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The Android Open Source Projectcbb10112009-03-03 19:31:44 -08001/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
The Android Open Source Project7a4c8392009-03-05 14:34:35 -080017// #define LOG_NDEBUG 0
The Android Open Source Projectcbb10112009-03-03 19:31:44 -080018#define LOG_TAG "libutils.threads"
19
Mark Salyzyn5bed8032014-04-30 11:10:46 -070020#include <assert.h>
21#include <errno.h>
22#include <memory.h>
The Android Open Source Projectcbb10112009-03-03 19:31:44 -080023#include <stdio.h>
24#include <stdlib.h>
Elliott Hughes6ed68cc2015-06-30 08:22:24 -070025#include <string.h>
The Android Open Source Projectcbb10112009-03-03 19:31:44 -080026#include <unistd.h>
27
Yabin Cui4a6e5a32015-01-26 19:48:54 -080028#if !defined(_WIN32)
The Android Open Source Projectcbb10112009-03-03 19:31:44 -080029# include <pthread.h>
30# include <sched.h>
31# include <sys/resource.h>
Yabin Cui4a6e5a32015-01-26 19:48:54 -080032#else
The Android Open Source Projectcbb10112009-03-03 19:31:44 -080033# include <windows.h>
34# include <stdint.h>
35# include <process.h>
36# define HAVE_CREATETHREAD // Cygwin, vs. HAVE__BEGINTHREADEX for MinGW
37#endif
38
Elliott Hughes292ccd32014-12-15 12:52:53 -080039#if defined(__linux__)
The Android Open Source Projectcbb10112009-03-03 19:31:44 -080040#include <sys/prctl.h>
41#endif
42
Mark Salyzyn5bed8032014-04-30 11:10:46 -070043#include <utils/threads.h>
44#include <utils/Log.h>
45
46#include <cutils/sched_policy.h>
47
Elliott Hughes9b828ad2015-07-30 08:47:35 -070048#if defined(__ANDROID__)
Mark Salyzyn5bed8032014-04-30 11:10:46 -070049# define __android_unused
50#else
51# define __android_unused __attribute__((__unused__))
52#endif
53
The Android Open Source Projectcbb10112009-03-03 19:31:44 -080054/*
55 * ===========================================================================
56 * Thread wrappers
57 * ===========================================================================
58 */
59
60using namespace android;
61
62// ----------------------------------------------------------------------------
Yabin Cui4a6e5a32015-01-26 19:48:54 -080063#if !defined(_WIN32)
The Android Open Source Projectcbb10112009-03-03 19:31:44 -080064// ----------------------------------------------------------------------------
65
66/*
Dianne Hackborn16d217e2010-09-03 17:07:07 -070067 * Create and run a new thread.
The Android Open Source Projectcbb10112009-03-03 19:31:44 -080068 *
69 * We create it "detached", so it cleans up after itself.
70 */
71
72typedef void* (*android_pthread_entry)(void*);
73
74struct thread_data_t {
75 thread_func_t entryFunction;
76 void* userData;
77 int priority;
78 char * threadName;
79
80 // we use this trampoline when we need to set the priority with
Glenn Kastend731f072011-07-11 15:59:22 -070081 // nice/setpriority, and name with prctl.
