text: /*
   * Event loop based on select() loop
   * Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
   *
   * This software may be distributed under the terms of the BSD license.
   * See README for more details.
   */
  
  #include "includes.h"
  #include <assert.h>
  
  #include "common.h"
  #include "trace.h"
  #include "list.h"
  #include "eloop.h"
  
  #if defined(CONFIG_ELOOP_POLL) && defined(CONFIG_ELOOP_EPOLL)
  #error Do not define both of poll and epoll
  #endif
  
  #if !defined(CONFIG_ELOOP_POLL) && !defined(CONFIG_ELOOP_EPOLL)
  #define CONFIG_ELOOP_SELECT
  #endif
  
  #ifdef CONFIG_ELOOP_POLL
  #include <poll.h>
  #endif /* CONFIG_ELOOP_POLL */
  
  #ifdef CONFIG_ELOOP_EPOLL
  #include <sys/epoll.h>
  #endif /* CONFIG_ELOOP_EPOLL */
  
  struct eloop_sock {
  	int sock;
  	void *eloop_data;
  	void *user_data;
  	eloop_sock_handler handler;
  	WPA_TRACE_REF(eloop);
  	WPA_TRACE_REF(user);
  	WPA_TRACE_INFO
  };
  
  struct eloop_timeout {
  	struct dl_list list;
  	struct os_reltime time;
  	void *eloop_data;
  	void *user_data;
  	eloop_timeout_handler handler;
  	WPA_TRACE_REF(eloop);
  	WPA_TRACE_REF(user);
  	WPA_TRACE_INFO
  };
  
  struct eloop_signal {
  	int sig;
  	void *user_data;
  	eloop_signal_handler handler;
  	int signaled;
  };
  
  struct eloop_sock_table {
  	int count;
  	struct eloop_sock *table;
  	eloop_event_type type;
  	int changed;
  };
  
  struct eloop_data {
  	int max_sock;
  
  	int count; /* sum of all table counts */
  #ifdef CONFIG_ELOOP_POLL
  	int max_pollfd_map; /* number of pollfds_map currently allocated */
  	int max_poll_fds; /* number of pollfds currently allocated */
  	struct pollfd *pollfds;
  	struct pollfd **pollfds_map;
  #endif /* CONFIG_ELOOP_POLL */
  #ifdef CONFIG_ELOOP_EPOLL
  	int epollfd;
  	int epoll_max_event_num;
  	int epoll_max_fd;
  	struct eloop_sock *epoll_table;
  	struct epoll_event *epoll_events;
  #endif /* CONFIG_ELOOP_EPOLL */
  	struct eloop_sock_table readers;
  	struct eloop_sock_table writers;
  	struct eloop_sock_table exceptions;
  
  	struct dl_list timeout;
  
  	int signal_count;
  	struct eloop_signal *signals;
  	int signaled;
  	int pending_terminate;
  
  	int terminate;
  };
  
  static struct eloop_data eloop;
  
  
  #ifdef WPA_TRACE
  
  static void eloop_sigsegv_handler(int sig)
  {
  	wpa_trace_show("eloop SIGSEGV");
  	abort();
  }
  
  static void eloop_trace_sock_add_ref(struct eloop_sock_table *table)
  {
  	int i;
  	if (table == NULL || table->table == NULL)
  		return;
  	for (i = 0; i < table->count; i++) {
  		wpa_trace_add_ref(&table->table[i], eloop,
  				  table->table[i].eloop_data);
  		wpa_trace_add_ref(&table->table[i], user,
  				  table->table[i].user_data);
  	}
  }
  
  
  static void eloop_trace_sock_remove_ref(struct eloop_sock_table *table)
  {
  	int i;
  	if (table == NULL || table->table == NULL)
  		return;
  	for (i = 0; i < table->count; i++) {
  		wpa_trace_remove_ref(&table->table[i], eloop,
  				     table->table[i].eloop_data);
  		wpa_trace_remove_ref(&table->table[i], user,
  				     table->table[i].user_data);
  	}
  }
  
  #else /* WPA_TRACE */
  
  #define eloop_trace_sock_add_ref(table) do { } while (0)
  #define eloop_trace_sock_remove_ref(table) do { } while (0)
  
