diff options
| -rw-r--r-- | ChangeLog | 7 | ||||
| -rw-r--r-- | configure.ac | 50 | ||||
| -rw-r--r-- | runtime/atomic.h | 23 | ||||
| -rw-r--r-- | runtime/debug.c | 16 | ||||
| -rw-r--r-- | runtime/debug.h | 3 | ||||
| -rw-r--r-- | runtime/msg.c | 4 | ||||
| -rw-r--r-- | runtime/queue.c | 12 | ||||
| -rw-r--r-- | tools/syslogd.c | 7 |
8 files changed, 102 insertions, 20 deletions
@@ -11,6 +11,13 @@ Version 3.21.5 [DEVEL] (rgerhards), 2008-09-?? each input module (else it is blank). - added system property "$myhostname", which contains the name of the local host as it knows itself. +- re-enabled gcc builtin atomic operations and added a proper + ./configure check +- bugfix: potential race condition when adding messages to queue + There was a wrong order of mutex lock operations. It is hard to + believe that really caused problems, but in theory it could and with + threading we often see that theory becomes practice if something is only + used long enough on a fast enough machine with enough CPUs ;) --------------------------------------------------------------------------- Version 3.21.4 [DEVEL] (rgerhards), 2008-09-04 - removed compile time fixed message size limit (was 2K), limit can now diff --git a/configure.ac b/configure.ac index 8e9f7807..fea7c063 100644 --- a/configure.ac +++ b/configure.ac @@ -107,6 +107,56 @@ AC_TRY_COMPILE([ AC_MSG_RESULT(no; defined as 64) ) +# check for availability of atomic operations +# rgerhards, 2008-09-18, added based on +# http://svn.apache.org/repos/asf/apr/apr/trunk/configure.in + +AC_CACHE_CHECK([whether the compiler provides atomic builtins], [ap_cv_atomic_builtins], +[AC_TRY_RUN([ +int main() +{ + unsigned long val = 1010, tmp, *mem = &val; + + if (__sync_fetch_and_add(&val, 1010) != 1010 || val != 2020) + return 1; + + tmp = val; + + if (__sync_fetch_and_sub(mem, 1010) != tmp || val != 1010) + return 1; + + if (__sync_sub_and_fetch(&val, 1010) != 0 || val != 0) + return 1; + + tmp = 3030; + + if (__sync_val_compare_and_swap(mem, 0, tmp) != 0 || val != tmp) + return 1; + + if (__sync_lock_test_and_set(&val, 4040) != 3030) + return 1; + + mem = &tmp; + + if (__sync_val_compare_and_swap(&mem, &tmp, &val) != &tmp) + return 1; + + __sync_synchronize(); + + if (mem != &val) + return 1; + + return 0; +}], [ap_cv_atomic_builtins=yes], [ap_cv_atomic_builtins=no], [ap_cv_atomic_builtins=no])]) + +if test "$ap_cv_atomic_builtins" = "yes"; then + AC_DEFINE(HAVE_ATOMIC_BUILTINS, 1, [Define if compiler provides atomic builtins]) +fi + + + + + # Large file support AC_ARG_ENABLE(largefile, [AS_HELP_STRING([--enable-largefile],[Enable large file support @<:@default=yes@:>@])], diff --git a/runtime/atomic.h b/runtime/atomic.h index 430ae7f0..2dbe7f52 100644 --- a/runtime/atomic.h +++ b/runtime/atomic.h @@ -1,6 +1,6 @@ /* This header supplies atomic operations. So far, we rely on GCC's - * atomic builtins. I have no idea if we can check them via autotools, - * but I am making the necessary provisioning to live without them if + * atomic builtins. During configure, we check if atomic operatons are + * available. If they are not, I am making the necessary provisioning to live without them if * they are not available. Please note that you should only use the macros * here if you think you can actually live WITHOUT an explicit atomic operation, * because in the non-presence of them, we simply do it without atomicitiy. @@ -36,16 +36,21 @@ #ifndef INCLUDED_ATOMIC_H #define INCLUDED_ATOMIC_H -/* set the following to 1 if we have atomic operations (and #undef it otherwise) */ -/* #define DO_HAVE_ATOMICS 1 */ /* for this release, we disable atomic calls because there seem to be some * portability problems and we can not fix that without destabilizing the build. * They simply came in too late. -- rgerhards, 2008-04-02 */ -/* make sure they are not used! -#define ATOMIC_INC(data) ((void) __sync_fetch_and_add(&data, 1)) -#define ATOMIC_DEC_AND_FETCH(data) __sync_sub_and_fetch(&data, 1) -*/ -#define ATOMIC_INC(data) (++(data)) +#ifdef HAVE_ATOMIC_BUILTINS +# define ATOMIC_INC(data) ((void) __sync_fetch_and_add(&(data), 1)) +# define ATOMIC_DEC_AND_FETCH(data) __sync_sub_and_fetch(&(data), 1) +# define ATOMIC_FETCH_32BIT(data) ((unsigned) __sync_fetch_and_and(&(data), 