Add a method to disable shutdown timer

Reviewed By: yfeldblum

Differential Revision: D22071829

fbshipit-source-id: c7f0e1bc5a4257731bafee09144c33c9fb474e10

folly/Singleton.cpp

@@ -393,6 +393,10 @@ void SingletonVault::startShutdownTimer() {
     return;
   }
 
+  if (!shutdownTimeout_.count()) {
+    return;
+  }
+
   struct sigevent sig;
   sig.sigev_notify = SIGEV_THREAD;
   sig.sigev_notify_function = fireShutdownSignalHelper;

folly/Singleton.h

@@ -520,6 +520,10 @@ class SingletonVault {
     shutdownTimeout_ = shutdownTimeout;
   }
 
+  void disableShutdownTimeout() {
+    shutdownTimeout_ = std::chrono::milliseconds::zero();
+  }
+
   void addToShutdownLog(std::string message);
 
   void startShutdownTimer();

folly/test/SingletonTest.cpp

@@ -1053,3 +1053,25 @@ TEST(Singleton, ShutdownTimer) {
   vault.startShutdownTimer();
   vault.destroyInstances();
 }
+
+TEST(Singleton, ShutdownTimerDisable) {
+  struct VaultTag {};
+  struct PrivateTag {};
+  struct Object {
+    ~Object() {
+      /* sleep override */ std::this_thread::sleep_for(shutdownDuration);
+    }
+
+    std::chrono::milliseconds shutdownDuration;
+  };
+  using SingletonObject = Singleton<Object, PrivateTag, VaultTag>;
+
+  auto& vault = *SingletonVault::singleton<VaultTag>();
+  SingletonObject object;
+  vault.registrationComplete();
+
+  vault.disableShutdownTimeout();
+  SingletonObject::try_get()->shutdownDuration = 100ms;
+  vault.startShutdownTimer();
+  vault.destroyInstances();
+}