Extract threading code into a new library.

Note that the workqueue code does *not* go here: it is logically at
a higher level, since it needs to use libevent and the networking
stack.

1 files changed, 0 insertions, 266 deletions

diff --git a/src/common/compat_pthreads.c b/src/common/compat_pthreads.c
deleted file mode 100644
index e345cfef0f..0000000000
--- a/src/common/compat_pthreads.c
+++ /dev/null
@@ -1,266 +0,0 @@
-/* Copyright (c) 2003-2004, Roger Dingledine
- * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2018, The Tor Project, Inc. */
-/* See LICENSE for licensing information */
-
-/**
- * \file compat_pthreads.c
- *
- * \brief Implementation for the pthreads-based multithreading backend
- * functions.
- */
-
-#include "orconfig.h"
-#include <pthread.h>
-#include <signal.h>
-#include <time.h>
-
-#include "common/compat.h"
-#include "lib/log/torlog.h"
-#include "common/util.h"
-
-/** Wraps a void (*)(void*) function and its argument so we can
- * invoke them in a way pthreads would expect.
- */
-typedef struct tor_pthread_data_t {
-  void (*func)(void *);
-  void *data;
-} tor_pthread_data_t;
-/** Given a tor_pthread_data_t <b>_data</b>, call _data-&gt;func(d-&gt;data)
- * and free _data.  Used to make sure we can call functions the way pthread
- * expects. */
-static void *
-tor_pthread_helper_fn(void *_data)
-{
-  tor_pthread_data_t *data = _data;
-  void (*func)(void*);
-  void *arg;
-  /* mask signals to worker threads to avoid SIGPIPE, etc */
-  sigset_t sigs;
-  /* We're in a subthread; don't handle any signals here. */
-  sigfillset(&sigs);
-  pthread_sigmask(SIG_SETMASK, &sigs, NULL);
-
-  func = data->func;
-  arg = data->data;
-  tor_free(_data);
-  func(arg);
-  return NULL;
-}
-/**
- * A pthread attribute to make threads start detached.
- */
-static pthread_attr_t attr_detached;
-/** True iff we've called tor_threads_init() */
-static int threads_initialized = 0;
-
-/** Minimalist interface to run a void function in the background.  On
- * Unix calls pthread_create, on win32 calls beginthread.  Returns -1 on
- * failure.
- * func should not return, but rather should call spawn_exit.
- *
- * NOTE: if <b>data</b> is used, it should not be allocated on the stack,
- * since in a multithreaded environment, there is no way to be sure that
- * the caller's stack will still be around when the called function is
- * running.
- */
-int
-spawn_func(void (*func)(void *), void *data)
-{
-  pthread_t thread;
-  tor_pthread_data_t *d;
-  if (PREDICT_UNLIKELY(!threads_initialized)) {
-    tor_threads_init();
-  }
-  d = tor_malloc(sizeof(tor_pthread_data_t));
-  d->data = data;
-  d->func = func;
-  if (pthread_create(&thread, &attr_detached, tor_pthread_helper_fn, d)) {
-    tor_free(d);
-    return -1;
-  }
-
-  return 0;
-}
-
-/** End the current thread/process.
- */
-void
-spawn_exit(void)
-{
-  pthread_exit(NULL);
-}
-
-/** Return an integer representing this thread. */
-unsigned long
-tor_get_thread_id(void)
-{
-  union {
-    pthread_t thr;
-    unsigned long id;
-  } r;
-  r.thr = pthread_self();
-  return r.id;
-}
-
-/* Conditions. */
-
-/** Initialize an already-allocated condition variable. */
-int
-tor_cond_init(tor_cond_t *cond)
-{
-  pthread_condattr_t condattr;
-
-  memset(cond, 0, sizeof(tor_cond_t));
-  /* Default condition attribute. Might be used if clock monotonic is
-   * available else this won't affect anything. */
-  if (pthread_condattr_init(&condattr)) {
-    return -1;
-  }
-
-#if defined(HAVE_CLOCK_GETTIME)
-#if defined(HAVE_PTHREAD_CONDATTR_SETCLOCK) && \
-  defined(CLOCK_MONOTONIC)
-  /* Use monotonic time so when we timedwait() on it, any clock adjustment
-   * won't affect the timeout value. */
-  if (pthread_condattr_setclock(&condattr, CLOCK_MONOTONIC)) {
-    return -1;
-  }
-#define USE_COND_CLOCK CLOCK_MONOTONIC
-#else /* !(defined(HAVE_PTHREAD_CONDATTR_SETCLOCK) && ...) */
