Bug 1714141 - Remove unused 'producer' condition variable r=sfink

This is unused since the internal thread pool has its own now.

Differential Revision: https://phabricator.services.mozilla.com/D117162

js/src/gc/GCParallelTask.cpp

@@ -101,7 +101,7 @@ void js::GCParallelTask::joinRunningOrFinishedTask(
 
   // Wait for the task to run to completion.
   while (!isFinished(lock)) {
-    HelperThreadState().wait(lock, GlobalHelperThreadState::CONSUMER);
+    HelperThreadState().wait(lock);
   }
 
   setIdle(lock);

js/src/vm/HelperThreadState.h

@@ -210,21 +210,9 @@ class GlobalHelperThreadState {
   void assertIsLockedByCurrentThread() const;
 #endif
 
-  enum CondVar {
-    // For notifying threads waiting for work that they may be able to make
-    // progress, ie, a work item has been completed by a helper thread and
-    // the thread that created the work item can now consume it.
-    CONSUMER,
-
-    // For notifying helper threads doing the work that they may be able to
-    // make progress, ie, a work item has been enqueued and an idle helper
-    // thread may pick up up the work item and perform it.
-    PRODUCER,
-  };
-
-  void wait(AutoLockHelperThreadState& locked, CondVar which,
+  void wait(AutoLockHelperThreadState& locked,
             mozilla::TimeDuration timeout = mozilla::TimeDuration::Forever());
-  void notifyAll(CondVar which, const AutoLockHelperThreadState&);
+  void notifyAll(const AutoLockHelperThreadState&);
 
   bool useInternalThreadPool(const AutoLockHelperThreadState& lock) const {
     return useInternalThreadPool_;
@@ -235,7 +223,7 @@ class GlobalHelperThreadState {
   }
 
  private:
-  void notifyOne(CondVar which, const AutoLockHelperThreadState&);
+  void notifyOne(const AutoLockHelperThreadState&);
 
  public:
   // Helper method for removing items from the vectors below while iterating
@@ -424,20 +412,9 @@ class GlobalHelperThreadState {
   void triggerFreeUnusedMemory();
 
  private:
-  /* Condvars for threads waiting/notifying each other. */
+  // Condition variable for notifiying the main thread that a helper task has
+  // completed some work.
   js::ConditionVariable consumerWakeup;
-  js::ConditionVariable producerWakeup;
-
-  js::ConditionVariable& whichWakeup(CondVar which) {
-    switch (which) {
-      case CONSUMER:
-        return consumerWakeup;
-      case PRODUCER:
-        return producerWakeup;
-      default:
-        MOZ_CRASH("Invalid CondVar in |whichWakeup|");
-    }
-  }
 
   void dispatch(const AutoLockHelperThreadState& locked);
 

js/src/vm/HelperThreads.cpp

@@ -235,7 +235,7 @@ static void CancelOffThreadWasmTier2GeneratorLocked(
           HelperThreadState().wasmTier2GeneratorsFinished(lock);
       while (HelperThreadState().wasmTier2GeneratorsFinished(lock) ==
              oldFinishedCount) {
-        HelperThreadState().wait(lock, GlobalHelperThreadState::CONSUMER);
+        HelperThreadState().wait(lock);
       }
 
       // At most one of these tasks.
@@ -398,7 +398,7 @@ static void CancelOffThreadIonCompileLocked(const CompilationSelector& selector,
       }
     }
     if (cancelled) {
-      HelperThreadState().wait(lock, GlobalHelperThreadState::CONSUMER);
+      HelperThreadState().wait(lock);
     }
   } while (cancelled);
 
@@ -926,7 +926,7 @@ static void WaitForOffThreadParses(JSRuntime* rt,
         break;
       }
     }
-    HelperThreadState().wait(lock, GlobalHelperThreadState::CONSUMER);
+    HelperThreadState().wait(lock);
   }
 
 #ifdef DEBUG
@@ -1438,19 +1438,17 @@ void GlobalHelperThreadState::dispatch(
 }
 
 void GlobalHelperThreadState::wait(
-    AutoLockHelperThreadState& locked, CondVar which,
+    AutoLockHelperThreadState& locked,
     TimeDuration timeout /* = TimeDuration::Forever() */) {
-  whichWakeup(which).wait_for(locked, timeout);
+  consumerWakeup.wait_for(locked, timeout);
 }
 
-void GlobalHelperThreadState::notifyAll(CondVar which,
-                                        const AutoLockHelperThreadState&) {
-  whichWakeup(which).notify_all();
+void GlobalHelperThreadState::notifyAll(const AutoLockHelperThreadState&) {
+  consumerWakeup.notify_all();
 }
 
-void GlobalHelperThreadState::notifyOne(CondVar which,
-                                        const AutoLockHelperThreadState&) {
-  whichWakeup(which).notify_one();
+void GlobalHelperThreadState::notifyOne(const AutoLockHelperThreadState&) {
+  consumerWakeup.notify_one();
 }
 
 bool GlobalHelperThreadState::hasActiveThreads(
@@ -1475,7 +1473,7 @@ void GlobalHelperThreadState::waitForAllTasksLocked(
 
   while (canStartTasks(lock) || tasksPending_ ||
          hasActiveThreads(lock)) {
-    wait(lock, CONSUMER);
+    wait(lock);
   }
 
   MOZ_ASSERT(gcParallelWorklist(lock).isEmpty());
@@ -2368,7 +2366,7 @@ void GlobalHelperThreadState::cancelParseTask(JSRuntime* rt, ParseTaskKind kind,
       break;
     }
 
-    HelperThreadState().wait(lock, GlobalHelperThreadState::CONSUMER);
+    HelperThreadState().wait(lock);
   }
 
   auto& finished = HelperThreadState().parseFinishedList(lock);
@@ -2497,7 +2495,7 @@ void js::CancelOffThreadCompressions(JSRuntime* runtime) {
       break;
     }
 
-    HelperThreadState().wait(lock, GlobalHelperThreadState::CONSUMER);
+    HelperThreadState().wait(lock);
   }
 
   // Clean up finished tasks.
@@ -2538,7 +2536,7 @@ void js::RunPendingSourceCompressions(JSRuntime* runtime) {
 
   // Wait until all tasks have started compression.
   while (!HelperThreadState().compressionWorklist(lock).empty()) {
-    HelperThreadState().wait(lock, GlobalHelperThreadState::CONSUMER);
+    HelperThreadState().wait(lock);
   }
 
   // Wait for all in-process compression tasks to complete.
@@ -2703,7 +2701,7 @@ void GlobalHelperThreadState::runOneTask(AutoLockHelperThreadState& lock) {
     dispatch(lock);
   }
 
-  notifyAll(GlobalHelperThreadState::CONSUMER, lock);
+  notifyAll(lock);
 }
 
 HelperThreadTask* GlobalHelperThreadState::findHighestPriorityTask(

js/src/wasm/WasmModule.cpp

@@ -72,7 +72,8 @@ class Module::Tier2GeneratorTaskImpl : public Tier2GeneratorTask {
 
     // During shutdown the main thread will wait for any ongoing (cancelled)
     // tier-2 generation to shut down normally.  To do so, it waits on the
-    // CONSUMER condition for the count of finished generators to rise.
+    // HelperThreadState's condition variable for the count of finished
+    // generators to rise.
     HelperThreadState().incWasmTier2GeneratorsFinished(locked);
 
     // The task is finished, release it.