diff options
Diffstat (limited to 'ghc/includes/OSThreads.h')
| -rw-r--r-- | ghc/includes/OSThreads.h | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/ghc/includes/OSThreads.h b/ghc/includes/OSThreads.h index c136aa5c6d..40c260bc0f 100644 --- a/ghc/includes/OSThreads.h +++ b/ghc/includes/OSThreads.h @@ -1,6 +1,6 @@ /* --------------------------------------------------------------------------- * - * (c) The GHC Team, 2001 + * (c) The GHC Team, 2001-2005 * * Accessing OS threads functionality in a (mostly) OS-independent * manner. @@ -23,7 +23,6 @@ typedef pthread_key_t ThreadLocalKey; #define OSThreadProcAttr /* nothing */ -#define INIT_MUTEX_VAR PTHREAD_MUTEX_INITIALIZER #define INIT_COND_VAR PTHREAD_COND_INITIALIZER #ifdef LOCK_DEBUG @@ -73,15 +72,35 @@ typedef pthread_key_t ThreadLocalKey; #include <windows.h> typedef HANDLE Condition; -typedef HANDLE Mutex; typedef DWORD OSThreadId; typedef DWORD ThreadLocalKey; #define OSThreadProcAttr __stdcall -#define INIT_MUTEX_VAR 0 #define INIT_COND_VAR 0 +// We have a choice for implementing Mutexes on Windows. Standard +// Mutexes are kernel objects that require kernel calls to +// acquire/release, whereas CriticalSections are spin-locks that block +// in the kernel after spinning for a configurable number of times. +// CriticalSections are *much* faster, so we use those. The Mutex +// implementation is left here for posterity. +#define USE_CRITICAL_SECTIONS 1 + +#if USE_CRITICAL_SECTIONS + +typedef CRITICAL_SECTION Mutex; +#define ACQUIRE_LOCK(mutex) EnterCriticalSection(mutex) +#define RELEASE_LOCK(mutex) LeaveCriticalSection(mutex) + +// I don't know how to do this. TryEnterCriticalSection() doesn't do +// the right thing. +#define ASSERT_LOCK_HELD(mutex) /* nothing */ + +#else + +typedef HANDLE Mutex; + // casting to (Mutex *) here required due to use in .cmm files where // the argument has (void *) type. #define ACQUIRE_LOCK(mutex) \ @@ -95,6 +114,7 @@ typedef DWORD ThreadLocalKey; } #define ASSERT_LOCK_HELD(mutex) /* nothing */ +#endif # else # error "Threads not supported" @@ -140,6 +160,6 @@ void setThreadLocalVar (ThreadLocalKey *key, void *value); #define RELEASE_LOCK(l) #define ASSERT_LOCK_HELD(l) -#endif /* defined(RTS_SUPPORTS_THREADS) */ +#endif /* defined(THREADED_RTS) */ #endif /* __OSTHREADS_H__ */ |