commit 97476172cc13aca726b9510cf64ebc126fda837d
author Andreas Huber <andih@google.com> Tue Mar 20 12:58:35 2018 -0700
committer Jorge Moreira Broche <jemoreira@google.com> Thu Mar 22 22:10:37 2018 +0000
tree 251d4327c2fbfe238a0b9ecebc0ce1eb0454d56a
parent 21b7af56a3646524127b7a3121d1f371d7a4325c

Fix RegionWorker thread exiting prematurely due to referencing

uninitialized memory.

Bug: 76021749
Test: manually
Merged-In: I5c3a9378dfd33f798f8a735698992a2cab7c543b
Change-Id: I5c3a9378dfd33f798f8a735698992a2cab7c543b

common/vsoc/lib/region_view.cpp

diff --git a/common/vsoc/lib/region_view.cpp b/common/vsoc/lib/region_view.cpp
index b86defd..4fcadc6 100644
--- a/common/vsoc/lib/region_view.cpp
+++ b/common/vsoc/lib/region_view.cpp
@@ -15,7 +15,12 @@
                                  std::shared_ptr<RegionControl> control)
     : control_(control),
       region_(region),
-      thread_(&vsoc::RegionWorker::Work, this) {}
+      stopping_(false) {}
+
+void vsoc::RegionWorker::start() {
+  CHECK(thread_ == nullptr);
+  thread_.reset(new std::thread(&vsoc::RegionWorker::Work, this));
+}
 
 void vsoc::RegionWorker::Work() {
   while (!stopping_) {
@@ -25,14 +30,17 @@
     }
     region_->ProcessSignalsFromPeer([this](uint32_t offset) {
         control_->SignalSelf(offset);
-      });
+    });
   }
 }
 
 vsoc::RegionWorker::~RegionWorker() {
   stopping_ = true;
-  region_->InterruptSelf();
-  thread_.join();
+
+  if (thread_ != nullptr) {
+    region_->InterruptSelf();
+    thread_->join();
+  }
 }
 
 vsoc::RegionView::~RegionView() {
@@ -179,8 +187,11 @@
 }
 
 std::unique_ptr<vsoc::RegionWorker> vsoc::RegionView::StartWorker() {
-  return std::unique_ptr<vsoc::RegionWorker>(new vsoc::RegionWorker(
-      this, control_));
+    std::unique_ptr<vsoc::RegionWorker> worker(
+            new vsoc::RegionWorker(this /* region */, control_));
+
+    worker->start();
+    return worker;
 }
 
 int vsoc::RegionView::WaitForSignal(std::atomic<uint32_t>* uaddr,

common/vsoc/lib/region_view.h

diff --git a/common/vsoc/lib/region_view.h b/common/vsoc/lib/region_view.h
index bfe29db..af089f3 100644
--- a/common/vsoc/lib/region_view.h
+++ b/common/vsoc/lib/region_view.h
@@ -50,13 +50,16 @@
  public:
   RegionWorker(RegionView* region, std::shared_ptr<RegionControl> control);
   ~RegionWorker();
+
+  void start();
+
   void Work();
 
  protected:
   std::shared_ptr<RegionControl> control_;
   RegionView* region_;
-  std::thread thread_;
-  volatile bool stopping_{};
+  std::unique_ptr<std::thread> thread_;
+  volatile bool stopping_;
 };
 
 /**