Merge topic 'monotonic-time'

749b7506 ProcessUNIX: Use monotonic clock in kwsysProcessTimeGetCurrent() for POSIX

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !57

CMakeLists.txt

@@ -445,8 +445,13 @@ KWSYS_PLATFORM_C_TEST(KWSYS_C_HAS_PTRDIFF_T
   "Checking whether C compiler has ptrdiff_t in stddef.h" DIRECT)
 KWSYS_PLATFORM_C_TEST(KWSYS_C_HAS_SSIZE_T
   "Checking whether C compiler has ssize_t in unistd.h" DIRECT)
+IF(KWSYS_USE_Process)
+  KWSYS_PLATFORM_C_TEST(KWSYS_C_HAS_CLOCK_GETTIME_MONOTONIC
+    "Checking whether C compiler has clock_gettime" DIRECT)
+ENDIF()
+
 SET_SOURCE_FILES_PROPERTIES(ProcessUNIX.c System.c PROPERTIES
-  COMPILE_FLAGS "-DKWSYS_C_HAS_PTRDIFF_T=${KWSYS_C_HAS_PTRDIFF_T} -DKWSYS_C_HAS_SSIZE_T=${KWSYS_C_HAS_SSIZE_T}"
+  COMPILE_FLAGS "-DKWSYS_C_HAS_PTRDIFF_T=${KWSYS_C_HAS_PTRDIFF_T} -DKWSYS_C_HAS_SSIZE_T=${KWSYS_C_HAS_SSIZE_T} -DKWSYS_C_HAS_CLOCK_GETTIME_MONOTONIC=${KWSYS_C_HAS_CLOCK_GETTIME_MONOTONIC}"
   )
 
 IF(DEFINED KWSYS_PROCESS_USE_SELECT)

ProcessUNIX.c

@@ -2026,7 +2026,15 @@ static kwsysProcessTime kwsysProcessTimeGetCurrent(void)
 {
   kwsysProcessTime current;
   kwsysProcessTimeNative current_native;
+#if KWSYS_C_HAS_CLOCK_GETTIME_MONOTONIC
+  struct timespec current_timespec;
+  clock_gettime(CLOCK_MONOTONIC, &current_timespec);
+
+  current_native.tv_sec = current_timespec.tv_sec;
+  current_native.tv_usec = current_timespec.tv_nsec / 1000;
+#else
   gettimeofday(&current_native, 0);
+#endif
   current.tv_sec = (long)current_native.tv_sec;
   current.tv_usec = (long)current_native.tv_usec;
   return current;

kwsysPlatformTestsC.c

@@ -55,6 +55,21 @@ int KWSYS_PLATFORM_TEST_C_MAIN()
 }
 #endif
 
+#ifdef TEST_KWSYS_C_HAS_CLOCK_GETTIME_MONOTONIC
+#if defined(__APPLE__)
+#include <AvailabilityMacros.h>
+#if MAC_OS_X_VERSION_MIN_REQUIRED < 101200
+#error "clock_gettime not available on macOS < 10.12"
+#endif
+#endif
+#include <time.h>
+int KWSYS_PLATFORM_TEST_C_MAIN()
+{
+  struct timespec ts;
+  return clock_gettime(CLOCK_MONOTONIC, &ts);
+}
+#endif
+
 #ifdef TEST_KWSYS_C_TYPE_MACROS
 char* info_macros =
 #if defined(__SIZEOF_SHORT__)