From: James Sedgwick <jsedgwick@fb.com>
Date: Fri, 19 Sep 2014 10:19:17 +0000 (-0700)
Subject: fix occasional crash in cpu pool
X-Git-Tag: v0.22.0~349
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e3e4ab20f6b07ac2c4b73d56228a0e8abeca5023;p=folly.git

fix occasional crash in cpu pool

Summary: need to initialize threadsToStop_ and make it signed so it doesn't underflow in rare races

Test Plan: cpu pool unit tests no longer crash if run a ton of times

Reviewed By: davejwatson@fb.com

Subscribers: fugalh, njormrod

FB internal diff: D1563524
---

diff --git a/folly/experimental/wangle/concurrent/CPUThreadPoolExecutor.h b/folly/experimental/wangle/concurrent/CPUThreadPoolExecutor.h
index 210fd673..575e23c6 100644
--- a/folly/experimental/wangle/concurrent/CPUThreadPoolExecutor.h
+++ b/folly/experimental/wangle/concurrent/CPUThreadPoolExecutor.h
@@ -53,8 +53,8 @@ class CPUThreadPoolExecutor : public ThreadPoolExecutor {
   void threadRun(ThreadPtr thread) override;
   void stopThreads(size_t n) override;
 
-  std::atomic<size_t> threadsToStop_;
   std::unique_ptr<BlockingQueue<Task>> taskQueue_;
+  std::atomic<ssize_t> threadsToStop_{0};
 };
 
 }} // folly::wangle