From 084b46b0d0d8e6e47df0882d8cbc301b53211bb8 Mon Sep 17 00:00:00 2001
From: Taras Glek <tglek@mozilla.com>
Date: Thu, 12 May 2011 11:22:25 -0700
Subject: [PATCH] bug 585196: Cycle-collector telemetry probe r=bent

---
 xpcom/base/nsCycleCollector.cpp | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/xpcom/base/nsCycleCollector.cpp b/xpcom/base/nsCycleCollector.cpp
index ea1529c3446..4700bb6ae39 100644
--- a/xpcom/base/nsCycleCollector.cpp
+++ b/xpcom/base/nsCycleCollector.cpp
@@ -125,6 +125,7 @@
 #endif
 #endif
 
+#include "base/basictypes.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsCycleCollectorUtils.h"
 #include "nsIProgrammingLanguage.h"
@@ -151,7 +152,8 @@
 #include "nsIXPConnect.h"
 #include "nsIJSRuntimeService.h"
 #include "xpcpublic.h"
-
+#include "base/histogram.h"
+#include "base/logging.h"
 #include <stdio.h>
 #include <string.h>
 #ifdef WIN32
@@ -981,7 +983,7 @@ struct nsCycleCollector
     PRBool mFollowupCollection;
     PRUint32 mCollectedObjects;
     PRBool mFirstCollection;
-    PRTime mCollectionStart;
+    TimeStamp mCollectionStart;
 
     nsCycleCollectionLanguageRuntime *mRuntimes[nsIProgrammingLanguage::MAX+1];
     nsCycleCollectionXPCOMRuntime mXPCOMRuntime;
@@ -2477,8 +2479,8 @@ nsCycleCollector::PrepareForCollection(nsTPtrArray<PtrInfo> *aWhiteNodes)
 
 #ifdef COLLECT_TIME_DEBUG
     printf("cc: nsCycleCollector::PrepareForCollection()\n");
-    mCollectionStart = PR_Now();
 #endif
+    mCollectionStart = TimeStamp::Now();
 
     mCollectionInProgress = PR_TRUE;
 
@@ -2508,10 +2510,13 @@ nsCycleCollector::CleanupAfterCollection()
     _heapmin();
 #endif
 
+    PRUint32 interval((TimeStamp::Now() - mCollectionStart).ToMilliseconds());
 #ifdef COLLECT_TIME_DEBUG
-    printf("cc: CleanupAfterCollection(), total time %lldms\n",
-           (PR_Now() - mCollectionStart) / PR_USEC_PER_MSEC);
+    printf("cc: CleanupAfterCollection(), total time %ums\n", interval);
 #endif
+    UMA_HISTOGRAM_TIMES("nsCycleCollector::Collect (ms)",
+                        base::TimeDelta::FromMilliseconds(interval));
+
 #ifdef DEBUG_CC
     ExplainLiveExpectedGarbage();
 #endif