ST: Use clock_gettime to prevent time jumping backwards. v7.0.17

trunk/3rdparty/st-srs/Makefile

@@ -185,11 +185,9 @@ endif
 # make EXTRA_CFLAGS=-UMD_HAVE_EPOLL <target>
 #
 # or to enable sendmmsg(2) support:
-#
 # make EXTRA_CFLAGS="-DMD_HAVE_SENDMMSG -D_GNU_SOURCE"
 #
 # or to enable stats for ST:
-#
 # make EXTRA_CFLAGS=-DDEBUG_STATS
 #
 # or cache the stack and reuse it:
@@ -201,6 +199,9 @@ endif
 # or enable support for asan:
 # make EXTRA_CFLAGS="-DMD_ASAN -fsanitize=address -fno-omit-frame-pointer"
 #
+# or to disable the clock_gettime for MacOS before 10.12, see https://github.com/ossrs/srs/issues/3978
+# make EXTRA_CFLAGS=-DMD_OSX_NO_CLOCK_GETTIME
+#
 # or enable the coverage for utest:
 # make UTEST_FLAGS="-fprofile-arcs -ftest-coverage"
 #

trunk/3rdparty/st-srs/md.h

@@ -101,10 +101,21 @@ extern void _st_md_cxt_restore(_st_jmp_buf_t env, int val);
         #error Unknown CPU architecture
     #endif
 
-    #define MD_GET_UTIME()            \
-        struct timeval tv;              \
-        (void) gettimeofday(&tv, NULL); \
-        return (tv.tv_sec * 1000000LL + tv.tv_usec)
+    #if defined (MD_OSX_NO_CLOCK_GETTIME)
+        #define MD_GET_UTIME()                          \
+            struct timeval tv;                          \
+            (void) gettimeofday(&tv, NULL);             \
+            return (tv.tv_sec * 1000000LL + tv.tv_usec)
+    #else
+        /*
+         * https://github.com/ossrs/srs/issues/3978
+         * use clock_gettime to get the timestamp in microseconds.
+         */
+        #define MD_GET_UTIME()                                 \
+            struct timespec ts;                                \
+            clock_gettime(CLOCK_MONOTONIC, &ts);               \
+            return (ts.tv_sec * 1000000LL + ts.tv_nsec / 1000)
+    #endif
 
 #elif defined (LINUX)
 
@@ -120,13 +131,13 @@ extern void _st_md_cxt_restore(_st_jmp_buf_t env, int val);
     #define MD_HAVE_SOCKLEN_T
 
     /*
-     * All architectures and flavors of linux have the gettimeofday
-     * function but if you know of a faster way, use it.
+     * https://github.com/ossrs/srs/issues/3978
+     * use clock_gettime to get the timestamp in microseconds.
      */
-    #define MD_GET_UTIME()            \
-        struct timeval tv;              \
-        (void) gettimeofday(&tv, NULL); \
-        return (tv.tv_sec * 1000000LL + tv.tv_usec)
+    #define MD_GET_UTIME()                                 \
+        struct timespec ts;                                \
+        clock_gettime(CLOCK_MONOTONIC, &ts);               \
+        return (ts.tv_sec * 1000000LL + ts.tv_nsec / 1000)
 
     #if defined(__i386__)
         #define MD_GET_SP(_t) *((long *)&((_t)->context[0].__jmpbuf[4]))

trunk/auto/depends.sh

@@ -266,6 +266,9 @@ fi
 # for osx, use darwin for st, donot use epoll.
 if [[ $SRS_OSX == YES ]]; then
     _ST_MAKE=darwin-debug && _ST_OBJ="DARWIN_`uname -r`_DBG"
+    if [[ $SRS_OSX_HAS_CLOCK_GETTIME != YES ]]; then
+        _ST_EXTRA_CFLAGS="$_ST_EXTRA_CFLAGS -DMD_OSX_NO_CLOCK_GETTIME"
+    fi
 fi
 # for windows/cygwin
 if [[ $SRS_CYGWIN64 = YES ]]; then

trunk/auto/options.sh

@@ -112,6 +112,8 @@ SRS_CROSS_BUILD_HOST=
 SRS_CROSS_BUILD_PREFIX=
 # For cache build
 SRS_BUILD_CACHE=YES
+# Only support MacOS 10.12+ for clock_gettime, see https://github.com/ossrs/srs/issues/3978
+SRS_OSX_HAS_CLOCK_GETTIME=YES
 #
 #####################################################################################
 # Toolchain for cross-build on Ubuntu for ARM or MIPS.
@@ -150,7 +152,9 @@ function apply_system_options() {
     OS_IS_RISCV=$(gcc -dM -E - </dev/null |grep -q '#define __riscv 1' && echo YES)
 
