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/* Copyright (c) 2003-2004, Roger Dingledine
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2015, The Tor Project, Inc. */
/* See LICENSE for licensing information */
#include "orconfig.h"
#define _GNU_SOURCE
#include <stdlib.h>
#include "compat.h"
#include "compat_threads.h"
#include "util.h"
#include "torlog.h"
#ifdef HAVE_SYS_EVENTFD_H
#include <sys/eventfd.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
/** Return a newly allocated, ready-for-use mutex. */
tor_mutex_t *
tor_mutex_new(void)
{
tor_mutex_t *m = tor_malloc_zero(sizeof(tor_mutex_t));
tor_mutex_init(m);
return m;
}
/** Release all storage and system resources held by <b>m</b>. */
void
tor_mutex_free(tor_mutex_t *m)
{
if (!m)
return;
tor_mutex_uninit(m);
tor_free(m);
}
tor_cond_t *
tor_cond_new(void)
{
tor_cond_t *cond = tor_malloc(sizeof(tor_cond_t));
if (tor_cond_init(cond)<0)
tor_free(cond);
return cond;
}
void
tor_cond_free(tor_cond_t *c)
{
if (!c)
return;
tor_cond_uninit(c);
tor_free(c);
}
/** Identity of the "main" thread */
static unsigned long main_thread_id = -1;
/** Start considering the current thread to be the 'main thread'. This has
* no effect on anything besides in_main_thread(). */
void
set_main_thread(void)
{
main_thread_id = tor_get_thread_id();
}
/** Return true iff called from the main thread. */
int
in_main_thread(void)
{
return main_thread_id == tor_get_thread_id();
}
#ifdef HAVE_EVENTFD
static int
eventfd_alert(int fd)
{
uint64_t u = 1;
int r = write(fd, (void*)&u, sizeof(u));
if (r < 0 && errno != EAGAIN)
return -1;
return 0;
}
static int
eventfd_drain(int fd)
{
uint64_t u = 0;
int r = read(fd, (void*)&u, sizeof(u));
if (r < 0 && errno != EAGAIN)
return -1;
return 0;
}
#endif
#ifdef HAVE_PIPE
static int
pipe_alert(int fd)
{
ssize_t r = write(fd, "x", 1);
if (r < 0 && errno != EAGAIN)
return -1;
return 0;
}
static int
pipe_drain(int fd)
{
char buf[32];
ssize_t r;
while ((r = read(fd, buf, sizeof(buf))) >= 0)
;
if (r == 0 || errno != EAGAIN)
return -1;
return 0;
}
#endif
static int
sock_alert(tor_socket_t fd)
{
ssize_t r = send(fd, "x", 1, 0);
if (r < 0 && !ERRNO_IS_EAGAIN(tor_socket_errno(fd)))
return -1;
return 0;
}
static int
sock_drain(tor_socket_t fd)
{
char buf[32];
ssize_t r;
while ((r = recv(fd, buf, sizeof(buf), 0)) >= 0)
;
if (r == 0 || !ERRNO_IS_EAGAIN(tor_socket_errno(fd)))
return -1;
return 0;
}
/** Allocate a new set of alert sockets. DOCDOC */
int
alert_sockets_create(alert_sockets_t *socks_out)
{
tor_socket_t socks[2];
#ifdef HAVE_EVENTFD
#if defined(EFD_CLOEXEC) && defined(EFD_NONBLOCK)
socks[0] = eventfd(0, EFD_CLOEXEC|EFD_NONBLOCK);
#else
socks[0] = -1;
#endif
if (socks[0] < 0) {
socks[0] = eventfd(0,0);
if (socks[0] >= 0) {
if (fcntl(socks[0], F_SETFD, FD_CLOEXEC) < 0 ||
set_socket_nonblocking(socks[0]) < 0) {
close(socks[0]);
return -1;
}
}
}
if (socks[0] >= 0) {
socks_out->read_fd = socks_out->write_fd = socks[0];
socks_out->alert_fn = eventfd_alert;
socks_out->drain_fn = eventfd_drain;
return 0;
}
#endif
#ifdef HAVE_PIPE2
if (pipe2(socks, O_NONBLOCK|O_CLOEXEC) == 0) {
socks_out->read_fd = socks[0];
socks_out->write_fd = socks[1];
socks_out->alert_fn = pipe_alert;
socks_out->drain_fn = pipe_drain;
return 0;
}
#endif
#ifdef HAVE_PIPE
if (pipe(socks) == 0) {
if (fcntl(socks[0], F_SETFD, FD_CLOEXEC) < 0 ||
fcntl(socks[1], F_SETFD, FD_CLOEXEC) < 0 ||
set_socket_nonblocking(socks[0]) < 0 ||
set_socket_nonblocking(socks[1]) < 0) {
close(socks[0]);
close(socks[1]);
return -1;
}
socks_out->read_fd = socks[0];
socks_out->write_fd = socks[1];
socks_out->alert_fn = pipe_alert;
socks_out->drain_fn = pipe_drain;
return 0;
}
#endif
if (tor_socketpair(AF_UNIX, SOCK_STREAM, 0, socks) == 0) {
set_socket_nonblocking(socks[0]);
set_socket_nonblocking(socks[1]);
socks_out->alert_fn = sock_alert;
socks_out->drain_fn = sock_drain;
return 0;
}
return -1;
}
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