X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/a60b397b6d2a25072c79fe0a5e29bea89a4d3786..9c00f078978e452d541ddc8a9a2b7704db2cb7f3:/src/bio.c?ds=sidebyside

diff --git a/src/bio.c b/src/bio.c
index a666f558..0fec24d0 100644
--- a/src/bio.c
+++ b/src/bio.c
@@ -26,11 +26,42 @@
  *
  * Currently there is no way for the creator of the job to be notified about
  * the completion of the operation, this will only be added when/if needed.
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
  */
 
+
 #include "redis.h"
 #include "bio.h"
 
+static pthread_t bio_threads[REDIS_BIO_NUM_OPS];
 static pthread_mutex_t bio_mutex[REDIS_BIO_NUM_OPS];
 static pthread_cond_t bio_condvar[REDIS_BIO_NUM_OPS];
 static list *bio_jobs[REDIS_BIO_NUM_OPS];
@@ -88,6 +119,7 @@ void bioInit(void) {
             redisLog(REDIS_WARNING,"Fatal: Can't initialize Background Jobs.");
             exit(1);
         }
+        bio_threads[j] = thread;
     }
 }
 
@@ -108,9 +140,22 @@ void bioCreateBackgroundJob(int type, void *arg1, void *arg2, void *arg3) {
 void *bioProcessBackgroundJobs(void *arg) {
     struct bio_job *job;
     unsigned long type = (unsigned long) arg;
+    sigset_t sigset;
+
+    /* Make the thread killable at any time, so that bioKillThreads()
+     * can work reliably. */
+    pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
+    pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
 
-    pthread_detach(pthread_self());
     pthread_mutex_lock(&bio_mutex[type]);
+    /* Block SIGALRM so we are sure that only the main thread will
+     * receive the watchdog signal. */
+    sigemptyset(&sigset);
+    sigaddset(&sigset, SIGALRM);
+    if (pthread_sigmask(SIG_BLOCK, &sigset, NULL))
+        redisLog(REDIS_WARNING,
+            "Warning: can't mask SIGALRM in bio.c thread: %s", strerror(errno));
+
     while(1) {
         listNode *ln;
 
@@ -153,50 +198,23 @@ unsigned long long bioPendingJobsOfType(int type) {
     return val;
 }
 
-/* Wait until the number of pending jobs of the specified type are
- * less or equal to the specified number.
- *
- * This function may block for long time, it should only be used to perform
- * the following tasks:
- *
- * 1) To avoid that the main thread is pushing jobs of a given time so fast
- *    that the background thread can't process them at the same speed.
- *    So before creating a new job of a given type the main thread should
- *    call something like: bioWaitPendingJobsLE(job_type,10000);
- * 2) In order to perform special operations that make it necessary to be sure
- *    no one is touching shared resourced in the background.
- */
-void bioWaitPendingJobsLE(int type, unsigned long long num) {
-    unsigned long long iteration = 0;
+/* Kill the running bio threads in an unclean way. This function should be
+ * used only when it's critical to stop the threads for some reason.
+ * Currently Redis does this only on crash (for instance on SIGSEGV) in order
+ * to perform a fast memory check without other threads messing with memory. */
+void bioKillThreads(void) {
+    int err, j;
 
-    /* We poll the jobs queue aggressively to start, and gradually relax
-     * the polling speed if it is going to take too much time. */
-    while(1) {
-        iteration++;
-        if (iteration > 1000 && iteration <= 10000) {
-            usleep(100);
-        } else if (iteration > 10000) {
-            usleep(1000);
+    for (j = 0; j < REDIS_BIO_NUM_OPS; j++) {
+        if (pthread_cancel(bio_threads[j]) == 0) {
+            if ((err = pthread_join(bio_threads[j],NULL)) != 0) {
+                redisLog(REDIS_WARNING,
+                    "Bio thread for job type #%d can be joined: %s",
+                        j, strerror(err));
+            } else {
+                redisLog(REDIS_WARNING,
+                    "Bio thread for job type #%d terminated",j);
+            }
         }
-        if (bioPendingJobsOfType(type) <= num) break;
     }
 }
-
-/* Return the older job of the specified type. */
-time_t bioOlderJobOfType(int type) {
-    time_t time;
-    listNode *ln;
-    struct bio_job *job;
-
-    pthread_mutex_lock(&bio_mutex[type]);
-    ln = listFirst(bio_jobs[type]);
-    if (ln == NULL) {
-        pthread_mutex_unlock(&bio_mutex[type]);
-        return 0;
-    }
-    job = ln->value;
-    time = job->time;
-    pthread_mutex_unlock(&bio_mutex[type]);
-    return time;
-}
-