netdata/libnetdata/locks/locks.c

727 lines
27 KiB
C

// SPDX-License-Identifier: GPL-3.0-or-later
#include "../libnetdata.h"
#ifdef NETDATA_TRACE_RWLOCKS
#ifndef NETDATA_TRACE_RWLOCKS_WAIT_TIME_TO_IGNORE_USEC
#define NETDATA_TRACE_RWLOCKS_WAIT_TIME_TO_IGNORE_USEC 10
#endif
#ifndef NETDATA_TRACE_RWLOCKS_HOLD_TIME_TO_IGNORE_USEC
#define NETDATA_TRACE_RWLOCKS_HOLD_TIME_TO_IGNORE_USEC 10000
#endif
#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
// ----------------------------------------------------------------------------
// automatic thread cancelability management, based on locks
static __thread int netdata_thread_first_cancelability = 0;
static __thread int netdata_thread_nested_disables = 0;
static __thread size_t netdata_locks_acquired_rwlocks = 0;
static __thread size_t netdata_locks_acquired_mutexes = 0;
inline void netdata_thread_disable_cancelability(void) {
int old;
int ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &old);
if(ret != 0)
error("THREAD_CANCELABILITY: pthread_setcancelstate() on thread %s returned error %d", netdata_thread_tag(), ret);
else {
if(!netdata_thread_nested_disables)
netdata_thread_first_cancelability = old;
netdata_thread_nested_disables++;
}
}
inline void netdata_thread_enable_cancelability(void) {
if(netdata_thread_nested_disables < 1) {
error("THREAD_CANCELABILITY: netdata_thread_enable_cancelability(): invalid thread cancelability count %d on thread %s - results will be undefined - please report this!",
netdata_thread_nested_disables, netdata_thread_tag());
}
else if(netdata_thread_nested_disables == 1) {
int old = 1;
int ret = pthread_setcancelstate(netdata_thread_first_cancelability, &old);
if(ret != 0)
error("THREAD_CANCELABILITY: pthread_setcancelstate() on thread %s returned error %d", netdata_thread_tag(), ret);
else {
if(old != PTHREAD_CANCEL_DISABLE)
error("THREAD_CANCELABILITY: netdata_thread_enable_cancelability(): old thread cancelability on thread %s was changed, expected DISABLED (%d), found %s (%d) - please report this!", netdata_thread_tag(), PTHREAD_CANCEL_DISABLE, (old == PTHREAD_CANCEL_ENABLE)?"ENABLED":"UNKNOWN", old);
}
netdata_thread_nested_disables = 0;
}
else
netdata_thread_nested_disables--;
}
// ----------------------------------------------------------------------------
// mutex
int __netdata_mutex_init(netdata_mutex_t *mutex) {
int ret = pthread_mutex_init(mutex, NULL);
if(unlikely(ret != 0))
error("MUTEX_LOCK: failed to initialize (code %d).", ret);
return ret;
}
int __netdata_mutex_destroy(netdata_mutex_t *mutex) {
int ret = pthread_mutex_destroy(mutex);
if(unlikely(ret != 0))
error("MUTEX_LOCK: failed to destroy (code %d).", ret);
return ret;
}
int __netdata_mutex_lock(netdata_mutex_t *mutex) {
netdata_thread_disable_cancelability();
int ret = pthread_mutex_lock(mutex);
if(unlikely(ret != 0)) {
netdata_thread_enable_cancelability();
error("MUTEX_LOCK: failed to get lock (code %d)", ret);
}
else
netdata_locks_acquired_mutexes++;
return ret;
}
int __netdata_mutex_trylock(netdata_mutex_t *mutex) {
netdata_thread_disable_cancelability();
int ret = pthread_mutex_trylock(mutex);
if(ret != 0)
netdata_thread_enable_cancelability();
else
netdata_locks_acquired_mutexes++;
return ret;
}
int __netdata_mutex_unlock(netdata_mutex_t *mutex) {
int ret = pthread_mutex_unlock(mutex);
if(unlikely(ret != 0))
error("MUTEX_LOCK: failed to unlock (code %d).", ret);
else {
netdata_locks_acquired_mutexes--;
netdata_thread_enable_cancelability();
}
return ret;
}
#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);
int ret = __netdata_mutex_init(mutex);
debug(D_LOCKS, "MUTEX_LOCK: netdata_mutex_init(%p) = %d, from %lu@%s, %s()", mutex, ret, line, file, function);
return ret;
}
int netdata_mutex_destroy_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_destroy(%p) from %lu@%s, %s()", mutex, line, file, function);
int ret = __netdata_mutex_destroy(mutex);
debug(D_LOCKS, "MUTEX_LOCK: netdata_mutex_destroy(%p) = %d, from %lu@%s, %s()", mutex, ret, line, file, function);
return ret;
}
int netdata_mutex_lock_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_lock(%p) from %lu@%s, %s()", mutex, line, file, function);
usec_t start_s = now_monotonic_high_precision_usec();
int ret = __netdata_mutex_lock(mutex);
usec_t end_s = now_monotonic_high_precision_usec();
// remove compiler unused variables warning
(void)start_s;
(void)end_s;
debug(D_LOCKS, "MUTEX_LOCK: netdata_mutex_lock(%p) = %d in %llu usec, from %lu@%s, %s()", mutex, ret, end_s - start_s, line, file, function);
return ret;
}
int netdata_mutex_trylock_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_trylock(%p) from %lu@%s, %s()", mutex, line, file, function);
