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Diffstat (limited to 'storage/xtradb/sync/sync0arr.c')
-rw-r--r--storage/xtradb/sync/sync0arr.c177
1 files changed, 122 insertions, 55 deletions
diff --git a/storage/xtradb/sync/sync0arr.c b/storage/xtradb/sync/sync0arr.c
index fb5829fb732..7f27fd926eb 100644
--- a/storage/xtradb/sync/sync0arr.c
+++ b/storage/xtradb/sync/sync0arr.c
@@ -2,6 +2,7 @@
Copyright (c) 1995, 2011, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2008, Google Inc.
+Copyright (c) 2013, 2014, SkySQL Ab. All Rights Reserved.
Portions of this file contain modifications contributed and copyrighted by
Google, Inc. Those modifications are gratefully acknowledged and are described
@@ -466,11 +467,13 @@ static
void
sync_array_cell_print(
/*==================*/
- FILE* file, /*!< in: file where to print */
- sync_cell_t* cell) /*!< in: sync cell */
+ FILE* file, /*!< in: file where to print */
+ sync_cell_t* cell, /*!< in: sync cell */
+ os_thread_id_t* reserver) /*!< out: write reserver or
+ 0 */
{
- mutex_t* mutex;
- rw_lock_t* rwlock;
+ mutex_t* mutex = NULL;
+ rw_lock_t* rwlock = NULL;
ulint type;
ulint writer;
@@ -483,32 +486,34 @@ sync_array_cell_print(
innobase_basename(cell->file), (ulong) cell->line,
difftime(time(NULL), cell->reservation_time));
- /* If stacktrace feature is enabled we will send a SIGUSR2
- signal to thread waiting for the semaphore. Signal handler
- will then dump the current stack to error log. */
- if (srv_use_stacktrace) {
-#ifdef __linux__
- pthread_kill(cell->thread, SIGUSR2);
-#endif
- }
-
if (type == SYNC_MUTEX) {
/* We use old_wait_mutex in case the cell has already
been freed meanwhile */
mutex = cell->old_wait_mutex;
- fprintf(file,
- "Mutex at %p '%s', lock var %lu\n"
+ if (mutex) {
+ fprintf(file,
+ "Mutex at %p '%s', lock var %lu\n"
#ifdef UNIV_SYNC_DEBUG
- "Last time reserved in file %s line %lu, "
+ "Last time reserved in file %s line %lu, "
#endif /* UNIV_SYNC_DEBUG */
- "waiters flag %lu\n",
- (void*) mutex, mutex->cmutex_name,
- (ulong) mutex->lock_word,
+ "waiters flag %lu\n",
+ (void*) mutex, mutex->cmutex_name,
+ (ulong) mutex->lock_word,
#ifdef UNIV_SYNC_DEBUG
- mutex->file_name, (ulong) mutex->line,
+ mutex->file_name, (ulong) mutex->line,
#endif /* UNIV_SYNC_DEBUG */
- (ulong) mutex->waiters);
+ (ulong) mutex->waiters);
+ }
+
+ /* If stacktrace feature is enabled we will send a SIGUSR2
+ signal to thread waiting for the semaphore. Signal handler
+ will then dump the current stack to error log. */
+ if (srv_use_stacktrace && cell && cell->thread) {
+#ifdef __linux__
+ pthread_kill(cell->thread, SIGUSR2);
+#endif
+ }
} else if (type == RW_LOCK_EX
|| type == RW_LOCK_WAIT_EX
@@ -520,40 +525,47 @@ sync_array_cell_print(
rwlock = cell->old_wait_rw_lock;
- fprintf(file,
- " RW-latch at %p '%s'\n",
- (void*) rwlock, rwlock->lock_name);
- writer = rw_lock_get_writer(rwlock);
- if (writer != RW_LOCK_NOT_LOCKED) {
+ if (rwlock) {
fprintf(file,
- "a writer (thread id %lu) has"
- " reserved it in mode %s",
- (ulong) os_thread_pf(rwlock->writer_thread),
- writer == RW_LOCK_EX
- ? " exclusive\n"
- : " wait exclusive\n");
- }
+ " RW-latch at %p '%s'\n",
+ (void*) rwlock, rwlock->lock_name);
- fprintf(file,
- "number of readers %lu, waiters flag %lu, "
- "lock_word: %lx\n"
- "Last time read locked in file %s line %lu\n"
- "Last time write locked in file %s line %lu\n",
- (ulong) rw_lock_get_reader_count(rwlock),
- (ulong) rwlock->waiters,
- rwlock->lock_word,
- innobase_basename(rwlock->last_s_file_name),
- (ulong) rwlock->last_s_line,
- rwlock->last_x_file_name,
- (ulong) rwlock->last_x_line);
+ writer = rw_lock_get_writer(rwlock);
- /* If stacktrace feature is enabled we will send a SIGUSR2
- signal to thread that has locked RW-latch with write mode.
