win: Add support for CPUTimes and StartTime to snapshot

util/win/time.cc

 // Copyright 2015 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 #include "util/win/time.h"
 
 #include <inttypes.h>
-#include <windows.h>
 
 #include "base/logging.h"
 
 namespace crashpad {
 
-void GetTimeOfDay(timeval* tv) {
-  FILETIME filetime;
-  GetSystemTimeAsFileTime(&filetime);
+namespace {
+const uint64_t kMicrosecondsPerSecond = static_cast<uint64_t>(1E6);
+}  // namespace
+
+timeval FiletimeToTimevalEpoch(const FILETIME& filetime) {
   uint64_t t = (static_cast<uint64_t>(filetime.dwHighDateTime) << 32) |
                filetime.dwLowDateTime;
   t /= 10;  // 100 nanosecond intervals to microseconds.
   // Windows epoch is 1601-01-01, and FILETIME ticks are 100 nanoseconds.
   // 1601 to 1970 is 369 years + 89 leap days = 134774 days * 86400 seconds per
   // day. It's not entirely clear, but it appears that these are solar seconds,
   // not SI seconds, so there are no leap seconds to be considered.
   const uint64_t kNumSecondsFrom1601To1970 = (369 * 365 + 89) * 86400ULL;
-  const uint64_t kMicrosecondsPerSecond = static_cast<uint64_t>(1E6);
   DCHECK_GE(t, kNumSecondsFrom1601To1970 * kMicrosecondsPerSecond);
   t -= kNumSecondsFrom1601To1970 * kMicrosecondsPerSecond;
-  tv->tv_sec = static_cast<long>(t / kMicrosecondsPerSecond);
-  tv->tv_usec = static_cast<long>(t % kMicrosecondsPerSecond);
+  timeval tv;
+  tv.tv_sec = static_cast<long>(t / kMicrosecondsPerSecond);
+  tv.tv_usec = static_cast<long>(t % kMicrosecondsPerSecond);
+  return tv;
+}
+
+timeval FiletimeToTimevalAmount(const FILETIME& filetime) {

[Mark Mentovai, 2015/05/04 21:29:24]

I’m on the fence about having these two functions be totally distinct or share
more code. I guess it comes out in favor of it being OK for them to not share,
but if they grew any longer, things might change.

[scottmg, 2015/05/05 16:45:48]

I was too. I made a MicrosecondsToTimeval helper.

+  uint64_t t = (static_cast<uint64_t>(filetime.dwHighDateTime) << 32) |
+               filetime.dwLowDateTime;
+  t /= 10;  // 100 nanosecond intervals to microseconds.
+  timeval tv;
+  tv.tv_sec = static_cast<long>(t / kMicrosecondsPerSecond);
+  tv.tv_usec = static_cast<long>(t % kMicrosecondsPerSecond);
+  return tv;
+}
+
+void GetTimeOfDay(timeval* tv) {
+  FILETIME filetime;
+  GetSystemTimeAsFileTime(&filetime);
+  *tv = FiletimeToTimevalEpoch(filetime);
 }
 
 }  // namespace crashpad