usec_t start_s = now_monotonic_high_precision_usec();
int ret = __netdata_mutex_trylock(mutex);
usec_t end_s = now_monotonic_high_precision_usec();
// remove compiler unused variables warning
(void)start_s;
(void)end_s;
debug(D_LOCKS, "MUTEX_LOCK: netdata_mutex_trylock(%p) = %d in %llu usec, from %lu@%s, %s()", mutex, ret, end_s - start_s, line, file, function);
return ret;
}
int netdata_mutex_unlock_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_unlock(%p) from %lu@%s, %s()", mutex, line, file, function);
usec_t start_s = now_monotonic_high_precision_usec();
int ret = __netdata_mutex_unlock(mutex);
usec_t end_s = now_monotonic_high_precision_usec();
// remove compiler unused variables warning
(void)start_s;
(void)end_s;
debug(D_LOCKS, "MUTEX_LOCK: netdata_mutex_unlock(%p) = %d in %llu usec, from %lu@%s, %s()", mutex, ret, end_s - start_s, line, file, function);
return ret;
}
#endif // NETDATA_TRACE_RWLOCKS
// ----------------------------------------------------------------------------
// rwlock
int __netdata_rwlock_destroy(netdata_rwlock_t *rwlock) {
int ret = pthread_rwlock_destroy(&rwlock->rwlock_t);
if(unlikely(ret != 0))
error("RW_LOCK: failed to destroy lock (code %d)", ret);
return ret;
}
int __netdata_rwlock_init(netdata_rwlock_t *rwlock) {
int ret = pthread_rwlock_init(&rwlock->rwlock_t, NULL);
if(unlikely(ret != 0))
error("RW_LOCK: failed to initialize lock (code %d)", ret);
return ret;
}
int __netdata_rwlock_rdlock(netdata_rwlock_t *rwlock) {
netdata_thread_disable_cancelability();
int ret = pthread_rwlock_rdlock(&rwlock->rwlock_t);
if(unlikely(ret != 0)) {
netdata_thread_enable_cancelability();
error("RW_LOCK: failed to obtain read lock (code %d)", ret);
}
else
netdata_locks_acquired_rwlocks++;
return ret;
}
int __netdata_rwlock_wrlock(netdata_rwlock_t *rwlock) {
netdata_thread_disable_cancelability();
int ret = pthread_rwlock_wrlock(&rwlock->rwlock_t);
if(unlikely(ret != 0)) {
error("RW_LOCK: failed to obtain write lock (code %d)", ret);
netdata_thread_enable_cancelability();
}
else
netdata_locks_acquired_rwlocks++;
return ret;
}
int __netdata_rwlock_unlock(netdata_rwlock_t *rwlock) {
int ret = pthread_rwlock_unlock(&rwlock->rwlock_t);
if(unlikely(ret != 0))
error("RW_LOCK: failed to release lock (code %d)", ret);
else {
netdata_thread_enable_cancelability();
netdata_locks_acquired_rwlocks--;
}
return ret;
}
int __netdata_rwlock_tryrdlock(netdata_rwlock_t *rwlock) {
netdata_thread_disable_cancelability();
int ret = pthread_rwlock_tryrdlock(&rwlock->rwlock_t);
if(ret != 0)
netdata_thread_enable_cancelability();
else
netdata_locks_acquired_rwlocks++;
return ret;
}
int __netdata_rwlock_trywrlock(netdata_rwlock_t *rwlock) {
netdata_thread_disable_cancelability();
int ret = pthread_rwlock_trywrlock(&rwlock->rwlock_t);
if(ret != 0)
netdata_thread_enable_cancelability();
else
netdata_locks_acquired_rwlocks++;
return ret;
}
#ifdef NETDATA_TRACE_RWLOCKS
// ----------------------------------------------------------------------------
// lockers list
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);
}
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);
}
}
}
}
__netdata_mutex_unlock(&rwlock->lockers_mutex);
// 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;
}
}
__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++;
__netdata_mutex_unlock(&rwlock->lockers_mutex);
return 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) {
usec_t end_s = now_monotonic_high_precision_usec();
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--;
}
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_unlock(&rwlock->lockers_mutex);
}
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;
__netdata_mutex_lock(&rwlock->lockers_mutex);
for(p = rwlock->lockers; p ;p = p->next) {
if(p->pid == pid) break;
}
__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;
}
}
// ----------------------------------------------------------------------------
// debug versions of rwlock
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 = 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
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);
return ret;
}
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");
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);
return ret;
}
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");
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);
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");
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);
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");
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);
return ret;
}
#endif // NETDATA_TRACE_RWLOCKS