diff options
Diffstat (limited to 'libnetdata/locks')
| -rw-r--r-- | libnetdata/locks/README.md | 5 | ||||
| -rw-r--r-- | libnetdata/locks/locks.c | 441 | ||||
| -rw-r--r-- | libnetdata/locks/locks.h | 31 |
3 files changed, 121 insertions, 356 deletions
diff --git a/libnetdata/locks/README.md b/libnetdata/locks/README.md index 9132edc43..8810e3d17 100644 --- a/libnetdata/locks/README.md +++ b/libnetdata/locks/README.md @@ -1,5 +1,10 @@ <!-- +title: "Locks" custom_edit_url: https://github.com/netdata/netdata/edit/master/libnetdata/locks/README.md +sidebar_label: "Locks" +learn_status: "Published" +learn_topic_type: "Tasks" +learn_rel_path: "Developers/libnetdata libraries" --> ## How to trace netdata locks diff --git a/libnetdata/locks/locks.c b/libnetdata/locks/locks.c index f7191be52..e73456d70 100644 --- a/libnetdata/locks/locks.c +++ b/libnetdata/locks/locks.c @@ -15,8 +15,6 @@ #ifndef NETDATA_THREAD_LOCKS_ARRAY_SIZE #define NETDATA_THREAD_LOCKS_ARRAY_SIZE 10 #endif -static __thread netdata_rwlock_t *netdata_thread_locks[NETDATA_THREAD_LOCKS_ARRAY_SIZE]; - #endif // NETDATA_TRACE_RWLOCKS @@ -120,8 +118,6 @@ int __netdata_mutex_unlock(netdata_mutex_t *mutex) { #ifdef NETDATA_TRACE_RWLOCKS -#warning NETDATA_TRACE_RWLOCKS ENABLED - EXPECT A LOT OF OUTPUT - int netdata_mutex_init_debug(const char *file __maybe_unused, const char *function __maybe_unused, const unsigned long line __maybe_unused, netdata_mutex_t *mutex) { debug(D_LOCKS, "MUTEX_LOCK: netdata_mutex_init(%p) from %lu@%s, %s()", mutex, line, file, function); @@ -283,12 +279,16 @@ int __netdata_rwlock_trywrlock(netdata_rwlock_t *rwlock) { // https://www.youtube.com/watch?v=rmGJc9PXpuE&t=41s void netdata_spinlock_init(SPINLOCK *spinlock) { - *spinlock = NETDATA_SPINLOCK_INITIALIZER; + memset(spinlock, 0, sizeof(SPINLOCK)); } void netdata_spinlock_lock(SPINLOCK *spinlock) { static const struct timespec ns = { .tv_sec = 0, .tv_nsec = 1 }; +#ifdef NETDATA_INTERNAL_CHECKS + size_t spins = 0; +#endif + netdata_thread_disable_cancelability(); for(int i = 1; @@ -296,254 +296,104 @@ void netdata_spinlock_lock(SPINLOCK *spinlock) { __atomic_test_and_set(&spinlock->locked, __ATOMIC_ACQUIRE) ; i++ ) { + +#ifdef NETDATA_INTERNAL_CHECKS + spins++; +#endif if(unlikely(i == 8)) { i = 0; nanosleep(&ns, NULL); } } + // we have the lock + +#ifdef NETDATA_INTERNAL_CHECKS + spinlock->spins += spins; + spinlock->locker_pid = gettid(); +#endif } void netdata_spinlock_unlock(SPINLOCK *spinlock) { +#ifdef NETDATA_INTERNAL_CHECKS + spinlock->locker_pid = 0; +#endif __atomic_clear(&spinlock->locked, __ATOMIC_RELEASE); netdata_thread_enable_cancelability(); } -#ifdef NETDATA_TRACE_RWLOCKS +bool netdata_spinlock_trylock(SPINLOCK *spinlock) { + netdata_thread_disable_cancelability(); -// ---------------------------------------------------------------------------- -// lockers list + if(!__atomic_load_n(&spinlock->locked, __ATOMIC_RELAXED) && + !__atomic_test_and_set(&spinlock->locked, __ATOMIC_ACQUIRE)) + // we got the lock + return true; -void not_supported_by_posix_rwlocks(const char *file, const char *function, const unsigned long line, netdata_rwlock_t *rwlock, char locktype, const char *reason) { - __netdata_mutex_lock(&rwlock->lockers_mutex); - fprintf(stderr, - "RW_LOCK FATAL ON LOCK %p: %d '%s' (function %s() %lu@%s) attempts to acquire a '%c' lock, but it is not supported by POSIX because: %s. At this attempt, the task is holding %zu rwlocks and %zu