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1 /**************************************************************************
2  *
3  * Copyright 1999-2006 Brian Paul
4  * Copyright 2008 VMware, Inc.
5  * All Rights Reserved.
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a
8  * copy of this software and associated documentation files (the "Software"),
9  * to deal in the Software without restriction, including without limitation
10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11  * and/or sell copies of the Software, and to permit persons to whom the
12  * Software is furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included
15  * in all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
23  * OTHER DEALINGS IN THE SOFTWARE.
24  *
25  **************************************************************************/
26 
27 #ifndef U_THREAD_H_
28 #define U_THREAD_H_
29 
30 #include <errno.h>
31 #include <stdint.h>
32 #include <stdbool.h>
33 #include <string.h>
34 
35 #include "c11/threads.h"
36 #include "detect_os.h"
37 #include "macros.h"
38 
39 #ifdef HAVE_PTHREAD
40 #include <signal.h>
41 #ifdef HAVE_PTHREAD_NP_H
42 #include <pthread_np.h>
43 #endif
44 #endif
45 
46 #ifdef __HAIKU__
47 #include <OS.h>
48 #endif
49 
50 #if DETECT_OS_LINUX && !defined(ANDROID)
51 #include <sched.h>
52 #elif defined(_WIN32) && !defined(__CYGWIN__) && _WIN32_WINNT >= 0x0600
53 #ifndef WIN32_LEAN_AND_MEAN
54 #define WIN32_LEAN_AND_MEAN 1
55 #endif
56 #include <windows.h>
57 #endif
58 
59 #ifdef __FreeBSD__
60 /* pthread_np.h -> sys/param.h -> machine/param.h
61  * - defines ALIGN which clashes with our ALIGN
62  */
63 #undef ALIGN
64 #define cpu_set_t cpuset_t
65 #endif
66 
67 /* For util_set_thread_affinity to size the mask. */
68 #define UTIL_MAX_CPUS               1024  /* this should be enough */
69 #define UTIL_MAX_L3_CACHES          UTIL_MAX_CPUS
70 
71 /* Some highly performance-sensitive thread-local variables like the current GL
72  * context are declared with the initial-exec model on Linux.  glibc allocates a
73  * fixed number of extra slots for initial-exec TLS variables at startup, and
74  * Mesa relies on (even if it's dlopen()ed after init) being able to fit into
75  * those.  This model saves the call to look up the address of the TLS variable.
76  *
77  * However, if we don't have this TLS model available on the platform, then we
78  * still want to use normal TLS (which involves a function call, but not the
79  * expensive pthread_getspecific() or its equivalent).
80  */
81 #if DETECT_OS_APPLE
82 /* Apple Clang emits wrappers when using thread_local that break module linkage,
83  * but not with __thread
84  */
85 #define __THREAD_INITIAL_EXEC __thread
86 #elif defined(__GLIBC__)
87 #define __THREAD_INITIAL_EXEC thread_local __attribute__((tls_model("initial-exec")))
88 #define REALLY_INITIAL_EXEC
89 #else
90 #define __THREAD_INITIAL_EXEC thread_local
91 #endif
92 
93 static inline int
util_get_current_cpu(void)94 util_get_current_cpu(void)
95 {
96 #if DETECT_OS_LINUX && !defined(ANDROID)
97    return sched_getcpu();
98 
99 #elif defined(_WIN32) && !defined(__CYGWIN__) && _WIN32_WINNT >= 0x0600
100    return GetCurrentProcessorNumber();
101 
102 #else
103    return -1;
104 #endif
105 }
106 
u_thread_create(thrd_t * thrd,int (* routine)(void *),void * param)107 static inline int u_thread_create(thrd_t *thrd, int (*routine)(void *), void *param)
108 {
109    int ret = thrd_error;
110 #ifdef HAVE_PTHREAD
111    sigset_t saved_set, new_set;
112 
113    sigfillset(&new_set);
114    sigdelset(&new_set, SIGSYS);
115 
116    /* SIGSEGV is commonly used by Vulkan API tracing layers in order to track
117     * accesses in device memory mapped to user space. Blocking the signal hinders
118     * that tracking mechanism.
