X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Ftimeval.c;h=6e415147e4047b3e83cf8d06cdbadb0398a7f018;hb=e018053f14beb09ac7f634687c48ac2a214208f2;hp=05f1c2d3643030dc16c20bdcacb44cc0f72311ac;hpb=f43e80e023378a2c1ef18d3caee9b76d6d2a6d23;p=sliver-openvswitch.git

diff --git a/lib/timeval.c b/lib/timeval.c
index 05f1c2d36..6e415147e 100644
--- a/lib/timeval.c
+++ b/lib/timeval.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,11 +16,7 @@
 
 #include <config.h>
 #include "timeval.h"
-#include <assert.h>
 #include <errno.h>
-#if HAVE_EXECINFO_H
-#include <execinfo.h>
-#endif
 #include <poll.h>
 #include <signal.h>
 #include <stdlib.h>
@@ -39,6 +35,15 @@
 #include "util.h"
 #include "vlog.h"
 
+/* backtrace() from <execinfo.h> is really useful, but it is not signal safe
+ * everywhere, such as on x86-64.  */
+#if HAVE_EXECINFO_H && !defined __x86_64__
+#  define USE_BACKTRACE 1
+#  include <execinfo.h>
+#else
+#  define USE_BACKTRACE 0
+#endif
+
 VLOG_DEFINE_THIS_MODULE(timeval);
 
 /* The clock to use for measuring time intervals.  This is CLOCK_MONOTONIC by
@@ -94,9 +99,7 @@ static void timespec_add(struct timespec *sum,
                          const struct timespec *a, const struct timespec *b);
 static unixctl_cb_func backtrace_cb;
 
-#ifndef HAVE_EXECINFO_H
-#define HAVE_EXECINFO_H 0
-
+#if !USE_BACKTRACE
 static int
 backtrace(void **buffer OVS_UNUSED, int size OVS_UNUSED)
 {
@@ -108,7 +111,7 @@ backtrace_symbols(void *const *buffer OVS_UNUSED, int size OVS_UNUSED)
 {
     NOT_REACHED();
 }
-#endif
+#endif  /* !USE_BACKTRACE */
 
 /* Initializes the timetracking module, if not already initialized. */
 static void
@@ -121,9 +124,19 @@ time_init(void)
     }
     inited = true;
 
+    /* The implementation of backtrace() in glibc does some one time
+     * initialization which is not signal safe.  This can cause deadlocks if
+     * run from the signal handler.  As a workaround, force the initialization
+     * to happen here. */
+    if (USE_BACKTRACE) {
+        void *bt[1];
+
+        backtrace(bt, ARRAY_SIZE(bt));
+    }
+
     memset(traces, 0, sizeof traces);
 
-    if (HAVE_EXECINFO_H && CACHE_TIME) {
+    if (USE_BACKTRACE && CACHE_TIME) {
         unixctl_command_register("backtrace", "", 0, 0, backtrace_cb, NULL);
     }
 
@@ -319,7 +332,7 @@ time_alarm(unsigned int secs)
     time_refresh();
 
     now = time_msec();
-    msecs = secs * 1000;
+    msecs = secs * 1000LL;
 
     block_sigalrm(&oldsigs);
     deadline = now < LLONG_MAX - msecs ? now + msecs : LLONG_MAX;
@@ -410,7 +423,7 @@ sigalrm_handler(int sig_nr OVS_UNUSED)
     wall_tick = true;
     monotonic_tick = true;
 
-    if (HAVE_EXECINFO_H && CACHE_TIME) {
+    if (USE_BACKTRACE && CACHE_TIME) {
         struct trace *trace = &traces[trace_head];
 
         trace->n_frames = backtrace(trace->backtrace,
@@ -507,7 +520,7 @@ log_poll_interval(long long int last_wakeup)
 {
     long long int interval = time_msec() - last_wakeup;
 
-    if (interval >= 1000) {
+    if (interval >= 1000 && !warp_offset.tv_sec && !warp_offset.tv_nsec) {
         const struct rusage *last_rusage = get_recent_rusage();
         struct rusage rusage;
 
@@ -624,7 +637,7 @@ format_backtraces(struct ds *ds, size_t min_count)
 {
     time_init();
 
-    if (HAVE_EXECINFO_H && CACHE_TIME) {
+    if (USE_BACKTRACE && CACHE_TIME) {
         struct hmap trace_map = HMAP_INITIALIZER(&trace_map);
         struct trace *trace, *next;
         sigset_t oldsigs;
@@ -721,7 +734,7 @@ backtrace_cb(struct unixctl_conn *conn,
 {
     struct ds ds = DS_EMPTY_INITIALIZER;
 
-    assert(HAVE_EXECINFO_H && CACHE_TIME);
+    ovs_assert(USE_BACKTRACE && CACHE_TIME);
     format_backtraces(&ds, 0);
     unixctl_command_reply(conn, ds_cstr(&ds));
     ds_destroy(&ds);