mutexes. There are %zu readers and %zu writers holding this lock:\n", - rwlock, - gettid(), netdata_thread_tag(), - function, line, file, - locktype, - reason, - netdata_locks_acquired_rwlocks, netdata_locks_acquired_mutexes, - rwlock->readers, rwlock->writers); - - int i; - usec_t now = now_monotonic_high_precision_usec(); - netdata_rwlock_locker *p; - for(i = 1, p = rwlock->lockers; p ;p = p->next, i++) { - fprintf(stderr, - " => %i: RW_LOCK %p: process %d '%s' (function %s() %lu@%s) is having %zu '%c' lock for %llu usec.\n", - i, rwlock, - p->pid, p->tag, - p->function, p->line, p->file, - p->callers, p->lock, - (now - p->start_s)); - } - __netdata_mutex_unlock(&rwlock->lockers_mutex); + // we didn't get the lock + return false; } -static void log_rwlock_lockers(const char *file, const char *function, const unsigned long line, netdata_rwlock_t *rwlock, const char *reason, char locktype) { - - // this function can only be used by one thread at a time - // because otherwise, the threads may deadlock waiting for each other - static netdata_mutex_t log_lockers_mutex = NETDATA_MUTEX_INITIALIZER; - __netdata_mutex_lock(&log_lockers_mutex); - - // now work on this locker - __netdata_mutex_lock(&rwlock->lockers_mutex); - fprintf(stderr, - "RW_LOCK ON LOCK %p: %d '%s' (function %s() %lu@%s) %s a '%c' lock (while holding %zu rwlocks and %zu mutexes). There are %zu readers and %zu writers holding this lock:\n", - rwlock, - gettid(), netdata_thread_tag(), - function, line, file, - reason, locktype, - netdata_locks_acquired_rwlocks, netdata_locks_acquired_mutexes, - rwlock->readers, rwlock->writers); - - int i; - usec_t now = now_monotonic_high_precision_usec(); - netdata_rwlock_locker *p; - for(i = 1, p = rwlock->lockers; p ;p = p->next, i++) { - fprintf(stderr, - " => %i: RW_LOCK %p: process %d '%s' (function %s() %lu@%s) is having %zu '%c' lock for %llu usec.\n", - i, rwlock, - p->pid, p->tag, - p->function, p->line, p->file, - p->callers, p->lock, - (now - p->start_s)); - - if(p->all_caller_locks) { - // find the lock in the netdata_thread_locks[] - // and remove it - int k; - for(k = 0; k < NETDATA_THREAD_LOCKS_ARRAY_SIZE ;k++) { - if (p->all_caller_locks[k] && p->all_caller_locks[k] != rwlock) { - - // lock the other lock lockers list - __netdata_mutex_lock(&p->all_caller_locks[k]->lockers_mutex); - - // print the list of lockers of the other lock - netdata_rwlock_locker *r; - int j; - for(j = 1, r = p->all_caller_locks[k]->lockers; r ;r = r->next, j++) { - fprintf( - stderr, - " ~~~> %i: RW_LOCK %p: process %d '%s' (function %s() %lu@%s) is having %zu '%c' lock for %llu usec.\n", - j, - p->all_caller_locks[k], - r->pid, - r->tag, - r->function, - r->line, - r->file, - r->callers, - r->lock, - (now - r->start_s)); - } - - // unlock the other lock lockers list - __netdata_mutex_unlock(&p->all_caller_locks[k]->lockers_mutex); - } - } - } +#ifdef NETDATA_TRACE_RWLOCKS - } - __netdata_mutex_unlock(&rwlock->lockers_mutex); +// ---------------------------------------------------------------------------- +// lockers list - // unlock this function for other threads - __netdata_mutex_unlock(&log_lockers_mutex); -} - -static netdata_rwlock_locker *add_rwlock_locker(const char *file, const char *function, const unsigned long line, netdata_rwlock_t *rwlock, char lock_type) { - netdata_rwlock_locker *p = mallocz(sizeof(netdata_rwlock_locker)); - p->pid = gettid(); - p->tag = netdata_thread_tag(); - p->lock = lock_type; - p->file = file; - p->function = function; - p->line = line; - p->callers = 1; - p->all_caller_locks = netdata_thread_locks; - p->start_s = now_monotonic_high_precision_usec(); - - // find a slot in the netdata_thread_locks[] - int i; - for(i = 0; i < NETDATA_THREAD_LOCKS_ARRAY_SIZE ;i++) { - if (!netdata_thread_locks[i]) { - netdata_thread_locks[i] = rwlock; - break; - } - } +static netdata_rwlock_locker *find_rwlock_locker(const char *file __maybe_unused, const char *function __maybe_unused, const unsigned long line __maybe_unused, netdata_rwlock_t *rwlock) { + pid_t pid = gettid(); + netdata_rwlock_locker *locker = NULL; __netdata_mutex_lock(&rwlock->lockers_mutex); - p->next = rwlock->lockers; - rwlock->lockers = p; - if(lock_type == 'R') rwlock->readers++; - if(lock_type == 'W') rwlock->writers++; + Pvoid_t *PValue = JudyLGet(rwlock->lockers_pid_JudyL, pid, PJE0); + if(PValue && *PValue) + locker = *PValue; __netdata_mutex_unlock(&rwlock->lockers_mutex); - return p; + return locker; } -static void remove_rwlock_locker(const char *file __maybe_unused, const char *function __maybe_unused, const unsigned long line __maybe_unused, netdata_rwlock_t *rwlock, netdata_rwlock_locker *locker) { - usec_t end_s = now_monotonic_high_precision_usec(); +static netdata_rwlock_locker *add_rwlock_locker(const char *file, const char *function, const unsigned long line, netdata_rwlock_t *rwlock, LOCKER_REQUEST lock_type) { + netdata_rwlock_locker *locker; - if(locker->callers == 0) - fprintf(stderr, - "RW_LOCK ON LOCK %p: %d, '%s' (function %s() %lu@%s) callers should be positive but it is zero\n", - rwlock, - locker->pid, locker->tag, - locker->function, locker->line, locker->file); - - if(locker->callers > 1 && locker->lock != 'R') - fprintf(stderr, - "RW_LOCK ON LOCK %p: %d, '%s' (function %s() %lu@%s) only 'R' locks support multiple holders, but here we have %zu callers holding a '%c' lock.\n", - rwlock, - locker->pid, locker->tag, - locker->function, locker->line, locker->file, - locker->callers, locker->lock); - - __netdata_mutex_lock(&rwlock->lockers_mutex); - locker->callers--; - - if(!locker->callers) { - int doit = 0; - - if (rwlock->lockers == locker) { - rwlock->lockers = locker->next; - doit = 1; - } else { - netdata_rwlock_locker *p; - for (p = rwlock->lockers; p && p->next != locker; p = p->next) - ; - if (p && p->next == locker) { - p->next = locker->next; - doit = 1; - } - } - if(doit) { - if(locker->lock == 'R') rwlock->readers--; - if(locker->lock == 'W') rwlock->writers--; - } + locker = find_rwlock_locker(file, function, line, rwlock); + if(locker) { + locker->lock |= lock_type; + locker->refcount++; + } + else { + locker = mallocz(sizeof(netdata_rwlock_locker)); + locker->pid = gettid(); + locker->tag = netdata_thread_tag(); + locker->refcount = 1; + locker->lock = lock_type; + locker->got_it = false; + locker->file = file; + locker->function = function; + locker->line = line; - if(!doit) { - fprintf(stderr, - "RW_LOCK ON LOCK %p: %d, '%s' (function %s() %lu@%s) with %zu x '%c' lock is not found.\n", - rwlock, - locker->pid, locker->tag, - locker->function, locker->line, locker->file, - locker->callers, locker->lock); - } - else { - // find the lock in the netdata_thread_locks[] - // and remove it - int i; - for(i = 0; i < NETDATA_THREAD_LOCKS_ARRAY_SIZE ;i++) { - if (netdata_thread_locks[i] == rwlock) - netdata_thread_locks[i] = NULL; - } - - if(end_s - locker->start_s >= NETDATA_TRACE_RWLOCKS_HOLD_TIME_TO_IGNORE_USEC) - fprintf(stderr, - "RW_LOCK ON LOCK %p: %d, '%s' (function %s() %lu@%s) holded a '%c' for %llu usec.