Subzero: Fixed deadlock with _start but no globals

src/IceInstrumentation.cpp

Index: src/IceInstrumentation.cpp
diff --git a/src/IceInstrumentation.cpp b/src/IceInstrumentation.cpp
index 0cd218abcbdbd7df2507cab8808dbcfdb7db5c20..b816a15d0a38ea5d62f99fe6552382a696f1f5ed 100644
--- a/src/IceInstrumentation.cpp
+++ b/src/IceInstrumentation.cpp
@@ -118,4 +118,17 @@ void Instrumentation::instrumentInst(LoweringContext &Context) {
   }
 }
 
+void Instrumentation::setHasSeenGlobals() {
+  std::unique_lock<std::mutex> GlobalsLock(GlobalsSeenMutex);

[Jim Stichnoth, 2016/07/19 22:39:00]

I think this could be simpler:

void Instrumentation::setHasSeenGlobals() {
  {
    std::unique_lock<std::mutex> _(GlobalsSeenMutex);
    HasSeenGlobals = true;
  }
  GlobalsSeenCV.notify_all();
}

[tlively, 2016/07/19 23:20:14]

Done.

+  HasSeenGlobals = true;
+  GlobalsLock.unlock();
+  GlobalsSeenCV.notify_all();
+}
+
+LockedPtr<VariableDeclarationList> Instrumentation::getGlobals() {
+  std::unique_lock<std::mutex> GlobalsLock(GlobalsSeenMutex);
+  GlobalsSeenCV.wait(GlobalsLock, [&] { return HasSeenGlobals; });

[Jim Stichnoth, 2016/07/19 22:39:00]

Instead of default capture, can you capture "this"?

  GlobalsSeenCV.wait(GlobalsLock, [this] { return HasSeenGlobals; });

[tlively, 2016/07/19 23:20:14]

Done.

+  return Ctx->getGlobals();
+}
+
 } // end of namespace Ice