The Android Open Source Projectcbb10112009-03-03 19:31:44 -080082 static int trampoline(const thread_data_t* t) {
83 thread_func_t f = t->entryFunction;
84 void* u = t->userData;
85 int prio = t->priority;
86 char * name = t->threadName;
87 delete t;
88 setpriority(PRIO_PROCESS, 0, prio);
Glenn Kastenfe34e452012-04-30 16:03:30 -070089 if (prio >= ANDROID_PRIORITY_BACKGROUND) {
90 set_sched_policy(0, SP_BACKGROUND);
91 } else {
92 set_sched_policy(0, SP_FOREGROUND);
Dianne Hackborna78bab02010-09-09 15:50:18 -070093 }
Yabin Cui4a6e5a32015-01-26 19:48:54 -080094
The Android Open Source Projectcbb10112009-03-03 19:31:44 -080095 if (name) {
Mathias Agopian6090df82013-03-07 15:34:28 -080096 androidSetThreadName(name);
The Android Open Source Projectcbb10112009-03-03 19:31:44 -080097 free(name);
98 }
99 return f(u);
100 }
101};
102
Mathias Agopian6090df82013-03-07 15:34:28 -0800103void androidSetThreadName(const char* name) {
Elliott Hughes292ccd32014-12-15 12:52:53 -0800104#if defined(__linux__)
Mathias Agopian6090df82013-03-07 15:34:28 -0800105 // Mac OS doesn't have this, and we build libutil for the host too
106 int hasAt = 0;
107 int hasDot = 0;
108 const char *s = name;
109 while (*s) {
110 if (*s == '.') hasDot = 1;
111 else if (*s == '@') hasAt = 1;
112 s++;
113 }
114 int len = s - name;
115 if (len < 15 || hasAt || !hasDot) {
116 s = name;
117 } else {
118 s = name + len - 15;
119 }
120 prctl(PR_SET_NAME, (unsigned long) s, 0, 0, 0);
121#endif
122}
123
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800124int androidCreateRawThreadEtc(android_thread_func_t entryFunction,
125 void *userData,
Mark Salyzyn5bed8032014-04-30 11:10:46 -0700126 const char* threadName __android_unused,
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800127 int32_t threadPriority,
128 size_t threadStackSize,
129 android_thread_id_t *threadId)
130{
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800131 pthread_attr_t attr;
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800132 pthread_attr_init(&attr);
133 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
134
Elliott Hughes9b828ad2015-07-30 08:47:35 -0700135#if defined(__ANDROID__) /* valgrind is rejecting RT-priority create reqs */
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800136 if (threadPriority != PRIORITY_DEFAULT || threadName != NULL) {
Glenn Kastend731f072011-07-11 15:59:22 -0700137 // Now that the pthread_t has a method to find the associated
138 // android_thread_id_t (pid) from pthread_t, it would be possible to avoid
139 // this trampoline in some cases as the parent could set the properties
140 // for the child. However, there would be a race condition because the
141 // child becomes ready immediately, and it doesn't work for the name.
142 // prctl(PR_SET_NAME) only works for self; prctl(PR_SET_THREAD_NAME) was
143 // proposed but not yet accepted.
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800144 thread_data_t* t = new thread_data_t;
145 t->priority = threadPriority;
146 t->threadName = threadName ? strdup(threadName) : NULL;
147 t->entryFunction = entryFunction;
148 t->userData = userData;
149 entryFunction = (android_thread_func_t)&thread_data_t::trampoline;
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800150 userData = t;
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800151 }
152#endif
153
154 if (threadStackSize) {
155 pthread_attr_setstacksize(&attr, threadStackSize);
156 }
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800157
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800158 errno = 0;
159 pthread_t thread;
160 int result = pthread_create(&thread, &attr,
161 (android_pthread_entry)entryFunction, userData);
Le-Chun Wud8734d12011-07-14 14:27:18 -0700162 pthread_attr_destroy(&attr);
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800163 if (result != 0) {
Elliott Hughes6ed68cc2015-06-30 08:22:24 -0700164 ALOGE("androidCreateRawThreadEtc failed (entry=%p, res=%d, %s)\n"
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800165 "(android threadPriority=%d)",
Elliott Hughes6ed68cc2015-06-30 08:22:24 -0700166 entryFunction, result, strerror(errno), threadPriority);
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800167 return 0;
168 }
169
Glenn Kastena538e262011-06-02 08:59:28 -0700170 // Note that *threadID is directly available to the parent only, as it is
171 // assigned after the child starts. Use memory barrier / lock if the child
172 // or other threads also need access.
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800173 if (threadId != NULL) {
174 *threadId = (android_thread_id_t)thread; // XXX: this is not portable
175 }
176 return 1;
177}
178
Elliott Hughes9b828ad2015-07-30 08:47:35 -0700179#if defined(__ANDROID__)
Glenn Kastend731f072011-07-11 15:59:22 -0700180static pthread_t android_thread_id_t_to_pthread(android_thread_id_t thread)
181{
182 return (pthread_t) thread;
183}
184#endif
185
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800186android_thread_id_t androidGetThreadId()
187{
188 return (android_thread_id_t)pthread_self();
189}
190
191// ----------------------------------------------------------------------------
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800192#else // !defined(_WIN32)
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800193// ----------------------------------------------------------------------------
194
195/*
196 * Trampoline to make us __stdcall-compliant.
