+
+/* ==================== Logging functions for debugging ===================== */
+
+void redisLogHexDump(int level, char *descr, void *value, size_t len) {
+ char buf[65], *b;
+ unsigned char *v = value;
+ char charset[] = "0123456789abcdef";
+
+ redisLog(level,"%s (hexdump):", descr);
+ b = buf;
+ while(len) {
+ b[0] = charset[(*v)>>4];
+ b[1] = charset[(*v)&0xf];
+ b[2] = '\0';
+ b += 2;
+ len--;
+ v++;
+ if (b-buf == 64 || len == 0) {
+ redisLogRaw(level|REDIS_LOG_RAW,buf);
+ b = buf;
+ }
+ }
+ redisLogRaw(level|REDIS_LOG_RAW,"\n");
+}
+
+/* =========================== Software Watchdog ============================ */
+#include <sys/time.h>
+
+void watchdogSignalHandler(int sig, siginfo_t *info, void *secret) {
+#ifdef HAVE_BACKTRACE
+ ucontext_t *uc = (ucontext_t*) secret;
+#endif
+ REDIS_NOTUSED(info);
+ REDIS_NOTUSED(sig);
+
+ redisLogFromHandler(REDIS_WARNING,"\n--- WATCHDOG TIMER EXPIRED ---");
+#ifdef HAVE_BACKTRACE
+ logStackTrace(uc);
+#else
+ redisLogFromHandler(REDIS_WARNING,"Sorry: no support for backtrace().");
+#endif
+ redisLogFromHandler(REDIS_WARNING,"--------\n");
+}
+
+/* Schedule a SIGALRM delivery after the specified period in milliseconds.
+ * If a timer is already scheduled, this function will re-schedule it to the
+ * specified time. If period is 0 the current timer is disabled. */
+void watchdogScheduleSignal(int period) {
+ struct itimerval it;
+
+ /* Will stop the timer if period is 0. */
+ it.it_value.tv_sec = period/1000;
+ it.it_value.tv_usec = (period%1000)*1000;
+ /* Don't automatically restart. */
+ it.it_interval.tv_sec = 0;
+ it.it_interval.tv_usec = 0;
+ setitimer(ITIMER_REAL, &it, NULL);
+}
+
+/* Enable the software watchdong with the specified period in milliseconds. */
+void enableWatchdog(int period) {
+ int min_period;
+
+ if (server.watchdog_period == 0) {
+ struct sigaction act;
+
+ /* Watchdog was actually disabled, so we have to setup the signal
+ * handler. */
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_SIGINFO;
+ act.sa_sigaction = watchdogSignalHandler;
+ sigaction(SIGALRM, &act, NULL);
+ }
+ /* If the configured period is smaller than twice the timer period, it is
+ * too short for the software watchdog to work reliably. Fix it now
+ * if needed. */
+ min_period = (1000/REDIS_HZ)*2;
+ if (period < min_period) period = min_period;
+ watchdogScheduleSignal(period); /* Adjust the current timer. */
+ server.watchdog_period = period;
+}
+
+/* Disable the software watchdog. */
+void disableWatchdog(void) {
+ struct sigaction act;
+ if (server.watchdog_period == 0) return; /* Already disabled. */
+ watchdogScheduleSignal(0); /* Stop the current timer. */
+
+ /* Set the signal handler to SIG_IGN, this will also remove pending
+ * signals from the queue. */
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = 0;
+ act.sa_handler = SIG_IGN;
+ sigaction(SIGALRM, &act, NULL);
+ server.watchdog_period = 0;
+}
projects / redis.git / blobdiff