text: /******************************************************************************
   *
   *  Copyright (C) 2016 Google, Inc.
   *
   *  Licensed under the Apache License, Version 2.0 (the "License");
   *  you may not use this file except in compliance with the License.
   *  You may obtain a copy of the License at:
   *
   *  http://www.apache.org/licenses/LICENSE-2.0
   *
   *  Unless required by applicable law or agreed to in writing, software
   *  distributed under the License is distributed on an "AS IS" BASIS,
   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *  See the License for the specific language governing permissions and
   *  limitations under the License.
   *
   ******************************************************************************/
  
  #pragma once
  
  #include <stdbool.h>
  #include <stdint.h>
  
  #define UNUSED_ATTR __attribute__((unused))
  #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
  #define INVALID_FD (-1)
  
  #define CONCAT(a, b) a##b
  
  // Use during compile time to check conditional values
  // NOTE: The the failures will present as a generic error
  // "error: initialization makes pointer from integer without a cast"
  // but the file and line number will present the condition that
  // failed.
  #define DUMMY_COUNTER(c) CONCAT(__osi_dummy_, c)
  #define DUMMY_PTR DUMMY_COUNTER(__COUNTER__)
  
  // base/macros.h defines a COMPILE_ASSERT macro to the C++11 keyword
  // "static_assert" (it undef's COMPILE_ASSERT before redefining it).
  // C++ code that includes base and osi/include/osi.h can thus easily default to
  // the definition from libbase but we should check here to avoid compile errors.
  #ifndef COMPILE_ASSERT
  #define COMPILE_ASSERT(COND) typedef int failed_compile_assert[(COND) ? 1 : -1] __attribute__ ((unused))
  #endif  // COMPILE_ASSERT
  
  // Macros for safe integer to pointer conversion. In the C language, data is
  // commonly cast to opaque pointer containers and back for generic parameter
  // passing in callbacks. These macros should be used sparingly in new code
  // (never in C++ code). Whenever integers need to be passed as a pointer, use
  // these macros.
  #define PTR_TO_UINT(p) ((unsigned int) ((uintptr_t) (p)))
  #define UINT_TO_PTR(u) ((void *) ((uintptr_t) (u)))
  
  #define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
  #define INT_TO_PTR(i) ((void *) ((intptr_t) (i)))
  
  // Obtain a random number between 0 and INT_MAX inclusive.
  // Taken from a system random source such as /dev/random.
  // No guarantees of distribution are made.
  // Effort is made for this to come from a real random source.
  int osi_rand(void);
  
  // Re-run |fn| system call until the system call doesn't cause EINTR.
  #define OSI_NO_INTR(fn)  do {} while ((fn) == -1 && errno == EINTR)
  