119     */
120    sigdelset(&new_set, SIGSEGV);
121    pthread_sigmask(SIG_BLOCK, &new_set, &saved_set);
122    ret = thrd_create(thrd, routine, param);
123    pthread_sigmask(SIG_SETMASK, &saved_set, NULL);
124 #else
125    ret = thrd_create(thrd, routine, param);
126 #endif
127 
128    return ret;
129 }
130 
u_thread_setname(const char * name)131 static inline void u_thread_setname( const char *name )
132 {
133 #if defined(HAVE_PTHREAD)
134 #if DETECT_OS_LINUX || DETECT_OS_CYGWIN || DETECT_OS_SOLARIS
135    int ret = pthread_setname_np(pthread_self(), name);
136    if (ret == ERANGE) {
137       char buf[16];
138       const size_t len = MIN2(strlen(name), ARRAY_SIZE(buf) - 1);
139       memcpy(buf, name, len);
140       buf[len] = '\0';
141       pthread_setname_np(pthread_self(), buf);
142    }
143 #elif DETECT_OS_FREEBSD || DETECT_OS_OPENBSD
144    pthread_set_name_np(pthread_self(), name);
145 #elif DETECT_OS_NETBSD
146    pthread_setname_np(pthread_self(), "%s", (void *)name);
147 #elif DETECT_OS_APPLE
148    pthread_setname_np(name);
149 #elif DETECT_OS_HAIKU
150    rename_thread(find_thread(NULL), name);
151 #else
152 #warning Not sure how to call pthread_setname_np
153 #endif
154 #endif
155    (void)name;
156 }
157 
158 /**
159  * Set thread affinity.
160  *
161  * \param thread         Thread
162  * \param mask           Set this affinity mask
163  * \param old_mask       Previous affinity mask returned if not NULL
164  * \param num_mask_bits  Number of bits in both masks
165  * \return  true on success
166  */
167 static inline bool
util_set_thread_affinity(thrd_t thread,const uint32_t * mask,uint32_t * old_mask,unsigned num_mask_bits)168 util_set_thread_affinity(thrd_t thread,
169                          const uint32_t *mask,
170                          uint32_t *old_mask,
171                          unsigned num_mask_bits)
172 {
173 #if defined(HAVE_PTHREAD_SETAFFINITY)
174    cpu_set_t cpuset;
175 
176    if (old_mask) {
177       if (pthread_getaffinity_np(thread, sizeof(cpuset), &cpuset) != 0)
178          return false;
179 
180       memset(old_mask, 0, num_mask_bits / 8);
181       for (unsigned i = 0; i < num_mask_bits && i < CPU_SETSIZE; i++) {
182          if (CPU_ISSET(i, &cpuset))
183             old_mask[i / 32] |= 1u << (i % 32);
184       }
185    }
186 
187    CPU_ZERO(&cpuset);
188    for (unsigned i = 0; i < num_mask_bits && i < CPU_SETSIZE; i++) {
189       if (mask[i / 32] & (1u << (i % 32)))
190          CPU_SET(i, &cpuset);
191    }
192    return pthread_setaffinity_np(thread, sizeof(cpuset), &cpuset) == 0;
193 
194 #elif defined(_WIN32) && !defined(__CYGWIN__)
195    DWORD_PTR m = mask[0];
196 
197    if (sizeof(m) > 4 && num_mask_bits > 32)
198       m |= (uint64_t)mask[1] << 32;
199 
200    m = SetThreadAffinityMask(thread, m);
201    if (!m)
202       return false;
203 
204    if (old_mask) {
205       memset(old_mask, 0, num_mask_bits / 8);
206 
207       old_mask[0] = m;
208 #ifdef _WIN64
209       old_mask[1] = m >> 32;
210 #endif
211    }
212 
213    return true;
214 #else
215    return false;
216 #endif
217 }
218 
219 static inline bool
util_set_current_thread_affinity(const uint32_t * mask,uint32_t * old_mask,unsigned num_mask_bits)220 util_set_current_thread_affinity(const uint32_t *mask,
221                                  uint32_t *old_mask,
222                                  unsigned num_mask_bits)
223 {
224 #if defined(HAVE_PTHREAD_SETAFFINITY)
225    return util_set_thread_affinity(pthread_self(), mask, old_mask,
226                                    num_mask_bits);
227 
228 #elif defined(_WIN32) && !defined(__CYGWIN__)
229    /* The GetCurrentThreadId() handle is only valid within the current thread. */
230    return util_set_thread_affinity(GetCurrentThread(), mask, old_mask,
231                                    num_mask_bits);
232 
233 #else
234    return false;
235 #endif
236 }
237 
238 
239 /*
240  * Thread statistics.
