xref: /aosp_15_r20/external/libusb/libusb/os/threads_posix.c (revision 86b64dcb59b3a0b37502ecd56e119234366a6f7e)
1 /*
2  * libusb synchronization using POSIX Threads
3  *
4  * Copyright © 2011 Vitali Lovich <[email protected]>
5  * Copyright © 2011 Peter Stuge <[email protected]>
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 #include "libusbi.h"
23 
24 #include <errno.h>
25 #include <limits.h>
26 #if defined(__ANDROID__)
27 # include <unistd.h>
28 #elif defined(__HAIKU__)
29 # include <os/kernel/OS.h>
30 #elif defined(__linux__)
31 # include <sys/syscall.h>
32 # include <unistd.h>
33 #elif defined(__NetBSD__)
34 # include <lwp.h>
35 #elif defined(__OpenBSD__)
36 # include <unistd.h>
37 #elif defined(__sun__)
38 # include <sys/lwp.h>
39 #endif
40 
usbi_cond_init(pthread_cond_t * cond)41 void usbi_cond_init(pthread_cond_t *cond)
42 {
43 #ifdef HAVE_PTHREAD_CONDATTR_SETCLOCK
44 	pthread_condattr_t condattr;
45 
46 	PTHREAD_CHECK(pthread_condattr_init(&condattr));
47 	PTHREAD_CHECK(pthread_condattr_setclock(&condattr, CLOCK_MONOTONIC));
48 	PTHREAD_CHECK(pthread_cond_init(cond, &condattr));
49 	PTHREAD_CHECK(pthread_condattr_destroy(&condattr));
50 #else
51 	PTHREAD_CHECK(pthread_cond_init(cond, NULL));
52 #endif
53 }
54 
usbi_cond_timedwait(pthread_cond_t * cond,pthread_mutex_t * mutex,const struct timeval * tv)55 int usbi_cond_timedwait(pthread_cond_t *cond,
56 	pthread_mutex_t *mutex, const struct timeval *tv)
57 {
58 	struct timespec timeout;
59 	int r;
60 
61 #ifdef HAVE_PTHREAD_CONDATTR_SETCLOCK
62 	usbi_get_monotonic_time(&timeout);
63 #else
64 	usbi_get_real_time(&timeout);
65 #endif
66 
67 	timeout.tv_sec += tv->tv_sec;
68 	timeout.tv_nsec += tv->tv_usec * 1000L;
69 	if (timeout.tv_nsec >= NSEC_PER_SEC) {
70 		timeout.tv_nsec -= NSEC_PER_SEC;
71 		timeout.tv_sec++;
72 	}
73 
74 	r = pthread_cond_timedwait(cond, mutex, &timeout);
75 	if (r == 0)
76 		return 0;
77 	else if (r == ETIMEDOUT)
78 		return LIBUSB_ERROR_TIMEOUT;
79 	else
80 		return LIBUSB_ERROR_OTHER;
81 }
82 
usbi_get_tid(void)83 unsigned long usbi_get_tid(void)
84 {
85 	static _Thread_local unsigned long tl_tid;
86 	unsigned long tid;
87 
88 	if (tl_tid)
89 		return tl_tid;
90 
91 #if defined(__ANDROID__)
92 	tid = (unsigned long)gettid();
93 #elif defined(__APPLE__)
94 #ifdef HAVE_PTHREAD_THREADID_NP
95 	uint64_t thread_id;
96 
97 	if (pthread_threadid_np(NULL, &thread_id) == 0)
98 		tid = (unsigned long)thread_id;
99 	else
100 		tid = ULONG_MAX;
101 #else
102 	tid = (unsigned long)pthread_mach_thread_np(pthread_self());
103 #endif
104 #elif defined(__HAIKU__)
105 	tid = (unsigned long)get_pthread_thread_id(pthread_self());
106 #elif defined(__linux__)
107 	tid = (unsigned long)syscall(SYS_gettid);
108 #elif defined(__NetBSD__)
109 	tid = (unsigned long)_lwp_self();
110 #elif defined(__OpenBSD__)
111 	tid = (unsigned long)getthrid();
112 #elif defined(__sun__)
113 	tid = (unsigned long)_lwp_self();
114 #else
115 	tid = ULONG_MAX;
116 #endif
117 
118 	if (tid == ULONG_MAX) {
119 		/* If we don't have a thread ID, at least return a unique
120 		 * value that can be used to distinguish individual
121 		 * threads. */
122 		tid = (unsigned long)(uintptr_t)pthread_self();
123 	}
124 
125 	return tl_tid = tid;
126 }
127