\n", - rwlock, - locker->pid, locker->tag, - locker->function, locker->line, locker->file, - locker->lock, end_s - locker->start_s); - - freez(locker); - } + __netdata_mutex_lock(&rwlock->lockers_mutex); + DOUBLE_LINKED_LIST_APPEND_UNSAFE(rwlock->lockers, locker, prev, next); + Pvoid_t *PValue = JudyLIns(&rwlock->lockers_pid_JudyL, locker->pid, PJE0); + *PValue = locker; + if (lock_type == RWLOCK_REQUEST_READ || lock_type == RWLOCK_REQUEST_TRYREAD) rwlock->readers++; + if (lock_type == RWLOCK_REQUEST_WRITE || lock_type == RWLOCK_REQUEST_TRYWRITE) rwlock->writers++; + __netdata_mutex_unlock(&rwlock->lockers_mutex); } - __netdata_mutex_unlock(&rwlock->lockers_mutex); + return locker; } -static netdata_rwlock_locker *find_rwlock_locker(const char *file __maybe_unused, const char *function __maybe_unused, const unsigned long line __maybe_unused, netdata_rwlock_t *rwlock) { - pid_t pid = gettid(); - netdata_rwlock_locker *p; - +static void remove_rwlock_locker(const char *file __maybe_unused, const char *function __maybe_unused, const unsigned long line __maybe_unused, netdata_rwlock_t *rwlock, netdata_rwlock_locker *locker) { __netdata_mutex_lock(&rwlock->lockers_mutex); - for(p = rwlock->lockers; p ;p = p->next) { - if(p->pid == pid) break; + locker->refcount--; + if(!locker->refcount) { + DOUBLE_LINKED_LIST_REMOVE_UNSAFE(rwlock->lockers, locker, prev, next); + JudyLDel(&rwlock->lockers_pid_JudyL, locker->pid, PJE0); + if (locker->lock == RWLOCK_REQUEST_READ || locker->lock == RWLOCK_REQUEST_TRYREAD) rwlock->readers--; + else if (locker->lock == RWLOCK_REQUEST_WRITE || locker->lock == RWLOCK_REQUEST_TRYWRITE) rwlock->writers--; + freez(locker); } __netdata_mutex_unlock(&rwlock->lockers_mutex); - - return p; -} - -static netdata_rwlock_locker *update_or_add_rwlock_locker(const char *file, const char *function, const unsigned long line, netdata_rwlock_t *rwlock, netdata_rwlock_locker *locker, char locktype) { - if(!locker) { - return add_rwlock_locker(file, function, line, rwlock, locktype); - } - else if(locker->lock == 'R' && locktype == 'R') { - __netdata_mutex_lock(&rwlock->lockers_mutex); - locker->callers++; - __netdata_mutex_unlock(&rwlock->lockers_mutex); - return locker; - } - else { - not_supported_by_posix_rwlocks(file, function, line, rwlock, locktype, "DEADLOCK - WANTS TO CHANGE LOCK TYPE BUT ALREADY HAS THIS LOCKED"); - return locker; - } } // ---------------------------------------------------------------------------- @@ -551,84 +401,41 @@ static netdata_rwlock_locker *update_or_add_rwlock_locker(const char *file, cons int netdata_rwlock_destroy_debug(const char *file __maybe_unused, const char *function __maybe_unused, const unsigned long line __maybe_unused, netdata_rwlock_t *rwlock) { - debug(D_LOCKS, "RW_LOCK: netdata_rwlock_destroy(%p) from %lu@%s, %s()", rwlock, line, file, function); - - if(rwlock->readers) - error("RW_LOCK: destroying a rwlock with %zu readers in it", rwlock->readers); - if(rwlock->writers) - error("RW_LOCK: destroying a rwlock with %zu writers in it", rwlock->writers); int ret = __netdata_rwlock_destroy(rwlock); if(!ret) { while (rwlock->lockers) remove_rwlock_locker(file, function, line, rwlock, rwlock->lockers); - - if (rwlock->readers) - error("RW_LOCK: internal error - empty rwlock with %zu