xref: /external/chromium_org/third_party/libusb/src/libusb/os/threads_posix.c

/*
 * libusbx synchronization using POSIX Threads
 *
 * Copyright © 2011 Vitali Lovich <vlovich@aliph.com>
 * Copyright © 2011 Peter Stuge <peter@stuge.se>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#if defined(__linux__) || defined(__OpenBSD__)
# include <unistd.h>
# include <sys/syscall.h>
#elif defined(__APPLE__)
# include <mach/mach.h>
#elif defined(__CYGWIN__)
# include <windows.h>
#endif

#include "threads_posix.h"

int usbi_mutex_init_recursive(pthread_mutex_t *mutex, pthread_mutexattr_t *attr)
{
	int err;
	pthread_mutexattr_t stack_attr;
	if (!attr) {
		attr = &stack_attr;
		err = pthread_mutexattr_init(&stack_attr);
		if (err != 0)
			return err;
	}

	/* mutexattr_settype requires _GNU_SOURCE or _XOPEN_SOURCE >= 500 on Linux */
	err = pthread_mutexattr_settype(attr, PTHREAD_MUTEX_RECURSIVE);
	if (err != 0)
		goto finish;

	err = pthread_mutex_init(mutex, attr);

finish:
	if (attr == &stack_attr)
		pthread_mutexattr_destroy(&stack_attr);

	return err;
}

int usbi_get_tid(void)
{
	int ret = -1;
#if defined(__linux__)
	ret = syscall(SYS_gettid);
#elif defined(__OpenBSD__)
	/* The following only works with OpenBSD > 5.1 as it requires
	   real thread support. For 5.1 and earlier, -1 is returned. */
	ret = syscall(SYS_getthrid);
#elif defined(__APPLE__)
	ret = mach_thread_self();
	mach_port_deallocate(mach_task_self(), ret);
#elif defined(__CYGWIN__)
	ret = GetCurrentThreadId();
#endif
/* TODO: NetBSD thread ID support */
	return ret;
}