197 *
198 * We're expected to delete "vDetails" when we're done.
199 */
200struct threadDetails {
201 int (*func)(void*);
202 void* arg;
203};
204static __stdcall unsigned int threadIntermediary(void* vDetails)
205{
206 struct threadDetails* pDetails = (struct threadDetails*) vDetails;
207 int result;
208
209 result = (*(pDetails->func))(pDetails->arg);
210
211 delete pDetails;
212
Steve Block8b4cf772011-10-12 17:27:03 +0100213 ALOG(LOG_VERBOSE, "thread", "thread exiting\n");
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800214 return (unsigned int) result;
215}
216
217/*
218 * Create and run a new thread.
219 */
220static bool doCreateThread(android_thread_func_t fn, void* arg, android_thread_id_t *id)
221{
222 HANDLE hThread;
223 struct threadDetails* pDetails = new threadDetails; // must be on heap
224 unsigned int thrdaddr;
225
226 pDetails->func = fn;
227 pDetails->arg = arg;
228
229#if defined(HAVE__BEGINTHREADEX)
230 hThread = (HANDLE) _beginthreadex(NULL, 0, threadIntermediary, pDetails, 0,
231 &thrdaddr);
232 if (hThread == 0)
233#elif defined(HAVE_CREATETHREAD)
234 hThread = CreateThread(NULL, 0,
235 (LPTHREAD_START_ROUTINE) threadIntermediary,
236 (void*) pDetails, 0, (DWORD*) &thrdaddr);
237 if (hThread == NULL)
238#endif
239 {
Steve Block8b4cf772011-10-12 17:27:03 +0100240 ALOG(LOG_WARN, "thread", "WARNING: thread create failed\n");
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800241 return false;
242 }
243
244#if defined(HAVE_CREATETHREAD)
245 /* close the management handle */
246 CloseHandle(hThread);
247#endif
248
249 if (id != NULL) {
250 *id = (android_thread_id_t)thrdaddr;
251 }
252
253 return true;
254}
255
256int androidCreateRawThreadEtc(android_thread_func_t fn,
257 void *userData,
Mark Salyzyn5bed8032014-04-30 11:10:46 -0700258 const char* /*threadName*/,
259 int32_t /*threadPriority*/,
260 size_t /*threadStackSize*/,
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800261 android_thread_id_t *threadId)
262{
263 return doCreateThread( fn, userData, threadId);
264}
265
266android_thread_id_t androidGetThreadId()
267{
268 return (android_thread_id_t)GetCurrentThreadId();
269}
270
271// ----------------------------------------------------------------------------
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800272#endif // !defined(_WIN32)
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800273
274// ----------------------------------------------------------------------------
275
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800276int androidCreateThread(android_thread_func_t fn, void* arg)
277{
278 return createThreadEtc(fn, arg);
279}
280
281int androidCreateThreadGetID(android_thread_func_t fn, void *arg, android_thread_id_t *id)
282{
283 return createThreadEtc(fn, arg, "android:unnamed_thread",
284 PRIORITY_DEFAULT, 0, id);
285}
286
287static android_create_thread_fn gCreateThreadFn = androidCreateRawThreadEtc;
288
289int androidCreateThreadEtc(android_thread_func_t entryFunction,
290 void *userData,
291 const char* threadName,
292 int32_t threadPriority,
293 size_t threadStackSize,
294 android_thread_id_t *threadId)
295{
296 return gCreateThreadFn(entryFunction, userData, threadName,
297 threadPriority, threadStackSize, threadId);
298}
299
300void androidSetCreateThreadFunc(android_create_thread_fn func)
301{
302 gCreateThreadFn = func;
303}
304
Elliott Hughes9b828ad2015-07-30 08:47:35 -0700305#if defined(__ANDROID__)
Dianne Hackborn235af972009-12-07 17:59:37 -0800306int androidSetThreadPriority(pid_t tid, int pri)
307{
308 int rc = 0;
309 int lasterr = 0;
310
Glenn Kastenfe34e452012-04-30 16:03:30 -0700311 if (pri >= ANDROID_PRIORITY_BACKGROUND) {
312 rc = set_sched_policy(tid, SP_BACKGROUND);
313 } else if (getpriority(PRIO_PROCESS, tid) >= ANDROID_PRIORITY_BACKGROUND) {
314 rc = set_sched_policy(tid, SP_FOREGROUND);
Dianne Hackborn235af972009-12-07 17:59:37 -0800315 }
316
317 if (rc) {
318 lasterr = errno;
319 }
320
321 if (setpriority(PRIO_PROCESS, tid, pri) < 0) {
322 rc = INVALID_OPERATION;