readers in it", rwlock->readers); - if (rwlock->writers) - error("RW_LOCK: internal error - empty rwlock with %zu writers in it", rwlock->writers); } - debug(D_LOCKS, "RW_LOCK: netdata_rwlock_destroy(%p) = %d, from %lu@%s, %s()", rwlock, ret, line, file, function); - return ret; } int netdata_rwlock_init_debug(const char *file __maybe_unused, const char *function __maybe_unused, const unsigned long line __maybe_unused, netdata_rwlock_t *rwlock) { - debug(D_LOCKS, "RW_LOCK: netdata_rwlock_init(%p) from %lu@%s, %s()", rwlock, line, file, function); int ret = __netdata_rwlock_init(rwlock); if(!ret) { __netdata_mutex_init(&rwlock->lockers_mutex); + rwlock->lockers_pid_JudyL = NULL; rwlock->lockers = NULL; rwlock->readers = 0; rwlock->writers = 0; } - debug(D_LOCKS, "RW_LOCK: netdata_rwlock_init(%p) = %d, from %lu@%s, %s()", rwlock, ret, line, file, function); - return ret; } int netdata_rwlock_rdlock_debug(const char *file __maybe_unused, const char *function __maybe_unused, const unsigned long line __maybe_unused, netdata_rwlock_t *rwlock) { - debug(D_LOCKS, "RW_LOCK: netdata_rwlock_rdlock(%p) from %lu@%s, %s()", rwlock, line, file, function); - - netdata_rwlock_locker *locker = find_rwlock_locker(file, function, line, rwlock); - -#ifdef NETDATA_TRACE_RWLOCKS_LOG_NESTED - if(locker && locker->lock == 'R') { - log_rwlock_lockers(file, function, line, rwlock, "NESTED READ LOCK REQUEST", 'R'); - } -#endif // NETDATA_TRACE_RWLOCKS_LOG_NESTED + netdata_rwlock_locker *locker = add_rwlock_locker(file, function, line, rwlock, RWLOCK_REQUEST_READ); - int log = 0; - if(rwlock->writers) { - log_rwlock_lockers(file, function, line, rwlock, "WANTS", 'R'); - log = 1; - } - - usec_t start_s = now_monotonic_high_precision_usec(); int ret = __netdata_rwlock_rdlock(rwlock); - usec_t end_s = now_monotonic_high_precision_usec(); - - if(!ret) { - locker = update_or_add_rwlock_locker(file, function, line, rwlock, locker, 'R'); - if(log) log_rwlock_lockers(file, function, line, rwlock, "GOT", 'R'); - - } - - if(end_s - start_s >= NETDATA_TRACE_RWLOCKS_WAIT_TIME_TO_IGNORE_USEC) - fprintf(stderr, - "RW_LOCK ON LOCK %p: %d, '%s' (function %s() %lu@%s) WAITED for a READ lock for %llu usec.\n", - rwlock, - gettid(), netdata_thread_tag(), - function, line, file, - end_s - start_s); - - debug(D_LOCKS, "RW_LOCK: netdata_rwlock_rdlock(%p) = %d in %llu usec, from %lu@%s, %s()", rwlock, ret, end_s - start_s, line, file, function); + if(!ret) + locker->got_it = true; + else + remove_rwlock_locker(file, function, line, rwlock, locker); return ret; } @@ -636,36 +443,13 @@ int netdata_rwlock_rdlock_debug(const char *file __maybe_unused, const char *fun int netdata_rwlock_wrlock_debug(const char *file __maybe_unused, const char *function __maybe_unused, const unsigned long line __maybe_unused, netdata_rwlock_t *rwlock) { - debug(D_LOCKS, "RW_LOCK: netdata_rwlock_wrlock(%p) from %lu@%s, %s()", rwlock, line, file, function); - - netdata_rwlock_locker *locker = find_rwlock_locker(file, function, line, rwlock); - if(locker) - not_supported_by_posix_rwlocks(file, function, line, rwlock, 'W', "DEADLOCK - WANTS A WRITE LOCK BUT ALREADY HAVE THIS LOCKED"); + netdata_rwlock_locker *locker = add_rwlock_locker(file, function, line, rwlock, RWLOCK_REQUEST_WRITE); - int log = 0; - if(rwlock->readers) { - log_rwlock_lockers(file, function, line, rwlock, "WANTS", 'W'); - log = 1; - } - - usec_t start_s = now_monotonic_high_precision_usec(); int ret = __netdata_rwlock_wrlock(rwlock); - usec_t end_s = now_monotonic_high_precision_usec(); - - if(!ret){ - locker = update_or_add_rwlock_locker(file, function, line, rwlock, locker, 'W'); - if(log) log_rwlock_lockers(file, function, line, rwlock, "GOT", 'W'); - } - - if(end_s - start_s >= NETDATA_TRACE_RWLOCKS_WAIT_TIME_TO_IGNORE_USEC) - fprintf(stderr, - "RW_LOCK ON LOCK %p: %d, '%s' (function %s() %lu@%s) WAITED for a WRITE lock for %llu usec.