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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
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 * 2 along with this work; if not, write to the Free Software Foundation,
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#ifndef SHARE_VM_GC_G1_G1ROOTPROCESSOR_HPP
#define SHARE_VM_GC_G1_G1ROOTPROCESSOR_HPP

#include "gc/shared/oopStorageParState.hpp"
#include "gc/shared/strongRootsScope.hpp"
#include "memory/allocation.hpp"
#include "runtime/mutex.hpp"

class CLDClosure;
class CodeBlobClosure;
class G1CollectedHeap;
class G1EvacuationRootClosures;
class G1GCPhaseTimes;
class G1ParScanThreadState;
class G1RootClosures;
class Monitor;
class OopClosure;
class SubTasksDone;

// Scoped object to assist in applying oop, CLD and code blob closures to
// root locations. Handles claiming of different root scanning tasks
// and takes care of global state for root scanning via a StrongRootsScope.
// In the parallel case there is a shared G1RootProcessor object where all
// worker thread call the process_roots methods.
class G1RootProcessor : public StackObj {
  G1CollectedHeap* _g1h;
  SubTasksDone _process_strong_tasks;
  StrongRootsScope _srs;
  OopStorage::ParState<false, false> _par_state_string;

  // Used to implement the Thread work barrier.
  Monitor _lock;
  volatile jint _n_workers_discovered_strong_classes;

  enum G1H_process_roots_tasks {
    G1RP_PS_Universe_oops_do,
    G1RP_PS_JNIHandles_oops_do,
    G1RP_PS_ObjectSynchronizer_oops_do,
    G1RP_PS_Management_oops_do,
    G1RP_PS_SystemDictionary_oops_do,
    G1RP_PS_ClassLoaderDataGraph_oops_do,
    G1RP_PS_jvmti_oops_do,
    G1RP_PS_CodeCache_oops_do,
    G1RP_PS_aot_oops_do,
    G1RP_PS_filter_satb_buffers,
    G1RP_PS_refProcessor_oops_do,
    G1RP_PS_weakProcessor_oops_do,
    // Leave this one last.
    G1RP_PS_NumElements
  };

  void worker_has_discovered_all_strong_classes();
  void wait_until_all_strong_classes_discovered();

  void process_all_roots(OopClosure* oops,
                         CLDClosure* clds,
                         CodeBlobClosure* blobs,
                         bool process_string_table);

  void process_java_roots(G1RootClosures* closures,
                          G1GCPhaseTimes* phase_times,
                          uint worker_i);

  void process_vm_roots(G1RootClosures* closures,
                        G1GCPhaseTimes* phase_times,
                        uint worker_i);

  void process_string_table_roots(G1RootClosures* closures,
                                  G1GCPhaseTimes* phase_times,
                                  uint worker_i);

  void process_code_cache_roots(CodeBlobClosure* code_closure,
                                G1GCPhaseTimes* phase_times,
                                uint worker_i);

public:
  G1RootProcessor(G1CollectedHeap* g1h, uint n_workers);

  // Apply correct closures from pss to the strongly and weakly reachable roots in the system
  // in a single pass.
  // Record and report timing measurements for sub phases using the worker_i
  void evacuate_roots(G1ParScanThreadState* pss, uint worker_id);

  // Apply oops, clds and blobs to all strongly reachable roots in the system
  void process_strong_roots(OopClosure* oops,
                            CLDClosure* clds,
                            CodeBlobClosure* blobs);

  // Apply oops, clds and blobs to strongly and weakly reachable roots in the system
  void process_all_roots(OopClosure* oops,
                         CLDClosure* clds,
                         CodeBlobClosure* blobs);

  // Apply oops, clds and blobs to strongly and weakly reachable roots in the system,
  // the only thing different from process_all_roots is that we skip the string table
  // to avoid keeping every string live when doing class unloading.
  void process_all_roots_no_string_table(OopClosure* oops,
                                         CLDClosure* clds,
                                         CodeBlobClosure* blobs);

  // Apply closure to weak roots in the system. Used during the adjust phase
  // for the Full GC.
  void process_full_gc_weak_roots(OopClosure* oops);

  // Number of worker threads used by the root processor.
  uint n_workers() const;
};

#endif // SHARE_VM_GC_G1_G1ROOTPROCESSOR_HPP