323 } else {
324 errno = lasterr;
325 }
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800326
Dianne Hackborn235af972009-12-07 17:59:37 -0800327 return rc;
328}
329
Andreas Huber8ddbed92011-09-15 12:21:40 -0700330int androidGetThreadPriority(pid_t tid) {
331 return getpriority(PRIO_PROCESS, tid);
332}
333
Jeff Brown27e6eaa2012-03-16 22:18:39 -0700334#endif
Glenn Kasten6fbe0a82011-06-22 16:20:37 -0700335
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800336namespace android {
337
338/*
339 * ===========================================================================
340 * Mutex class
341 * ===========================================================================
342 */
343
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800344#if !defined(_WIN32)
Mathias Agopian15554362009-07-12 23:11:20 -0700345// implemented as inlines in threads.h
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800346#else
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800347
348Mutex::Mutex()
349{
350 HANDLE hMutex;
351
352 assert(sizeof(hMutex) == sizeof(mState));
353
354 hMutex = CreateMutex(NULL, FALSE, NULL);
355 mState = (void*) hMutex;
356}
357
358Mutex::Mutex(const char* name)
359{
360 // XXX: name not used for now
361 HANDLE hMutex;
362
David 'Digit' Turner9bafd122009-08-01 00:20:17 +0200363 assert(sizeof(hMutex) == sizeof(mState));
364
365 hMutex = CreateMutex(NULL, FALSE, NULL);
366 mState = (void*) hMutex;
367}
368
369Mutex::Mutex(int type, const char* name)
370{
371 // XXX: type and name not used for now
372 HANDLE hMutex;
373
374 assert(sizeof(hMutex) == sizeof(mState));
375
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800376 hMutex = CreateMutex(NULL, FALSE, NULL);
377 mState = (void*) hMutex;
378}
379
380Mutex::~Mutex()
381{
382 CloseHandle((HANDLE) mState);
383}
384
385status_t Mutex::lock()
386{
387 DWORD dwWaitResult;
388 dwWaitResult = WaitForSingleObject((HANDLE) mState, INFINITE);
389 return dwWaitResult != WAIT_OBJECT_0 ? -1 : NO_ERROR;
390}
391
392void Mutex::unlock()
393{
394 if (!ReleaseMutex((HANDLE) mState))
Steve Block8b4cf772011-10-12 17:27:03 +0100395 ALOG(LOG_WARN, "thread", "WARNING: bad result from unlocking mutex\n");
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800396}
397
398status_t Mutex::tryLock()
399{
400 DWORD dwWaitResult;
401
402 dwWaitResult = WaitForSingleObject((HANDLE) mState, 0);
403 if (dwWaitResult != WAIT_OBJECT_0 && dwWaitResult != WAIT_TIMEOUT)
Steve Block8b4cf772011-10-12 17:27:03 +0100404 ALOG(LOG_WARN, "thread", "WARNING: bad result from try-locking mutex\n");
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800405 return (dwWaitResult == WAIT_OBJECT_0) ? 0 : -1;
406}
407
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800408#endif // !defined(_WIN32)
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800409
410
411/*
412 * ===========================================================================
413 * Condition class
414 * ===========================================================================
415 */
416
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800417#if !defined(_WIN32)
Mathias Agopian15554362009-07-12 23:11:20 -0700418// implemented as inlines in threads.h
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800419#else
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800420
421/*
422 * Windows doesn't have a condition variable solution. It's possible
423 * to create one, but it's easy to get it wrong. For a discussion, and
424 * the origin of this implementation, see:
425 *
426 * http://www.cs.wustl.edu/~schmidt/win32-cv-1.html
427 *
428 * The implementation shown on the page does NOT follow POSIX semantics.
429 * As an optimization they require acquiring the external mutex before
430 * calling signal() and broadcast(), whereas POSIX only requires grabbing
431 * it before calling wait(). The implementation here has been un-optimized
432 * to have the correct behavior.
433 */
434typedef struct WinCondition {
435 // Number of waiting threads.
