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-rw-r--r--ChangeLog4
-rw-r--r--runtime/debug.c69
-rw-r--r--runtime/debug.h4
-rw-r--r--runtime/wti.c10
-rw-r--r--runtime/wtp.c20
-rw-r--r--runtime/wtp.h1
6 files changed, 102 insertions, 6 deletions
diff --git a/ChangeLog b/ChangeLog
index f797f854..a94eb24a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+- bugfix: potential abort with DA queue after high watermark is reached
+ There exists a race condition that can lead to a segfault. Thanks
+ go to vbernetr, who performed the analysis and provided patch, which
+ I only tweaked a very little bit.
---------------------------------------------------------------------------
Version 3.20.5 [v3-stable] (rgerhards), 2009-0?-??
- fixed bugs in RainerScript:
diff --git a/runtime/debug.c b/runtime/debug.c
index 1450d029..9d45c737 100644
--- a/runtime/debug.c
+++ b/runtime/debug.c
@@ -473,6 +473,55 @@ static inline void dbgMutexLockLog(pthread_mutex_t *pmut, dbgFuncDB_t *pFuncDB,
dbgprintf("%s:%d:%s: mutex %p aquired\n", pFuncDB->file, lockLn, pFuncDB->func, (void*)pmut);
}
+
+/* report trylock on a mutex and add it to the mutex log */
+static inline void dbgMutexPreTryLockLog(pthread_mutex_t *pmut, dbgFuncDB_t *pFuncDB, int ln)
+{
+ dbgMutLog_t *pHolder;
+ dbgMutLog_t *pLog;
+ char pszBuf[128];
+ char pszHolderThrdName[64];
+ char *pszHolder;
+
+ pthread_mutex_lock(&mutMutLog);
+ pHolder = dbgMutLogFindHolder(pmut);
+ pLog = dbgMutLogAddEntry(pmut, MUTOP_TRYLOCK, pFuncDB, ln);
+
+ if(pHolder == NULL)
+ pszHolder = "[NONE]";
+ else {
+ dbgGetThrdName(pszHolderThrdName, sizeof(pszHolderThrdName), pHolder->thrd, 1);
+ snprintf(pszBuf, sizeof(pszBuf)/sizeof(char), "%s:%d [%s]", pHolder->pFuncDB->file, pHolder->lockLn, pszHolderThrdName);
+ pszHolder = pszBuf;
+ }
+
+ if(bPrintMutexAction)
+ dbgprintf("%s:%d:%s: mutex %p trying to get lock, held by %s\n", pFuncDB->file, ln, pFuncDB->func, (void*)pmut, pszHolder);
+ pthread_mutex_unlock(&mutMutLog);
+}
+
+
+/* report attempted mutex lock */
+static inline void dbgMutexTryLockLog(pthread_mutex_t *pmut, dbgFuncDB_t *pFuncDB, int lockLn)
+{
+ dbgMutLog_t *pLog;
+
+ pthread_mutex_lock(&mutMutLog);
+
+ /* find and delete "trylock" entry */
+ pLog = dbgMutLogFindSpecific(pmut, MUTOP_TRYLOCK, pFuncDB);
+ assert(pLog != NULL);
+ dbgMutLogDelEntry(pLog);
+
+ /* add "lock" entry */
+ pLog = dbgMutLogAddEntry(pmut, MUTOP_LOCK, pFuncDB, lockLn);
+ dbgFuncDBAddMutexLock(pFuncDB, pmut, lockLn);
+ pthread_mutex_unlock(&mutMutLog);
+ if(bPrintMutexAction)
+ dbgprintf("%s:%d:%s: mutex %p aquired\n", pFuncDB->file, lockLn, pFuncDB->func, (void*)pmut);
+}
+
+
/* if we unlock, we just remove the lock aquired entry from the log list */
static inline void dbgMutexUnlockLog(pthread_mutex_t *pmut, dbgFuncDB_t *pFuncDB, int unlockLn)
{
@@ -515,6 +564,26 @@ int dbgMutexLock(pthread_mutex_t *pmut, dbgFuncDB_t *pFuncDB, int ln, int iStack
}
