source: source/ariba/communication/modules/transport/protlib/threads.h@ 4721

Last change on this file since 4721 was 4721, checked in by Christoph Mayer, 15 years ago

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1/// ----------------------------------------*- mode: C++; -*--
2/// @file threads.h
3/// Thread support functions (classes thread and threadstarter) based on POSIX threads
4/// ----------------------------------------------------------
5/// $Id: threads.h 2549 2007-04-02 22:17:37Z bless $
6/// $HeadURL: https://svn.ipv6.tm.uka.de/nsis/protlib/trunk/include/threads.h $
7// ===========================================================
8//
9// Copyright (C) 2005-2007, all rights reserved by
10// - Institute of Telematics, Universitaet Karlsruhe (TH)
11//
12// More information and contact:
13// https://projekte.tm.uka.de/trac/NSIS
14//
15// This program is free software; you can redistribute it and/or modify
16// it under the terms of the GNU General Public License as published by
17// the Free Software Foundation; version 2 of the License
18//
19// This program is distributed in the hope that it will be useful,
20// but WITHOUT ANY WARRANTY; without even the implied warranty of
21// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22// GNU General Public License for more details.
23//
24// You should have received a copy of the GNU General Public License along
25// with this program; if not, write to the Free Software Foundation, Inc.,
26// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
27//
28// ===========================================================
29
30/**
31 * Classes to support multi-threaded programming.
32 *
33 * @ingroup thread
34 *
35 * A Thread module class must inherit from Thread. Several instances may run
36 * simultaneously but they share exactly one module object. So you must take
37 * care of this fact when writing the module code and use locks accordingly.
38 *
39 * Use lock(), unlock(), wait_cond() and signal_cond() the way you would use
40 * the corresponding POSIX thread functions.
41 *
42 * Use the ThreadStarter template class to create threads.
43 */
44
45#ifndef PROTLIB__THREADS_H
46#define PROTLIB__THREADS_H
47
48#include <pthread.h>
49#include <signal.h>
50#include <sys/times.h>
51#include <string>
52
53#include "protlib_types.h"
54#include "logfile.h"
55#include "fqueue.h"
56
57namespace protlib {
58 using namespace log;
59
60/** @addtogroup thread Threads
61 * @{
62 */
63
64
65/**
66 * Call the method start_processing of a Thread instance.
67 *
68 * @param thread_object a Thread instance
69 */
70template <class T> void *thread_starter(void *thread_object) {
71
72 pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
73 pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL);
74
75 (static_cast<T*>(thread_object))->start_processing();
76 return NULL;
77}
78
79
80/**
81 * Base class for thread object parameters.
82 *
83 * This is used by ThreadStarter to extract and store overall data like the
84 * sleep time and is also accessible to the thread object.
85 */
86class ThreadParam {
87 public:
88 ThreadParam();
89 ThreadParam(uint32 wait, const char* name,
90 uint32 minc=1, uint32 maxc=(uint32)-1);
91
92 static uint32 default_sleep_time;
93 /// sleep time
94 const uint32 sleep_time;
95 const std::string name;
96 /// minimum thread count
97 const uint32 min_count;
98 /// maximum thread count
99 const uint32 max_count;
100};
101
102
103/**
104 * This exception will be thrown if there is some trouble with threading.
105 */
106class ThreadError : public ProtLibException {
107 public:
108 enum error_t {
109 ERROR_THREAD_CREATION, ERROR_RUNNING, ERROR_STOPPING,
110 ERROR_ABORTING, ERROR_STILL_RUNNING, ERROR_UNINITIALIZED,
111 ERROR_INTERNAL, ERROR_NOT_STARTED
112 };
113
114 ThreadError(error_t e) : err(e) { }
115 virtual ~ThreadError() throw () { }
116
117 virtual const char* getstr() const;
118 virtual const char *what() const throw() { return getstr(); }
119 const error_t err;
120
121 protected:
122 static const char* const errstr[];
123};
124
125
126/**
127 * Abstract interface for thread modules.
