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131 lines
3.3 KiB
Text
131 lines
3.3 KiB
Text
/******************************************************
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The interface to the operating system synchronization primitives.
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(c) 1995 Innobase Oy
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Created 9/6/1995 Heikki Tuuri
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*******************************************************/
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#ifdef __WIN__
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#include <winbase.h>
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#endif
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/**************************************************************
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Acquires ownership of a fast mutex. Currently in Windows this is the same
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as os_fast_mutex_lock! */
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UNIV_INLINE
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ulint
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os_fast_mutex_trylock(
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/*==================*/
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/* out: 0 if success, != 0 if
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was reserved by another
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thread */
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os_fast_mutex_t* fast_mutex) /* in: mutex to acquire */
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{
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#ifdef __WIN__
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EnterCriticalSection(fast_mutex);
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return(0);
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#else
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#if defined(UNIV_HOTBACKUP) && defined(UNIV_HPUX10)
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/* Since the hot backup version is standalone, MySQL does not redefine
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pthread_mutex_trylock for HP-UX-10.20, and consequently we must invert
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the return value here */
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return((ulint) (1 - pthread_mutex_trylock(fast_mutex)));
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#else
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/* NOTE that the MySQL my_pthread.h redefines pthread_mutex_trylock
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so that it returns 0 on success. In the operating system
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libraries, HP-UX-10.20 follows the old Posix 1003.4a Draft 4 and
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returns 1 on success (but MySQL remaps that to 0), while Linux,
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FreeBSD, Solaris, AIX, Tru64 Unix, HP-UX-11.0 return 0 on success. */
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return((ulint) pthread_mutex_trylock(fast_mutex));
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#endif
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#endif
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}
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#ifdef UNIV_SYNC_ATOMIC
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/**************************************************************
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Atomic compare-and-swap for InnoDB. Currently requires GCC atomic builtins
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or Solaris atomic_* functions. */
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UNIV_INLINE
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ibool
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os_compare_and_swap(
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/*================*/
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/* out: true if swapped */
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volatile lint* ptr, /* in: pointer to target */
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lint oldVal, /* in: value to compare to */
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lint newVal) /* in: value to swap in */
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{
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#ifdef HAVE_GCC_ATOMIC_BUILTINS
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return (__sync_bool_compare_and_swap(ptr, oldVal, newVal));
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#elif HAVE_SOLARIS_ATOMIC
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lint retVal = (lint)atomic_cas_ulong((volatile ulong_t *)ptr,
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oldVal, newVal);
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return (retVal == oldVal);
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#else
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#error "Need support for atomic ops"
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#endif
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}
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/**************************************************************
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Memory barrier for load */
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UNIV_INLINE
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void
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os_memory_barrier_load()
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{
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#ifdef HAVE_GCC_ATOMIC_BUILTINS
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__sync_synchronize();
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#elif HAVE_SOLARIS_ATOMIC
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membar_consumer();
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#endif
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}
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/**************************************************************
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Memory barrier for store */
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UNIV_INLINE
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void
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os_memory_barrier_store()
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{
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#ifdef HAVE_GCC_ATOMIC_BUILTINS
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__sync_synchronize();
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#elif HAVE_SOLARIS_ATOMIC
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membar_producer();
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#endif
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}
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/**************************************************************
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Memory barrier */
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UNIV_INLINE
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void
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os_memory_barrier()
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{
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#ifdef HAVE_GCC_ATOMIC_BUILTINS
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__sync_synchronize();
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#elif HAVE_SOLARIS_ATOMIC
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membar_enter();
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#endif
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}
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/**************************************************************
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Atomic increment for InnoDB. Currently requires GCC atomic builtins. */
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UNIV_INLINE
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lint
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os_atomic_increment(
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/*================*/
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/* out: resulting value */
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volatile lint* ptr, /* in: pointer to target */
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lint amount) /* in: amount of increment */
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{
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#ifdef HAVE_GCC_ATOMIC_BUILTINS
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return (__sync_add_and_fetch(ptr, amount));
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#elif HAVE_SOLARIS_ATOMIC
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return ((lint)atomic_add_long_nv((volatile ulong_t *)ptr, amount));
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#else
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#error "Need support for atomic ops"
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#endif
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}
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#endif /* UNIV_SYNC_ATOMIC */
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