436 int waitersCount;
437
438 // Serialize access to waitersCount.
439 CRITICAL_SECTION waitersCountLock;
440
441 // Semaphore used to queue up threads waiting for the condition to
442 // become signaled.
443 HANDLE sema;
444
445 // An auto-reset event used by the broadcast/signal thread to wait
446 // for all the waiting thread(s) to wake up and be released from
447 // the semaphore.
448 HANDLE waitersDone;
449
450 // This mutex wouldn't be necessary if we required that the caller
451 // lock the external mutex before calling signal() and broadcast().
452 // I'm trying to mimic pthread semantics though.
453 HANDLE internalMutex;
454
455 // Keeps track of whether we were broadcasting or signaling. This
456 // allows us to optimize the code if we're just signaling.
457 bool wasBroadcast;
458
459 status_t wait(WinCondition* condState, HANDLE hMutex, nsecs_t* abstime)
460 {
461 // Increment the wait count, avoiding race conditions.
462 EnterCriticalSection(&condState->waitersCountLock);
463 condState->waitersCount++;
464 //printf("+++ wait: incr waitersCount to %d (tid=%ld)\n",
465 // condState->waitersCount, getThreadId());
466 LeaveCriticalSection(&condState->waitersCountLock);
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800467
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800468 DWORD timeout = INFINITE;
469 if (abstime) {
470 nsecs_t reltime = *abstime - systemTime();
471 if (reltime < 0)
472 reltime = 0;
473 timeout = reltime/1000000;
474 }
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800475
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800476 // Atomically release the external mutex and wait on the semaphore.
477 DWORD res =
478 SignalObjectAndWait(hMutex, condState->sema, timeout, FALSE);
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800479
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800480 //printf("+++ wait: awake (tid=%ld)\n", getThreadId());
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800481
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800482 // Reacquire lock to avoid race conditions.
483 EnterCriticalSection(&condState->waitersCountLock);
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800484
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800485 // No longer waiting.
486 condState->waitersCount--;
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800487
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800488 // Check to see if we're the last waiter after a broadcast.
489 bool lastWaiter = (condState->wasBroadcast && condState->waitersCount == 0);
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800490
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800491 //printf("+++ wait: lastWaiter=%d (wasBc=%d wc=%d)\n",
492 // lastWaiter, condState->wasBroadcast, condState->waitersCount);
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800493
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800494 LeaveCriticalSection(&condState->waitersCountLock);
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800495
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800496 // If we're the last waiter thread during this particular broadcast
497 // then signal broadcast() that we're all awake. It'll drop the
498 // internal mutex.
499 if (lastWaiter) {
500 // Atomically signal the "waitersDone" event and wait until we
501 // can acquire the internal mutex. We want to do this in one step
502 // because it ensures that everybody is in the mutex FIFO before
503 // any thread has a chance to run. Without it, another thread
504 // could wake up, do work, and hop back in ahead of us.
505 SignalObjectAndWait(condState->waitersDone, condState->internalMutex,
506 INFINITE, FALSE);
507 } else {
508 // Grab the internal mutex.
509 WaitForSingleObject(condState->internalMutex, INFINITE);
510 }
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800511
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800512 // Release the internal and grab the external.
513 ReleaseMutex(condState->internalMutex);
514 WaitForSingleObject(hMutex, INFINITE);
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800515
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800516 return res == WAIT_OBJECT_0 ? NO_ERROR : -1;
517 }
518} WinCondition;
519
520/*
521 * Constructor. Set up the WinCondition stuff.
522 */
523Condition::Condition()
524{
525 WinCondition* condState = new WinCondition;
526
527 condState->waitersCount = 0;
528 condState->wasBroadcast = false;
529 // semaphore: no security, initial value of 0
530 condState->sema = CreateSemaphore(NULL, 0, 0x7fffffff, NULL);
531 InitializeCriticalSection(&condState->waitersCountLock);
532 // auto-reset event, not signaled initially
533 condState->waitersDone = CreateEvent(NULL, FALSE, FALSE, NULL);
534 // used so we don't have to lock external mutex on signal/broadcast
535 condState->internalMutex = CreateMutex(NULL, FALSE, NULL);
536
537 mState = condState;
538}
539
540/*
541 * Destructor. Free Windows resources as well as our allocated storage.