     # Set the os option automatically.
-    if [[ $OS_IS_OSX == YES ]]; then SRS_OSX=YES; fi
+    if [[ $OS_IS_OSX == YES ]]; then
+        SRS_OSX=YES;
+    fi
     if [[ $OS_IS_CYGWIN == YES ]]; then SRS_CYGWIN64=YES; fi
 
     if [[ $OS_IS_OSX == YES ]]; then SRS_JOBS=$(sysctl -n hw.ncpu 2>/dev/null || echo 1); fi

trunk/configure

@@ -464,7 +464,8 @@ if [[ $SRS_UTEST == YES ]]; then
     MODULE_FILES=("srs_utest" "srs_utest_amf0" "srs_utest_kernel" "srs_utest_core"
         "srs_utest_config" "srs_utest_rtmp" "srs_utest_http" "srs_utest_avc" "srs_utest_reload"
         "srs_utest_mp4" "srs_utest_service" "srs_utest_app" "srs_utest_rtc" "srs_utest_config2"
-        "srs_utest_protocol" "srs_utest_protocol2" "srs_utest_kernel2" "srs_utest_protocol3")
+        "srs_utest_protocol" "srs_utest_protocol2" "srs_utest_kernel2" "srs_utest_protocol3" 
+        "srs_utest_st")
     if [[ $SRS_SRT == YES ]]; then
         MODULE_FILES+=("srs_utest_srt")
     fi

trunk/doc/CHANGELOG.md

@@ -7,6 +7,7 @@ The changelog for SRS.
 <a name="v7-changes"></a>
 
 ## SRS 7.0 Changelog
+* v7.0, 2024-10-15, Merge [#3979](https://github.com/ossrs/srs/pull/3979): ST: Use clock_gettime to prevent time jumping backwards. v7.0.17 (#3979)
 * v7.0, 2024-09-09, Merge [#4158](https://github.com/ossrs/srs/pull/4158): Proxy: Support proxy server for SRS. v7.0.16 (#4158)
 * v7.0, 2024-09-09, Merge [#4171](https://github.com/ossrs/srs/pull/4171): Heartbeat: Report ports for proxy server. v7.0.15 (#4171)
 * v7.0, 2024-09-01, Merge [#4165](https://github.com/ossrs/srs/pull/4165): FLV: Refine source and http handler. v7.0.14 (#4165)

trunk/src/core/srs_core_version7.hpp

@@ -9,6 +9,6 @@
 
 #define VERSION_MAJOR       7
 #define VERSION_MINOR       0
-#define VERSION_REVISION    16
+#define VERSION_REVISION    17
 