\n", - rwlock, - gettid(), netdata_thread_tag(), - function, line, file, - end_s - start_s); - - debug(D_LOCKS, "RW_LOCK: netdata_rwlock_wrlock(%p) = %d in %llu usec, from %lu@%s, %s()", rwlock, ret, end_s - start_s, line, file, function); + if(!ret) + locker->got_it = true; + else + remove_rwlock_locker(file, function, line, rwlock, locker); return ret; } @@ -673,83 +457,42 @@ int netdata_rwlock_wrlock_debug(const char *file __maybe_unused, const char *fun int netdata_rwlock_unlock_debug(const char *file __maybe_unused, const char *function __maybe_unused, const unsigned long line __maybe_unused, netdata_rwlock_t *rwlock) { - debug(D_LOCKS, "RW_LOCK: netdata_rwlock_unlock(%p) from %lu@%s, %s()", rwlock, line, file, function); - netdata_rwlock_locker *locker = find_rwlock_locker(file, function, line, rwlock); + if(unlikely(!locker)) - not_supported_by_posix_rwlocks(file, function, line, rwlock, 'U', "UNLOCK WITHOUT LOCK"); + fatal("UNLOCK WITHOUT LOCK"); - usec_t start_s = now_monotonic_high_precision_usec(); int ret = __netdata_rwlock_unlock(rwlock); - usec_t end_s = now_monotonic_high_precision_usec(); - - if(end_s - start_s >= NETDATA_TRACE_RWLOCKS_WAIT_TIME_TO_IGNORE_USEC) - fprintf(stderr, - "RW_LOCK ON LOCK %p: %d, '%s' (function %s() %lu@%s) WAITED to UNLOCK for %llu usec.\n", - rwlock, - gettid(), netdata_thread_tag(), - function, line, file, - end_s - start_s); - - if(likely(!ret && locker)) remove_rwlock_locker(file, function, line, rwlock, locker); - - debug(D_LOCKS, "RW_LOCK: netdata_rwlock_unlock(%p) = %d in %llu usec, from %lu@%s, %s()", rwlock, ret, end_s - start_s, line, file, function); + if(likely(!ret)) + remove_rwlock_locker(file, function, line, rwlock, locker); return ret; } int netdata_rwlock_tryrdlock_debug(const char *file __maybe_unused, const char *function __maybe_unused, const unsigned long line __maybe_unused, netdata_rwlock_t *rwlock) { - debug(D_LOCKS, "RW_LOCK: netdata_rwlock_tryrdlock(%p) from %lu@%s, %s()", rwlock, line, file, function); - netdata_rwlock_locker *locker = find_rwlock_locker(file, function, line, rwlock); - if(locker && locker->lock == 'W') - not_supported_by_posix_rwlocks(file, function, line, rwlock, 'R', "DEADLOCK - WANTS A READ LOCK BUT IT HAS A WRITE LOCK ALREADY"); + netdata_rwlock_locker *locker = add_rwlock_locker(file, function, line, rwlock, RWLOCK_REQUEST_TRYREAD); - usec_t start_s = now_monotonic_high_precision_usec(); int ret = __netdata_rwlock_tryrdlock(rwlock); - usec_t end_s = now_monotonic_high_precision_usec(); - if(!ret) - locker = update_or_add_rwlock_locker(file, function, line, rwlock, locker, 'R'); - - if(end_s - start_s >= NETDATA_TRACE_RWLOCKS_WAIT_TIME_TO_IGNORE_USEC) - fprintf(stderr, - "RW_LOCK ON LOCK %p: %d, '%s' (function %s() %lu@%s) WAITED to TRYREAD for %llu usec.