Implement Time::ThreadNow() on Mac.

base/time/time_mac.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/time/time.h"
 
 #include <CoreFoundation/CFDate.h>
 #include <CoreFoundation/CFTimeZone.h>
+#include <mach/mach_init.h>

[Robert Sesek, 2013/11/05 18:32:07]

Include mach/mach.h instead. It will also include mach_port.h.

[fmeawad, 2013/11/05 19:34:25]

Done.

+#include <mach/mach_port.h>
 #include <mach/mach_time.h>
+#include <mach/thread_act.h>
+

[Robert Sesek, 2013/11/05 18:32:07]

nit: remove this blank line

[fmeawad, 2013/11/05 19:34:25]

Done.

 #include <sys/sysctl.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <time.h>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/mac/scoped_cftyperef.h"
 
 namespace {
@@ skipping 37 matching lines @@
       mach_absolute_time() / base::Time::kNanosecondsPerMicrosecond *
       timebase_info.numer / timebase_info.denom;
 
   // Don't bother with the rollover handling that the Windows version does.
   // With numer and denom = 1 (the expected case), the 64-bit absolute time
   // reported in nanoseconds is enough to last nearly 585 years.
   return absolute_micro;
 #endif  // defined(OS_IOS)
 }
 
+uint64_t ComputeThreadTicks() {
+#if defined(OS_IOS)
+  NOTREACHED();

[Robert Sesek, 2013/11/05 18:32:07]

NOTREACHED() or NOTIMPLEMENTED()? Can this be implemented?

[fmeawad, 2013/11/05 19:34:25]

It can be implemented, but it should not be reached at the moment, since each
call of ThreadNow is guarded by a IsThreadNowSupported check. I would be happy
to change it.

[fmeawad, 2013/11/05 21:59:49]

Done.

+  return 0;
+#else
+  mach_port_t thread;

[Robert Sesek, 2013/11/05 18:32:07]

Why break up declaration from initialization?

[fmeawad, 2013/11/05 19:34:25]

Done.

+  mach_msg_type_number_t thread_info_count = THREAD_BASIC_INFO_COUNT;
+  thread_basic_info_data_t thread_info_data;
+
+  thread = mach_thread_self();

[Robert Sesek, 2013/11/05 18:32:07]

This is leaked. Store this in a ScopedMachPort.

[fmeawad, 2013/11/05 19:34:25]

Done.

+  if (thread == MACH_PORT_NULL)
+    return 0;
+
+  kern_return_t kr;

[Robert Sesek, 2013/11/05 18:32:07]

Same. No need to break up declaration from initialization.

[fmeawad, 2013/11/05 19:34:25]

Done.

+
+  kr = thread_info(thread,
+                   THREAD_BASIC_INFO,
+                   reinterpret_cast<thread_info_t>(&thread_info_data),
+                   &thread_info_count);
+
+  if (kr != KERN_SUCCESS) {
+    return 0;

[Robert Sesek, 2013/11/05 18:32:07]

No logging or DCHECKing for failure?

[fmeawad, 2013/11/05 19:34:25]

Done.

+  }
+
+  return (thread_info_data.user_time.seconds *
+              base::Time::kMicrosecondsPerSecond) +
+             thread_info_data.user_time.microseconds;

[Robert Sesek, 2013/11/05 18:32:07]

nit: align this to underneath the (

[fmeawad, 2013/11/05 19:34:25]

Done.

+#endif  // defined(OS_IOS)
+}
+
 }  // namespace
 
 namespace base {
 
 // The Time routines in this file use Mach and CoreFoundation APIs, since the
 // POSIX definition of time_t in Mac OS X wraps around after 2038--and
 // there are already cookie expiration dates, etc., past that time out in
 // the field.  Using CFDate prevents that problem, and using mach_absolute_time
 // for TimeTicks gives us nice high-resolution interval timing.
 
@@ skipping 112 matching lines @@
   return Now();
 }
 
 // static
 bool TimeTicks::IsHighResNowFastAndReliable() {
   return true;
 }
 
 // static
 TimeTicks TimeTicks::ThreadNow() {
-  NOTREACHED();
-  return TimeTicks();
+  return TimeTicks(ComputeThreadTicks());
 }
 
 // static
 TimeTicks TimeTicks::NowFromSystemTraceTime() {
   return HighResNow();
 }
 
 }  // namespace base