0xffffffff)) +# define ATOMIC_STORE_1_TO_32BIT(data) __sync_lock_test_and_set(&(data), 1) +#else +# warning "atomic builtins not available, using nul operations" +# define ATOMIC_INC(data) (++(data)) +# define ATOMIC_DEC_AND_FETCH(data) (--(data)) +# define ATOMIC_FETCH_32BIT(data) (data) +# define ATOMIC_STORE_1_TO_32BIT(data) (data) = 1 +#endif #endif /* #ifndef INCLUDED_ATOMIC_H */ diff --git a/runtime/debug.c b/runtime/debug.c index 1450d029..7ed1442b 100644 --- a/runtime/debug.c +++ b/runtime/debug.c @@ -480,7 +480,23 @@ static inline void dbgMutexUnlockLog(pthread_mutex_t *pmut, dbgFuncDB_t *pFuncDB pthread_mutex_lock(&mutMutLog); pLog = dbgMutLogFindSpecific(pmut, MUTOP_LOCK, NULL); +#if 0 /* toggle for testing */ assert(pLog != NULL); +#else +/* the change below seems not to work - the problem seems to be a real race... I keep this code in just in case + * I need to re-use it. It should be removed once we are finished analyzing this problem. -- rgerhards, 2008-09-17 + */ +if(pLog == NULL) { + /* this may happen due to some races. We do not try to avoid + * this, as it would complicate the "real" code. This is not justified + * just to keep the debug info system up. -- rgerhards, 2008-09-17 + */ + pthread_mutex_unlock(&mutMutLog); + dbgprintf("%s:%d:%s: mutex %p UNlocked [but we did not yet know this mutex!]\n", + pFuncDB->file, unlockLn, pFuncDB->func, (void*)pmut); + return; /* if we don't know it yet, we can not clean up... */ +} +#endif /* we found the last lock entry. We now need to see from which FuncDB we need to * remove it. This is recorded inside the mutex log entry. diff --git a/runtime/debug.h b/runtime/debug.h index 214b7c05..d9d576b5 100644 --- a/runtime/debug.h +++ b/runtime/debug.h @@ -130,7 +130,8 @@ void dbgPrintAllDebugInfo(void); /* debug aides */ -#ifdef RTINST +//#ifdef RTINST +#if 0 // temporarily removed for helgrind #define d_pthread_mutex_lock(x) dbgMutexLock(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 ) diff --git a/runtime/msg.c b/runtime/msg.c index f4eb9414..346bbc5f 100644 --- a/runtime/msg.c +++ b/runtime/msg.c @@ -276,8 +276,10 @@ CODESTARTobjDestruct(msg) # ifdef DO_HAVE_ATOMICS currRefCount = ATOMIC_DEC_AND_FETCH(pThis->iRefCount); # else + MsgLock(pThis); currRefCount = --pThis->iRefCount; # endif +// we need a mutex, because we may be suspended after getting the refcount but before if(currRefCount == 0) { /* DEV Debugging Only! dbgprintf("msgDestruct\t0x%lx, RefCount now 0, doing DESTROY\n", (unsigned long)pThis); */ @@ -337,9 +339,11 @@ CODESTARTobjDestruct(msg) rsCStrDestruct(&pThis->pCSPROCID); if(pThis->pCSMSGID != NULL) rsCStrDestruct(&pThis->pCSMSGID); + MsgUnlock(pThis); funcDeleteMutex(pThis); } else { pThis = NULL; /* tell framework not to destructing the object! */ + MsgUnlock(pThis); } ENDobjDestruct(msg) diff --git a/runtime/queue.c b/runtime/queue.c index 7e7d4152..c0a37019 100644 --- a/runtime/queue.c +++ b/runtime/queue.c @@ -2171,17 +2171,17 @@ queueEnqObj(queue_t *pThis, flowControl_t flowCtlType, void *pUsr) finalize_it: if(pThis->qType != QUEUETYPE_DIRECT) { - d_pthread_mutex_unlock(pThis->mut); + /* make sure at least one worker is running. */ + if(pThis->qType != QUEUETYPE_DIRECT) { + queueAdviseMaxWorkers(pThis); + } + /* and release the mutex */ i = pthread_cond_signal(&pThis->notEmpty); + d_pthread_mutex_unlock(pThis->mut); dbgoprint((obj_t*) pThis, "EnqueueMsg signaled condition (%d)\n", i); pthread_setcancelstate(iCancelStateSave, NULL); } - /* make sure at least one worker is running. */ - if(pThis->qType != QUEUETYPE_DIRECT) { - queueAdviseMaxWorkers(pThis); - } - RETiRet; } diff --git a/tools/syslogd.c b/tools/syslogd.c index b6e1d826..3a637dd8 100644 --- a/tools/syslogd.c +++ b/tools/syslogd.c @@ -2832,9 +2832,8 @@ static rsRetVal mainThread() CHKiRet(init()); - if(Debug) { + if(Debug && debugging_on) { dbgprintf("Debugging enabled, SIGUSR1 to turn off debugging.\n"); - debugging_on = 1; } /* Send a signal to the parent so it can terminate. */ @@ -3082,9 +3081,9 @@ doGlblProcessInit(void) fputs(" Already running.\n", stderr); exit(1); /* "good" exit, done if syslogd is already running */ } - } - else + } else { debugging_on = 1; + } /* tuck my process id away */ dbgprintf("Writing pidfile %s.\n", PidFile); |