summaryrefslogtreecommitdiff
path: root/runtime/wti.c
blob: 3e0554a8ad3ad89ec6e1139f02d6f124fd88f2ce (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
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
/* wti.c
 *
 * This file implements the worker thread instance (wti) class.
 * 
 * File begun on 2008-01-20 by RGerhards based on functions from the 
 * previous queue object class (the wti functions have been extracted)
 *
 * There is some in-depth documentation available in doc/dev_queue.html
 * (and in the web doc set on http://www.rsyslog.com/doc). Be sure to read it
 * if you are getting aquainted to the object.
 *
 * Copyright 2008-2012 Adiscon GmbH.
 *
 * This file is part of the rsyslog runtime library.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *       http://www.apache.org/licenses/LICENSE-2.0
 *       -or-
 *       see COPYING.ASL20 in the source distribution
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <signal.h>
#include <pthread.h>
#include <errno.h>

#include "rsyslog.h"
#include "stringbuf.h"
#include "srUtils.h"
#include "wtp.h"
#include "wti.h"
#include "obj.h"
#include "glbl.h"
#include "action.h"
#include "atomic.h"

/* static data */
DEFobjStaticHelpers
DEFobjCurrIf(glbl)

pthread_key_t thrd_wti_key;

/* forward-definitions */

/* methods */

/* get the header for debug messages
 * The caller must NOT free or otherwise modify the returned string!
 */
static inline uchar *
wtiGetDbgHdr(wti_t *pThis)
{
	ISOBJ_TYPE_assert(pThis, wti);

	if(pThis->pszDbgHdr == NULL)
		return (uchar*) "wti"; /* should not normally happen */
	else
		return pThis->pszDbgHdr;
}


/* return the current worker processing state. For the sake of
 * simplicity, we do not use the iRet interface. -- rgerhards, 2009-07-17
 */
sbool
wtiGetState(wti_t *pThis)
{
	return ATOMIC_FETCH_32BIT(&pThis->bIsRunning, &pThis->mutIsRunning);
}


/* Set this thread to "always running" state (can not be unset)
 * rgerhards, 2009-07-20
 */
rsRetVal
wtiSetAlwaysRunning(wti_t *pThis)
{
	ISOBJ_TYPE_assert(pThis, wti);
	pThis->bAlwaysRunning = RSTRUE;
	return RS_RET_OK;
}

/* Set status (thread is running or not), actually an property of
 * use for wtp, but we need to have it per thread instance (thus it
 * is inside wti). -- rgerhards, 2009-07-17
 */
rsRetVal
wtiSetState(wti_t *pThis, sbool bNewVal)
{
	ISOBJ_TYPE_assert(pThis, wti);
	if(bNewVal) {
		ATOMIC_STORE_1_TO_INT(&pThis->bIsRunning, &pThis->mutIsRunning);
	} else {
		ATOMIC_STORE_0_TO_INT(&pThis->bIsRunning, &pThis->mutIsRunning);
	}
	return RS_RET_OK;
}


/* advise all workers to start by interrupting them. That should unblock all srSleep()
 * calls.
 */
rsRetVal
wtiWakeupThrd(wti_t *pThis)
{
	DEFiRet;

	ISOBJ_TYPE_assert(pThis, wti);


	if(wtiGetState(pThis)) {
		/* we first try the cooperative "cancel" interface */
		pthread_kill(pThis->thrdID, SIGTTIN);
		DBGPRINTF("sent SIGTTIN to worker thread 0x%x\n", (unsigned) pThis->thrdID);
	}

	RETiRet;
}


/* Cancel the thread. If the thread is not running. But it is save and legal to
 * call wtiCancelThrd() in such situations. This function only returns when the
 * thread has terminated. Else we may get race conditions all over the code...
 * Note that when waiting for the thread to terminate, we do a busy wait, checking
 * progress every 10ms. It is very unlikely that we will ever cancel a thread
 * and, if so, it will only happen at the end of the rsyslog run. So doing this
 * kind of non-optimal wait is considered preferable over using condition variables.
 * rgerhards, 2008-02-26
 */
rsRetVal
wtiCancelThrd(wti_t *pThis)
{
	DEFiRet;

