libusb/os/threads_posix.c

   1 /*
   2  * libusbx synchronization using POSIX Threads
   3  *
   4  * Copyright © 2011 Vitali Lovich <vlovich@aliph.com>
   5  * Copyright © 2011 Peter Stuge <peter@stuge.se>
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #if defined(__linux__) || defined(__OpenBSD__)
  23 # if defined(__linux__)
  24 #  define _GNU_SOURCE
  25 # else
  26 #  define _BSD_SOURCE
  27 # endif
  28 # include <unistd.h>
  29 # include <sys/syscall.h>
  30 #elif defined(__APPLE__)
  31 # include <mach/mach.h>
  32 #elif defined(__CYGWIN__)
  33 # include <windows.h>
  34 #endif
  35
  36 #include "threads_posix.h"
  37
  38 int usbi_mutex_init_recursive(pthread_mutex_t *mutex, pthread_mutexattr_t *attr)
  39 {
  40         int err;
  41         pthread_mutexattr_t stack_attr;
  42         if (!attr) {
  43                 attr = &stack_attr;
  44                 err = pthread_mutexattr_init(&stack_attr);
  45                 if (err != 0)
  46                         return err;
  47         }
  48
  49         /* mutexattr_settype requires _GNU_SOURCE or _XOPEN_SOURCE >= 500 on Linux */
  50         err = pthread_mutexattr_settype(attr, PTHREAD_MUTEX_RECURSIVE);
  51         if (err != 0)
  52                 goto finish;
  53
  54         err = pthread_mutex_init(mutex, attr);
  55
  56 finish:
  57         if (attr == &stack_attr)
  58                 pthread_mutexattr_destroy(&stack_attr);
  59
  60         return err;
  61 }
  62
  63 int usbi_get_tid(void)
  64 {
  65         int ret = -1;
  66 #if defined(__ANDROID__)
  67         ret = gettid();
  68 #elif defined(__linux__)
  69         ret = syscall(SYS_gettid);
  70 #elif defined(__OpenBSD__)
  71         /* The following only works with OpenBSD > 5.1 as it requires
  72            real thread support. For 5.1 and earlier, -1 is returned. */
  73         ret = syscall(SYS_getthrid);
  74 #elif defined(__APPLE__)
  75         ret = mach_thread_self();
  76         mach_port_deallocate(mach_task_self(), ret);
  77 #elif defined(__CYGWIN__)
  78         ret = GetCurrentThreadId();
  79 #endif
  80 /* TODO: NetBSD thread ID support */
  81         return ret;
  82 }