summaryrefslogtreecommitdiff
path: root/indra/llcommon/llthread.cpp
blob: a4171729dbb8db1805e80ca1dc198b182c58f243 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
/** 
 * @file llthread.cpp
 *
 * $LicenseInfo:firstyear=2004&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010-2013, Linden Research, Inc.
 * 
 * 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;
 * version 2.1 of the License only.
 * 
 * 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
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#include "linden_common.h"
#include "llapr.h"

#include "apr_portable.h"

#include "llthread.h"
#include "llmutex.h"

#include "lltimer.h"
#include "lltrace.h"
#include "lltracethreadrecorder.h"
#include "llexception.h"

#if LL_LINUX || LL_SOLARIS
#include <sched.h>
#endif


#ifdef LL_WINDOWS
const DWORD MS_VC_EXCEPTION=0x406D1388;

#pragma pack(push,8)
typedef struct tagTHREADNAME_INFO
{
    DWORD dwType; // Must be 0x1000.
    LPCSTR szName; // Pointer to name (in user addr space).
    DWORD dwThreadID; // Thread ID (-1=caller thread).
    DWORD dwFlags; // Reserved for future use, must be zero.
} THREADNAME_INFO;
#pragma pack(pop)

void set_thread_name( DWORD dwThreadID, const char* threadName)
{
    THREADNAME_INFO info;
    info.dwType = 0x1000;
    info.szName = threadName;
    info.dwThreadID = dwThreadID;
    info.dwFlags = 0;

    __try
    {
        ::RaiseException( MS_VC_EXCEPTION, 0, sizeof(info)/sizeof(DWORD), (ULONG_PTR*)&info );
    }
    __except(EXCEPTION_CONTINUE_EXECUTION)
    {
    }
}
#endif


//----------------------------------------------------------------------------
// Usage:
// void run_func(LLThread* thread)
// {
// }
// LLThread* thread = new LLThread();
// thread->run(run_func);
// ...
// thread->setQuitting();
// while(!timeout)
// {
//   if (thread->isStopped())
//   {
//     delete thread;
//     break;
//   }
// }
// 
//----------------------------------------------------------------------------

U32 LL_THREAD_LOCAL sThreadID = 0;

U32 LLThread::sIDIter = 0;


LL_COMMON_API void assert_main_thread()
{
    static U32 s_thread_id = LLThread::currentID();
    if (LLThread::currentID() != s_thread_id)
    {
        LL_WARNS() << "Illegal execution from thread id " << (S32) LLThread::currentID()
            << " outside main thread " << (S32) s_thread_id << LL_ENDL;
    }
}

void LLThread::registerThreadID()
{
    sThreadID = ++sIDIter;
}

//
// Handed to the APR thread creation function
//
void LLThread::threadRun()
{
#ifdef LL_WINDOWS
    set_thread_name(-1, mName.c_str());
#endif

    // for now, hard code all LLThreads to report to single master thread recorder, which is known to be running on main thread
    mRecorder = new LLTrace::ThreadRecorder(*LLTrace::get_master_thread_recorder());

    sThreadID = mID;

    // Run the user supplied function
    do 
    {
        try
        {
            run();
        }
        catch (const LLContinueError &e)
        {
            LL_WARNS("THREAD") << "ContinueException on thread '" << mName <<
                "' reentering run(). Error what is: '" << e.what() << "'" << LL_ENDL;
            //output possible call stacks to log file.
            LLError::LLCallStacks::print();

            LOG_UNHANDLED_EXCEPTION("LLThread");
            continue;
        }
        break;

    } while (true);

    //LL_INFOS() << "LLThread::staticRun() Exiting: " << threadp->mName << LL_ENDL;


    delete mRecorder;
    mRecorder = NULL;

    // We're done with the run function, this thread is done executing now.
    //NB: we are using this flag to sync across threads...we really need memory barriers here
    // Todo: add LLMutex per thread instead of flag?
    // We are using "while (mStatus != STOPPED) {ms_sleep();}" everywhere.
    mStatus = STOPPED;
}

LLThread::LLThread(const std::string& name, apr_pool_t *poolp) :
    mPaused(FALSE),
    mName(name),
    mThreadp(NULL),
    mStatus(STOPPED),
    mRecorder(NULL)
{

    mID = ++sIDIter;
    mRunCondition = new LLCondition();
    mDataLock = new LLMutex();
    mLocalAPRFilePoolp = NULL ;
}


LLThread::~LLThread()
{
    shutdown();

    if (isCrashed())
    {
        LL_WARNS("THREAD") << "Destroying crashed thread named '" << mName << "'" << LL_ENDL;
    }

    if(mLocalAPRFilePoolp)
    {
        delete mLocalAPRFilePoolp ;
        mLocalAPRFilePoolp = NULL ;
    }
}

void LLThread::shutdown()
{
    if (isCrashed())
    {
        LL_WARNS("THREAD") << "Shutting down crashed thread named '" << mName << "'" << LL_ENDL;
    }