128 *
129 * Don't confuse this Thread class with POSIX threads. A Thread class only
130 * provides a main_loop method which will be executed by one or more POSIX
131 * threads simultaneously. The Thread instance provides a central point for
132 * all those POSIX threads to store data. Don't forget to lock() the Thread
133 * instance to avoid race conditions if you want to access and/or modify
134 * the data.
135 */
136class Thread {
137 public:
138 Thread(const ThreadParam& p,
139 bool create_queue=true, bool exp_allow=true);
140 virtual ~Thread();
141
142 void *start_processing();
143 void stop_processing(bool do_lock=true);
144 void abort_processing(bool do_lock=true);
145
146 bool is_running(bool do_lock=true);
147
148 virtual void main_loop(uint32 thread_num) = 0;
149
150 void lock();
151 void unlock();
152
153 void signal_cond();
154 void broadcast_cond();
155 void wait_cond();
156 int wait_cond(const struct timespec& ts);
157 int wait_cond(int32 sec, int32 nsec=0);
158
159 /**
160 * State of a thread.
161 *
162 * The state of a thread does not really tell whether there are threads
163 * active or not. It only represents a state in the life cycle of a
164 * thread object.
165 */
166 enum state_t {
167 STATE_INIT, STATE_RUN, STATE_STOP, STATE_ABORT
168 };
169
170 state_t get_state(bool do_lock=true);
171 FastQueue* get_fqueue() { return fq; }
172
173 static void get_time_of_day(struct timespec& ts);
174
175 private:
176 /// This counter records the number of threads running on this object.
177 uint32 running_threads;
178
179 /// This counter records the number of started threads.
180 uint32 started_threads;
181
182 /**
183 * Thread-global mutex.
184 *
185 * This mutex is used to lock the thread object when data common to all
186 * threads on this object is modified.
187 */
188 pthread_mutex_t mutex;
189
190 /// thread object condition
191 pthread_cond_t cond;
192
193 /// thread state
194 state_t state;
195
196 /// Thread parameters.
197 const ThreadParam tparam;
198
199 /// The input queue where threads can get messages from.
200 FastQueue* fq;
201
202 void inc_running_threads();
203 void dec_running_threads();
204 uint32 get_running_threads() const;
205 void inc_started_threads();
206 uint32 get_started_threads() const;
207};
208
209
210inline void Thread::lock() {
211 if ( pthread_mutex_lock(&mutex) != 0 ) {
212 ERRLog(tparam.name, "Error while locking mutex");
213 }
214}
215
216inline void Thread::unlock() {
217 int ret = pthread_mutex_unlock(&mutex);
218 assert( ret == 0 );
219}
220
221inline void Thread::signal_cond() {
222 pthread_cond_signal(&cond);
223}
224
225inline void Thread::broadcast_cond() {
226 pthread_cond_broadcast(&cond);
227}
228
229inline void Thread::wait_cond() {
230 pthread_cond_wait(&cond,&mutex);
231}
232
233
234/**
235 * @param ts absolute time
236 * @return 0, ETIMEDOUT or EINTR.
237 */
238inline int Thread::wait_cond(const struct timespec& ts) {
239 return pthread_cond_timedwait(&cond, &mutex, &ts);
240}
241
242
243inline void Thread::inc_running_threads() {
244 running_threads++;
245}
246
247inline void Thread::dec_running_threads() {
248 assert( running_threads > 0 );
249 running_threads--;
250}
251
252inline uint32 Thread::get_running_threads() const {
253 return running_threads;
254}
255
256inline void Thread::inc_started_threads() {
257 started_threads++;
258}
259
260inline uint32 Thread::get_started_threads() const {
261 return started_threads;
262}
263
264
265/**
266 * A template class used to start threads.
267 *
268 * Note that the ThreadStarter template class is not thread-safe yet, so it
269 * may only be accessed by one thread at a time.
270 */
271template <class T, class TParam> class ThreadStarter {
272 public:
273 ThreadStarter(uint32 count, const TParam& param);
274 ~ThreadStarter();
275
276 void start_processing();
277 void stop_processing();
278 bool sleepuntilstop(); // deprecated!
