6988353: refactor contended sync subsystem

Reduce complexity by factoring synchronizer.cpp

Reviewed-by: dholmes, never, coleenp

hotspot/src/share/vm/runtime/thread.hpp

@@ -30,6 +30,7 @@ class JvmtiGetLoadedClassesClosure;
 class ThreadStatistics;
 class ConcurrentLocksDump;
 class ParkEvent ;
+class Parker;
 
 class ciEnv;
 class CompileThread;
@@ -544,7 +545,6 @@ public:
   static void muxAcquire  (volatile intptr_t * Lock, const char * Name) ;
   static void muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) ;
   static void muxRelease  (volatile intptr_t * Lock) ;
-
 };
 
 // Inline implementation of Thread::current()
@@ -1769,100 +1769,3 @@ public:
   }
 };
 
-// ParkEvents are type-stable and immortal.
-//
-// Lifecycle: Once a ParkEvent is associated with a thread that ParkEvent remains
-// associated with the thread for the thread's entire lifetime - the relationship is
-// stable. A thread will be associated at most one ParkEvent.  When the thread
-// expires, the ParkEvent moves to the EventFreeList.  New threads attempt to allocate from
-// the EventFreeList before creating a new Event.  Type-stability frees us from
-// worrying about stale Event or Thread references in the objectMonitor subsystem.
-// (A reference to ParkEvent is always valid, even though the event may no longer be associated
-// with the desired or expected thread.  A key aspect of this design is that the callers of
-// park, unpark, etc must tolerate stale references and spurious wakeups).
-//
-// Only the "associated" thread can block (park) on the ParkEvent, although
-// any other thread can unpark a reachable parkevent.  Park() is allowed to
-// return spuriously.  In fact park-unpark a really just an optimization to
-// avoid unbounded spinning and surrender the CPU to be a polite system citizen.
-// A degenerate albeit "impolite" park-unpark implementation could simply return.
-// See http://blogs.sun.com/dave for more details.
-//
-// Eventually I'd like to eliminate Events and ObjectWaiters, both of which serve as
-// thread proxies, and simply make the THREAD structure type-stable and persistent.
-// Currently, we unpark events associated with threads, but ideally we'd just
-// unpark threads.
-//
-// The base-class, PlatformEvent, is platform-specific while the ParkEvent is
-// platform-independent.  PlatformEvent provides park(), unpark(), etc., and
-// is abstract -- that is, a PlatformEvent should never be instantiated except
-// as part of a ParkEvent.
-// Equivalently we could have defined a platform-independent base-class that
-// exported Allocate(), Release(), etc.  The platform-specific class would extend
-// that base-class, adding park(), unpark(), etc.
-//
-// A word of caution: The JVM uses 2 very similar constructs:
-// 1. ParkEvent are used for Java-level "monitor" synchronization.
-// 2. Parkers are used by JSR166-JUC park-unpark.
-//
-// We'll want to eventually merge these redundant facilities and use ParkEvent.
-
-
-class ParkEvent : public os::PlatformEvent {
-  private:
-    ParkEvent * FreeNext ;
-
-    // Current association
-    Thread * AssociatedWith ;
-    intptr_t RawThreadIdentity ;        // LWPID etc
-    volatile int Incarnation ;
-
-    // diagnostic : keep track of last thread to wake this thread.
-    // this is useful for construction of dependency graphs.
-    void * LastWaker ;
-
-  public:
-    // MCS-CLH list linkage and Native Mutex/Monitor
-    ParkEvent * volatile ListNext ;
-    ParkEvent * volatile ListPrev ;
-    volatile intptr_t OnList ;
-    volatile int TState ;
-    volatile int Notified ;             // for native monitor construct
-    volatile int IsWaiting ;            // Enqueued on WaitSet
-
-
-  private:
-    static ParkEvent * volatile FreeList ;
-    static volatile int ListLock ;
-
-    // It's prudent to mark the dtor as "private"
-    // ensuring that it's not visible outside the package.
-    // Unfortunately gcc warns about such usage, so
-    // we revert to the less desirable "protected" visibility.
-    // The other compilers accept private dtors.
-
-  protected:        // Ensure dtor is never invoked
-    ~ParkEvent() { guarantee (0, "invariant") ; }
-
-    ParkEvent() : PlatformEvent() {
-       AssociatedWith = NULL ;
-       FreeNext       = NULL ;
-       ListNext       = NULL ;
-       ListPrev       = NULL ;
-       OnList         = 0 ;
-       TState         = 0 ;
-       Notified       = 0 ;
-       IsWaiting      = 0 ;
-    }
-
-    // We use placement-new to force ParkEvent instances to be
-    // aligned on 256-byte address boundaries.  This ensures that the least
-    // significant byte of a ParkEvent address is always 0.
-
-    void * operator new (size_t sz) ;
-    void operator delete (void * a) ;
-
-  public:
-    static ParkEvent * Allocate (Thread * t) ;
-    static void Release (ParkEvent * e) ;
-} ;