llvm/lib/Support/TimeValue.cpp
Pavel Labath bca3cda284 Add Chrono.h - std::chrono support header
Summary:
std::chrono mostly covers the functionality of llvm::sys::TimeValue and
lldb_private::TimeValue. This header adds a bit of utility functions and
typedefs, which make the usage of the library and porting code from TimeValues
easier.

Rationale:
- TimePoint typedef - precision of system_clock is implementation defined -
  using a well-defined precision helps maintain consistency between platforms,
  makes it interact better with existing TimeValue classes, and avoids cases
  there a time point is implicitly convertible to a specific precision on some
  platforms but not on others.
- system_clock::to_time_t only accepts time_points with the default system
  precision (even though time_t has only second precision on all platforms we
  support). To avoid the need for explicit casts, I have added a toTimeT()
  wrapper function. toTimePoint(time_t) was not strictly necessary, but I have
  added it for symmetry.

Reviewers: zturner, mehdi_amini

Subscribers: beanz, mgorny, llvm-commits, modocache

Differential Revision: https://reviews.llvm.org/D25416

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284590 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-19 13:58:55 +00:00

56 lines
1.5 KiB
C++

//===-- TimeValue.cpp - Implement OS TimeValue Concept ----------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the operating system TimeValue concept.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/TimeValue.h"
#include "llvm/Support/Chrono.h"
#include "llvm/Support/ScopedPrinter.h"
namespace llvm {
using namespace sys;
const TimeValue::SecondsType
TimeValue::PosixZeroTimeSeconds = -946684800;
const TimeValue::SecondsType
TimeValue::Win32ZeroTimeSeconds = -12591158400ULL;
void TimeValue::normalize() {
if ( nanos_ >= NANOSECONDS_PER_SECOND ) {
do {
seconds_++;
nanos_ -= NANOSECONDS_PER_SECOND;
} while ( nanos_ >= NANOSECONDS_PER_SECOND );
} else if (nanos_ <= -NANOSECONDS_PER_SECOND ) {
do {
seconds_--;
nanos_ += NANOSECONDS_PER_SECOND;
} while (nanos_ <= -NANOSECONDS_PER_SECOND);
}
if (seconds_ >= 1 && nanos_ < 0) {
seconds_--;
nanos_ += NANOSECONDS_PER_SECOND;
} else if (seconds_ < 0 && nanos_ > 0) {
seconds_++;
nanos_ -= NANOSECONDS_PER_SECOND;
}
}
std::string TimeValue::str() const { return to_string(TimePoint<>(*this)); }
TimeValue TimeValue::now() {
return TimePoint<>(std::chrono::system_clock::now());
}
} // namespace llvm