src/hotspot/share/gc/shared/stringdedup/stringDedupStorageUse.hpp

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#ifndef SHARE_GC_SHARED_STRINGDEDUP_STRINGDEDUPSTORAGEUSE_HPP
#define SHARE_GC_SHARED_STRINGDEDUP_STRINGDEDUPSTORAGEUSE_HPP

#include "gc/shared/stringdedup/stringDedup.hpp"
#include "memory/allocation.hpp"
#include "utilities/globalDefinitions.hpp"
#include "utilities/macros.hpp"

class OopStorage;

// Manage access to one of the OopStorage objects used for requests.
class StringDedup::StorageUse : public CHeapObj<mtStringDedup> {
  OopStorage* const _storage;
  volatile size_t _use_count;

  NONCOPYABLE(StorageUse);

public:
  explicit StorageUse(OopStorage* storage);

  OopStorage* storage() const { return _storage; }

  // Return true if the storage is currently in use for registering requests.
  bool is_used_acquire() const;

  // Get the current requests object, and increment its in-use count.
  static StorageUse* obtain(StorageUse* volatile* ptr);

  // Discard a prior "obtain" request, decrementing the in-use count, and
  // permitting the deduplication thread to start processing if needed.
  void relinquish();
};

#endif // SHARE_GC_SHARED_STRINGDEDUP_STRINGDEDUPSTORAGEUSE_HPP