commit 769f35fc0fedc21730a76608ad94050a6c6eb533
author Tej Singh <singhtejinder@google.com> Sat Apr 11 03:39:12 2020 -0700
committer Tej Singh <singhtejinder@google.com> Tue Apr 14 16:50:12 2020 -0700
tree 63f9a1d07a74fb8051b1d6c1bb2971da126cc73a
parent 1dcd8f4116397e8edc82bd77434533211efcae39

Add NamedLatch to statsd

This is a sychronizing primitive that is similar to a latch, but a
thread must count down with an identifier. It will be used to make sure
the boot complete, uid map, and all pullers signals are received before
triggering the bucket split.

The latch's countDown operation takes in a string identifier, so that if
the same operation happens twice, it is only counted once.

Bug: 144099206
Test: atest statsd_test

Change-Id: I261a3e50eabbc4998ca30ddf2d67a9a1e788911e

cmds/statsd/src/StatsService.cpp

diff --git a/cmds/statsd/src/StatsService.cpp b/cmds/statsd/src/StatsService.cpp
index dd1d400..ae7a8d0 100644
--- a/cmds/statsd/src/StatsService.cpp
+++ b/cmds/statsd/src/StatsService.cpp
@@ -118,8 +118,9 @@
                   }
               })),
       mEventQueue(queue),
-      mStatsCompanionServiceDeathRecipient(AIBinder_DeathRecipient_new(
-              StatsService::statsCompanionServiceDied)) {
+      mBootCompleteLatch({kBootCompleteTag, kUidMapReceivedTag, kAllPullersRegisteredTag}),
+      mStatsCompanionServiceDeathRecipient(
+              AIBinder_DeathRecipient_new(StatsService::statsCompanionServiceDied)) {
     mUidMap = UidMap::getInstance();
     mPullerManager = new StatsPullerManager();
     StatsPuller::SetUidMap(mUidMap);
@@ -164,6 +165,12 @@
         std::thread pushedEventThread([this] { readLogs(); });
         pushedEventThread.detach();
     }
+
+    std::thread bootCompletedThread([this] {
+        mBootCompleteLatch.wait();
+        VLOG("In the boot completed thread");
+    });
+    bootCompletedThread.detach();
 }
 
 StatsService::~StatsService() {
@@ -939,6 +946,7 @@
                        packageNames,
                        installers);
 
+    mBootCompleteLatch.countDown(kUidMapReceivedTag);
     VLOG("StatsService::informAllUidData UidData proto parsed successfully.");
     return Status::ok();
 }
@@ -1058,7 +1066,7 @@
     ENFORCE_UID(AID_SYSTEM);
 
     VLOG("StatsService::bootCompleted was called");
-
+    mBootCompleteLatch.countDown(kBootCompleteTag);
     return Status::ok();
 }
 
@@ -1227,7 +1235,7 @@
     ENFORCE_UID(AID_SYSTEM);
 
     VLOG("StatsService::allPullersFromBootRegistered was called");
-
+    mBootCompleteLatch.countDown(kAllPullersRegisteredTag);
     return Status::ok();
 }