	ISOBJ_TYPE_assert(pThis, wti);


	if(wtiGetState(pThis)) {
		/* we first try the cooperative "cancel" interface */
		pthread_kill(pThis->thrdID, SIGTTIN);
		DBGPRINTF("sent SIGTTIN to worker thread 0x%x, giving it a chance to terminate\n", (unsigned) pThis->thrdID);
		srSleep(0, 10000);
	}

	if(wtiGetState(pThis)) {
		DBGPRINTF("cooperative worker termination failed, using cancellation...\n");
		DBGOPRINT((obj_t*) pThis, "canceling worker thread\n");
		pthread_cancel(pThis->thrdID);
		/* now wait until the thread terminates... */
		while(wtiGetState(pThis)) {
			srSleep(0, 10000);
		}
	}

	RETiRet;
}


/* Destructor */
BEGINobjDestruct(wti) /* be sure to specify the object type also in END and CODESTART macros! */
CODESTARTobjDestruct(wti)
	/* actual destruction */
	batchFree(&pThis->batch);
	free(pThis->actWrkrInfo);
	pthread_cond_destroy(&pThis->pcondBusy);
	DESTROY_ATOMIC_HELPER_MUT(pThis->mutIsRunning);
	free(pThis->pszDbgHdr);
ENDobjDestruct(wti)


/* Standard-Constructor for the wti object
 */
BEGINobjConstruct(wti) /* be sure to specify the object type also in END macro! */
	INIT_ATOMIC_HELPER_MUT(pThis->mutIsRunning);
	pthread_cond_init(&pThis->pcondBusy, NULL);
ENDobjConstruct(wti)


/* Construction finalizer
 * rgerhards, 2008-01-17
 */
rsRetVal
wtiConstructFinalize(wti_t *pThis)
{
	DEFiRet;
	int iDeqBatchSize;

	ISOBJ_TYPE_assert(pThis, wti);

	DBGPRINTF("%s: finalizing construction of worker instance data (for %d actions)\n",
		  wtiGetDbgHdr(pThis), iActionNbr);

	/* initialize our thread instance descriptor (no concurrency here) */
	pThis->bIsRunning = RSFALSE; 

	/* must use calloc as we need zero-init */
	CHKmalloc(pThis->actWrkrInfo = calloc(iActionNbr, sizeof(actWrkrInfo_t)));

	if(pThis->pWtp == NULL) {
		dbgprintf("wtiConstructFinalize: pWtp not set, this may be intentional\n");
		FINALIZE;
	}

	/* we now alloc the array for user pointers. We obtain the max from the queue itself. */
	CHKiRet(pThis->pWtp->pfGetDeqBatchSize(pThis->pWtp->pUsr, &iDeqBatchSize));
	CHKiRet(batchInit(&pThis->batch, iDeqBatchSize));

finalize_it:
	RETiRet;
}


/* cancellation cleanup handler for queueWorker ()
 * Most importantly, it must bring back the batch into a consistent state.
 * Keep in mind that cancellation is disabled if we run into
 * the cancel cleanup handler (and have been cancelled).
 * rgerhards, 2008-01-16
 */
static void
wtiWorkerCancelCleanup(void *arg)
{
	wti_t *pThis = (wti_t*) arg;
	wtp_t *pWtp;

	BEGINfunc
	ISOBJ_TYPE_assert(pThis, wti);
	pWtp = pThis->pWtp;
	ISOBJ_TYPE_assert(pWtp, wtp);

	DBGPRINTF("%s: cancelation cleanup handler called.\n", wtiGetDbgHdr(pThis));
	pWtp->pfObjProcessed(pWtp->pUsr, pThis);
	DBGPRINTF("%s: done cancelation cleanup handler.\n", wtiGetDbgHdr(pThis));
	
	ENDfunc
}


/* wait for queue to become non-empty or timeout
 * helper to wtiWorker. Note the the predicate is
 * re-tested by the caller, so it is OK to NOT do it here.
 * rgerhards, 2009-05-20
 */
static inline void
doIdleProcessing(wti_t *pThis, wtp_t *pWtp, int *pbInactivityTOOccured)
{
	struct timespec t;

	BEGINfunc
	DBGPRINTF("%s: worker IDLE, waiting for work.\n", wtiGetDbgHdr(pThis));

	if(pThis->bAlwaysRunning) {
		/* never shut down any started worker */
		d_pthread_cond_wait(&pThis->pcondBusy, pWtp->pmutUsr);
	} else {
		timeoutComp(&t, pWtp->toWrkShutdown);/* get absolute timeout */
		if(d_pthread_cond_timedwait(&pThis->pcondBusy, pWtp->pmutUsr, &t) != 0) {
			DBGPRINTF("%s: inactivity timeout, worker terminating...\n", wtiGetDbgHdr(pThis));
			*pbInactivityTOOccured = 1; /* indicate we had a timeout */
		}
	}
	DBGOPRINT((obj_t*) pThis, "worker awoke from idle processing\n");
	ENDfunc
}


