Use recent libevent features when possible

svn:r3940

configure.in

@@ -152,7 +152,7 @@ dnl These headers are not essential
 
 AC_CHECK_HEADERS(stdint.h sys/types.h inttypes.h sys/param.h sys/wait.h sys/limits.h netinet/in.h arpa/inet.h machine/limits.h syslog.h sys/time.h sys/resource.h pthread.h stddef.h inttypes.h)
 
-AC_CHECK_FUNCS(gettimeofday ftime socketpair uname inet_aton strptime getrlimit setrlimit strlcat strlcpy strtoull getpwnam ftello pthread_create getaddrinfo localtime_r gmtime_r)
+AC_CHECK_FUNCS(gettimeofday ftime socketpair uname inet_aton strptime getrlimit setrlimit strlcat strlcpy strtoull getpwnam ftello pthread_create getaddrinfo localtime_r gmtime_r event_get_version event_get_method event_set_log_callback)
 AC_FUNC_FSEEKO
 
 AC_CHECK_MEMBERS([struct timeval.tv_sec])

src/common/log.c

@@ -17,6 +17,12 @@ const char log_c_id[] = "$Id$";
 #include "./util.h"
 #include "./log.h"
 
+#ifdef HAVE_EVENT_H
+#include <event.h>
+#else
+#error "Tor requires libevent to build."
+#endif
+
 #define TRUNCATED_STR "[...truncated]"
 #define TRUNCATED_STR_LEN 14
 
@@ -475,3 +481,31 @@ void switch_logs_debug(void)
   }
 }
 
+#ifdef HAVE_EVENT_SET_LOG_CALLBACK
+void libevent_logging_callback(int severity, const char *msg)
+{
+  switch (severity) {
+    case _EVENT_LOG_DEBUG:
+      log(LOG_DEBUG, "Message from libevent: %s", msg);
+      break;
+    case _EVENT_LOG_MSG:
+      log(LOG_INFO, "Message from libevent: %s", msg);
+      break;
+    case _EVENT_LOG_WARN:
+      log(LOG_WARN, "Warning from libevent: %s", msg);
+      break;
+    case _EVENT_LOG_ERR:
+      log(LOG_ERR, "Error from libevent: %s", msg);
+      break;
+    default:
+      log(LOG_WARN, "Message [%d] from libevent: %s", severity, msg);
+      break;
+  }
+}
+void configure_libevent_logging(void)
+{
+  event_set_log_callback(libevent_logging_callback);
+}
+#else
+void configure_libevent_logging(void) {}
+#endif

src/common/log.h

@@ -66,6 +66,7 @@ void reset_logs(void);
 void add_temp_log(void);
 void close_temp_logs(void);
 void mark_logs_temp(void);
+void configure_libevent_logging(void);
 
 /* Outputs a message to stdout */
 void _log(int severity, const char *format, ...) CHECK_PRINTF(2,3);

src/or/config.c

@@ -269,7 +269,16 @@ options_act(void) {
     start_daemon(options->DataDirectory);
   }
   if (!libevent_initialized) {
+    configure_libevent_logging();
     event_init();
+#if defined(HAVE_EVENT_GET_VERSION) && defined(HAVE_EVENT_GET_METHOD)
+    /* Making this a NOTICE for now so we can link bugs to a libevent versions
+     * or methods better. */
+    log_fn(LOG_NOTICE, "Initialized libevent version %s using method %s",
+           event_get_version(), event_get_method());
+#else
+    log_fn(LOG_NOTICE, "Initialized old libevent (version 1.0b or earlier)");
+#endif
     libevent_initialized = 1;
   }
 

src/or/main.c

@@ -953,8 +953,13 @@ static int do_main_loop(void) {
       int e = errno;
       /* let the program survive things like ^z */
       if (e != EINTR) {
-        log_fn(LOG_ERR,"event poll failed: %s [%d]",
+#ifdef HAVE_EVENT_GET_METHOD
+        log_fn(LOG_ERR,"libevent poll with %s failed: %s [%d]",
+               event_get_method(), tor_socket_strerror(e), e);
+#else
+        log_fn(LOG_ERR,"libevent poll failed: %s [%d]",
                tor_socket_strerror(e), e);
+#endif
         return -1;
       } else {
         log_fn(LOG_DEBUG,"event poll interrupted.");