Use clock_gettime()'s CLOCK_REALTIME instead of gettimeofday().
The system_clock::now() function currently uses gettimeofday(). The
problem with gettimeofday() is that it is an obsolete XSI function,
hence unavailable on CloudABI. See:
http://pubs.opengroup.org/onlinepubs/9699919799/functions/gettimeofday.html
Change this code to use clock_gettime() with CLOCK_REALTIME instead,
which is more consistent, as clock_gettime() is already used for
steady_clock.
A previous version of this change actually attempted to change
system_clock::duration, but I reverted this part as it breaks the
existing ABI.
Differential Revision: http://reviews.llvm.org/D8253
Approved by: jroelofs
llvm-svn: 237390
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 4f0f708bf1a6f2604ce15929ad4deb10f462a85f
diff --git a/src/chrono.cpp b/src/chrono.cpp
index 4569411..57c7417 100644
--- a/src/chrono.cpp
+++ b/src/chrono.cpp
@@ -8,14 +8,21 @@
//===----------------------------------------------------------------------===//
#include "chrono"
-#include <sys/time.h> //for gettimeofday and timeval
-#ifdef __APPLE__
-#include <mach/mach_time.h> // mach_absolute_time, mach_timebase_info_data_t
-#else /* !__APPLE__ */
#include <cerrno> // errno
#include <system_error> // __throw_system_error
-#include <time.h> // clock_gettime, CLOCK_MONOTONIC
-#endif // __APPLE__
+#include <time.h> // clock_gettime, CLOCK_MONOTONIC and CLOCK_REALTIME
+
+#if !defined(CLOCK_REALTIME)
+#include <sys/time.h> // for gettimeofday and timeval
+#endif
+
+#if !defined(_LIBCPP_HAS_NO_MONOTONIC_CLOCK) && !defined(CLOCK_MONOTONIC)
+#if __APPLE__
+#include <mach/mach_time.h> // mach_absolute_time, mach_timebase_info_data_t
+#else
+#error "Monotonic clock not implemented"
+#endif
+#endif
_LIBCPP_BEGIN_NAMESPACE_STD
@@ -29,9 +36,16 @@
system_clock::time_point
system_clock::now() _NOEXCEPT
{
+#ifdef CLOCK_REALTIME
+ struct timespec tp;
+ if (0 != clock_gettime(CLOCK_REALTIME, &tp))
+ __throw_system_error(errno, "clock_gettime(CLOCK_REALTIME) failed");
+ return time_point(seconds(tp.tv_sec) + microseconds(tp.tv_nsec / 1000));
+#else // !CLOCK_REALTIME
timeval tv;
gettimeofday(&tv, 0);
return time_point(seconds(tv.tv_sec) + microseconds(tv.tv_usec));
+#endif // CLOCK_REALTIME
}
time_t
@@ -48,10 +62,26 @@
#ifndef _LIBCPP_HAS_NO_MONOTONIC_CLOCK
// steady_clock
+//
+// Warning: If this is not truly steady, then it is non-conforming. It is
+// better for it to not exist and have the rest of libc++ use system_clock
+// instead.
const bool steady_clock::is_steady;
-#ifdef __APPLE__
+#ifdef CLOCK_MONOTONIC
+
+steady_clock::time_point
+steady_clock::now() _NOEXCEPT
+{
+ struct timespec tp;
+ if (0 != clock_gettime(CLOCK_MONOTONIC, &tp))
+ __throw_system_error(errno, "clock_gettime(CLOCK_MONOTONIC) failed");
+ return time_point(seconds(tp.tv_sec) + nanoseconds(tp.tv_nsec));
+}
+
+#elif defined(__APPLE__)
+
// mach_absolute_time() * MachInfo.numer / MachInfo.denom is the number of
// nanoseconds since the computer booted up. MachInfo.numer and MachInfo.denom
// are run time constants supplied by the OS. This clock has no relationship
@@ -108,23 +138,9 @@
return time_point(duration(fp()));
}
-#else // __APPLE__
-// FIXME: if _LIBCPP_HAS_NO_MONOTONIC_CLOCK, then clock_gettime isn't going to
-// work. It may be possible to fall back on something else, depending on the system.
-
-// Warning: If this is not truly steady, then it is non-conforming. It is
-// better for it to not exist and have the rest of libc++ use system_clock
-// instead.
-
-steady_clock::time_point
-steady_clock::now() _NOEXCEPT
-{
- struct timespec tp;
- if (0 != clock_gettime(CLOCK_MONOTONIC, &tp))
- __throw_system_error(errno, "clock_gettime(CLOCK_MONOTONIC) failed");
- return time_point(seconds(tp.tv_sec) + nanoseconds(tp.tv_nsec));
-}
-#endif // __APPLE__
+#else
+#error "Monotonic clock not implemented"
+#endif
#endif // !_LIBCPP_HAS_NO_MONOTONIC_CLOCK