\n", - rwlock, - gettid(), netdata_thread_tag(), - function, line, file, - end_s - start_s); - - debug(D_LOCKS, "RW_LOCK: netdata_rwlock_tryrdlock(%p) = %d in %llu usec, from %lu@%s, %s()", rwlock, ret, end_s - start_s, line, file, function); + locker->got_it = true; + else + remove_rwlock_locker(file, function, line, rwlock, locker); return ret; } int netdata_rwlock_trywrlock_debug(const char *file __maybe_unused, const char *function __maybe_unused, const unsigned long line __maybe_unused, netdata_rwlock_t *rwlock) { - debug(D_LOCKS, "RW_LOCK: netdata_rwlock_trywrlock(%p) from %lu@%s, %s()", rwlock, line, file, function); - netdata_rwlock_locker *locker = find_rwlock_locker(file, function, line, rwlock); - if(locker) - not_supported_by_posix_rwlocks(file, function, line, rwlock, 'W', "ALREADY HAS THIS LOCK"); + netdata_rwlock_locker *locker = add_rwlock_locker(file, function, line, rwlock, RWLOCK_REQUEST_TRYWRITE); - usec_t start_s = now_monotonic_high_precision_usec(); int ret = __netdata_rwlock_trywrlock(rwlock); - usec_t end_s = now_monotonic_high_precision_usec(); - if(!ret) - locker = update_or_add_rwlock_locker(file, function, line, rwlock, locker, 'W'); - - if(end_s - start_s >= NETDATA_TRACE_RWLOCKS_WAIT_TIME_TO_IGNORE_USEC) - fprintf(stderr, - "RW_LOCK ON LOCK %p: %d, '%s' (function %s() %lu@%s) WAITED to TRYWRITE for %llu usec.\n", - rwlock, - gettid(), netdata_thread_tag(), - function, line, file, - end_s - start_s); - - debug(D_LOCKS, "RW_LOCK: netdata_rwlock_trywrlock(%p) = %d in %llu usec, from %lu@%s, %s()", rwlock, ret, end_s - start_s, line, file, function); + locker->got_it = true; + else + remove_rwlock_locker(file, function, line, rwlock, locker); return ret; } diff --git a/libnetdata/locks/locks.h b/libnetdata/locks/locks.h index 4d2d1655c..89b110d5e 100644 --- a/libnetdata/locks/locks.h +++ b/libnetdata/locks/locks.h @@ -11,24 +11,39 @@ typedef pthread_mutex_t netdata_mutex_t; typedef struct netdata_spinlock { bool locked; +#ifdef NETDATA_INTERNAL_CHECKS + pid_t locker_pid; + size_t spins; +#endif } SPINLOCK; -#define NETDATA_SPINLOCK_INITIALIZER (SPINLOCK){ .locked = false } + +#define NETDATA_SPINLOCK_INITIALIZER \ + { .locked = false } + void netdata_spinlock_init(SPINLOCK *spinlock); void netdata_spinlock_lock(SPINLOCK *spinlock); void netdata_spinlock_unlock(SPINLOCK *spinlock); +bool netdata_spinlock_trylock(SPINLOCK *spinlock); #ifdef NETDATA_TRACE_RWLOCKS + +typedef enum { + RWLOCK_REQUEST_READ = (1 << 0), + RWLOCK_REQUEST_WRITE = (1 << 1), + RWLOCK_REQUEST_TRYREAD = (1 << 2), + RWLOCK_REQUEST_TRYWRITE = (1 << 3), +} LOCKER_REQUEST; + typedef struct netdata_rwlock_locker { + LOCKER_REQUEST lock; + bool got_it; pid_t pid; + size_t refcount; const char *tag; - char lock; // 'R', 'W' const char *file; const char *function; unsigned long line; - size_t callers; - usec_t start_s; - struct netdata_rwlock_t **all_caller_locks; - struct netdata_rwlock_locker *next; + struct netdata_rwlock_locker *next, *prev; } netdata_rwlock_locker; typedef struct netdata_rwlock_t { @@ -37,6 +52,7 @@ typedef struct netdata_rwlock_t { size_t writers; // the number of writers on the lock netdata_mutex_t lockers_mutex; // a mutex to protect the linked list of the lock holding threads netdata_rwlock_locker *lockers; // the linked list of the lock holding threads + Pvoid_t lockers_pid_JudyL; } netdata_rwlock_t; #define NETDATA_RWLOCK_INITIALIZER { \ @@ -44,7 +60,8 @@ typedef struct netdata_rwlock_t { .readers = 0, \ .writers = 0, \ .lockers_mutex = NETDATA_MUTEX_INITIALIZER, \ - .lockers = NULL \ + .lockers = NULL, \ + .lockers_pid_JudyL = NULL, \ } #else // NETDATA_TRACE_RWLOCKS |