    // Warning!  If you somehow call the thread destructor from itself,
    // the thread will die in an unclean fashion!
    if (mThreadp)
    {
        if (!isStopped())
        {
            // The thread isn't already stopped
            // First, set the flag that indicates that we're ready to die
            setQuitting();

            //LL_INFOS() << "LLThread::~LLThread() Killing thread " << mName << " Status: " << mStatus << LL_ENDL;
            // Now wait a bit for the thread to exit
            // It's unclear whether I should even bother doing this - this destructor
            // should never get called unless we're already stopped, really...
            S32 counter = 0;
            const S32 MAX_WAIT = 600;
            while (counter < MAX_WAIT)
            {
                if (isStopped())
                {
                    break;
                }
                // Sleep for a tenth of a second
                ms_sleep(100);
                yield();
                counter++;
            }
        }

        if (!isStopped())
        {
            // This thread just wouldn't stop, even though we gave it time
            //LL_WARNS() << "LLThread::~LLThread() exiting thread before clean exit!" << LL_ENDL;
            // Put a stake in its heart. (A very hostile method to force a thread to quit)
#if		LL_WINDOWS
            TerminateThread(mNativeHandle, 0);
#else
            pthread_cancel(mNativeHandle);
#endif

            delete mRecorder;
            mRecorder = NULL;
            mStatus = STOPPED;
            return;
        }
        mThreadp = NULL;
    }

    delete mRunCondition;
    mRunCondition = NULL;

    delete mDataLock;
    mDataLock = NULL;

    if (mRecorder)
    {
        // missed chance to properly shut down recorder (needs to be done in thread context)
        // probably due to abnormal thread termination
        // so just leak it and remove it from parent
        LLTrace::get_master_thread_recorder()->removeChildRecorder(mRecorder);
    }
}


void LLThread::start()
{
    llassert(isStopped());
    
    // Set thread state to running
    mStatus = RUNNING;

    try
    {
        mThreadp = new std::thread(std::bind(&LLThread::threadRun, this));
        mNativeHandle = mThreadp->native_handle();
    }
    catch (std::system_error& ex)
    {
        mStatus = STOPPED;
        LL_WARNS() << "failed to start thread " << mName << " " << ex.what() << LL_ENDL;
    }

}

//============================================================================
// Called from MAIN THREAD.

// Request that the thread pause/resume.
// The thread will pause when (and if) it calls checkPause()
void LLThread::pause()
{
    if (!mPaused)
    {
        // this will cause the thread to stop execution as soon as checkPause() is called
        mPaused = 1;        // Does not need to be atomic since this is only set/unset from the main thread
    }   
}

void LLThread::unpause()
{
    if (mPaused)
    {
        mPaused = 0;
    }

    wake(); // wake up the thread if necessary
}

// virtual predicate function -- returns true if the thread should wake up, false if it should sleep.
bool LLThread::runCondition(void)
{
    // by default, always run.  Handling of pause/unpause is done regardless of this function's result.
    return true;
}

//============================================================================
// Called from run() (CHILD THREAD).
// Stop thread execution if requested until unpaused.
void LLThread::checkPause()
{
    mDataLock->lock();

    // This is in a while loop because the pthread API allows for spurious wakeups.
    while(shouldSleep())
    {
        mDataLock->unlock();
        mRunCondition->wait(); // unlocks mRunCondition
        mDataLock->lock();
        // mRunCondition is locked when the thread wakes up
    }
    
    mDataLock->unlock();
}

//============================================================================

void LLThread::setQuitting()
{
    mDataLock->lock();
    if (mStatus == RUNNING)
    {
        mStatus = QUITTING;
    }
    mDataLock->unlock();
    wake();
}

// static
U32 LLThread::currentID()
{
    return sThreadID;
}

// static
void LLThread::yield()
{
    std::this_thread::yield();
}

void LLThread::wake()
{
    mDataLock->lock();
    if(!shouldSleep())
    {
        mRunCondition->signal();
    }
    mDataLock->unlock();
}

void LLThread::wakeLocked()
{
    if(!shouldSleep())
    {
        mRunCondition->signal();
    }
}

//============================================================================

//----------------------------------------------------------------------------

//static
LLMutex* LLThreadSafeRefCount::sMutex = 0;

//static
void LLThreadSafeRefCount::initThreadSafeRefCount()
{
    if (!sMutex)
    {
        sMutex = new LLMutex();
    }
}

//static
void LLThreadSafeRefCount::cleanupThreadSafeRefCount()
{
    delete sMutex;
    sMutex = NULL;
}
    

//----------------------------------------------------------------------------

LLThreadSafeRefCount::LLThreadSafeRefCount() :
    mRef(0)
{
}

LLThreadSafeRefCount::LLThreadSafeRefCount(const LLThreadSafeRefCount& src)
{
    mRef = 0;
}

LLThreadSafeRefCount::~LLThreadSafeRefCount()
{ 
    if (mRef != 0)
    {
		LL_ERRS() << "deleting referenced object mRef = " << mRef << LL_ENDL;
    }
}

//============================================================================

LLResponder::~LLResponder()
{
}

//============================================================================