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24 
25 #ifndef SHARE_JFR_UTILITIES_JFRTRYLOCK_HPP
26 #define SHARE_JFR_UTILITIES_JFRTRYLOCK_HPP
27 
28 #include "runtime/atomic.hpp"
29 #include "runtime/orderAccess.hpp"
30 #include "runtime/mutexLocker.hpp"
31 #include "utilities/debug.hpp"
32 
33 class JfrTryLock {
34  private:
35   volatile int* const _lock;
36   bool _has_lock;
37 
38  public:
JfrTryLock(volatile int * lock)39   JfrTryLock(volatile int* lock) : _lock(lock), _has_lock(Atomic::cmpxchg(lock, 0, 1) == 0) {}
40 
~JfrTryLock()41   ~JfrTryLock() {
42     if (_has_lock) {
43       OrderAccess::fence();
44       *_lock = 0;
45     }
46   }
47 
has_lock() const48   bool has_lock() const {
49     return _has_lock;
50   }
51 };
52 
53 class JfrMonitorTryLock : public StackObj {
54  private:
55   Monitor* _lock;
56   bool _acquired;
57 
58  public:
JfrMonitorTryLock(Monitor * lock)59   JfrMonitorTryLock(Monitor* lock) : _lock(lock), _acquired(lock->try_lock()) {}
60 
~JfrMonitorTryLock()61   ~JfrMonitorTryLock() {
62     if (_acquired) {
63       assert(_lock->owned_by_self(), "invariant");
64       _lock->unlock();
65     }
66   }
67 
acquired() const68   bool acquired() const {
69     return _acquired;
70   }
71 
72 };
73 
74 #endif // SHARE_JFR_UTILITIES_JFRTRYLOCK_HPP
75