241  */
242 
243 /* Return the time of a thread's CPU time clock. */
244 static inline int64_t
util_thread_get_time_nano(thrd_t thread)245 util_thread_get_time_nano(thrd_t thread)
246 {
247 #if defined(HAVE_PTHREAD) && !defined(__APPLE__) && !defined(__HAIKU__)
248    struct timespec ts;
249    clockid_t cid;
250 
251    pthread_getcpuclockid(thread, &cid);
252    clock_gettime(cid, &ts);
253    return (int64_t)ts.tv_sec * 1000000000 + ts.tv_nsec;
254 #else
255    (void)thread;
256    return 0;
257 #endif
258 }
259 
260 /* Return the time of the current thread's CPU time clock. */
261 static inline int64_t
util_current_thread_get_time_nano(void)262 util_current_thread_get_time_nano(void)
263 {
264 #if defined(HAVE_PTHREAD)
265    return util_thread_get_time_nano(pthread_self());
266 
267 #elif defined(_WIN32) && !defined(__CYGWIN__)
268    /* The GetCurrentThreadId() handle is only valid within the current thread. */
269    return util_thread_get_time_nano(GetCurrentThread());
270 
271 #else
272    return 0;
273 #endif
274 }
275 
u_thread_is_self(thrd_t thread)276 static inline bool u_thread_is_self(thrd_t thread)
277 {
278 #if defined(HAVE_PTHREAD)
279    return pthread_equal(pthread_self(), thread);
280 #endif
281    return false;
282 }
283 
284 /*
285  * util_barrier
286  */
287 
288 #if defined(HAVE_PTHREAD) && !defined(__APPLE__) && !defined(__HAIKU__)
289 
290 typedef pthread_barrier_t util_barrier;
291 
util_barrier_init(util_barrier * barrier,unsigned count)292 static inline void util_barrier_init(util_barrier *barrier, unsigned count)
293 {
294    pthread_barrier_init(barrier, NULL, count);
295 }
296 
util_barrier_destroy(util_barrier * barrier)297 static inline void util_barrier_destroy(util_barrier *barrier)
298 {
299    pthread_barrier_destroy(barrier);
300 }
301 
util_barrier_wait(util_barrier * barrier)302 static inline bool util_barrier_wait(util_barrier *barrier)
303 {
304    return pthread_barrier_wait(barrier) == PTHREAD_BARRIER_SERIAL_THREAD;
305 }
306 
307 
308 #else /* If the OS doesn't have its own, implement barriers using a mutex and a condvar */
309 
310 typedef struct {
311    unsigned count;
312    unsigned waiters;
313    uint64_t sequence;
314    mtx_t mutex;
315    cnd_t condvar;
316 } util_barrier;
317 
util_barrier_init(util_barrier * barrier,unsigned count)318 static inline void util_barrier_init(util_barrier *barrier, unsigned count)
319 {
320    barrier->count = count;
321    barrier->waiters = 0;
322    barrier->sequence = 0;
323    (void) mtx_init(&barrier->mutex, mtx_plain);
324    cnd_init(&barrier->condvar);
325 }
326 
util_barrier_destroy(util_barrier * barrier)327 static inline void util_barrier_destroy(util_barrier *barrier)
328 {
329    assert(barrier->waiters == 0);
330    mtx_destroy(&barrier->mutex);
331    cnd_destroy(&barrier->condvar);
332 }
333 
util_barrier_wait(util_barrier * barrier)334 static inline bool util_barrier_wait(util_barrier *barrier)
335 {
336    mtx_lock(&barrier->mutex);
337 
338    assert(barrier->waiters < barrier->count);
339    barrier->waiters++;
340 
341    if (barrier->waiters < barrier->count) {
342       uint64_t sequence = barrier->sequence;
343 
344       do {
345          cnd_wait(&barrier->condvar, &barrier->mutex);
346       } while (sequence == barrier->sequence);
347    } else {
348       barrier->waiters = 0;
349       barrier->sequence++;
350       cnd_broadcast(&barrier->condvar);
351    }
352 
353    mtx_unlock(&barrier->mutex);
354 
355    return true;
356 }
357 
358 #endif
359 
360 /*
361  * Thread-id's.
362  *
363  * thrd_current() is not portable to windows (or at least not in a desirable
364  * way), so thread_id's provide an alternative mechanism
365  */
366 
367 #ifdef _WIN32
368 typedef DWORD thread_id;
369 #else
370 typedef thrd_t thread_id;
371 #endif
372 
373 static inline thread_id
util_get_thread_id(void)374 util_get_thread_id(void)
375 {
376    /*
377     * XXX: Callers of of this function assume it is a lightweight function.
378     * But unfortunately C11's thrd_current() gives no such guarantees.  In
379     * fact, it's pretty hard to have a compliant implementation of
380     * thrd_current() on Windows with such characteristics.  So for now, we
381     * side-step this mess and use Windows thread primitives directly here.
382     */
383 #ifdef _WIN32
384    return GetCurrentThreadId();
385 #else
386    return thrd_current();
387 #endif
388 }
389 
390 
391 static inline int
util_thread_id_equal(thread_id t1,thread_id t2)392 util_thread_id_equal(thread_id t1, thread_id t2)
393 {
394 #ifdef _WIN32
395    return t1 == t2;
396 #else
397    return thrd_equal(t1, t2);
398 #endif
399 }
400 
401 #endif /* U_THREAD_H_ */
402