
    Init(&argc, const_cast<const char**>(argv), &exec_argc, &exec_argv);
  
  #if HAVE_OPENSSL
    // V8 on Windows doesn't have a good source of entropy. Seed it from
    // OpenSSL's pool.
    V8::SetEntropySource(crypto::EntropySource);
  #endif
  
    V8::InitializePlatform(new Platform(4));
  
    int code;
    V8::Initialize();
    node_is_initialized = true;
  
    // Fetch a reference to the main isolate, so we have a reference to it
    // even when we need it to access it from another (debugger) thread.
    node_isolate = Isolate::New();
    {
      Locker locker(node_isolate);
      Isolate::Scope isolate_scope(node_isolate);
      HandleScope handle_scope(node_isolate);
      Local<Context> context = Context::New(node_isolate);
      Environment* env = CreateEnvironment(
          node_isolate,
          uv_default_loop(),
          context,
          argc,
          argv,
          exec_argc,
          exec_argv);
      Context::Scope context_scope(context);
  
      // Start debug agent when argv has --debug
      if (use_debug_agent)
        StartDebug(env, debug_wait_connect);
  
      LoadEnvironment(env);
  
      // Enable debugger
      if (use_debug_agent)
        EnableDebug(env);
  
      bool more;
      do {
        more = uv_run(env->event_loop(), UV_RUN_ONCE);
        if (more == false) {
          EmitBeforeExit(env);
  
          // Emit `beforeExit` if the loop became alive either after emitting
          // event, or after running some callbacks.
          more = uv_loop_alive(env->event_loop());
          if (uv_run(env->event_loop(), UV_RUN_NOWAIT) != 0)
            more = true;
        }
      } while (more == true);
      code = EmitExit(env);
      RunAtExit(env);
  
      env->Dispose();
      env = nullptr;
    }
  
    CHECK_NE(node_isolate, nullptr);
    node_isolate->Dispose();
    node_isolate = nullptr;
    V8::Dispose();
  
    delete[] exec_argv;
    exec_argv = nullptr;
  
    return code;
  }
  
  
  }  // namespace node
  