Index: third_party/libcxx/src/chrono.cpp |
=================================================================== |
--- third_party/libcxx/src/chrono.cpp (revision 0) |
+++ third_party/libcxx/src/chrono.cpp (revision 0) |
@@ -0,0 +1,132 @@ |
+//===------------------------- chrono.cpp ---------------------------------===// |
+// |
+// The LLVM Compiler Infrastructure |
+// |
+// This file is dual licensed under the MIT and the University of Illinois Open |
+// Source Licenses. See LICENSE.TXT for details. |
+// |
+//===----------------------------------------------------------------------===// |
+ |
+#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__ |
+ |
+_LIBCPP_BEGIN_NAMESPACE_STD |
+ |
+namespace chrono |
+{ |
+ |
+// system_clock |
+ |
+const bool system_clock::is_steady; |
+ |
+system_clock::time_point |
+system_clock::now() _NOEXCEPT |
+{ |
+ timeval tv; |
+ gettimeofday(&tv, 0); |
+ return time_point(seconds(tv.tv_sec) + microseconds(tv.tv_usec)); |
+} |
+ |
+time_t |
+system_clock::to_time_t(const time_point& t) _NOEXCEPT |
+{ |
+ return time_t(duration_cast<seconds>(t.time_since_epoch()).count()); |
+} |
+ |
+system_clock::time_point |
+system_clock::from_time_t(time_t t) _NOEXCEPT |
+{ |
+ return system_clock::time_point(seconds(t)); |
+} |
+ |
+// steady_clock |
+ |
+const bool steady_clock::is_steady; |
+ |
+#ifdef __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 |
+// to the Gregorian calendar. It's main use is as a high resolution timer. |
+ |
+// MachInfo.numer / MachInfo.denom is often 1 on the latest equipment. Specialize |
+// for that case as an optimization. |
+ |
+#pragma GCC visibility push(hidden) |
+ |
+static |
+steady_clock::rep |
+steady_simplified() |
+{ |
+ return static_cast<steady_clock::rep>(mach_absolute_time()); |
+} |
+ |
+static |
+double |
+compute_steady_factor() |
+{ |
+ mach_timebase_info_data_t MachInfo; |
+ mach_timebase_info(&MachInfo); |
+ return static_cast<double>(MachInfo.numer) / MachInfo.denom; |
+} |
+ |
+static |
+steady_clock::rep |
+steady_full() |
+{ |
+ static const double factor = compute_steady_factor(); |
+ return static_cast<steady_clock::rep>(mach_absolute_time() * factor); |
+} |
+ |
+typedef steady_clock::rep (*FP)(); |
+ |
+static |
+FP |
+init_steady_clock() |
+{ |
+ mach_timebase_info_data_t MachInfo; |
+ mach_timebase_info(&MachInfo); |
+ if (MachInfo.numer == MachInfo.denom) |
+ return &steady_simplified; |
+ return &steady_full; |
+} |
+ |
+#pragma GCC visibility pop |
+ |
+steady_clock::time_point |
+steady_clock::now() _NOEXCEPT |
+{ |
+ static FP fp = init_steady_clock(); |
+ return time_point(duration(fp())); |
+} |
+ |
+#else // __APPLE__ |
+// FIXME: We assume that clock_gettime(CLOCK_MONOTONIC) works on |
+// non-apple systems. Instead, we should check _POSIX_TIMERS and |
+// _POSIX_MONOTONIC_CLOCK and fall back to something else if those |
+// don't exist. |
+ |
+// 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__ |
+ |
+} |
+ |
+_LIBCPP_END_NAMESPACE_STD |
Property changes on: third_party/libcxx/src/chrono.cpp |
___________________________________________________________________ |
Added: svn:eol-style |
+ LF |