 #endif

trunk/src/utest/srs_utest_st.cpp

@@ -0,0 +1,117 @@
+//
+// Copyright (c) 2013-2024 The SRS Authors
+//
+// SPDX-License-Identifier: MIT
+//
+#include <srs_utest_st.hpp>
+#include <sys/time.h>
+#include <time.h>
+#include <unistd.h>
+
+using namespace std;
+
+VOID TEST(StTest, StUtimeInMicroseconds)
+{
+	st_utime_t st_time_1 = st_utime();
+	// sleep 1 microsecond
+#if !defined(SRS_CYGWIN64)
+	usleep(1);
+#endif
+	st_utime_t st_time_2 = st_utime();
+
+	EXPECT_GT(st_time_1, 0);
+	EXPECT_GT(st_time_2, 0);
+	EXPECT_GE(st_time_2, st_time_1);
+	// st_time_2 - st_time_1 should be in range of [1, 100] microseconds
+	EXPECT_GE(st_time_2 - st_time_1, 0);
+	EXPECT_LE(st_time_2 - st_time_1, 100);
+}
+
+static inline st_utime_t time_gettimeofday() {
+	struct timeval tv;
+	gettimeofday(&tv, NULL);
+	return (tv.tv_sec * 1000000LL + tv.tv_usec);
+}
+
+VOID TEST(StTest, StUtimePerformance)
+{
+	clock_t start;
+	int gettimeofday_elapsed_time = 0;
+	int st_utime_elapsed_time = 0;
+
+	// Both the st_utime(clock_gettime or gettimeofday) and gettimeofday's
+	// elpased time to execute is dependence on whether it is the first time be called.
+	// In general, the gettimeofday has better performance, but the gap between
+	// them is really small, maybe less than 10 clock ~ 10 microseconds.
+
+	// check st_utime first, then gettimeofday
+	{
+		start = clock();
+		st_utime_t t2 = st_utime();
+		int elapsed_time = clock() - start;
+		st_utime_elapsed_time += elapsed_time;
+		EXPECT_GT(t2, 0);
+
+		start = clock();
+		st_utime_t t1 = time_gettimeofday();
+		elapsed_time = clock() - start;
+		gettimeofday_elapsed_time += elapsed_time;
+		EXPECT_GT(t1, 0);
+
+
+		EXPECT_GE(gettimeofday_elapsed_time, 0);
+		EXPECT_GE(st_utime_elapsed_time, 0);
+
+		// pass the test, if 
+		EXPECT_LT(gettimeofday_elapsed_time > st_utime_elapsed_time ?
+				  gettimeofday_elapsed_time - st_utime_elapsed_time :
+				  st_utime_elapsed_time - gettimeofday_elapsed_time, 10);
+	}
+
+	// check gettimeofday first, then st_utime
+	{
+		start = clock();
+		st_utime_t t1 = time_gettimeofday();
+		int elapsed_time = clock() - start;
+		gettimeofday_elapsed_time += elapsed_time;
+		EXPECT_GT(t1, 0);
+
+		start = clock();
+		st_utime_t t2 = st_utime();
+		elapsed_time = clock() - start;
+		st_utime_elapsed_time += elapsed_time;
+		EXPECT_GT(t2, 0);
+
+		EXPECT_GE(gettimeofday_elapsed_time, 0);
+		EXPECT_GE(st_utime_elapsed_time, 0);
+
+		EXPECT_LT(gettimeofday_elapsed_time > st_utime_elapsed_time ?
+				  gettimeofday_elapsed_time - st_utime_elapsed_time :
+				  st_utime_elapsed_time - gettimeofday_elapsed_time, 10);
+	}
+
+	// compare st_utime & gettimeofday in a loop
+	for (int i = 0; i < 100; i++) {
+		    start = clock();
+			st_utime_t t2 = st_utime();
+			int elapsed_time = clock() - start;
+			st_utime_elapsed_time = elapsed_time;
+			EXPECT_GT(t2, 0);
+			usleep(1);
+
+			start = clock();
+			st_utime_t t1 = time_gettimeofday();
+			elapsed_time = clock() - start;
+			gettimeofday_elapsed_time = elapsed_time;
+			EXPECT_GT(t1, 0);
+			usleep(1);
+
+			EXPECT_GE(gettimeofday_elapsed_time, 0);
+			EXPECT_GE(st_utime_elapsed_time, 0);
+
+			EXPECT_LT(gettimeofday_elapsed_time > st_utime_elapsed_time ?
+					  gettimeofday_elapsed_time - st_utime_elapsed_time :
+					  st_utime_elapsed_time - gettimeofday_elapsed_time, 10);
+
+	}
+}

trunk/src/utest/srs_utest_st.hpp

@@ -0,0 +1,15 @@
+//
+// Copyright (c) 2013-2024 The SRS Authors
+//
+// SPDX-License-Identifier: MIT
+//
+
+#ifndef SRS_UTEST_ST_HPP
+#define SRS_UTEST_ST_HPP
+
+#include <srs_utest.hpp>
+
+#include <st.h>
+
+#endif // SRS_UTEST_ST_HPP
+