  #endif /* WPA_TRACE */
  
  
  int eloop_init(void)
  {
  	os_memset(&eloop, 0, sizeof(eloop));
  	dl_list_init(&eloop.timeout);
  #ifdef CONFIG_ELOOP_EPOLL
  	eloop.epollfd = epoll_create1(0);
  	if (eloop.epollfd < 0) {
  		wpa_printf(MSG_ERROR, "%s: epoll_create1 failed. %s\n",
  			   __func__, strerror(errno));
  		return -1;
  	}
  	eloop.readers.type = EVENT_TYPE_READ;
  	eloop.writers.type = EVENT_TYPE_WRITE;
  	eloop.exceptions.type = EVENT_TYPE_EXCEPTION;
  #endif /* CONFIG_ELOOP_EPOLL */
  #ifdef WPA_TRACE
  	signal(SIGSEGV, eloop_sigsegv_handler);
  #endif /* WPA_TRACE */
  	return 0;
  }
  
  
  static int eloop_sock_table_add_sock(struct eloop_sock_table *table,
                                       int sock, eloop_sock_handler handler,
                                       void *eloop_data, void *user_data)
  {
  #ifdef CONFIG_ELOOP_EPOLL
  	struct eloop_sock *temp_table;
  	struct epoll_event ev, *temp_events;
  	int next;
  #endif /* CONFIG_ELOOP_EPOLL */
  	struct eloop_sock *tmp;
  	int new_max_sock;
  
  	if (sock > eloop.max_sock)
  		new_max_sock = sock;
  	else
  		new_max_sock = eloop.max_sock;
  
  	if (table == NULL)
  		return -1;
  
  #ifdef CONFIG_ELOOP_POLL
  	if (new_max_sock >= eloop.max_pollfd_map) {
  		struct pollfd **nmap;
  		nmap = os_realloc_array(eloop.pollfds_map, new_max_sock + 50,
  					sizeof(struct pollfd *));
  		if (nmap == NULL)
  			return -1;
  
  		eloop.max_pollfd_map = new_max_sock + 50;
  		eloop.pollfds_map = nmap;
  	}
  
  	if (eloop.count + 1 > eloop.max_poll_fds) {
  		struct pollfd *n;
  		int nmax = eloop.count + 1 + 50;
  		n = os_realloc_array(eloop.pollfds, nmax,
  				     sizeof(struct pollfd));
  		if (n == NULL)
  			return -1;
  
  		eloop.max_poll_fds = nmax;
  		eloop.pollfds = n;
  	}
  #endif /* CONFIG_ELOOP_POLL */
  #ifdef CONFIG_ELOOP_EPOLL
  	if (new_max_sock >= eloop.epoll_max_fd) {
  		next = eloop.epoll_max_fd == 0 ? 16 : eloop.epoll_max_fd * 2;
  		temp_table = os_realloc_array(eloop.epoll_table, next,
  					      sizeof(struct eloop_sock));
  		if (temp_table == NULL)
  			return -1;
  
  		eloop.epoll_max_fd = next;
  		eloop.epoll_table = temp_table;
  	}
  
  	if (eloop.count + 1 > eloop.epoll_max_event_num) {
  		next = eloop.epoll_max_event_num == 0 ? 8 :
  			eloop.epoll_max_event_num * 2;
  		temp_events = os_realloc_array(eloop.epoll_events, next,
  					       sizeof(struct epoll_event));
  		if (temp_events == NULL) {
  			wpa_printf(MSG_ERROR, "%s: malloc for epoll failed. "
  				   "%s\n", __func__, strerror(errno));
  			return -1;
  		}
  
  		eloop.epoll_max_event_num = next;
  		eloop.epoll_events = temp_events;
  	}
  #endif /* CONFIG_ELOOP_EPOLL */
  
  	eloop_trace_sock_remove_ref(table);
  	tmp = os_realloc_array(table->table, table->count + 1,
  			       sizeof(struct eloop_sock));
  	if (tmp == NULL) {
  		eloop_trace_sock_add_ref(table);
  		return -1;
  	}
  
  	tmp[table->count].sock = sock;
  	tmp[table->count].eloop_data = eloop_data;
  	tmp[table->count].user_data = user_data;
  	tmp[table->count].handler = handler;
  	wpa_trace_record(&tmp[table->count]);
  	table->count++;
  	table->table = tmp;
  	eloop.max_sock = new_max_sock;
  	eloop.count++;
  	table->changed = 1;
  	eloop_trace_sock_add_ref(table);
  
  #ifdef CONFIG_ELOOP_EPOLL
  	os_memset(&ev, 0, sizeof(ev));
  	switch (table->type) {
  	case EVENT_TYPE_READ:
  		ev.events = EPOLLIN;
  		break;
  	case EVENT_TYPE_WRITE:
  		ev.events = EPOLLOUT;
  		break;
  	/*
  	 * Exceptions are always checked when using epoll, but I suppose it's
  	 * possible that someone registered a socket *only* for exception
  	 * handling.
  	 */
  	case EVENT_TYPE_EXCEPTION:
  		ev.events = EPOLLERR | EPOLLHUP;
  		break;
  	}
  	ev.data.fd = sock;
  	if (epoll_ctl(eloop.epollfd, EPOLL_CTL_ADD, sock, &ev) < 0) {
  		wpa_printf(MSG_ERROR, "%s: epoll_ctl(ADD) for fd=%d "
  			   "failed. %s\n", __func__, sock, strerror(errno));
  		return -1;
  	}
  	os_memcpy(&eloop.epoll_table[sock], &table->table[table->count - 1],
  		  sizeof(struct eloop_sock));
  #endif /* CONFIG_ELOOP_EPOLL */
  	return 0;
  }
  
