Use TimeTicks instead of gettimeofday in ProcessMetrics.

No real behavior change, but if the user changes their system time there
shouldn't be a jump in %cpu for one call.

BUG=none

Review URL: https://codereview.chromium.org/139103007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@262059 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 18 insertions, 51 deletions

diff --git a/base/process/process_metrics.h b/base/process/process_metrics.h
index 45f2ef9..840f933 100644
--- a/base/process/process_metrics.h
+++ b/base/process/process_metrics.h
@@ -205,11 +205,11 @@ class BASE_EXPORT ProcessMetrics {
 
   // Used to store the previous times and CPU usage counts so we can
   // compute the CPU usage between calls.
-  int64 last_cpu_time_;
+  TimeTicks last_cpu_time_;
   int64 last_system_time_;
 
   // Same thing for idle wakeups.
-  int64 last_idle_wakeups_time_;
+  TimeTicks last_idle_wakeups_time_;
   int64 last_absolute_idle_wakeups_;
 
 #if !defined(OS_IOS)
diff --git a/base/process/process_metrics_freebsd.cc b/base/process/process_metrics_freebsd.cc
index b0c20d2e..9d4149d 100644
--- a/base/process/process_metrics_freebsd.cc
+++ b/base/process/process_metrics_freebsd.cc
@@ -14,7 +14,6 @@ namespace base {
 
 ProcessMetrics::ProcessMetrics(ProcessHandle process)
     : process_(process),
-      last_cpu_time_(0),
       last_system_time_(0),
       last_cpu_(0) {
   processor_count_ = base::SysInfo::NumberOfProcessors();
@@ -87,11 +86,6 @@ double ProcessMetrics::GetCPUUsage() {
   int mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_PID, process_ };
   size_t length = sizeof(info);
 
-  struct timeval now;
-  int retval = gettimeofday(&now, NULL);
-  if (retval)
-    return 0;
-
   if (sysctl(mib, arraysize(mib), &info, &length, NULL, 0) < 0)
     return 0;
 
diff --git a/base/process/process_metrics_linux.cc b/base/process/process_metrics_linux.cc
index 7fa5092..0e12595 100644
--- a/base/process/process_metrics_linux.cc
+++ b/base/process/process_metrics_linux.cc
@@ -182,20 +182,16 @@ bool ProcessMetrics::GetWorkingSetKBytes(WorkingSetKBytes* ws_usage) const {
 }
 
 double ProcessMetrics::GetCPUUsage() {
-  struct timeval now;
-  int retval = gettimeofday(&now, NULL);
-  if (retval)
-    return 0;
-  int64 time = TimeValToMicroseconds(now);
+  TimeTicks time = TimeTicks::Now();
 
-  if (last_cpu_time_ == 0) {
+  if (last_cpu_ == 0) {
     // First call, just set the last values.
     last_cpu_time_ = time;
     last_cpu_ = GetProcessCPU(process_);
     return 0;
   }
 
-  int64 time_delta = time - last_cpu_time_;
+  int64 time_delta = (time - last_cpu_time_).InMicroseconds();
   DCHECK_NE(time_delta, 0);
   if (time_delta == 0)
     return 0;
@@ -263,7 +259,6 @@ bool ProcessMetrics::GetIOCounters(IoCounters* io_counters) const {
 
 ProcessMetrics::ProcessMetrics(ProcessHandle process)
     : process_(process),
-      last_cpu_time_(0),
       last_system_time_(0),
       last_cpu_(0) {
   processor_count_ = base::SysInfo::NumberOfProcessors();
diff --git a/base/process/process_metrics_mac.cc b/base/process/process_metrics_mac.cc
index 8566861..1b2e61b 100644
--- a/base/process/process_metrics_mac.cc
+++ b/base/process/process_metrics_mac.cc
@@ -267,15 +267,10 @@ double ProcessMetrics::GetCPUUsage() {
   timeradd(&user_timeval, &task_timeval, &task_timeval);
   timeradd(&system_timeval, &task_timeval, &task_timeval);
 
-  struct timeval now;
-  int retval = gettimeofday(&now, NULL);
-  if (retval)
-    return 0;
-
-  int64 time = TimeValToMicroseconds(now);
+  TimeTicks time = TimeTicks::Now();
   int64 task_time = TimeValToMicroseconds(task_timeval);
 
-  if (last_cpu_time_ == 0) {
+  if (last_system_time_ == 0) {
     // First call, just set the last values.
     last_cpu_time_ = time;
     last_system_time_ = task_time;
@@ -283,7 +278,7 @@ double ProcessMetrics::GetCPUUsage() {
   }
 
   int64 system_time_delta = task_time - last_system_time_;
-  int64 time_delta = time - last_cpu_time_;
+  int64 time_delta = (time - last_cpu_time_).InMicroseconds();
   DCHECK_NE(0U, time_delta);
   if (time_delta == 0)
     return 0;
@@ -314,14 +309,9 @@ int ProcessMetrics::GetIdleWakeupsPerSecond() {
   }
   uint64_t absolute_idle_wakeups = power_info_data.task_platform_idle_wakeups;
 