/* generic worker thread framework. Note that we prohibit cancellation
 * during almost all times, because it can have very undesired side effects.
 * However, we may need to cancel a thread if the consumer blocks for too
 * long (during shutdown). So what we do is block cancellation, and every
 * consumer must enable it during the periods where it is safe.
 */
#pragma GCC diagnostic ignored "-Wempty-body"
rsRetVal
wtiWorker(wti_t *__restrict__ const pThis)
{
	wtp_t *__restrict__ const pWtp = pThis->pWtp; /* our worker thread pool -- shortcut */
	const action_t *__restrict__ pAction;
	int bInactivityTOOccured = 0;
	rsRetVal localRet;
	rsRetVal terminateRet;
	actWrkrInfo_t *__restrict__ wrkrInfo;
	int iCancelStateSave;
	int i, j, k;
	DEFiRet;

	dbgSetThrdName(pThis->pszDbgHdr);
	pthread_cleanup_push(wtiWorkerCancelCleanup, pThis);
	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &iCancelStateSave);
	DBGPRINTF("wti %p: worker starting\n", pThis);
	/* now we have our identity, on to real processing */

	/* note: in this loop, the mutex is "never" unlocked. Of course,
	 * this is not true: it actually is unlocked when the actual processing
	 * is done, as part of pWtp->pfDoWork() processing. Note that this
	 * function is required to re-lock it when done. We cannot do the
	 * lock/unlock here ourselfs, as pfDoWork() needs to access queue
	 * structures itself.
	 * The same goes for pfRateLimiter(). While we could unlock/lock when
	 * we call it, in practice the function is often called without any
	 * ratelimiting actually done. Only the rate limiter itself knows
	 * that. As such, it needs to bear the burden of doing the locking
	 * when required. -- rgerhards, 2013-11-20
	 */
	d_pthread_mutex_lock(pWtp->pmutUsr);
	while(1) { /* loop will be broken below */
		if(pWtp->pfRateLimiter != NULL) { /* call rate-limiter, if defined */
			pWtp->pfRateLimiter(pWtp->pUsr);
		}
		
		/* first check if we are in shutdown process (but evaluate a bit later) */
		terminateRet = wtpChkStopWrkr(pWtp, MUTEX_ALREADY_LOCKED);
		if(terminateRet == RS_RET_TERMINATE_NOW) {
			/* we now need to free the old batch */
			localRet = pWtp->pfObjProcessed(pWtp->pUsr, pThis);
			DBGOPRINT((obj_t*) pThis, "terminating worker because of "
				  "TERMINATE_NOW mode, del iRet %d\n", localRet);
			break;
		}

		/* try to execute and process whatever we have */
		localRet = pWtp->pfDoWork(pWtp->pUsr, pThis);

		if(localRet == RS_RET_ERR_QUEUE_EMERGENCY) {
			break;	/* end of loop */
		} else if(localRet == RS_RET_IDLE) {
			if(terminateRet == RS_RET_TERMINATE_WHEN_IDLE || bInactivityTOOccured) {
				DBGOPRINT((obj_t*) pThis, "terminating worker terminateRet=%d, bInactivityTOOccured=%d\n",
					  terminateRet, bInactivityTOOccured);
				break;	/* end of loop */
			}
			doIdleProcessing(pThis, pWtp, &bInactivityTOOccured);
			continue; /* request next iteration */
		}

		bInactivityTOOccured = 0; /* reset for next run */
	}

	d_pthread_mutex_unlock(pWtp->pmutUsr);

