//===------- Collection.cpp - Implementation of the Collection class  -----===//
//
//                              The VMKit project
//
// This file is distributed under the University of Illinois Open Source 
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "debug.h"
#include "vmkit/VirtualMachine.h"
#include "MMTkObject.h"
#include "VmkitGC.h"

namespace mmtk {

extern "C" bool Java_org_j3_mmtk_Collection_isEmergencyAllocation__ (MMTkObject* C) {
  // TODO: emergency when OOM.
  return false;
}

extern "C" void Java_org_j3_mmtk_Collection_reportAllocationSuccess__ (MMTkObject* C) {
  vmkit::MutatorThread::get()->CollectionAttempts = 0;
}

extern "C" void JnJVM_org_j3_bindings_Bindings_collect__I(int why);

extern "C" void Java_org_j3_mmtk_Collection_triggerCollection__I (MMTkObject* C, int why) {
  vmkit::MutatorThread* th = vmkit::MutatorThread::get();
  if (why > 2) th->CollectionAttempts++;

  // Verify that another collection is not happening.
  th->MyVM->rendezvous.startRV();
  if (th->MyVM->rendezvous.getInitiator() != NULL) {
    th->MyVM->rendezvous.cancelRV();
    th->MyVM->rendezvous.join();
    return;
  } else {
    th->MyVM->startCollection();
    th->MyVM->rendezvous.synchronize();

    JnJVM_org_j3_bindings_Bindings_collect__I(why);

    th->MyVM->rendezvous.finishRV();
    th->MyVM->endCollection();
  }

}

extern "C" void Java_org_j3_mmtk_Collection_joinCollection__ (MMTkObject* C) {
  vmkit::Thread* th = vmkit::Thread::get();
  assert(th->inRV && "Joining collection without a rendezvous");
  th->MyVM->rendezvous.join();
}

extern "C" int Java_org_j3_mmtk_Collection_rendezvous__I (MMTkObject* C, int where) {
  return 1;
}

extern "C" int Java_org_j3_mmtk_Collection_maximumCollectionAttempt__ (MMTkObject* C) {
  vmkit::MutatorThread* th = vmkit::MutatorThread::get();
  vmkit::MutatorThread* tcur = th;

  uint32_t max = 0; 
  do {
    if (tcur->CollectionAttempts > max) {
      max = tcur->CollectionAttempts;
    }
    tcur = (vmkit::MutatorThread*)tcur->next();
  } while (tcur != th);

  return max;
}

extern "C" void Java_org_j3_mmtk_Collection_prepareCollector__Lorg_mmtk_plan_CollectorContext_2 (MMTkObject* C, MMTkObject* CC) {
  // Nothing to do.
}

extern "C" void Java_org_j3_mmtk_Collection_prepareMutator__Lorg_mmtk_plan_MutatorContext_2 (MMTkObject* C, MMTkObject* MC) {
}

extern "C" int32_t Java_org_j3_mmtk_Collection_activeGCThreads__ (MMTkObject* C) { return 1; }
extern "C" int32_t Java_org_j3_mmtk_Collection_activeGCThreadOrdinal__ (MMTkObject* C) { return 1; }


extern "C" void Java_org_j3_mmtk_Collection_reportPhysicalAllocationFailed__ (MMTkObject* C) { UNIMPLEMENTED(); }
extern "C" void Java_org_j3_mmtk_Collection_triggerAsyncCollection__I (MMTkObject* C, sint32 val) {
  vmkit::Thread::get()->doYield = true;
}

extern "C" uint8_t Java_org_j3_mmtk_Collection_noThreadsInGC__ (MMTkObject* C) {
  vmkit::Thread* th = vmkit::Thread::get();
  bool threadInGC = th->doYield;
  return !threadInGC;
}

extern "C" void Java_org_j3_mmtk_Collection_requestMutatorFlush__ (MMTkObject* C) { UNIMPLEMENTED(); }

} // namespace mmtk