Remove coordinator thread

MMTk PR: mmtk/mmtk-core#1067

Change-Id: I316728aeefd0127b5d1fc1d85e464062cc629aa8

Author: k-sareen

runtime/mmtk-art/mmtk_gc_thread.cc

@@ -102,17 +102,6 @@ void MmtkCollectorThread::Run() {
   mmtk_start_gc_worker_thread((void*) thread_, (void*) context_);
 }
 
-MmtkControllerThread::MmtkControllerThread(const std::string& name,
-                                           void* context)
-                                    : MmtkWorkerThread(name, context) {
-  CreateWorkerThread(this);
-}
-
-void MmtkControllerThread::Run() {
-  LOG(INFO) << "Starting MmtkControllerThread " << thread_ << " with context " << context_;
-  mmtk_start_gc_controller_thread((void*) thread_, (void*) context_);
-}
-
 MmtkVmCompanionThread::MmtkVmCompanionThread(const std::string& name)
                                     : MmtkWorkerThread(name, nullptr),
                                       current_state_(StwState::Resumed),

runtime/mmtk-art/mmtk_gc_thread.h

@@ -72,16 +72,6 @@ class MmtkCollectorThread : MmtkWorkerThread {
   void Run() override;
 };
 
-// MMTk GC Controller thread. There is only a single such thread. It is
-// responsible for coordinating garbage collection.
-class MmtkControllerThread : MmtkWorkerThread {
- public:
-  MmtkControllerThread(const std::string& name, void* context);
-
- protected:
-  void Run() override;
-};
-
 enum StwState {
   Resumed,
   Suspended,

runtime/mmtk-art/mmtk_upcalls.cc

@@ -75,10 +75,6 @@ static void block_for_gc(void* tls) {
 static void spawn_gc_thread(void* tls, GcThreadKind kind, void* ctx) {
   UNUSED(tls);
   switch (kind) {
-    case MmtkGcController: {
-      new art::MmtkControllerThread("MMTk Controller Context Thread", ctx);
-      break;
-    }
     case MmtkGcWorker: {
       new art::MmtkCollectorThread("MMTk Collector Thread", ctx);
       break;