+/* wrapper for pthread_mutex_trylock() */
+int dbgMutexTryLock(pthread_mutex_t *pmut, dbgFuncDB_t *pFuncDB, int ln, int iStackPtr)
+{
+ int ret;
+
+ dbgRecordExecLocation(iStackPtr, ln);
+ dbgMutexPreLockLog(pmut, pFuncDB, ln); // TODO : update this
+ ret = pthread_mutex_trylock(pmut);
+ if(ret == 0 || ret == EBUSY) {
+ // TODO : update this
+ dbgMutexLockLog(pmut, pFuncDB, ln);
+ } else {
+ dbgprintf("%s:%d:%s: ERROR: pthread_mutex_trylock() for mutex %p failed with error %d\n",
+ pFuncDB->file, ln, pFuncDB->func, (void*)pmut, ret);
+ }
+
+ return ret;
+}
+
+
/* wrapper for pthread_mutex_unlock() */
int dbgMutexUnlock(pthread_mutex_t *pmut, dbgFuncDB_t *pFuncDB, int ln, int iStackPtr)
{
diff --git a/runtime/debug.h b/runtime/debug.h
index 214b7c05..ed914677 100644
--- a/runtime/debug.h
+++ b/runtime/debug.h
@@ -89,6 +89,7 @@ void sigsegvHdlr(int signum);
void dbgoprint(obj_t *pObj, char *fmt, ...) __attribute__((format(printf, 2, 3)));
void dbgprintf(char *fmt, ...) __attribute__((format(printf, 1, 2)));
int dbgMutexLock(pthread_mutex_t *pmut, dbgFuncDB_t *pFuncD, int ln, int iStackPtr);
+int dbgMutexTryLock(pthread_mutex_t *pmut, dbgFuncDB_t *pFuncD, int ln, int iStackPtr);
int dbgMutexUnlock(pthread_mutex_t *pmut, dbgFuncDB_t *pFuncD, int ln, int iStackPtr);
int dbgCondWait(pthread_cond_t *cond, pthread_mutex_t *pmut, dbgFuncDB_t *pFuncD, int ln, int iStackPtr);
int dbgCondTimedWait(pthread_cond_t *cond, pthread_mutex_t *pmut, const struct timespec *abstime, dbgFuncDB_t *pFuncD, int ln, int iStackPtr);
@@ -127,17 +128,20 @@ void dbgPrintAllDebugInfo(void);
#define MUTOP_LOCKWAIT 1
#define MUTOP_LOCK 2
#define MUTOP_UNLOCK 3
+#define MUTOP_TRYLOCK 4
/* debug aides */
#ifdef RTINST
#define d_pthread_mutex_lock(x) dbgMutexLock(x, pdbgFuncDB, __LINE__, dbgCALLStaCK_POP_POINT )
+#define d_pthread_mutex_trylock(x) dbgMutexTryLock(x, pdbgFuncDB, __LINE__, dbgCALLStaCK_POP_POINT )
#define d_pthread_mutex_unlock(x) dbgMutexUnlock(x, pdbgFuncDB, __LINE__, dbgCALLStaCK_POP_POINT )
#define d_pthread_cond_wait(cond, mut) dbgCondWait(cond, mut, pdbgFuncDB, __LINE__, dbgCALLStaCK_POP_POINT )
#define d_pthread_cond_timedwait(cond, mut, to) dbgCondTimedWait(cond, mut, to, pdbgFuncDB, __LINE__, dbgCALLStaCK_POP_POINT )
#define d_free(x) dbgFree(x, pdbgFuncDB, __LINE__, dbgCALLStaCK_POP_POINT )
#else
#define d_pthread_mutex_lock(x) pthread_mutex_lock(x)
+#define d_pthread_mutex_trylock(x) pthread_mutex_trylock(x)
#define d_pthread_mutex_unlock(x) pthread_mutex_unlock(x)
#define d_pthread_cond_wait(cond, mut) pthread_cond_wait(cond, mut)
#define d_pthread_cond_timedwait(cond, mut, to) pthread_cond_timedwait(cond, mut, to)
diff --git a/runtime/wti.c b/runtime/wti.c
index 13554232..a2531499 100644
--- a/runtime/wti.c
+++ b/runtime/wti.c
@@ -238,10 +238,14 @@ wtiJoinThrd(wti_t *pThis)
ISOBJ_TYPE_assert(pThis, wti);
dbgprintf("waiting for worker %s termination, current state %d\n", wtiGetDbgHdr(pThis), pThis->tCurrCmd);