542 */
543Condition::~Condition()
544{
545 WinCondition* condState = (WinCondition*) mState;
546 if (condState != NULL) {
547 CloseHandle(condState->sema);
548 CloseHandle(condState->waitersDone);
549 delete condState;
550 }
551}
552
553
554status_t Condition::wait(Mutex& mutex)
555{
556 WinCondition* condState = (WinCondition*) mState;
557 HANDLE hMutex = (HANDLE) mutex.mState;
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800558
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800559 return ((WinCondition*)mState)->wait(condState, hMutex, NULL);
560}
561
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800562status_t Condition::waitRelative(Mutex& mutex, nsecs_t reltime)
563{
David 'Digit' Turner9bafd122009-08-01 00:20:17 +0200564 WinCondition* condState = (WinCondition*) mState;
565 HANDLE hMutex = (HANDLE) mutex.mState;
566 nsecs_t absTime = systemTime()+reltime;
567
568 return ((WinCondition*)mState)->wait(condState, hMutex, &absTime);
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800569}
570
571/*
572 * Signal the condition variable, allowing one thread to continue.
573 */
574void Condition::signal()
575{
576 WinCondition* condState = (WinCondition*) mState;
577
578 // Lock the internal mutex. This ensures that we don't clash with
579 // broadcast().
580 WaitForSingleObject(condState->internalMutex, INFINITE);
581
582 EnterCriticalSection(&condState->waitersCountLock);
583 bool haveWaiters = (condState->waitersCount > 0);
584 LeaveCriticalSection(&condState->waitersCountLock);
585
586 // If no waiters, then this is a no-op. Otherwise, knock the semaphore
587 // down a notch.
588 if (haveWaiters)
589 ReleaseSemaphore(condState->sema, 1, 0);
590
591 // Release internal mutex.
592 ReleaseMutex(condState->internalMutex);
593}
594
595/*
596 * Signal the condition variable, allowing all threads to continue.
597 *
598 * First we have to wake up all threads waiting on the semaphore, then
599 * we wait until all of the threads have actually been woken before
600 * releasing the internal mutex. This ensures that all threads are woken.
601 */
602void Condition::broadcast()
603{
604 WinCondition* condState = (WinCondition*) mState;
605
606 // Lock the internal mutex. This keeps the guys we're waking up
607 // from getting too far.
608 WaitForSingleObject(condState->internalMutex, INFINITE);
609
610 EnterCriticalSection(&condState->waitersCountLock);
611 bool haveWaiters = false;
612
613 if (condState->waitersCount > 0) {
614 haveWaiters = true;
615 condState->wasBroadcast = true;
616 }
617
618 if (haveWaiters) {
619 // Wake up all the waiters.
620 ReleaseSemaphore(condState->sema, condState->waitersCount, 0);
621
622 LeaveCriticalSection(&condState->waitersCountLock);
623
624 // Wait for all awakened threads to acquire the counting semaphore.
625 // The last guy who was waiting sets this.
626 WaitForSingleObject(condState->waitersDone, INFINITE);
627
628 // Reset wasBroadcast. (No crit section needed because nobody
629 // else can wake up to poke at it.)
630 condState->wasBroadcast = 0;
631 } else {
632 // nothing to do
633 LeaveCriticalSection(&condState->waitersCountLock);
634 }
635
636 // Release internal mutex.
637 ReleaseMutex(condState->internalMutex);
638}
639
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800640#endif // !defined(_WIN32)
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800641
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800642// ----------------------------------------------------------------------------
643
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800644/*
645 * This is our thread object!
