2 * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
3 * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
4 * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved.
5 * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved.
8 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
9 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
11 * Permission is hereby granted to use or copy this program
12 * for any purpose, provided the above notices are retained on all copies.
13 * Permission to modify the code and to distribute modified code is granted,
14 * provided the above notices are retained, and a notice that the code was
15 * modified is included with the above copyright notice.
22 * Mutual exclusion between allocator/collector routines.
23 * Needed if there is more than one allocator thread.
24 * DCL_LOCK_STATE declares any local variables needed by LOCK and UNLOCK.
26 * Note that I_HOLD_LOCK and I_DONT_HOLD_LOCK are used only positively
27 * in assertions, and may return TRUE in the "don't know" case.
31 # if defined(GC_PTHREADS) && !defined(GC_WIN32_THREADS)
32 # include "atomic_ops.h"
35 GC_API void GC_CALL GC_noop1(word);
37 # include <base/PCR_Base.h>
38 # include <th/PCR_Th.h>
39 GC_EXTERN PCR_Th_ML GC_allocate_ml;
40 # define DCL_LOCK_STATE \
41 PCR_ERes GC_fastLockRes; PCR_sigset_t GC_old_sig_mask
42 # define UNCOND_LOCK() PCR_Th_ML_Acquire(&GC_allocate_ml)
43 # define UNCOND_UNLOCK() PCR_Th_ML_Release(&GC_allocate_ml)
46 # if !defined(AO_HAVE_test_and_set_acquire) && defined(GC_PTHREADS)
47 # define USE_PTHREAD_LOCKS
50 # if defined(GC_WIN32_THREADS) && defined(GC_PTHREADS)
51 # define USE_PTHREAD_LOCKS
54 # if defined(GC_RTEMS_PTHREADS)
55 # define USE_PTHREAD_LOCKS
58 # if defined(GC_WIN32_THREADS) && !defined(USE_PTHREAD_LOCKS)
59 # ifndef WIN32_LEAN_AND_MEAN
60 # define WIN32_LEAN_AND_MEAN 1
64 # define NO_THREAD (DWORD)(-1)
65 GC_EXTERN DWORD GC_lock_holder;
66 GC_EXTERN CRITICAL_SECTION GC_allocate_ml;
68 # define UNCOND_LOCK() \
69 { EnterCriticalSection(&GC_allocate_ml); \
71 # define UNCOND_UNLOCK() \
72 { GC_ASSERT(I_HOLD_LOCK()); UNSET_LOCK_HOLDER(); \
73 LeaveCriticalSection(&GC_allocate_ml); }
75 # define UNCOND_LOCK() EnterCriticalSection(&GC_allocate_ml)
76 # define UNCOND_UNLOCK() LeaveCriticalSection(&GC_allocate_ml)
77 # endif /* !GC_ASSERTIONS */
78 # define SET_LOCK_HOLDER() GC_lock_holder = GetCurrentThreadId()
79 # define UNSET_LOCK_HOLDER() GC_lock_holder = NO_THREAD
80 # define I_HOLD_LOCK() (!GC_need_to_lock \
81 || GC_lock_holder == GetCurrentThreadId())
82 # define I_DONT_HOLD_LOCK() (!GC_need_to_lock \
83 || GC_lock_holder != GetCurrentThreadId())
84 # elif defined(SN_TARGET_PS3)
86 GC_EXTERN pthread_mutex_t GC_allocate_ml;
87 # define LOCK() pthread_mutex_lock(&GC_allocate_ml)
88 # define UNLOCK() pthread_mutex_unlock(&GC_allocate_ml)
89 # elif defined(GC_PTHREADS)
92 /* Posix allows pthread_t to be a struct, though it rarely is. */
93 /* Unfortunately, we need to use a pthread_t to index a data */
94 /* structure. It also helps if comparisons don't involve a */
95 /* function call. Hence we introduce platform-dependent macros */
96 /* to compare pthread_t ids and to map them to integers. */
97 /* the mapping to integers does not need to result in different */
98 /* integers for each thread, though that should be true as much */
100 /* Refine to exclude platforms on which pthread_t is struct */
101 # if !defined(GC_WIN32_PTHREADS)
102 # define NUMERIC_THREAD_ID(id) ((unsigned long)(id))
103 # define THREAD_EQUAL(id1, id2) ((id1) == (id2))
104 # define NUMERIC_THREAD_ID_UNIQUE
106 # define NUMERIC_THREAD_ID(id) ((unsigned long)(id.p))
107 /* Using documented internal details of win32-pthread library. */
108 /* Faster than pthread_equal(). Should not change with */