279 void wait_until_stopped();
280 void abort_processing(bool kill=false);
281
282 /// get a pointer to the thread object
283 inline T *get_thread_object() { return &thread_object; }
284
285 /// Are all threads finished: TODO
286 inline bool is_running() const { return thread_object.is_running(); }
287
288 private:
289 /// The Thread object on which the threads run.
290 T thread_object;
291
292 /// For debugging, the name of the thread as given by TParam.
293 const TParam thread_param;
294
295 /// Contains the handles of all pthreads that we created.
296 std::vector<pthread_t> pthreads;
297};
298
299
300/**
301 * Constructor.
302 *
303 * @param count the number of threads to start
304 * @param param thread parameters
305 */
306template <class T, class TParam>
307ThreadStarter<T, TParam>::ThreadStarter(uint32 count, const TParam& param)
308 : thread_object(param), thread_param(param), pthreads(count) {
309
310 // TODO: fix all Thread subclasses that use an invalid count!
311 if ( count < param.min_count )
312 count = param.min_count;
313 else if ( count > param.max_count )
314 count = param.max_count;
315
316 assert( count >= param.min_count && count <= param.max_count );
317
318 pthreads.resize(count); // TODO: remove
319}
320
321
322/**
323 * Destructor.
324 *
325 * This cancels all running threads if there are still some.
326 */
327template <class T, class TParam> ThreadStarter<T, TParam>::~ThreadStarter() {
328
329 if ( thread_object.is_running() ) {
330 catch_all(stop_processing());
331 sleepuntilstop();
332 catch_all(abort_processing(true));
333 }
334}
335
336
337/**
338 * Start the threads.
339 */
340template <class T, class TParam>
341void ThreadStarter<T, TParam>::start_processing() {
342
343 thread_object.lock();
344
345 /*
346 * Check if this is a fresh Thread. If it is or was already running,
347 * we have detected a programming error.
348 */
349 if ( thread_object.is_running(false) ) {
350 thread_object.unlock();
351
352 ERRLog("Threads", "start_processing(): " << thread_param.name
353 << " is already running");
354
355 throw ThreadError(ThreadError::ERROR_INTERNAL);
356 }
357
358
359 /*
360 * Create the requested number of threads.
361 */
362 int res;
363 pthread_attr_t attr;
364 pthread_attr_init(&attr);
365 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
366
367 for (unsigned i = 0; i < pthreads.size(); i++) {
368 // Create a posix thread. It will start running immediately.
369 res = pthread_create(&pthreads[i], &attr,
370 &thread_starter<T>, &thread_object);
371
372 if ( res != 0 ) {
373 thread_object.unlock();
374 ERRLog("Threads", "pthread_create() failed starting a "
375 << "thread for " << thread_param.name);
376
377 throw ThreadError(ThreadError::ERROR_THREAD_CREATION);
378 }
379 }
380
381 ILog("Threads", pthreads.size() << " " << thread_param.name
382 << " thread(s) sucessfully created");
383
384 pthread_attr_destroy(&attr); // has no effect on the created threads
385
386 thread_object.unlock();
387}
388
389
390/**
391 * Ask all threads to stop (politely).
392 */
393template <class T, class TParam>
394void ThreadStarter<T, TParam>::stop_processing() {
395
396 thread_object.lock();
397
398 typename T::state_t state = thread_object.get_state(false);
399
400 switch (state) {
401
402 case T::STATE_INIT:
403 thread_object.unlock();
404 DLog("Threads", "Thread " << thread_param.name
405 << " has not been started yet.");
406 throw ThreadError(ThreadError::ERROR_NOT_STARTED);
407 break;
408
409 case T::STATE_RUN:
410 thread_object.stop_processing(false);
411 thread_object.unlock();
412
413 ILog("Threads", "Thread(s) "
414 << thread_param.name << " asked to stop");
415 break;
416
417 case T::STATE_STOP:
418 thread_object.unlock();
419 DLog("Threads", "Thread(s) "
420 << thread_param.name << " is already in state stop.");
421 throw ThreadError(ThreadError::ERROR_STOPPING);
422 break;
423
424 case T::STATE_ABORT:
425 //thread_object.unlock();
426 DLog("Threads", "Thread "
427 << thread_param.name << " is in state abort.");
428 //throw ThreadError(ThreadError::ERROR_ABORTING);
429 break;
430
431 default:
432 assert( false ); // unknown state
433
434 }
435}
436
437
438/**
439 * Wait for the thread to stop running (DEPRECATED).
