Line data    Source code

       1             : /* Copyright (c) 2003-2004, Roger Dingledine
       2             :  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
       3             :  * Copyright (c) 2007-2021, The Tor Project, Inc. */
       4             : /* See LICENSE for licensing information */
       5             : 
       6             : /**
       7             :  * \file compat_mutex.c
       8             :  *
       9             :  * \brief Portable wrapper for platform mutex implementations.
      10             :  **/
      11             : 
      12             : #include "lib/lock/compat_mutex.h"
      13             : #include "lib/malloc/malloc.h"
      14             : 
      15             : /** Return a newly allocated, ready-for-use mutex. */
      16             : tor_mutex_t *
      17          91 : tor_mutex_new(void)
      18             : {
      19          91 :   tor_mutex_t *m = tor_malloc_zero(sizeof(tor_mutex_t));
      20          91 :   tor_mutex_init(m);
      21          91 :   return m;
      22             : }
      23             : /** Return a newly allocated, ready-for-use mutex.  This one might be
      24             :  * non-recursive, if that's faster. */
      25             : tor_mutex_t *
      26           2 : tor_mutex_new_nonrecursive(void)
      27             : {
      28           2 :   tor_mutex_t *m = tor_malloc_zero(sizeof(tor_mutex_t));
      29           2 :   tor_mutex_init_nonrecursive(m);
      30           2 :   return m;
      31             : }
      32             : /** Release all storage and system resources held by <b>m</b>.
      33             :  *
      34             :  * Destroying a locked mutex is undefined behaviour. Global mutexes may be
      35             :  * locked when they are passed to this function, because multiple threads can
      36             :  * still access them. So we can either:
      37             :  *  - destroy on shutdown, and re-initialise when tor re-initialises, or
      38             :  *  - skip destroying and re-initialisation, using a sentinel variable.
      39             :  * See #31735 for details.
      40             :  */
      41             : void
      42         272 : tor_mutex_free_(tor_mutex_t *m)
      43             : {
      44         272 :   if (!m)
      45             :     return;
      46          60 :   tor_mutex_uninit(m);
      47          60 :   tor_free(m);
      48             : }