646 */
647
648Thread::Thread(bool canCallJava)
649 : mCanCallJava(canCallJava),
650 mThread(thread_id_t(-1)),
651 mLock("Thread::mLock"),
652 mStatus(NO_ERROR),
653 mExitPending(false), mRunning(false)
Elliott Hughes9b828ad2015-07-30 08:47:35 -0700654#if defined(__ANDROID__)
Glenn Kasten966a48f2011-02-01 11:32:29 -0800655 , mTid(-1)
656#endif
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800657{
658}
659
660Thread::~Thread()
661{
662}
663
664status_t Thread::readyToRun()
665{
666 return NO_ERROR;
667}
668
669status_t Thread::run(const char* name, int32_t priority, size_t stack)
670{
Brian Carlstrome71b9142016-03-12 16:08:12 -0800671 LOG_ALWAYS_FATAL_IF(name == nullptr, "thread name not provided to Thread::run");
672
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800673 Mutex::Autolock _l(mLock);
674
675 if (mRunning) {
676 // thread already started
677 return INVALID_OPERATION;
678 }
679
680 // reset status and exitPending to their default value, so we can
681 // try again after an error happened (either below, or in readyToRun())
682 mStatus = NO_ERROR;
683 mExitPending = false;
684 mThread = thread_id_t(-1);
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800685
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800686 // hold a strong reference on ourself
687 mHoldSelf = this;
688
The Android Open Source Project7a4c8392009-03-05 14:34:35 -0800689 mRunning = true;
690
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800691 bool res;
692 if (mCanCallJava) {
693 res = createThreadEtc(_threadLoop,
694 this, name, priority, stack, &mThread);
695 } else {
696 res = androidCreateRawThreadEtc(_threadLoop,
697 this, name, priority, stack, &mThread);
698 }
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800699
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800700 if (res == false) {
701 mStatus = UNKNOWN_ERROR; // something happened!
702 mRunning = false;
703 mThread = thread_id_t(-1);
The Android Open Source Project7a4c8392009-03-05 14:34:35 -0800704 mHoldSelf.clear(); // "this" may have gone away after this.
705
706 return UNKNOWN_ERROR;
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800707 }
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800708
The Android Open Source Project7a4c8392009-03-05 14:34:35 -0800709 // Do not refer to mStatus here: The thread is already running (may, in fact
710 // already have exited with a valid mStatus result). The NO_ERROR indication
711 // here merely indicates successfully starting the thread and does not
712 // imply successful termination/execution.
713 return NO_ERROR;
Glenn Kasten966a48f2011-02-01 11:32:29 -0800714
715 // Exiting scope of mLock is a memory barrier and allows new thread to run
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800716}
717
718int Thread::_threadLoop(void* user)
719{
720 Thread* const self = static_cast<Thread*>(user);
Glenn Kasten966a48f2011-02-01 11:32:29 -0800721
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800722 sp<Thread> strong(self->mHoldSelf);
723 wp<Thread> weak(strong);
724 self->mHoldSelf.clear();
725
Elliott Hughes9b828ad2015-07-30 08:47:35 -0700726#if defined(__ANDROID__)
Mathias Agopian51ce3ad2009-09-09 02:38:13 -0700727 // this is very useful for debugging with gdb
728 self->mTid = gettid();
729#endif
730
The Android Open Source Project7a4c8392009-03-05 14:34:35 -0800731 bool first = true;
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800732
733 do {
The Android Open Source Project7a4c8392009-03-05 14:34:35 -0800734 bool result;
735 if (first) {
736 first = false;
737 self->mStatus = self->readyToRun();
738 result = (self->mStatus == NO_ERROR);
739
Glenn Kasten966a48f2011-02-01 11:32:29 -0800740 if (result && !self->exitPending()) {
The Android Open Source Project7a4c8392009-03-05 14:34:35 -0800741 // Binder threads (and maybe others) rely on threadLoop
742 // running at least once after a successful ::readyToRun()
743 // (unless, of course, the thread has already been asked to exit
744 // at that point).
745 // This is because threads are essentially used like this:
746 // (new ThreadSubclass())->run();
747 // The caller therefore does not retain a strong reference to
748 // the thread and the thread would simply disappear after the
749 // successful ::readyToRun() call instead of entering the
750 // threadLoop at least once.
751 result = self->threadLoop();
752 }
753 } else {
754 result = self->threadLoop();
755 }
756
Glenn Kasten966a48f2011-02-01 11:32:29 -0800757 // establish a scope for mLock
758 {
759 Mutex::Autolock _l(self->mLock);
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800760 if (result == false || self->mExitPending) {
761 self->mExitPending = true;
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800762 self->mRunning = false;
Eric Laurentfe2c4632011-01-04 11:58:04 -0800763 // clear thread ID so that requestExitAndWait() does not exit if
764 // called by a new thread using the same thread ID as this one.
