1 files changed, 151 insertions, 0 deletions
diff --git a/src/common/compat_threads.h b/src/common/compat_threads.h
new file mode 100644
index 0000000000..171a9f93ff
--- /dev/null
+++ b/src/common/compat_threads.h
@@ -0,0 +1,151 @@
+/* Copyright (c) 2003-2004, Roger Dingledine
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2016, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#ifndef TOR_COMPAT_THREADS_H
+#define TOR_COMPAT_THREADS_H
+
+#include "orconfig.h"
+#include "torint.h"
+#include "testsupport.h"
+
+#if defined(HAVE_PTHREAD_H) && !defined(_WIN32)
+#include <pthread.h>
+#endif
+
+#if defined(_WIN32)
+#define USE_WIN32_THREADS
+#elif defined(HAVE_PTHREAD_H) && defined(HAVE_PTHREAD_CREATE)
+#define USE_PTHREADS
+#else
+#error "No threading system was found"
+#endif
+
+int spawn_func(void (*func)(void *), void *data);
+void spawn_exit(void) ATTR_NORETURN;
+
+/* Because we use threads instead of processes on most platforms (Windows,
+ * Linux, etc), we need locking for them.  On platforms with poor thread
+ * support or broken gethostbyname_r, these functions are no-ops. */
+
+/** A generic lock structure for multithreaded builds. */
+typedef struct tor_mutex_t {
+#if defined(USE_WIN32_THREADS)
+  /** Windows-only: on windows, we implement locks with CRITICAL_SECTIONS. */
+  CRITICAL_SECTION mutex;
+#elif defined(USE_PTHREADS)
+  /** Pthreads-only: with pthreads, we implement locks with
+   * pthread_mutex_t. */
+  pthread_mutex_t mutex;
+#else
+  /** No-threads only: Dummy variable so that tor_mutex_t takes up space. */
+  int _unused;
+#endif
+} tor_mutex_t;
+
+tor_mutex_t *tor_mutex_new(void);
+tor_mutex_t *tor_mutex_new_nonrecursive(void);
+void tor_mutex_init(tor_mutex_t *m);
+void tor_mutex_init_nonrecursive(tor_mutex_t *m);
+void tor_mutex_acquire(tor_mutex_t *m);
+void tor_mutex_release(tor_mutex_t *m);
+void tor_mutex_free(tor_mutex_t *m);
+void tor_mutex_uninit(tor_mutex_t *m);
+unsigned long tor_get_thread_id(void);
+void tor_threads_init(void);
+
+/** Conditions need nonrecursive mutexes with pthreads. */
+#define tor_mutex_init_for_cond(m) tor_mutex_init_nonrecursive(m)
+
+void set_main_thread(void);
+int in_main_thread(void);
+
+typedef struct tor_cond_t {
+#ifdef USE_PTHREADS
+  pthread_cond_t cond;
+#elif defined(USE_WIN32_THREADS)
+  HANDLE event;
+
+  CRITICAL_SECTION lock;
+  int n_waiting;
+  int n_to_wake;
+  int generation;
+#else
+#error no known condition implementation.
+#endif
+} tor_cond_t;
+
+tor_cond_t *tor_cond_new(void);
+void tor_cond_free(tor_cond_t *cond);
+int tor_cond_init(tor_cond_t *cond);
+void tor_cond_uninit(tor_cond_t *cond);
+int tor_cond_wait(tor_cond_t *cond, tor_mutex_t *mutex,
+                  const struct timeval *tv);
+void tor_cond_signal_one(tor_cond_t *cond);
+void tor_cond_signal_all(tor_cond_t *cond);
+
+/** Helper type used to manage waking up the main thread while it's in
+ * the libevent main loop.  Used by the work queue code. */
+typedef struct alert_sockets_s {
+  /* XXXX This structure needs a better name. */
+  /** Socket that the main thread should listen for EV_READ events on.
+   * Note that this socket may be a regular fd on a non-Windows platform.
+   */
+  tor_socket_t read_fd;
+  /** Socket to use when alerting the main thread. */
+  tor_socket_t write_fd;
+  /** Function to alert the main thread */
+  int (*alert_fn)(tor_socket_t write_fd);
+  /** Function to make the main thread no longer alerted. */
+  int (*drain_fn)(tor_socket_t read_fd);
+} alert_sockets_t;
+
+/* Flags to disable one or more alert_sockets backends. */
+#define ASOCKS_NOEVENTFD2   (1u<<0)
+#define ASOCKS_NOEVENTFD    (1u<<1)
+#define ASOCKS_NOPIPE2      (1u<<2)
+#define ASOCKS_NOPIPE       (1u<<3)
+#define ASOCKS_NOSOCKETPAIR (1u<<4)
+
+int alert_sockets_create(alert_sockets_t *socks_out, uint32_t flags);
+void alert_sockets_close(alert_sockets_t *socks);
+
+typedef struct tor_threadlocal_s {
+#ifdef _WIN32
+  DWORD index;
+#else
+  pthread_key_t key;
+#endif
+} tor_threadlocal_t;
+
+/** Initialize a thread-local variable.
+ *
+ * After you call this function on a tor_threadlocal_t, you can call
+ * tor_threadlocal_set to change the current value of this variable for the
+ * current thread, and tor_threadlocal_get to retrieve the current value for
+ * the current thread.  Each thread has its own value.
+ **/
+int tor_threadlocal_init(tor_threadlocal_t *threadlocal);
+/**
+ * Release all resource associated with a thread-local variable.
+ */
+void tor_threadlocal_destroy(tor_threadlocal_t *threadlocal);
+/**
+ * Return the current value of a thread-local variable for this thread.
+ *
+ * It's undefined behavior to use this function if the threadlocal hasn't
+ * been initialized, or has been destroyed.
+ */
+void *tor_threadlocal_get(tor_threadlocal_t *threadlocal);
+/**
+ * Change the current value of a thread-local variable for this thread to
+ * <b>value</b>.
+ *
+ * It's undefined behavior to use this function if the threadlocal hasn't
+ * been initialized, or has been destroyed.
+ */
+void tor_threadlocal_set(tor_threadlocal_t *threadlocal, void *value);
+
+#endif
+