Replace all uses of strerror() by ovs_strerror(), for thread safety.

[sliver-openvswitch.git] / lib / fatal-signal.c

diff --git a/lib/fatal-signal.c b/lib/fatal-signal.c
index 80ecfc3..1770457 100644 (file)
--- a/lib/fatal-signal.c
+++ b/lib/fatal-signal.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010 Nicira Networks.
+ * 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.
@@ -15,7 +15,6 @@
  */
 #include <config.h>
 #include "fatal-signal.h"
-#include <assert.h>
 #include <errno.h>
 #include <signal.h>
 #include <stdbool.h>
@@ -26,12 +25,20 @@
 #include <unistd.h>
 #include "poll-loop.h"
 #include "shash.h"
+#include "sset.h"
+#include "signals.h"
 #include "socket-util.h"
 #include "util.h"
-
-#define THIS_MODULE VLM_fatal_signal
 #include "vlog.h"
 
+#include "type-props.h"
+
+#ifndef SIG_ATOMIC_MAX
+#define SIG_ATOMIC_MAX TYPE_MAXIMUM(sig_atomic_t)
+#endif
+
+VLOG_DEFINE_THIS_MODULE(fatal_signal);
+
 /* Signals to catch. */
 static const int fatal_signals[] = { SIGTERM, SIGINT, SIGHUP, SIGALRM };
 
@@ -66,11 +73,7 @@ fatal_signal_init(void)
 
         inited = true;
 
-        if (pipe(signal_fds)) {
-            ovs_fatal(errno, "could not create pipe");
-        }
-        set_nonblocking(signal_fds[0]);
-        set_nonblocking(signal_fds[1]);
+        xpipe_nonblocking(signal_fds);
 
         sigemptyset(&fatal_signal_set);
         for (i = 0; i < ARRAY_SIZE(fatal_signals); i++) {
@@ -78,12 +81,10 @@ fatal_signal_init(void)
             struct sigaction old_sa;
 
             sigaddset(&fatal_signal_set, sig_nr);
-            if (sigaction(sig_nr, NULL, &old_sa)) {
-                ovs_fatal(errno, "sigaction");
-            }
+            xsigaction(sig_nr, NULL, &old_sa);
             if (old_sa.sa_handler == SIG_DFL
                 && signal(sig_nr, fatal_signal_handler) == SIG_ERR) {
-                ovs_fatal(errno, "signal");
+                VLOG_FATAL("signal failed (%s)", ovs_strerror(errno));
             }
         }
         atexit(atexit_handler);
@@ -110,7 +111,7 @@ fatal_signal_add_hook(void (*hook_cb)(void *aux), void (*cancel_cb)(void *aux),
 {
     fatal_signal_init();
 
-    assert(n_hooks < MAX_HOOKS);
+    ovs_assert(n_hooks < MAX_HOOKS);
     hooks[n_hooks].hook_cb = hook_cb;
     hooks[n_hooks].cancel_cb = cancel_cb;
     hooks[n_hooks].aux = aux;
@@ -134,12 +135,30 @@ fatal_signal_handler(int sig_nr)
     stored_sig_nr = sig_nr;
 }
 
+/* Check whether a fatal signal has occurred and, if so, call the fatal signal
+ * hooks and exit.
+ *
+ * This function is called automatically by poll_block(), but specialized
+ * programs that may not always call poll_block() on a regular basis should
+ * also call it periodically.  (Therefore, any function with "block" in its
+ * name should call fatal_signal_run() each time it is called, either directly
+ * or through poll_block(), because such functions can only used by specialized
+ * programs that can afford to block outside their main loop around
+ * poll_block().)
+ */
 void
 fatal_signal_run(void)
 {
-    int sig_nr = stored_sig_nr;
+    sig_atomic_t sig_nr;
 
+    fatal_signal_init();
+
+    sig_nr = stored_sig_nr;
     if (sig_nr != SIG_ATOMIC_MAX) {
+        char namebuf[SIGNAL_NAME_BUFSIZE];
+
+        VLOG_WARN("terminating with signal %d (%s)",
+                  (int)sig_nr, signal_name(sig_nr, namebuf, sizeof namebuf));
         call_hooks(sig_nr);
 
         /* Re-raise the signal with the default handling so that the program
@@ -152,6 +171,7 @@ fatal_signal_run(void)
 void
 fatal_signal_wait(void)
 {
+    fatal_signal_init();
     poll_fd_wait(signal_fds[0], POLLIN);
 }
 
@@ -179,8 +199,8 @@ call_hooks(int sig_nr)
     }
 }
 \f
-/* Files to delete on exit.  (The 'data' member of each node is unused.) */
-static struct shash files = SHASH_INITIALIZER(&files);
+/* Files to delete on exit. */
+static struct sset files = SSET_INITIALIZER(&files);
 
 /* Has a hook function been registered with fatal_signal_add_hook() (and not
  * cleared by fatal_signal_fork())? */
@@ -200,9 +220,7 @@ fatal_signal_add_file_to_unlink(const char *file)
         fatal_signal_add_hook(unlink_files, cancel_files, NULL, true);
     }
 
-    if (!shash_find(&files, file)) {
-        shash_add(&files, file, NULL);
-    }
+    sset_add(&files, file);
 }
 
 /* Unregisters 'file' from being unlinked when the program terminates via
@@ -210,12 +228,7 @@ fatal_signal_add_file_to_unlink(const char *file)
 void
 fatal_signal_remove_file_to_unlink(const char *file)
 {
-    struct shash_node *node;
-
-    node = shash_find(&files, file);
-    if (node) {
-        shash_delete(&files, node);
-    }
+    sset_find_and_delete(&files, file);
 }
 
 /* Like fatal_signal_remove_file_to_unlink(), but also unlinks 'file'.
@@ -225,7 +238,7 @@ fatal_signal_unlink_file_now(const char *file)
 {
     int error = unlink(file) ? errno : 0;
     if (error) {
-        VLOG_WARN("could not unlink \"%s\" (%s)", file, strerror(error));
+        VLOG_WARN("could not unlink \"%s\" (%s)", file, ovs_strerror(error));
     }
 
     fatal_signal_remove_file_to_unlink(file);
@@ -236,23 +249,23 @@ fatal_signal_unlink_file_now(const char *file)
 static void
 unlink_files(void *aux OVS_UNUSED)
 {
-    do_unlink_files(); 
+    do_unlink_files();
 }
 
 static void
 cancel_files(void *aux OVS_UNUSED)
 {
-    shash_clear(&files);
+    sset_clear(&files);
     added_hook = false;
 }
 
 static void
 do_unlink_files(void)
 {
-    struct shash_node *node;
+    const char *file;
 
-    SHASH_FOR_EACH (node, &files) {
-        unlink(node->name);
+    SSET_FOR_EACH (file, &files) {
+        unlink(file);
     }
 }
 \f