  
  static void eloop_sock_table_remove_sock(struct eloop_sock_table *table,
                                           int sock)
  {
  	int i;
  
  	if (table == NULL || table->table == NULL || table->count == 0)
  		return;
  
  	for (i = 0; i < table->count; i++) {
  		if (table->table[i].sock == sock)
  			break;
  	}
  	if (i == table->count)
  		return;
  	eloop_trace_sock_remove_ref(table);
  	if (i != table->count - 1) {
  		os_memmove(&table->table[i], &table->table[i + 1],
  			   (table->count - i - 1) *
  			   sizeof(struct eloop_sock));
  	}
  	table->count--;
  	eloop.count--;
  	table->changed = 1;
  	eloop_trace_sock_add_ref(table);
  #ifdef CONFIG_ELOOP_EPOLL
  	if (epoll_ctl(eloop.epollfd, EPOLL_CTL_DEL, sock, NULL) < 0) {
  		wpa_printf(MSG_ERROR, "%s: epoll_ctl(DEL) for fd=%d "
  			   "failed. %s\n", __func__, sock, strerror(errno));
  		return;
  	}
  	os_memset(&eloop.epoll_table[sock], 0, sizeof(struct eloop_sock));
  #endif /* CONFIG_ELOOP_EPOLL */
  }
  
  
  #ifdef CONFIG_ELOOP_POLL
  
  static struct pollfd * find_pollfd(struct pollfd **pollfds_map, int fd, int mx)
  {
  	if (fd < mx && fd >= 0)
  		return pollfds_map[fd];
  	return NULL;
  }
  
  
  static int eloop_sock_table_set_fds(struct eloop_sock_table *readers,
  				    struct eloop_sock_table *writers,
  				    struct eloop_sock_table *exceptions,
  				    struct pollfd *pollfds,
  				    struct pollfd **pollfds_map,
  				    int max_pollfd_map)
  {
  	int i;
  	int nxt = 0;
  	int fd;
  	struct pollfd *pfd;
  
  	/* Clear pollfd lookup map. It will be re-populated below. */
  	os_memset(pollfds_map, 0, sizeof(struct pollfd *) * max_pollfd_map);
  
  	if (readers && readers->table) {
  		for (i = 0; i < readers->count; i++) {
  			fd = readers->table[i].sock;
  			assert(fd >= 0 && fd < max_pollfd_map);
  			pollfds[nxt].fd = fd;
  			pollfds[nxt].events = POLLIN;
  			pollfds[nxt].revents = 0;
  			pollfds_map[fd] = &(pollfds[nxt]);
  			nxt++;
  		}
  	}
  
  	if (writers && writers->table) {
  		for (i = 0; i < writers->count; i++) {
  			/*
  			 * See if we already added this descriptor, update it
  			 * if so.
  			 */
  			fd = writers->table[i].sock;
  			assert(fd >= 0 && fd < max_pollfd_map);
  			pfd = pollfds_map[fd];
  			if (!pfd) {
  				pfd = &(pollfds[nxt]);
  				pfd->events = 0;
  				pfd->fd = fd;
  				pollfds[i].revents = 0;
  				pollfds_map[fd] = pfd;
  				nxt++;
  			}
  			pfd->events |= POLLOUT;
  		}
  	}
  
  	/*
  	 * Exceptions are always checked when using poll, but I suppose it's
  	 * possible that someone registered a socket *only* for exception
  	 * handling. Set the POLLIN bit in this case.
  	 */
  	if (exceptions && exceptions->table) {
  		for (i = 0; i < exceptions->count; i++) {
  			/*
  			 * See if we already added this descriptor, just use it
  			 * if so.
  			 */
  			fd = exceptions->table[i].sock;
  			assert(fd >= 0 && fd < max_pollfd_map);
  			pfd = pollfds_map[fd];
  			if (!pfd) {
  				pfd = &(pollfds[nxt]);
  				pfd->events = POLLIN;
  				pfd->fd = fd;
  				pollfds[i].revents = 0;
  				pollfds_map[fd] = pfd;
  				nxt++;
  			}
  		}
  	}
  
  	return nxt;
  }
  
  
  static int eloop_sock_table_dispatch_table(struct eloop_sock_table *table,
  					   struct pollfd **pollfds_map,
  					   int max_pollfd_map,
  					   short int revents)
  {
  	int i;
  	struct pollfd *pfd;
  
  	if (!table || !table->table)
  		return 0;
  
  	table->changed = 0;
  	for (i = 0; i < table->count; i++) {
  		pfd = find_pollfd(pollfds_map, table->table[i].sock,
  				  max_pollfd_map);
  		if (!pfd)
  			continue;
  
  		if (!(pfd->revents & revents))
  			continue;
  