	DBGPRINTF("DDDD: wti %p: worker cleanup action instances\n", pThis);
	for(i = 0 ; i < iActionNbr ; ++i) {
		wrkrInfo = &(pThis->actWrkrInfo[i]);
		dbgprintf("wti %p, action %d, ptr %p\n", pThis, i, wrkrInfo->actWrkrData);
		if(wrkrInfo->actWrkrData != NULL) {
			pAction = wrkrInfo->pAction;
			pAction->pMod->mod.om.freeWrkrInstance(wrkrInfo->actWrkrData);
			if(pAction->isTransactional) {
				/* free iparam "cache" - we need to go through to max! */
				for(j = 0 ; j < wrkrInfo->p.tx.maxIParams ; ++j) {
					for(k = 0 ; k < pAction->iNumTpls ; ++k) {
						free(actParam(wrkrInfo->p.tx.iparams,
							      pAction->iNumTpls, j, k).param);
					}
				}
				free(wrkrInfo->p.tx.iparams);
				wrkrInfo->p.tx.iparams = NULL;
				wrkrInfo->p.tx.currIParam = 0;
				wrkrInfo->p.tx.maxIParams = 0;
			}
			wrkrInfo->actWrkrData = NULL; /* re-init for next activation */
		}
	}

	/* indicate termination */
	pthread_cleanup_pop(0); /* remove cleanup handler */
	pthread_setcancelstate(iCancelStateSave, NULL);
	dbgprintf("wti %p: worker exiting\n", pThis);

	RETiRet;
}
#pragma GCC diagnostic warning "-Wempty-body"


/* some simple object access methods */
DEFpropSetMeth(wti, pWtp, wtp_t*)

/* set the debug header message
 * The passed-in string is duplicated. So if the caller does not need
 * it any longer, it must free it. Must be called only before object is finalized.
 * rgerhards, 2008-01-09
 */
rsRetVal
wtiSetDbgHdr(wti_t *pThis, uchar *pszMsg, size_t lenMsg)
{
	DEFiRet;

	ISOBJ_TYPE_assert(pThis, wti);
	assert(pszMsg != NULL);
	
	if(lenMsg < 1)
		ABORT_FINALIZE(RS_RET_PARAM_ERROR);

	if(pThis->pszDbgHdr != NULL) {
		free(pThis->pszDbgHdr);
	}

	if((pThis->pszDbgHdr = MALLOC(sizeof(uchar) * lenMsg + 1)) == NULL)
		ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);

	memcpy(pThis->pszDbgHdr, pszMsg, lenMsg + 1); /* always think about the \0! */

finalize_it:
	RETiRet;
}


/* This function returns (and creates if necessary) a dummy wti suitable
 * for use by the rule engine. It is intended to be used for direct-mode
 * main queues (folks, don't do that!). Once created, data is stored in
 * thread-specific storage.
 * Note: we do NOT do error checking -- if this functions fails, all the
 * rest will fail as well... (also, it will only fail under OOM, so...).
 * Memleak: we leak pWti's when run in direct mode. However, this is only
 * a cosmetic leak, as we need them until all inputs are terminated,
 * what means essentially until rsyslog itself is terminated. So we
 * don't care -- it's just not nice in valgrind, but that's it.
 */
wti_t *
wtiGetDummy(void)
{
	wti_t *pWti;

	pWti = (wti_t*) pthread_getspecific(thrd_wti_key);
	if(pWti == NULL) {
		wtiConstruct(&pWti);
		wtiConstructFinalize(pWti);
		if(pthread_setspecific(thrd_wti_key, pWti) != 0) {
			DBGPRINTF("wtiGetDummy: error setspecific thrd_wti_key\n");
		}
	}
	return pWti;
}

/* dummy */
rsRetVal wtiQueryInterface(void) { return RS_RET_NOT_IMPLEMENTED; }

/* exit our class
 */
BEGINObjClassExit(wti, OBJ_IS_CORE_MODULE) /* CHANGE class also in END MACRO! */
CODESTARTObjClassExit(nsdsel_gtls)
	/* release objects we no longer need */
	objRelease(glbl, CORE_COMPONENT);
	pthread_key_delete(thrd_wti_key);
ENDObjClassExit(wti)


/* Initialize the wti class. Must be called as the very first method
 * before anything else is called inside this class.
 * rgerhards, 2008-01-09
 */
BEGINObjClassInit(wti, 1, OBJ_IS_CORE_MODULE) /* one is the object version (most important for persisting) */
	int r;
	/* request objects we use */
	CHKiRet(objUse(glbl, CORE_COMPONENT));
	r = pthread_key_create(&thrd_wti_key, NULL);
	if(r != 0) {
		dbgprintf("wti.c: pthread_key_create failed\n");
		iRet = RS_RET_ERR;
	}
ENDObjClassInit(wti)

/* vi:set ai:
 */