765 self->mThread = thread_id_t(-1);
Glenn Kasten966a48f2011-02-01 11:32:29 -0800766 // note that interested observers blocked in requestExitAndWait are
767 // awoken by broadcast, but blocked on mLock until break exits scope
Mathias Agopian51ce3ad2009-09-09 02:38:13 -0700768 self->mThreadExitedCondition.broadcast();
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800769 break;
770 }
Glenn Kasten966a48f2011-02-01 11:32:29 -0800771 }
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800772
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800773 // Release our strong reference, to let a chance to the thread
774 // to die a peaceful death.
775 strong.clear();
Mathias Agopian51ce3ad2009-09-09 02:38:13 -0700776 // And immediately, re-acquire a strong reference for the next loop
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800777 strong = weak.promote();
778 } while(strong != 0);
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800779
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800780 return 0;
781}
782
783void Thread::requestExit()
784{
Glenn Kasten966a48f2011-02-01 11:32:29 -0800785 Mutex::Autolock _l(mLock);
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800786 mExitPending = true;
787}
788
789status_t Thread::requestExitAndWait()
790{
Glenn Kastena538e262011-06-02 08:59:28 -0700791 Mutex::Autolock _l(mLock);
The Android Open Source Project7a4c8392009-03-05 14:34:35 -0800792 if (mThread == getThreadId()) {
Steve Block61d341b2012-01-05 23:22:43 +0000793 ALOGW(
The Android Open Source Project7a4c8392009-03-05 14:34:35 -0800794 "Thread (this=%p): don't call waitForExit() from this "
795 "Thread object's thread. It's a guaranteed deadlock!",
796 this);
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800797
The Android Open Source Project7a4c8392009-03-05 14:34:35 -0800798 return WOULD_BLOCK;
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800799 }
Yabin Cui4a6e5a32015-01-26 19:48:54 -0800800
Glenn Kastena538e262011-06-02 08:59:28 -0700801 mExitPending = true;
The Android Open Source Project7a4c8392009-03-05 14:34:35 -0800802
The Android Open Source Project7a4c8392009-03-05 14:34:35 -0800803 while (mRunning == true) {
804 mThreadExitedCondition.wait(mLock);
805 }
Glenn Kasten966a48f2011-02-01 11:32:29 -0800806 // This next line is probably not needed any more, but is being left for
807 // historical reference. Note that each interested party will clear flag.
The Android Open Source Project7a4c8392009-03-05 14:34:35 -0800808 mExitPending = false;
809
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800810 return mStatus;
811}
812
Glenn Kasten6839e8e2011-06-23 12:55:29 -0700813status_t Thread::join()
814{
815 Mutex::Autolock _l(mLock);
816 if (mThread == getThreadId()) {
Steve Block61d341b2012-01-05 23:22:43 +0000817 ALOGW(
Glenn Kasten6839e8e2011-06-23 12:55:29 -0700818 "Thread (this=%p): don't call join() from this "
819 "Thread object's thread. It's a guaranteed deadlock!",
820 this);
821
822 return WOULD_BLOCK;
823 }
824
825 while (mRunning == true) {
826 mThreadExitedCondition.wait(mLock);
827 }
828
829 return mStatus;
830}
831
Romain Guy31ba37f2013-03-11 14:34:56 -0700832bool Thread::isRunning() const {
833 Mutex::Autolock _l(mLock);
834 return mRunning;
835}
836
Elliott Hughes9b828ad2015-07-30 08:47:35 -0700837#if defined(__ANDROID__)
Glenn Kastend731f072011-07-11 15:59:22 -0700838pid_t Thread::getTid() const
839{
840 // mTid is not defined until the child initializes it, and the caller may need it earlier
841 Mutex::Autolock _l(mLock);
842 pid_t tid;
843 if (mRunning) {
844 pthread_t pthread = android_thread_id_t_to_pthread(mThread);
Elliott Hughes7bf5f202014-09-12 10:19:08 -0700845 tid = pthread_gettid_np(pthread);
Glenn Kastend731f072011-07-11 15:59:22 -0700846 } else {
847 ALOGW("Thread (this=%p): getTid() is undefined before run()", this);
848 tid = -1;
849 }
850 return tid;
851}
852#endif
853
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800854bool Thread::exitPending() const
855{
Glenn Kasten966a48f2011-02-01 11:32:29 -0800856 Mutex::Autolock _l(mLock);
The Android Open Source Projectcbb10112009-03-03 19:31:44 -0800857 return mExitPending;
858}
859
860
861
862}; // namespace android