- Signal handler will then dump the current stack to error log. */
- if (writer != RW_LOCK_NOT_LOCKED && srv_use_stacktrace) {
+ if (writer && writer != RW_LOCK_NOT_LOCKED) {
+ fprintf(file,
+ "a writer (thread id %lu) has"
+ " reserved it in mode %s",
+ (ulong) os_thread_pf(rwlock->writer_thread),
+ writer == RW_LOCK_EX
+ ? " exclusive\n"
+ : " wait exclusive\n");
+
+ *reserver = rwlock->writer_thread;
+ }
+
+ fprintf(file,
+ "number of readers %lu, waiters flag %lu, "
+ "lock_word: %lx\n"
+ "Last time read locked in file %s line %lu\n"
+ "Last time write locked in file %s line %lu\n",
+ (ulong) rw_lock_get_reader_count(rwlock),
+ (ulong) rwlock->waiters,
+ rwlock->lock_word,
+ innobase_basename(rwlock->last_s_file_name),
+ (ulong) rwlock->last_s_line,
+ rwlock->last_x_file_name,
+ (ulong) rwlock->last_x_line);
+
+ /* If stacktrace feature is enabled we will send a SIGUSR2
+ signal to thread that has locked RW-latch with write mode.
+ Signal handler will then dump the current stack to error log. */
+ if (writer != RW_LOCK_NOT_LOCKED && srv_use_stacktrace &&
+ rwlock && rwlock->writer_thread) {
#ifdef __linux__
- pthread_kill(rwlock->writer_thread, SIGUSR2);
+ pthread_kill(rwlock->writer_thread, SIGUSR2);
#endif
+ }
}
} else {
@@ -565,7 +577,6 @@ sync_array_cell_print(
}
}
-#ifdef UNIV_SYNC_DEBUG
/******************************************************************//**
Looks for a cell with the given thread id.
@return pointer to cell or NULL if not found */
@@ -593,6 +604,8 @@ sync_array_find_thread(
return(NULL); /* Not found */
}
+#ifdef UNIV_SYNC_DEBUG
+
/******************************************************************//**
Recursion step for deadlock detection.
@return TRUE if deadlock detected */
@@ -964,6 +977,7 @@ sync_array_print_long_waits(
double diff;
void* wait_object;
+ os_thread_id_t reserver=0;
cell = sync_array_get_nth_cell(sync_primary_wait_array, i);
@@ -979,7 +993,7 @@ sync_array_print_long_waits(
if (diff > SYNC_ARRAY_TIMEOUT) {
fputs("InnoDB: Warning: a long semaphore wait:\n",
stderr);
- sync_array_cell_print(stderr, cell);
+ sync_array_cell_print(stderr, cell, &reserver);
noticed = TRUE;
}
@@ -994,6 +1008,58 @@ sync_array_print_long_waits(
}
}
+ /* We found a long semaphore wait, wait all threads that are
+ waiting for a semaphore. */
+ if (noticed) {
+ for (i = 0; i < sync_primary_wait_array->n_cells; i++) {
+ void* wait_object;
+ os_thread_id_t reserver=ULINT_UNDEFINED;
+ ulint loop=0;
+
+ cell = sync_array_get_nth_cell(sync_primary_wait_array, i);
+
+ wait_object = cell->wait_object;
+
+ if (wait_object == NULL || !cell->waiting) {
+
+ continue;
+ }
+
+ fputs("InnoDB: Warning: semaphore wait:\n",
+ stderr);
+ sync_array_cell_print(stderr, cell, &reserver);
+ noticed = TRUE;
+
+ /* Try to output cell information for writer recursive way */
+ while (reserver != ULINT_UNDEFINED) {
+ sync_cell_t* reserver_wait;
+
+ reserver_wait = sync_array_find_thread(sync_primary_wait_array, reserver);
+
+ if (reserver_wait &&
+ reserver_wait->wait_object != NULL &&
+ reserver_wait->waiting) {
+ fputs("InnoDB: Warning: Writer thread is waiting this semaphore:\n",
+ stderr);
+ reserver = ULINT_UNDEFINED;
+ sync_array_cell_print(stderr, reserver_wait, &reserver);
+ loop++;
+
+ if (reserver_wait->thread == reserver) {
+ reserver = ULINT_UNDEFINED;
+ }
+ } else {
+ reserver = ULINT_UNDEFINED;
+ }
+ /* This is protection against loop */
+ if (loop > 100) {
+ fputs("InnoDB: Warning: Too many waiting threads.\n", stderr);
+ break;
+ }
+ }
+ }
+ }
+
sync_array_exit(sync_primary_wait_array);
if (noticed) {
@@ -1042,6 +1108,7 @@ sync_array_output_info(
sync_cell_t* cell;
ulint count;
ulint i;
+ os_thread_id_t r;
fprintf(file,
"OS WAIT ARRAY INFO: reservation count %ld, signal count %ld\n",
@@ -1053,9 +1120,9 @@ sync_array_output_info(
cell = sync_array_get_nth_cell(arr, i);
- if (cell->wait_object != NULL) {
- count++;
- sync_array_cell_print(file, cell);
+ if (cell->wait_object != NULL) {
+ count++;
+ sync_array_cell_print(file, cell, &r);
}
i++;
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