440 *
441 * Sleeps until all threads have stopped running but not longer than
442 * sleep_time seconds.
443 *
444 * This method is deprecated because it suffers from a race condition:
445 * If none of the pthreads created in start_processing() has been run yet,
446 * then this method returns immediately. Use wait_until_stopped() instead.
447 *
448 * @return true if the threads have stopped
449 *
450 * @see ThreadParam
451 */
452template <class T, class TParam>
453bool ThreadStarter<T, TParam>::sleepuntilstop() {
454
455 for (uint32 i = 0; thread_object.is_running()
456 && i < thread_param.sleep_time; i++)
457 sleep(1);
458
459 return ( thread_object.is_running() ? false : true );
460}
461
462
463/**
464 * Wait until all threads have stopped running.
465 *
466 * Threads that haven't been running yet (state IDLE) are not considered
467 * as stopped!
468 */
469template <class T, class TParam>
470void ThreadStarter<T, TParam>::wait_until_stopped() {
471
472 DLog("Threads",
473 "Waiting for Thread " << thread_param.name << " to stop");
474
475 Thread::state_t state = thread_object.get_state(false);
476
477 while ( state == Thread::STATE_INIT || thread_object.is_running() ) {
478 sleep(1);
479 state = thread_object.get_state(false);
480 }
481
482 DLog("Threads", "Thread " << thread_param.name << " has stopped");
483}
484
485
486/**
487 * Stop and kill the threads.
488 *
489 * @param kill kill the threads if they do not stop.
490 */
491template <class T, class TParam>
492void ThreadStarter<T, TParam>::abort_processing(bool kill) {
493
494 thread_object.lock();
495
496 switch ( thread_object.get_state(false) ) {
497
498 case T::STATE_INIT:
499 thread_object.unlock();
500 DLog("Threads", "Thread "
501 << thread_param.name << " has not been started yet.");
502 throw ThreadError(ThreadError::ERROR_NOT_STARTED);
503 break;
504
505 case T::STATE_ABORT:
506 if ( ! kill ) {
507 //thread_object.unlock();
508 DLog("Threads", "Thread " << thread_param.name
509 << " is already in state abort.");
510
511 //throw ThreadError(ThreadError::ERROR_ABORTING);
512 }
513 break;
514
515 default:
516 break;
517 }
518
519 if ( thread_object.is_running(false) ) {
520 thread_object.stop_processing(false);
521 // unlock and sleep so the threads have a chance to stop.
522 thread_object.unlock();
523 sleepuntilstop();
524 thread_object.lock();
525 }
526
527 thread_object.abort_processing(false);
528
529 // unlock and let the thread abort
530 thread_object.unlock();
531 sleepuntilstop();
532 thread_object.lock();
533
534 if ( thread_object.is_running(false) ) {
535 // unlock and maybe kill
536 thread_object.unlock();
537 if (kill) {
538 for (unsigned i = 0; i < pthreads.size(); i++)
539 pthread_cancel( pthreads[i] );
540
541 sleepuntilstop();
542
543 for (unsigned i = 0; i < pthreads.size(); i++)
544 pthread_kill(pthreads[i], 9);
545
546 ILog("Threads", pthreads.size() << " thread(s) "
547 << thread_param.name << " killed");
548 } else {
549 ILog("Threads", pthreads.size() << " thread(s) "
550 << thread_param.name << " refused to abort");
551
552 throw ThreadError(ThreadError::ERROR_STILL_RUNNING);
553 }
554
555 } else {
556 thread_object.unlock();
557 ILog("Threads", pthreads.size() << " thread(s) "
558 << thread_param.name << " have terminated");
559 }
560}
561
562
563//@}
564
565} // namespace protlib
566
567#endif // PROTLIB__THREADS_H
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