-  /* On OSX Sierra, there is no pthread_condattr_setclock, so we are stuck
-   * with the realtime clock.
-   */
-#define USE_COND_CLOCK CLOCK_REALTIME
-#endif /* defined(HAVE_PTHREAD_CONDATTR_SETCLOCK) && ... */
-#endif /* defined(HAVE_CLOCK_GETTIME) */
-  if (pthread_cond_init(&cond->cond, &condattr)) {
-    return -1;
-  }
-  return 0;
-}
-
-/** Release all resources held by <b>cond</b>, but do not free <b>cond</b>
- * itself. */
-void
-tor_cond_uninit(tor_cond_t *cond)
-{
-  if (pthread_cond_destroy(&cond->cond)) {
-    // LCOV_EXCL_START
-    log_warn(LD_GENERAL,"Error freeing condition: %s", strerror(errno));
-    return;
-    // LCOV_EXCL_STOP
-  }
-}
-/** Wait until one of the tor_cond_signal functions is called on <b>cond</b>.
- * (If <b>tv</b> is set, and that amount of time passes with no signal to
- * <b>cond</b>, return anyway.  All waiters on the condition must wait holding
- * the same <b>mutex</b>.  All signallers should hold that mutex.  The mutex
- * needs to have been allocated with tor_mutex_init_for_cond().
- *
- * Returns 0 on success, -1 on failure, 1 on timeout. */
-int
-tor_cond_wait(tor_cond_t *cond, tor_mutex_t *mutex, const struct timeval *tv)
-{
-  int r;
-  if (tv == NULL) {
-    while (1) {
-      r = pthread_cond_wait(&cond->cond, &mutex->mutex);
-      if (r == EINTR) {
-        /* EINTR should be impossible according to POSIX, but POSIX, like the
-         * Pirate's Code, is apparently treated "more like what you'd call
-         * guidelines than actual rules." */
-        continue; // LCOV_EXCL_LINE
-      }
-      return r ? -1 : 0;
-    }
-  } else {
-    struct timeval tvnow, tvsum;
-    struct timespec ts;
-    while (1) {
-#if defined(HAVE_CLOCK_GETTIME) && defined(USE_COND_CLOCK)
-      if (clock_gettime(USE_COND_CLOCK, &ts) < 0) {
-        return -1;
-      }
-      tvnow.tv_sec = ts.tv_sec;
-      tvnow.tv_usec = (int)(ts.tv_nsec / 1000);
-      timeradd(tv, &tvnow, &tvsum);
-#else /* !(defined(HAVE_CLOCK_GETTIME) && defined(USE_COND_CLOCK)) */
-      if (gettimeofday(&tvnow, NULL) < 0)
-        return -1;
-      timeradd(tv, &tvnow, &tvsum);
-#endif /* defined(HAVE_CLOCK_GETTIME) && defined(USE_COND_CLOCK) */
-
-      ts.tv_sec = tvsum.tv_sec;
-      ts.tv_nsec = tvsum.tv_usec * 1000;
-
-      r = pthread_cond_timedwait(&cond->cond, &mutex->mutex, &ts);
-      if (r == 0)
-        return 0;
-      else if (r == ETIMEDOUT)
-        return 1;
-      else if (r == EINTR)
-        continue;
-      else
-        return -1;
-    }
-  }
-}
-/** Wake up one of the waiters on <b>cond</b>. */
-void
-tor_cond_signal_one(tor_cond_t *cond)
-{
-  pthread_cond_signal(&cond->cond);
-}
-/** Wake up all of the waiters on <b>cond</b>. */
-void
-tor_cond_signal_all(tor_cond_t *cond)
-{
-  pthread_cond_broadcast(&cond->cond);
-}
-
-int
-tor_threadlocal_init(tor_threadlocal_t *threadlocal)
-{
-  int err = pthread_key_create(&threadlocal->key, NULL);
-  return err ? -1 : 0;
-}
-
-void
-tor_threadlocal_destroy(tor_threadlocal_t *threadlocal)
-{
-  pthread_key_delete(threadlocal->key);
-  memset(threadlocal, 0, sizeof(tor_threadlocal_t));
-}
-
-void *
-tor_threadlocal_get(tor_threadlocal_t *threadlocal)
-{
-  return pthread_getspecific(threadlocal->key);
-}
-
-void
-tor_threadlocal_set(tor_threadlocal_t *threadlocal, void *value)
-{
-  int err = pthread_setspecific(threadlocal->key, value);
-  tor_assert(err == 0);
-}
-
-/** Set up common structures for use by threading. */
-void
-tor_threads_init(void)
-{
-  if (!threads_initialized) {
-    tor_locking_init();
-    const int ret1 = pthread_attr_init(&attr_detached);
-    tor_assert(ret1 == 0);
-#ifndef PTHREAD_CREATE_DETACHED
-#define PTHREAD_CREATE_DETACHED 1
-#endif
-    const int ret2 =
-      pthread_attr_setdetachstate(&attr_detached, PTHREAD_CREATE_DETACHED);
-    tor_assert(ret2 == 0);
-    threads_initialized = 1;
-    set_main_thread();
-  }
-}