  		table->table[i].handler(table->table[i].sock,
  					table->table[i].eloop_data,
  					table->table[i].user_data);
  		if (table->changed)
  			return 1;
  	}
  
  	return 0;
  }
  
  
  static void eloop_sock_table_dispatch(struct eloop_sock_table *readers,
  				      struct eloop_sock_table *writers,
  				      struct eloop_sock_table *exceptions,
  				      struct pollfd **pollfds_map,
  				      int max_pollfd_map)
  {
  	if (eloop_sock_table_dispatch_table(readers, pollfds_map,
  					    max_pollfd_map, POLLIN | POLLERR |
  					    POLLHUP))
  		return; /* pollfds may be invalid at this point */
  
  	if (eloop_sock_table_dispatch_table(writers, pollfds_map,
  					    max_pollfd_map, POLLOUT))
  		return; /* pollfds may be invalid at this point */
  
  	eloop_sock_table_dispatch_table(exceptions, pollfds_map,
  					max_pollfd_map, POLLERR | POLLHUP);
  }
  
  #endif /* CONFIG_ELOOP_POLL */
  
  #ifdef CONFIG_ELOOP_SELECT
  
  static void eloop_sock_table_set_fds(struct eloop_sock_table *table,
  				     fd_set *fds)
  {
  	int i;
  
  	FD_ZERO(fds);
  
  	if (table->table == NULL)
  		return;
  
  	for (i = 0; i < table->count; i++) {
  		assert(table->table[i].sock >= 0);
  		FD_SET(table->table[i].sock, fds);
  	}
  }
  
  
  static void eloop_sock_table_dispatch(struct eloop_sock_table *table,
  				      fd_set *fds)
  {
  	int i;
  
  	if (table == NULL || table->table == NULL)
  		return;
  
  	table->changed = 0;
  	for (i = 0; i < table->count; i++) {
  		if (FD_ISSET(table->table[i].sock, fds)) {
  			table->table[i].handler(table->table[i].sock,
  						table->table[i].eloop_data,
  						table->table[i].user_data);
  			if (table->changed)
  				break;
  		}
  	}
  }
  
  #endif /* CONFIG_ELOOP_SELECT */
  
  
  #ifdef CONFIG_ELOOP_EPOLL
  static void eloop_sock_table_dispatch(struct epoll_event *events, int nfds)
  {
  	struct eloop_sock *table;
  	int i;
  
  	for (i = 0; i < nfds; i++) {
  		table = &eloop.epoll_table[events[i].data.fd];
  		if (table->handler == NULL)
  			continue;
  		table->handler(table->sock, table->eloop_data,
  			       table->user_data);
  		if (eloop.readers.changed ||
  		    eloop.writers.changed ||
  		    eloop.exceptions.changed)
  			break;
  	}
  }
  #endif /* CONFIG_ELOOP_EPOLL */
  
  
  static void eloop_sock_table_destroy(struct eloop_sock_table *table)
  {
  	if (table) {
  		int i;
  		for (i = 0; i < table->count && table->table; i++) {
  			wpa_printf(MSG_INFO, "ELOOP: remaining socket: "
  				   "sock=%d eloop_data=%p user_data=%p "
  				   "handler=%p",
  				   table->table[i].sock,
  				   table->table[i].eloop_data,
  				   table->table[i].user_data,
  				   table->table[i].handler);
  			wpa_trace_dump_funcname("eloop unregistered socket "
  						"handler",
  						table->table[i].handler);
  			wpa_trace_dump("eloop sock", &table->table[i]);
  		}
  		os_free(table->table);
  	}
  }
  
  
  int eloop_register_read_sock(int sock, eloop_sock_handler handler,
  			     void *eloop_data, void *user_data)
  {
  	return eloop_register_sock(sock, EVENT_TYPE_READ, handler,
  				   eloop_data, user_data);
  }
  
  
  void eloop_unregister_read_sock(int sock)
  {
  	eloop_unregister_sock(sock, EVENT_TYPE_READ);
  }
  
  
  static struct eloop_sock_table *eloop_get_sock_table(eloop_event_type type)
  {
  	switch (type) {
  	case EVENT_TYPE_READ:
  		return &eloop.readers;
  	case EVENT_TYPE_WRITE:
  		return &eloop.writers;
  	case EVENT_TYPE_EXCEPTION:
  		return &eloop.exceptions;
  	}
  
  	return NULL;
  }
  
  
  int eloop_register_sock(int sock, eloop_event_type type,
  			eloop_sock_handler handler,
  			void *eloop_data, void *user_data)
  {
  	struct eloop_sock_table *table;
  
  	assert(sock >= 0);
  	table = eloop_get_sock_table(type);
  	return eloop_sock_table_add_sock(table, sock, handler,
  					 eloop_data, user_data);
  }
  
  
  void eloop_unregister_sock(int sock, eloop_event_type type)
  {
  	struct eloop_sock_table *table;
  
