22  * questions.
  23  *
  24  */
  25 
  26 #include "precompiled.hpp"
  27 #include "runtime/mutex.hpp"
  28 #include "runtime/osThread.hpp"
  29 #include "utilities/events.hpp"
  30 #ifdef TARGET_OS_FAMILY_linux
  31 # include "mutex_linux.inline.hpp"
  32 # include "thread_linux.inline.hpp"
  33 #endif
  34 #ifdef TARGET_OS_FAMILY_solaris
  35 # include "mutex_solaris.inline.hpp"
  36 # include "thread_solaris.inline.hpp"
  37 #endif
  38 #ifdef TARGET_OS_FAMILY_windows
  39 # include "mutex_windows.inline.hpp"
  40 # include "thread_windows.inline.hpp"
  41 #endif




  42 
  43 // o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o
  44 //
  45 // Native Monitor-Mutex locking - theory of operations
  46 //
  47 // * Native Monitors are completely unrelated to Java-level monitors,
  48 //   although the "back-end" slow-path implementations share a common lineage.
  49 //   See objectMonitor:: in synchronizer.cpp.
  50 //   Native Monitors do *not* support nesting or recursion but otherwise
  51 //   they're basically Hoare-flavor monitors.
  52 //
  53 // * A thread acquires ownership of a Monitor/Mutex by CASing the LockByte
  54 //   in the _LockWord from zero to non-zero.  Note that the _Owner field
  55 //   is advisory and is used only to verify that the thread calling unlock()
  56 //   is indeed the last thread to have acquired the lock.
  57 //
  58 // * Contending threads "push" themselves onto the front of the contention
  59 //   queue -- called the cxq -- with CAS and then spin/park.
  60 //   The _LockWord contains the LockByte as well as the pointer to the head
  61 //   of the cxq.  Colocating the LockByte with the cxq precludes certain races.

  22  * questions.
  23  *
  24  */
  25 
  26 #include "precompiled.hpp"
  27 #include "runtime/mutex.hpp"
  28 #include "runtime/osThread.hpp"
  29 #include "utilities/events.hpp"
  30 #ifdef TARGET_OS_FAMILY_linux
  31 # include "mutex_linux.inline.hpp"
  32 # include "thread_linux.inline.hpp"
  33 #endif
  34 #ifdef TARGET_OS_FAMILY_solaris
  35 # include "mutex_solaris.inline.hpp"
  36 # include "thread_solaris.inline.hpp"
  37 #endif
  38 #ifdef TARGET_OS_FAMILY_windows
  39 # include "mutex_windows.inline.hpp"
  40 # include "thread_windows.inline.hpp"
  41 #endif
  42 #ifdef TARGET_OS_FAMILY_bsd
  43 # include "mutex_bsd.inline.hpp"
  44 # include "thread_bsd.inline.hpp"
  45 #endif
  46 
  47 // o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o
  48 //
  49 // Native Monitor-Mutex locking - theory of operations
  50 //
  51 // * Native Monitors are completely unrelated to Java-level monitors,
  52 //   although the "back-end" slow-path implementations share a common lineage.
  53 //   See objectMonitor:: in synchronizer.cpp.
  54 //   Native Monitors do *not* support nesting or recursion but otherwise
  55 //   they're basically Hoare-flavor monitors.
  56 //
  57 // * A thread acquires ownership of a Monitor/Mutex by CASing the LockByte
  58 //   in the _LockWord from zero to non-zero.  Note that the _Owner field
  59 //   is advisory and is used only to verify that the thread calling unlock()
  60 //   is indeed the last thread to have acquired the lock.
  61 //
  62 // * Contending threads "push" themselves onto the front of the contention
  63 //   queue -- called the cxq -- with CAS and then spin/park.
  64 //   The _LockWord contains the LockByte as well as the pointer to the head
  65 //   of the cxq.  Colocating the LockByte with the cxq precludes certain races.