fix isse #35: the gettimeofday jitter, log warn message

@@ -338,7 +338,7 @@ CORE_OBJS="${MODULE_OBJS[@]}"
 MODULE_ID="KERNEL" 
 MODULE_DEPENDS=("CORE") 
 ModuleLibIncs=(${SRS_OBJS})
-MODULE_FILES=("srs_kernel_error" "srs_kernel_log" "srs_kernel_stream" "srs_kernel_buffer")
+MODULE_FILES=("srs_kernel_error" "srs_kernel_log" "srs_kernel_stream" "srs_kernel_buffer" "srs_kernel_utility")
 KERNEL_INCS="src/kernel"; MODULE_DIR=${KERNEL_INCS} . auto/modules.sh
 KERNEL_OBJS="${MODULE_OBJS[@]}"
 #

@@ -34,6 +34,7 @@ using namespace std;
 #include <srs_protocol_rtmp_stack.hpp>
 #include <srs_app_config.hpp>
 #include <srs_core_autofree.hpp>
+#include <srs_kernel_utility.hpp>
 
 SrsBandwidth::SrsBandwidth()
 {

@@ -37,6 +37,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <srs_kernel_error.hpp>
 #include <srs_app_client.hpp>
 #include <srs_app_config.hpp>
+#include <srs_kernel_utility.hpp>
 
 #define SERVER_LISTEN_BACKLOG 512
 #define SRS_TIME_RESOLUTION_MS 500

@@ -24,6 +24,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <srs_app_socket.hpp>
 
 #include <srs_kernel_error.hpp>
+#include <srs_kernel_utility.hpp>
 
 SrsSocket::SrsSocket(st_netfd_t client_stfd)
 {

@@ -24,30 +24,9 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <srs_core.hpp>
 
 #include <string.h>
-#include <sys/time.h>
 #include <netdb.h>
 #include <arpa/inet.h>
 
-static int64_t _srs_system_time_us_cache = 0;
-
-int64_t srs_get_system_time_ms()
-{
-    return _srs_system_time_us_cache / 1000;
-}
-
-void srs_update_system_time_ms()
-{
-    timeval now;
-    
-    gettimeofday(&now, NULL);
-
-    // @see: https://github.com/winlinvip/simple-rtmp-server/issues/35
-    // we must convert the tv_sec/tv_usec to int64_t.
-    _srs_system_time_us_cache = ((int64_t)now.tv_sec) * 1000 * 1000 + (int64_t)now.tv_usec;
-    
-    _srs_system_time_us_cache = srs_max(0, _srs_system_time_us_cache);
-}
-
 std::string srs_replace(std::string str, std::string old_str, std::string new_str)
 {
     std::string ret = str;

@@ -86,11 +86,6 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define srs_min(a, b) (((a) < (b))? (a) : (b))
 #define srs_max(a, b) (((a) < (b))? (b) : (a))
 
-// get current system time in ms, use cache to avoid performance problem
-extern int64_t srs_get_system_time_ms();
-// the deamon st-thread will update it.
-extern void srs_update_system_time_ms();
-
 // signal defines.
 #define SIGNAL_RELOAD SIGHUP
 

+/*
+The MIT License (MIT)
+
+Copyright (c) 2013-2014 winlin
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#include <srs_kernel_utility.hpp>
+
+#include <sys/time.h>
+
+#include <srs_kernel_log.hpp>
+
+static int64_t _srs_system_time_us_cache = 0;
+
+int64_t srs_get_system_time_ms()
+{
+    return _srs_system_time_us_cache / 1000;
+}
+
+void srs_update_system_time_ms()
+{
+    timeval now;
+    
+    if (gettimeofday(&now, NULL) < 0) {
+        srs_warn("gettimeofday failed, ignore");
+        return;
+    }
+
+    // @see: https://github.com/winlinvip/simple-rtmp-server/issues/35
+    // we must convert the tv_sec/tv_usec to int64_t.
+    int64_t now_us = ((int64_t)now.tv_sec) * 1000 * 1000 + (int64_t)now.tv_usec;
+    if (now_us < _srs_system_time_us_cache) {
+        srs_warn("system time negative, "
+            "history=%"PRId64"us, now=%"PRId64"", _srs_system_time_us_cache, now_us);
+    }
+    
+    _srs_system_time_us_cache = now_us;
+}

+/*
+The MIT License (MIT)
+
+Copyright (c) 2013-2014 winlin
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#ifndef SRS_KERNEL_UTILITY_HPP
+#define SRS_KERNEL_UTILITY_HPP
+
+/*
+#include <srs_kernel_utility.hpp>
+*/
+
+#include <srs_core.hpp>
+
+// get current system time in ms, use cache to avoid performance problem
+extern int64_t srs_get_system_time_ms();
+// the deamon st-thread will update it.
+extern void srs_update_system_time_ms();
+
+#endif

@@ -23,6 +23,8 @@ file
     ..\kernel\srs_kernel_log.cpp,
     ..\kernel\srs_kernel_stream.hpp,
     ..\kernel\srs_kernel_stream.cpp,
+    ..\kernel\srs_kernel_utility.hpp,
+    ..\kernel\srs_kernel_utility.cpp,
     rtmp-protocol readonly separator,
     ..\rtmp\srs_protocol_amf0.hpp,
     ..\rtmp\srs_protocol_amf0.cpp,