  	table = eloop_get_sock_table(type);
  	eloop_sock_table_remove_sock(table, sock);
  }
  
  
  int eloop_register_timeout(unsigned int secs, unsigned int usecs,
  			   eloop_timeout_handler handler,
  			   void *eloop_data, void *user_data)
  {
  	struct eloop_timeout *timeout, *tmp;
  	os_time_t now_sec;
  
  	timeout = os_zalloc(sizeof(*timeout));
  	if (timeout == NULL)
  		return -1;
  	if (os_get_reltime(&timeout->time) < 0) {
  		os_free(timeout);
  		return -1;
  	}
  	now_sec = timeout->time.sec;
  	timeout->time.sec += secs;
  	if (timeout->time.sec < now_sec) {
  		/*
  		 * Integer overflow - assume long enough timeout to be assumed
  		 * to be infinite, i.e., the timeout would never happen.
  		 */
  		wpa_printf(MSG_DEBUG, "ELOOP: Too long timeout (secs=%u) to "
  			   "ever happen - ignore it", secs);
  		os_free(timeout);
  		return 0;
  	}
  	timeout->time.usec += usecs;
  	while (timeout->time.usec >= 1000000) {
  		timeout->time.sec++;
  		timeout->time.usec -= 1000000;
  	}
  	timeout->eloop_data = eloop_data;
  	timeout->user_data = user_data;
  	timeout->handler = handler;
  	wpa_trace_add_ref(timeout, eloop, eloop_data);
  	wpa_trace_add_ref(timeout, user, user_data);
  	wpa_trace_record(timeout);
  
  	/* Maintain timeouts in order of increasing time */
  	dl_list_for_each(tmp, &eloop.timeout, struct eloop_timeout, list) {
  		if (os_reltime_before(&timeout->time, &tmp->time)) {
  			dl_list_add(tmp->list.prev, &timeout->list);
  			return 0;
  		}
  	}
  	dl_list_add_tail(&eloop.timeout, &timeout->list);
  
  	return 0;
  }
  
  
  static void eloop_remove_timeout(struct eloop_timeout *timeout)
  {
  	dl_list_del(&timeout->list);
  	wpa_trace_remove_ref(timeout, eloop, timeout->eloop_data);
  	wpa_trace_remove_ref(timeout, user, timeout->user_data);
  	os_free(timeout);
  }
  
  
  int eloop_cancel_timeout(eloop_timeout_handler handler,
  			 void *eloop_data, void *user_data)
  {
  	struct eloop_timeout *timeout, *prev;
  	int removed = 0;
  
  	dl_list_for_each_safe(timeout, prev, &eloop.timeout,
  			      struct eloop_timeout, list) {
  		if (timeout->handler == handler &&
  		    (timeout->eloop_data == eloop_data ||
  		     eloop_data == ELOOP_ALL_CTX) &&
  		    (timeout->user_data == user_data ||
  		     user_data == ELOOP_ALL_CTX)) {
  			eloop_remove_timeout(timeout);
  			removed++;
  		}
  	}
  
  	return removed;
  }
  
  
  int eloop_cancel_timeout_one(eloop_timeout_handler handler,
  			     void *eloop_data, void *user_data,
  			     struct os_reltime *remaining)
  {
  	struct eloop_timeout *timeout, *prev;
  	int removed = 0;
  	struct os_reltime now;
  
  	os_get_reltime(&now);
  	remaining->sec = remaining->usec = 0;
  
  	dl_list_for_each_safe(timeout, prev, &eloop.timeout,
  			      struct eloop_timeout, list) {
  		if (timeout->handler == handler &&
  		    (timeout->eloop_data == eloop_data) &&
  		    (timeout->user_data == user_data)) {
  			removed = 1;
  			if (os_reltime_before(&now, &timeout->time))
  				os_reltime_sub(&timeout->time, &now, remaining);
  			eloop_remove_timeout(timeout);
  			break;
  		}
  	}
  	return removed;
  }
  
  
  int eloop_is_timeout_registered(eloop_timeout_handler handler,
  				void *eloop_data, void *user_data)
  {
  	struct eloop_timeout *tmp;
  
  	dl_list_for_each(tmp, &eloop.timeout, struct eloop_timeout, list) {
  		if (tmp->handler == handler &&
  		    tmp->eloop_data == eloop_data &&
  		    tmp->user_data == user_data)
  			return 1;
  	}
  
  	return 0;
  }
  
  
  int eloop_deplete_timeout(unsigned int req_secs, unsigned int req_usecs,
  			  eloop_timeout_handler handler, void *eloop_data,
  			  void *user_data)
  {
  	struct os_reltime now, requested, remaining;
  	struct eloop_timeout *tmp;
  