109 /* future versions of win32-pthread library. */
110 # define THREAD_EQUAL(id1, id2) ((id1.p == id2.p) && (id1.x == id2.x))
111 # undef NUMERIC_THREAD_ID_UNIQUE
112 /* Generic definitions based on pthread_equal() always work but */
113 /* will result in poor performance (as NUMERIC_THREAD_ID is */
114 /* defined to just a constant) and weak assertion checking. */
116 # define NO_THREAD ((unsigned long)(-1l))
117 /* != NUMERIC_THREAD_ID(pthread_self()) for any thread */
119 # if !defined(THREAD_LOCAL_ALLOC) && !defined(USE_PTHREAD_LOCKS)
120 /* In the THREAD_LOCAL_ALLOC case, the allocation lock tends to */
121 /* be held for long periods, if it is held at all. Thus spinning */
122 /* and sleeping for fixed periods are likely to result in */
123 /* significant wasted time. We thus rely mostly on queued locks. */
124 # define USE_SPIN_LOCK
125 GC_EXTERN volatile AO_TS_t GC_allocate_lock;
126 GC_INNER void GC_lock(void);
127 /* Allocation lock holder. Only set if acquired by client through */
128 /* GC_call_with_alloc_lock. */
129 # ifdef GC_ASSERTIONS
130 # define UNCOND_LOCK() \
131 { if (AO_test_and_set_acquire(&GC_allocate_lock) == AO_TS_SET) \
134 # define UNCOND_UNLOCK() \
135 { GC_ASSERT(I_HOLD_LOCK()); UNSET_LOCK_HOLDER(); \
136 AO_CLEAR(&GC_allocate_lock); }
138 # define UNCOND_LOCK() \
139 { if (AO_test_and_set_acquire(&GC_allocate_lock) == AO_TS_SET) \
141 # define UNCOND_UNLOCK() AO_CLEAR(&GC_allocate_lock)
142 # endif /* !GC_ASSERTIONS */
143 # else /* THREAD_LOCAL_ALLOC || USE_PTHREAD_LOCKS */
144 # ifndef USE_PTHREAD_LOCKS
145 # define USE_PTHREAD_LOCKS
147 # endif /* THREAD_LOCAL_ALLOC || USE_PTHREAD_LOCK */
148 # ifdef USE_PTHREAD_LOCKS
149 # include <pthread.h>
150 GC_EXTERN pthread_mutex_t GC_allocate_ml;
151 # ifdef GC_ASSERTIONS
152 # define UNCOND_LOCK() { GC_lock(); SET_LOCK_HOLDER(); }
153 # define UNCOND_UNLOCK() \
154 { GC_ASSERT(I_HOLD_LOCK()); UNSET_LOCK_HOLDER(); \
155 pthread_mutex_unlock(&GC_allocate_ml); }
156 # else /* !GC_ASSERTIONS */
157 # if defined(NO_PTHREAD_TRYLOCK)
158 # define UNCOND_LOCK() GC_lock()
159 # else /* !defined(NO_PTHREAD_TRYLOCK) */
160 # define UNCOND_LOCK() \
161 { if (0 != pthread_mutex_trylock(&GC_allocate_ml)) \
164 # define UNCOND_UNLOCK() pthread_mutex_unlock(&GC_allocate_ml)
165 # endif /* !GC_ASSERTIONS */
166 # endif /* USE_PTHREAD_LOCKS */
167 # define SET_LOCK_HOLDER() \
168 GC_lock_holder = NUMERIC_THREAD_ID(pthread_self())
169 # define UNSET_LOCK_HOLDER() GC_lock_holder = NO_THREAD
170 # define I_HOLD_LOCK() \
171 (!GC_need_to_lock || \
172 GC_lock_holder == NUMERIC_THREAD_ID(pthread_self()))
173 # ifndef NUMERIC_THREAD_ID_UNIQUE
174 # define I_DONT_HOLD_LOCK() 1 /* Conservatively say yes */
176 # define I_DONT_HOLD_LOCK() \
178 || GC_lock_holder != NUMERIC_THREAD_ID(pthread_self()))
180 GC_EXTERN volatile GC_bool GC_collecting;
181 # define ENTER_GC() GC_collecting = 1;
182 # define EXIT_GC() GC_collecting = 0;
183 GC_INNER void GC_lock(void);
184 GC_EXTERN unsigned long GC_lock_holder;
185 # if defined(GC_ASSERTIONS) && defined(PARALLEL_MARK)
186 GC_EXTERN unsigned long GC_mark_lock_holder;
188 # endif /* GC_PTHREADS with linux_threads.c implementation */
189 GC_EXTERN GC_bool GC_need_to_lock;
191 # else /* !THREADS */
194 # define SET_LOCK_HOLDER()
195 # define UNSET_LOCK_HOLDER()
196 # define I_HOLD_LOCK() TRUE
197 # define I_DONT_HOLD_LOCK() TRUE
198 /* Used only in positive assertions or to test whether */
199 /* we still need to acquire the lock. TRUE works in */
201 # endif /* !THREADS */
203 #if defined(UNCOND_LOCK) && !defined(LOCK)
204 /* At least two thread running; need to lock. */
205 # define LOCK() { if (GC_need_to_lock) UNCOND_LOCK(); }
206 # define UNLOCK() { if (GC_need_to_lock) UNCOND_UNLOCK(); }
214 # ifndef DCL_LOCK_STATE
215 # define DCL_LOCK_STATE
218 #endif /* GC_LOCKS_H */