- pthread_join(pThis->thrdID, NULL);
- wtiSetState(pThis, eWRKTHRD_STOPPED, 0, MUTEX_ALREADY_LOCKED); /* back to virgin... */
- pThis->thrdID = 0; /* invalidate the thread ID so that we do not accidently find reused ones */
+ if (pThis->thrdID == 0) {
+ dbgprintf("worker %s was already stopped\n", wtiGetDbgHdr(pThis));
+ } else {
+ pthread_join(pThis->thrdID, NULL);
+ wtiSetState(pThis, eWRKTHRD_STOPPED, 0, MUTEX_ALREADY_LOCKED); /* back to virgin... */
+ pThis->thrdID = 0; /* invalidate the thread ID so that we do not accidently find reused ones */
dbgprintf("worker %s has stopped\n", wtiGetDbgHdr(pThis));
+ }
RETiRet;
}
diff --git a/runtime/wtp.c b/runtime/wtp.c
index 8b041ea2..fcefa1d8 100644
--- a/runtime/wtp.c
+++ b/runtime/wtp.c
@@ -76,6 +76,7 @@ static rsRetVal NotImplementedDummy() { return RS_RET_OK; }
*/
BEGINobjConstruct(wtp) /* be sure to specify the object type also in END macro! */
pthread_mutex_init(&pThis->mut, NULL);
+ pthread_mutex_init(&pThis->mutThrdShutdwn, NULL);
pthread_cond_init(&pThis->condThrdTrm, NULL);
/* set all function pointers to "not implemented" dummy so that we can safely call them */
pThis->pfChkStopWrkr = NotImplementedDummy;
@@ -140,6 +141,7 @@ CODESTARTobjDestruct(wtp)
/* actual destruction */
pthread_cond_destroy(&pThis->condThrdTrm);
pthread_mutex_destroy(&pThis->mut);
+ pthread_mutex_destroy(&pThis->mutThrdShutdwn);
if(pThis->pszDbgHdr != NULL)
free(pThis->pszDbgHdr);
@@ -189,11 +191,23 @@ wtpProcessThrdChanges(wtp_t *pThis)
if(pThis->bThrdStateChanged == 0)
FINALIZE;
- /* go through all threads */
- for(i = 0 ; i < pThis->iNumWorkerThreads ; ++i) {
- wtiProcessThrdChanges(pThis->pWrkr[i], LOCK_MUTEX);
+ if(d_pthread_mutex_trylock(&(pThis->mutThrdShutdwn)) != 0) {
+ /* another thread is already in the loop */
+ FINALIZE;
}
+ do {
+ /* reset the change marker */
+ pThis->bThrdStateChanged = 0;
+ /* go through all threads */
+ for(i = 0 ; i < pThis->iNumWorkerThreads ; ++i) {
+ wtiProcessThrdChanges(pThis->pWrkr[i], LOCK_MUTEX);
+ }
+ /* restart if another change occured while we were processing the changes */
+ } while(pThis->bThrdStateChanged != 0);
+
+ d_pthread_mutex_unlock(&(pThis->mutThrdShutdwn));
+
finalize_it:
RETiRet;
}
diff --git a/runtime/wtp.h b/runtime/wtp.h
index 13ebe536..0f21ac11 100644
--- a/runtime/wtp.h
+++ b/runtime/wtp.h
@@ -60,6 +60,7 @@ typedef struct wtp_s {
int bInactivityGuard;/* prevents inactivity due to race condition */
rsRetVal (*pConsumer)(void *); /* user-supplied consumer function for dewtpd messages */
/* synchronization variables */
+ pthread_mutex_t mutThrdShutdwn; /* mutex to guard thread shutdown processing */
pthread_mutex_t mut; /* mutex for the wtp's thread management */
pthread_cond_t condThrdTrm;/* signalled when threads terminate */
int bThrdStateChanged; /* at least one thread state has changed if 1 */
generated by cgit (git 2.34.1) at 2024-11-12 23:09:35 +0000