  	dl_list_for_each(tmp, &eloop.timeout, struct eloop_timeout, list) {
  		if (tmp->handler == handler &&
  		    tmp->eloop_data == eloop_data &&
  		    tmp->user_data == user_data) {
  			requested.sec = req_secs;
  			requested.usec = req_usecs;
  			os_get_reltime(&now);
  			os_reltime_sub(&tmp->time, &now, &remaining);
  			if (os_reltime_before(&requested, &remaining)) {
  				eloop_cancel_timeout(handler, eloop_data,
  						     user_data);
  				eloop_register_timeout(requested.sec,
  						       requested.usec,
  						       handler, eloop_data,
  						       user_data);
  				return 1;
  			}
  			return 0;
  		}
  	}
  
  	return -1;
  }
  
  
  int eloop_replenish_timeout(unsigned int req_secs, unsigned int req_usecs,
  			    eloop_timeout_handler handler, void *eloop_data,
  			    void *user_data)
  {
  	struct os_reltime now, requested, remaining;
  	struct eloop_timeout *tmp;
  
  	dl_list_for_each(tmp, &eloop.timeout, struct eloop_timeout, list) {
  		if (tmp->handler == handler &&
  		    tmp->eloop_data == eloop_data &&
  		    tmp->user_data == user_data) {
  			requested.sec = req_secs;
  			requested.usec = req_usecs;
  			os_get_reltime(&now);
  			os_reltime_sub(&tmp->time, &now, &remaining);
  			if (os_reltime_before(&remaining, &requested)) {
  				eloop_cancel_timeout(handler, eloop_data,
  						     user_data);
  				eloop_register_timeout(requested.sec,
  						       requested.usec,
  						       handler, eloop_data,
  						       user_data);
  				return 1;
  			}
  			return 0;
  		}
  	}
  
  	return -1;
  }
  
  
  #ifndef CONFIG_NATIVE_WINDOWS
  static void eloop_handle_alarm(int sig)
  {
  	wpa_printf(MSG_ERROR, "eloop: could not process SIGINT or SIGTERM in "
  		   "two seconds. Looks like there\n"
  		   "is a bug that ends up in a busy loop that "
  		   "prevents clean shutdown.\n"
  		   "Killing program forcefully.\n");
  	exit(1);
  }
  #endif /* CONFIG_NATIVE_WINDOWS */
  
  
  static void eloop_handle_signal(int sig)
  {
  	int i;
  
  #ifndef CONFIG_NATIVE_WINDOWS
  	if ((sig == SIGINT || sig == SIGTERM) && !eloop.pending_terminate) {
  		/* Use SIGALRM to break out from potential busy loops that
  		 * would not allow the program to be killed. */
  		eloop.pending_terminate = 1;
  		signal(SIGALRM, eloop_handle_alarm);
  		alarm(2);
  	}
  #endif /* CONFIG_NATIVE_WINDOWS */
  
  	eloop.signaled++;
  	for (i = 0; i < eloop.signal_count; i++) {
  		if (eloop.signals[i].sig == sig) {
  			eloop.signals[i].signaled++;
  			break;
  		}
  	}
  }
  
  
  static void eloop_process_pending_signals(void)
  {
  	int i;
  
  	if (eloop.signaled == 0)
  		return;
  	eloop.signaled = 0;
  
  	if (eloop.pending_terminate) {
  #ifndef CONFIG_NATIVE_WINDOWS
  		alarm(0);
  #endif /* CONFIG_NATIVE_WINDOWS */
  		eloop.pending_terminate = 0;
  	}
  
  	for (i = 0; i < eloop.signal_count; i++) {
  		if (eloop.signals[i].signaled) {
  			eloop.signals[i].signaled = 0;
  			eloop.signals[i].handler(eloop.signals[i].sig,
  						 eloop.signals[i].user_data);
  		}
  	}
  }
  
  
  int eloop_register_signal(int sig, eloop_signal_handler handler,
  			  void *user_data)
  {
  	struct eloop_signal *tmp;
  
  	tmp = os_realloc_array(eloop.signals, eloop.signal_count + 1,
  			       sizeof(struct eloop_signal));
  	if (tmp == NULL)
  		return -1;
  
  	tmp[eloop.signal_count].sig = sig;
  	tmp[eloop.signal_count].user_data = user_data;
  	tmp[eloop.signal_count].handler = handler;
  	tmp[eloop.signal_count].signaled = 0;
  	eloop.signal_count++;
  	eloop.signals = tmp;
  	signal(sig, eloop_handle_signal);
  
  	return 0;
  }
  
  
  int eloop_register_signal_terminate(eloop_signal_handler handler,
  				    void *user_data)
  {
  	int ret = eloop_register_signal(SIGINT, handler, user_data);
  	if (ret == 0)
  		ret = eloop_register_signal(SIGTERM, handler, user_data);
  	return ret;
  }
  