-  struct timeval now;
-  int retval = gettimeofday(&now, NULL);
-  if (retval)
-    return 0;
-
-  int64 time = TimeValToMicroseconds(now);
+  TimeTicks time = TimeTicks::Now();
 
-  if (last_idle_wakeups_time_ == 0) {
+  if (last_absolute_idle_wakeups_ == 0) {
     // First call, just set the last values.
     last_idle_wakeups_time_ = time;
     last_absolute_idle_wakeups_ = absolute_idle_wakeups;
@@ -329,7 +319,7 @@ int ProcessMetrics::GetIdleWakeupsPerSecond() {
   }
 
   int64 wakeups_delta = absolute_idle_wakeups - last_absolute_idle_wakeups_;
-  int64 time_delta = time - last_idle_wakeups_time_;
+  int64 time_delta = (time - last_idle_wakeups_time_).InMicroseconds();
   DCHECK_NE(0U, time_delta);
   if (time_delta == 0)
     return 0;
@@ -349,9 +339,7 @@ bool ProcessMetrics::GetIOCounters(IoCounters* io_counters) const {
 ProcessMetrics::ProcessMetrics(ProcessHandle process,
                                ProcessMetrics::PortProvider* port_provider)
     : process_(process),
-      last_cpu_time_(0),
       last_system_time_(0),
-      last_idle_wakeups_time_(0),
       last_absolute_idle_wakeups_(0),
       port_provider_(port_provider) {
   processor_count_ = SysInfo::NumberOfProcessors();
diff --git a/base/process/process_metrics_openbsd.cc b/base/process/process_metrics_openbsd.cc
index a374362..72927a1 100644
--- a/base/process/process_metrics_openbsd.cc
+++ b/base/process/process_metrics_openbsd.cc
@@ -106,22 +106,16 @@ static int GetProcessCPU(pid_t pid) {
 }
 
 double ProcessMetrics::GetCPUUsage() {
-  struct timeval now;
+  TimeTicks time = TimeTicks::Now();
 
-  int retval = gettimeofday(&now, NULL);
-  if (retval)
-    return 0;
-
-  int64 time = TimeValToMicroseconds(now);
-
-  if (last_cpu_time_ == 0) {
+  if (last_cpu_ == 0) {
     // First call, just set the last values.
     last_cpu_time_ = time;
     last_cpu_ = GetProcessCPU(process_);
     return 0;
   }
 
-  int64 time_delta = time - last_cpu_time_;
+  int64 time_delta = (time - last_cpu_time_).InMicroseconds();
   DCHECK_NE(time_delta, 0);
 
   if (time_delta == 0)
@@ -139,7 +133,6 @@ double ProcessMetrics::GetCPUUsage() {
 
 ProcessMetrics::ProcessMetrics(ProcessHandle process)
     : process_(process),
-      last_cpu_time_(0),
       last_system_time_(0),
       last_cpu_(0) {
 
diff --git a/base/process/process_metrics_win.cc b/base/process/process_metrics_win.cc
index 0dd19cb..b1810b4 100644
--- a/base/process/process_metrics_win.cc
+++ b/base/process/process_metrics_win.cc
@@ -195,14 +195,11 @@ static uint64 FileTimeToUTC(const FILETIME& ftime) {
 }
 
 double ProcessMetrics::GetCPUUsage() {
-  FILETIME now;
   FILETIME creation_time;
   FILETIME exit_time;
   FILETIME kernel_time;
   FILETIME user_time;
 
-  GetSystemTimeAsFileTime(&now);
-
   if (!GetProcessTimes(process_, &creation_time, &exit_time,
                        &kernel_time, &user_time)) {
     // We don't assert here because in some cases (such as in the Task Manager)
@@ -212,9 +209,9 @@ double ProcessMetrics::GetCPUUsage() {
   }
   int64 system_time = (FileTimeToUTC(kernel_time) + FileTimeToUTC(user_time)) /
                         processor_count_;
-  int64 time = FileTimeToUTC(now);
+  TimeTicks time = TimeTicks::Now();
 
-  if ((last_system_time_ == 0) || (last_cpu_time_ == 0)) {
+  if (last_system_time_ == 0) {
     // First call, just set the last values.
     last_system_time_ = system_time;
     last_cpu_time_ = time;
@@ -222,7 +219,8 @@ double ProcessMetrics::GetCPUUsage() {
   }
 
   int64 system_time_delta = system_time - last_system_time_;
-  int64 time_delta = time - last_cpu_time_;
+  // FILETIME is in 100-nanosecond units, so this needs microseconds times 10.
+  int64 time_delta = (time - last_cpu_time_).InMicroseconds() * 10;
   DCHECK_NE(0U, time_delta);
   if (time_delta == 0)
     return 0;
@@ -269,7 +267,6 @@ bool ProcessMetrics::GetIOCounters(IoCounters* io_counters) const {
 ProcessMetrics::ProcessMetrics(ProcessHandle process)
     : process_(process),
       processor_count_(base::SysInfo::NumberOfProcessors()),
-      last_cpu_time_(0),
       last_system_time_(0) {
 }