Reset GC timings after SIGQUIT.

We now reset the GC timings when a SIGQUIT happens, this is useful
for excluding GCs which happen during the initialization of an app
when measuring GC performance.

Change-Id: I68c79bdb279290c12ae588bc7e95ac24908c157e

3 files changed, 13 insertions, 1 deletions

diff --git a/runtime/gc/collector/garbage_collector.cc b/runtime/gc/collector/garbage_collector.cc
index 82340f5..a700c73 100644
--- a/runtime/gc/collector/garbage_collector.cc
+++ b/runtime/gc/collector/garbage_collector.cc
@@ -204,6 +204,14 @@ uint64_t GarbageCollector::GetEstimatedLastIterationThroughput() const {
   return (static_cast<uint64_t>(freed_bytes_) * 1000) / (NsToMs(GetDurationNs()) + 1);
 }
 
+void GarbageCollector::ResetMeasurements() {
+  cumulative_timings_.Reset();
+  pause_histogram_.Reset();
+  total_time_ns_ = 0;
+  total_freed_objects_ = 0;
+  total_freed_bytes_ = 0;
+}
+
 }  // namespace collector
 }  // namespace gc
 }  // namespace art
diff --git a/runtime/gc/collector/garbage_collector.h b/runtime/gc/collector/garbage_collector.h
index 5b7b8a2..b19ac3f 100644
--- a/runtime/gc/collector/garbage_collector.h
+++ b/runtime/gc/collector/garbage_collector.h
@@ -110,6 +110,9 @@ class GarbageCollector {
     return pause_histogram_;
   }
 
+  // Reset the cumulative timings and pause histogram.
+  void ResetMeasurements();
+
   // Returns the estimated throughput in bytes / second.
   uint64_t GetEstimatedMeanThroughput() const;
 
diff --git a/runtime/gc/heap.cc b/runtime/gc/heap.cc
index e3fa834..feb7a48 100644
--- a/runtime/gc/heap.cc
+++ b/runtime/gc/heap.cc
@@ -660,7 +660,7 @@ void Heap::DumpGcPerformanceInfo(std::ostream& os) {
 
   // Dump cumulative loggers for each GC type.
   uint64_t total_paused_time = 0;
-  for (const auto& collector : garbage_collectors_) {
+  for (auto& collector : garbage_collectors_) {
     const CumulativeLogger& logger = collector->GetCumulativeTimings();
     if (logger.GetTotalNs() != 0) {
       os << ConstDumpable<CumulativeLogger>(logger);
@@ -680,6 +680,7 @@ void Heap::DumpGcPerformanceInfo(std::ostream& os) {
       total_duration += total_ns;
       total_paused_time += total_pause_ns;
     }
+    collector->ResetMeasurements();
   }
   uint64_t allocation_time = static_cast<uint64_t>(total_allocation_time_) * kTimeAdjust;
   if (total_duration != 0) {