  
  int eloop_register_signal_reconfig(eloop_signal_handler handler,
  				   void *user_data)
  {
  #ifdef CONFIG_NATIVE_WINDOWS
  	return 0;
  #else /* CONFIG_NATIVE_WINDOWS */
  	return eloop_register_signal(SIGHUP, handler, user_data);
  #endif /* CONFIG_NATIVE_WINDOWS */
  }
  
  
  void eloop_run(void)
  {
  #ifdef CONFIG_ELOOP_POLL
  	int num_poll_fds;
  	int timeout_ms = 0;
  #endif /* CONFIG_ELOOP_POLL */
  #ifdef CONFIG_ELOOP_SELECT
  	fd_set *rfds, *wfds, *efds;
  	struct timeval _tv;
  #endif /* CONFIG_ELOOP_SELECT */
  #ifdef CONFIG_ELOOP_EPOLL
  	int timeout_ms = -1;
  #endif /* CONFIG_ELOOP_EPOLL */
  	int res;
  	struct os_reltime tv, now;
  
  #ifdef CONFIG_ELOOP_SELECT
  	rfds = os_malloc(sizeof(*rfds));
  	wfds = os_malloc(sizeof(*wfds));
  	efds = os_malloc(sizeof(*efds));
  	if (rfds == NULL || wfds == NULL || efds == NULL)
  		goto out;
  #endif /* CONFIG_ELOOP_SELECT */
  
  	while (!eloop.terminate &&
  	       (!dl_list_empty(&eloop.timeout) || eloop.readers.count > 0 ||
  		eloop.writers.count > 0 || eloop.exceptions.count > 0)) {
  		struct eloop_timeout *timeout;
  		timeout = dl_list_first(&eloop.timeout, struct eloop_timeout,
  					list);
  		if (timeout) {
  			os_get_reltime(&now);
  			if (os_reltime_before(&now, &timeout->time))
  				os_reltime_sub(&timeout->time, &now, &tv);
  			else
  				tv.sec = tv.usec = 0;
  #if defined(CONFIG_ELOOP_POLL) || defined(CONFIG_ELOOP_EPOLL)
  			timeout_ms = tv.sec * 1000 + tv.usec / 1000;
  #endif /* defined(CONFIG_ELOOP_POLL) || defined(CONFIG_ELOOP_EPOLL) */
  #ifdef CONFIG_ELOOP_SELECT
  			_tv.tv_sec = tv.sec;
  			_tv.tv_usec = tv.usec;
  #endif /* CONFIG_ELOOP_SELECT */
  		}
  
  #ifdef CONFIG_ELOOP_POLL
  		num_poll_fds = eloop_sock_table_set_fds(
  			&eloop.readers, &eloop.writers, &eloop.exceptions,
  			eloop.pollfds, eloop.pollfds_map,
  			eloop.max_pollfd_map);
  		res = poll(eloop.pollfds, num_poll_fds,
  			   timeout ? timeout_ms : -1);
  #endif /* CONFIG_ELOOP_POLL */
  #ifdef CONFIG_ELOOP_SELECT
  		eloop_sock_table_set_fds(&eloop.readers, rfds);
  		eloop_sock_table_set_fds(&eloop.writers, wfds);
  		eloop_sock_table_set_fds(&eloop.exceptions, efds);
  		res = select(eloop.max_sock + 1, rfds, wfds, efds,
  			     timeout ? &_tv : NULL);
  #endif /* CONFIG_ELOOP_SELECT */
  #ifdef CONFIG_ELOOP_EPOLL
  		if (eloop.count == 0) {
  			res = 0;
  		} else {
  			res = epoll_wait(eloop.epollfd, eloop.epoll_events,
  					 eloop.count, timeout_ms);
  		}
  #endif /* CONFIG_ELOOP_EPOLL */
  		if (res < 0 && errno != EINTR && errno != 0) {
  			wpa_printf(MSG_ERROR, "eloop: %s: %s",
  #ifdef CONFIG_ELOOP_POLL
  				   "poll"
  #endif /* CONFIG_ELOOP_POLL */
  #ifdef CONFIG_ELOOP_SELECT
  				   "select"
  #endif /* CONFIG_ELOOP_SELECT */
  #ifdef CONFIG_ELOOP_EPOLL
  				   "epoll"
  #endif /* CONFIG_ELOOP_EPOLL */
  				   , strerror(errno));
  			goto out;
  		}
  
  		eloop.readers.changed = 0;
  		eloop.writers.changed = 0;
  		eloop.exceptions.changed = 0;
  
  		eloop_process_pending_signals();
  
  		/* check if some registered timeouts have occurred */
  		timeout = dl_list_first(&eloop.timeout, struct eloop_timeout,
  					list);
  		if (timeout) {
  			os_get_reltime(&now);
  			if (!os_reltime_before(&now, &timeout->time)) {
  				void *eloop_data = timeout->eloop_data;
  				void *user_data = timeout->user_data;
  				eloop_timeout_handler handler =
  					timeout->handler;
  				eloop_remove_timeout(timeout);
  				handler(eloop_data, user_data);
  			}
  
