diff options
Diffstat (limited to 'jam-files/engine/boehm_gc/include/private/gc_locks.h')
| -rw-r--r-- | jam-files/engine/boehm_gc/include/private/gc_locks.h | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/jam-files/engine/boehm_gc/include/private/gc_locks.h b/jam-files/engine/boehm_gc/include/private/gc_locks.h new file mode 100644 index 000000000..d7c83b07b --- /dev/null +++ b/jam-files/engine/boehm_gc/include/private/gc_locks.h @@ -0,0 +1,210 @@ +/* + * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers + * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved. + * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved. + * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved. + * + * + * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED + * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. + * + * Permission is hereby granted to use or copy this program + * for any purpose, provided the above notices are retained on all copies. + * Permission to modify the code and to distribute modified code is granted, + * provided the above notices are retained, and a notice that the code was + * modified is included with the above copyright notice. + */ + +#ifndef GC_LOCKS_H +#define GC_LOCKS_H + +/* + * Mutual exclusion between allocator/collector routines. + * Needed if there is more than one allocator thread. + * DCL_LOCK_STATE declares any local variables needed by LOCK and UNLOCK. + * + * Note that I_HOLD_LOCK and I_DONT_HOLD_LOCK are used only positively + * in assertions, and may return TRUE in the "dont know" case. + */ +# ifdef THREADS +# include <atomic_ops.h> + + void GC_noop1(word); +# ifdef PCR +# include <base/PCR_Base.h> +# include <th/PCR_Th.h> + extern PCR_Th_ML GC_allocate_ml; +# define DCL_LOCK_STATE \ + PCR_ERes GC_fastLockRes; PCR_sigset_t GC_old_sig_mask +# define LOCK() PCR_Th_ML_Acquire(&GC_allocate_ml) +# define UNLOCK() PCR_Th_ML_Release(&GC_allocate_ml) +# endif + +# if !defined(AO_HAVE_test_and_set_acquire) && defined(GC_PTHREADS) +# define USE_PTHREAD_LOCKS +# endif + +# if defined(GC_WIN32_THREADS) && defined(GC_PTHREADS) +# define USE_PTHREAD_LOCKS +# endif + +# if defined(GC_WIN32_THREADS) && !defined(USE_PTHREAD_LOCKS) +# include <windows.h> +# define NO_THREAD (DWORD)(-1) + extern DWORD GC_lock_holder; + GC_API CRITICAL_SECTION GC_allocate_ml; +# ifdef GC_ASSERTIONS +# define UNCOND_LOCK() \ + { EnterCriticalSection(&GC_allocate_ml); \ + SET_LOCK_HOLDER(); } +# define UNCOND_UNLOCK() \ + { GC_ASSERT(I_HOLD_LOCK()); UNSET_LOCK_HOLDER(); \ + LeaveCriticalSection(&GC_allocate_ml); } +# else +# define UNCOND_LOCK() EnterCriticalSection(&GC_allocate_ml); +# define UNCOND_UNLOCK() LeaveCriticalSection(&GC_allocate_ml); +# endif /* !GC_ASSERTIONS */ +# define SET_LOCK_HOLDER() GC_lock_holder = GetCurrentThreadId() +# define UNSET_LOCK_HOLDER() GC_lock_holder = NO_THREAD +# define I_HOLD_LOCK() (!GC_need_to_lock \ + || GC_lock_holder == GetCurrentThreadId()) +# define I_DONT_HOLD_LOCK() (!GC_need_to_lock \ + || GC_lock_holder != GetCurrentThreadId()) +# elif defined(GC_PTHREADS) +# include <pthread.h> + + /* Posix allows pthread_t to be a struct, though it rarely is. */ + /* Unfortunately, we need to use a pthread_t to index a data */ + /* structure. It also helps if comparisons don't involve a */ + /* function call. Hence we introduce platform-dependent macros */ + /* to compare pthread_t ids and to map them to integers. */ + /* the mapping to integers does not need to result in different */ + /* integers for each thread, though that should be true as much */ + /* as possible. */ + /* Refine to exclude platforms on which pthread_t is struct */ +# if !defined(GC_WIN32_PTHREADS) +# define NUMERIC_THREAD_ID(id) ((unsigned long)(id)) +# define THREAD_EQUAL(id1, id2) ((id1) == (id2)) +# define NUMERIC_THREAD_ID_UNIQUE +# else +# if defined(GC_WIN32_PTHREADS) +# define NUMERIC_THREAD_ID(id) ((unsigned long)(id.p)) + /* Using documented internal details of win32_pthread library. */ + /* Faster than pthread_equal(). Should not change with */ + /* future versions of win32_pthread library. */ +# define THREAD_EQUAL(id1, id2) ((id1.p == id2.p) && (id1.x == id2.x)) +# undef NUMERIC_THREAD_ID_UNIQUE +# else + /* Generic definitions that always work, but will result in */ + /* poor performance and weak assertion checking. */ +# define NUMERIC_THREAD_ID(id) 1l +# define THREAD_EQUAL(id1, id2) pthread_equal(id1, id2) +# undef NUMERIC_THREAD_ID_UNIQUE +# endif +# endif +# define NO_THREAD (-1l) + /* != NUMERIC_THREAD_ID(pthread_self()) for any thread */ + +# if !defined(THREAD_LOCAL_ALLOC) && !defined(USE_PTHREAD_LOCKS) + /* In the THREAD_LOCAL_ALLOC case, the allocation lock tends to */ + /* be held for long periods, if it is held at all. Thus spinning */ + /* and sleeping for fixed periods are likely to result in */ + /* significant wasted time. We thus rely mostly on queued locks. */ +# define USE_SPIN_LOCK + extern volatile AO_TS_t GC_allocate_lock; + extern void GC_lock(void); + /* Allocation lock holder. Only set if acquired by client through */ + /* GC_call_with_alloc_lock. */ +# ifdef GC_ASSERTIONS +# define UNCOND_LOCK() \ + { if (AO_test_and_set_acquire(&GC_allocate_lock) == AO_TS_SET) \ + GC_lock(); \ + SET_LOCK_HOLDER(); } +# define UNCOND_UNLOCK() \ + { GC_ASSERT(I_HOLD_LOCK()); UNSET_LOCK_HOLDER(); \ + AO_CLEAR(&GC_allocate_lock); } +# else +# define UNCOND_LOCK() \ + { if (AO_test_and_set_acquire(&GC_allocate_lock) == AO_TS_SET) \ + GC_lock(); } +# define UNCOND_UNLOCK() \ + AO_CLEAR(&GC_allocate_lock) +# endif /* !GC_ASSERTIONS */ +# else /* THREAD_LOCAL_ALLOC || USE_PTHREAD_LOCKS */ +# ifndef USE_PTHREAD_LOCKS +# define USE_PTHREAD_LOCKS +# endif +# endif /* THREAD_LOCAL_ALLOC || USE_PTHREAD_LOCK */ +# ifdef USE_PTHREAD_LOCKS +# include <pthread.h> + extern pthread_mutex_t GC_allocate_ml; +# ifdef GC_ASSERTIONS +# define UNCOND_LOCK() \ + { GC_lock(); \ + SET_LOCK_HOLDER(); } +# define UNCOND_UNLOCK() \ + { GC_ASSERT(I_HOLD_LOCK()); UNSET_LOCK_HOLDER(); \ + pthread_mutex_unlock(&GC_allocate_ml); } +# else /* !GC_ASSERTIONS */ +# if defined(NO_PTHREAD_TRYLOCK) +# define UNCOND_LOCK() GC_lock(); +# else /* !defined(NO_PTHREAD_TRYLOCK) */ +# define UNCOND_LOCK() \ + { if (0 != pthread_mutex_trylock(&GC_allocate_ml)) GC_lock(); } +# endif +# define UNCOND_UNLOCK() pthread_mutex_unlock(&GC_allocate_ml) +# endif /* !GC_ASSERTIONS */ +# endif /* USE_PTHREAD_LOCKS */ +# define SET_LOCK_HOLDER() \ + GC_lock_holder = NUMERIC_THREAD_ID(pthread_self()) +# define UNSET_LOCK_HOLDER() GC_lock_holder = NO_THREAD +# define I_HOLD_LOCK() \ + (!GC_need_to_lock || \ + GC_lock_holder == NUMERIC_THREAD_ID(pthread_self())) +# ifndef NUMERIC_THREAD_ID_UNIQUE +# define I_DONT_HOLD_LOCK() 1 /* Conservatively say yes */ +# else +# define I_DONT_HOLD_LOCK() \ + (!GC_need_to_lock \ + || GC_lock_holder != NUMERIC_THREAD_ID(pthread_self())) +# endif + extern volatile GC_bool GC_collecting; +# define ENTER_GC() GC_collecting = 1; +# define EXIT_GC() GC_collecting = 0; + extern void GC_lock(void); + extern unsigned long GC_lock_holder; +# ifdef GC_ASSERTIONS + extern unsigned long GC_mark_lock_holder; +# endif +# endif /* GC_PTHREADS with linux_threads.c implementation */ + + +# else /* !THREADS */ +# define LOCK() +# define UNLOCK() +# define SET_LOCK_HOLDER() +# define UNSET_LOCK_HOLDER() +# define I_HOLD_LOCK() TRUE +# define I_DONT_HOLD_LOCK() TRUE + /* Used only in positive assertions or to test whether */ + /* we still need to acaquire the lock. TRUE works in */ + /* either case. */ +# endif /* !THREADS */ + +#if defined(UNCOND_LOCK) && !defined(LOCK) + GC_API GC_bool GC_need_to_lock; + /* At least two thread running; need to lock. */ +# define LOCK() if (GC_need_to_lock) { UNCOND_LOCK(); } +# define UNLOCK() if (GC_need_to_lock) { UNCOND_UNLOCK(); } +#endif + +# ifndef ENTER_GC +# define ENTER_GC() +# define EXIT_GC() +# endif + +# ifndef DCL_LOCK_STATE +# define DCL_LOCK_STATE +# endif + +#endif /* GC_LOCKS_H */ |