  		}
  
  		if (res <= 0)
  			continue;
  
  		if (eloop.readers.changed ||
  		    eloop.writers.changed ||
  		    eloop.exceptions.changed) {
  			 /*
  			  * Sockets may have been closed and reopened with the
  			  * same FD in the signal or timeout handlers, so we
  			  * must skip the previous results and check again
  			  * whether any of the currently registered sockets have
  			  * events.
  			  */
  			continue;
  		}
  
  #ifdef CONFIG_ELOOP_POLL
  		eloop_sock_table_dispatch(&eloop.readers, &eloop.writers,
  					  &eloop.exceptions, eloop.pollfds_map,
  					  eloop.max_pollfd_map);
  #endif /* CONFIG_ELOOP_POLL */
  #ifdef CONFIG_ELOOP_SELECT
  		eloop_sock_table_dispatch(&eloop.readers, rfds);
  		eloop_sock_table_dispatch(&eloop.writers, wfds);
  		eloop_sock_table_dispatch(&eloop.exceptions, efds);
  #endif /* CONFIG_ELOOP_SELECT */
  #ifdef CONFIG_ELOOP_EPOLL
  		eloop_sock_table_dispatch(eloop.epoll_events, res);
  #endif /* CONFIG_ELOOP_EPOLL */
  	}
  
  	eloop.terminate = 0;
  out:
  #ifdef CONFIG_ELOOP_SELECT
  	os_free(rfds);
  	os_free(wfds);
  	os_free(efds);
  #endif /* CONFIG_ELOOP_SELECT */
  	return;
  }
  
  
  void eloop_terminate(void)
  {
  	eloop.terminate = 1;
  }
  
  
  void eloop_destroy(void)
  {
  	struct eloop_timeout *timeout, *prev;
  	struct os_reltime now;
  
  	os_get_reltime(&now);
  	dl_list_for_each_safe(timeout, prev, &eloop.timeout,
  			      struct eloop_timeout, list) {
  		int sec, usec;
  		sec = timeout->time.sec - now.sec;
  		usec = timeout->time.usec - now.usec;
  		if (timeout->time.usec < now.usec) {
  			sec--;
  			usec += 1000000;
  		}
  		wpa_printf(MSG_INFO, "ELOOP: remaining timeout: %d.%06d "
  			   "eloop_data=%p user_data=%p handler=%p",
  			   sec, usec, timeout->eloop_data, timeout->user_data,
  			   timeout->handler);
  		wpa_trace_dump_funcname("eloop unregistered timeout handler",
  					timeout->handler);
  		wpa_trace_dump("eloop timeout", timeout);
  		eloop_remove_timeout(timeout);
  	}
  	eloop_sock_table_destroy(&eloop.readers);
  	eloop_sock_table_destroy(&eloop.writers);
  	eloop_sock_table_destroy(&eloop.exceptions);
  	os_free(eloop.signals);
  
  #ifdef CONFIG_ELOOP_POLL
  	os_free(eloop.pollfds);
  	os_free(eloop.pollfds_map);
  #endif /* CONFIG_ELOOP_POLL */
  #ifdef CONFIG_ELOOP_EPOLL
  	os_free(eloop.epoll_table);
  	os_free(eloop.epoll_events);
  	close(eloop.epollfd);
  #endif /* CONFIG_ELOOP_EPOLL */
  }
  
  
  int eloop_terminated(void)
  {
  	return eloop.terminate;
  }
  
  
  void eloop_wait_for_read_sock(int sock)
  {
  #ifdef CONFIG_ELOOP_POLL
  	struct pollfd pfd;
  
  	if (sock < 0)
  		return;
  
  	os_memset(&pfd, 0, sizeof(pfd));
  	pfd.fd = sock;
  	pfd.events = POLLIN;
  
  	poll(&pfd, 1, -1);
  #endif /* CONFIG_ELOOP_POLL */
  #if defined(CONFIG_ELOOP_SELECT) || defined(CONFIG_ELOOP_EPOLL)
  	/*
  	 * We can use epoll() here. But epoll() requres 4 system calls.
  	 * epoll_create1(), epoll_ctl() for ADD, epoll_wait, and close() for
  	 * epoll fd. So select() is better for performance here.
  	 */
  	fd_set rfds;
  
  	if (sock < 0)
  		return;
  
  	FD_ZERO(&rfds);
  	FD_SET(sock, &rfds);
  	select(sock + 1, &rfds, NULL, NULL, NULL);
  #endif /* defined(CONFIG_ELOOP_SELECT) || defined(CONFIG_ELOOP_EPOLL) */
  }
  
  #ifdef CONFIG_ELOOP_SELECT
  #undef CONFIG_ELOOP_SELECT
  #endif /* CONFIG_ELOOP_SELECT */
  