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| -rw-r--r-- | gc/include/private/gc_locks.h | 496 |
1 files changed, 0 insertions, 496 deletions
diff --git a/gc/include/private/gc_locks.h b/gc/include/private/gc_locks.h deleted file mode 100644 index 2dbc6ca..0000000 --- a/gc/include/private/gc_locks.h +++ /dev/null @@ -1,496 +0,0 @@ -/* - * 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. - * FASTLOCK() is assumed to try to acquire the lock in a cheap and - * dirty way that is acceptable for a few instructions, e.g. by - * inhibiting preemption. This is assumed to have succeeded only - * if a subsequent call to FASTLOCK_SUCCEEDED() returns TRUE. - * FASTUNLOCK() is called whether or not FASTLOCK_SUCCEEDED(). - * If signals cannot be tolerated with the FASTLOCK held, then - * FASTLOCK should disable signals. The code executed under - * FASTLOCK is otherwise immune to interruption, provided it is - * not restarted. - * DCL_LOCK_STATE declares any local variables needed by LOCK and UNLOCK - * and/or DISABLE_SIGNALS and ENABLE_SIGNALS and/or FASTLOCK. - * (There is currently no equivalent for FASTLOCK.) - * - * In the PARALLEL_MARK case, we also need to define a number of - * other inline finctions here: - * GC_bool GC_compare_and_exchange( volatile GC_word *addr, - * GC_word old, GC_word new ) - * GC_word GC_atomic_add( volatile GC_word *addr, GC_word how_much ) - * void GC_memory_barrier( ) - * - */ -# ifdef THREADS - void GC_noop1 GC_PROTO((word)); -# ifdef PCR_OBSOLETE /* Faster, but broken with multiple lwp's */ -# include "th/PCR_Th.h" -# include "th/PCR_ThCrSec.h" - extern struct PCR_Th_MLRep GC_allocate_ml; -# define DCL_LOCK_STATE 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) -# define UNLOCK() PCR_Th_ML_Release(&GC_allocate_ml) -# define FASTLOCK() PCR_ThCrSec_EnterSys() - /* Here we cheat (a lot): */ -# define FASTLOCK_SUCCEEDED() (*(int *)(&GC_allocate_ml) == 0) - /* TRUE if nobody currently holds the lock */ -# define FASTUNLOCK() PCR_ThCrSec_ExitSys() -# endif -# 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) -# define FASTLOCK() (GC_fastLockRes = PCR_Th_ML_Try(&GC_allocate_ml)) -# define FASTLOCK_SUCCEEDED() (GC_fastLockRes == PCR_ERes_okay) -# define FASTUNLOCK() {\ - if( FASTLOCK_SUCCEEDED() ) PCR_Th_ML_Release(&GC_allocate_ml); } -# endif -# ifdef SRC_M3 - extern GC_word RT0u__inCritical; -# define LOCK() RT0u__inCritical++ -# define UNLOCK() RT0u__inCritical-- -# endif -# ifdef GC_SOLARIS_THREADS -# include <thread.h> -# include <signal.h> - extern mutex_t GC_allocate_ml; -# define LOCK() mutex_lock(&GC_allocate_ml); -# define UNLOCK() mutex_unlock(&GC_allocate_ml); -# endif - -/* Try to define GC_TEST_AND_SET and a matching GC_CLEAR for spin lock */ -/* acquisition and release. We need this for correct operation of the */ -/* incremental GC. */ -# ifdef __GNUC__ -# if defined(I386) - inline static int GC_test_and_set(volatile unsigned int *addr) { - int oldval; - /* Note: the "xchg" instruction does not need a "lock" prefix */ - __asm__ __volatile__("xchgl %0, %1" - : "=r"(oldval), "=m"(*(addr)) - : "0"(1), "m"(*(addr)) : "memory"); - return oldval; - } -# define GC_TEST_AND_SET_DEFINED -# endif -# if defined(IA64) - inline static int GC_test_and_set(volatile unsigned int *addr) { - long oldval, n = 1; - __asm__ __volatile__("xchg4 %0=%1,%2" - : "=r"(oldval), "=m"(*addr) - : "r"(n), "1"(*addr) : "memory"); - return oldval; - } -# define GC_TEST_AND_SET_DEFINED - /* Should this handle post-increment addressing?? */ - inline static void GC_clear(volatile unsigned int *addr) { - __asm__ __volatile__("st4.rel %0=r0" : "=m" (*addr) : : "memory"); - } -# define GC_CLEAR_DEFINED -# endif -# ifdef SPARC - inline static int GC_test_and_set(volatile unsigned int *addr) { - int oldval; - - __asm__ __volatile__("ldstub %1,%0" - : "=r"(oldval), "=m"(*addr) - : "m"(*addr) : "memory"); - return oldval; - } -# define GC_TEST_AND_SET_DEFINED -# endif -# ifdef M68K - /* Contributed by Tony Mantler. I'm not sure how well it was */ - /* tested. */ - inline static int GC_test_and_set(volatile unsigned int *addr) { - char oldval; /* this must be no longer than 8 bits */ - - /* The return value is semi-phony. */ - /* 'tas' sets bit 7 while the return */ - /* value pretends bit 0 was set */ - __asm__ __volatile__( - "tas %1@; sne %0; negb %0" - : "=d" (oldval) - : "a" (addr) : "memory"); - return oldval; - } -# define GC_TEST_AND_SET_DEFINED -# endif -# if defined(POWERPC) - inline static int GC_test_and_set(volatile unsigned int *addr) { - int oldval; - int temp = 1; /* locked value */ - - __asm__ __volatile__( - "1:\tlwarx %0,0,%3\n" /* load and reserve */ - "\tcmpwi %0, 0\n" /* if load is */ - "\tbne 2f\n" /* non-zero, return already set */ - "\tstwcx. %2,0,%1\n" /* else store conditional */ - "\tbne- 1b\n" /* retry if lost reservation */ - "2:\t\n" /* oldval is zero if we set */ - : "=&r"(oldval), "=p"(addr) - : "r"(temp), "1"(addr) - : "memory"); - return (int)oldval; - } -# define GC_TEST_AND_SET_DEFINED - inline static void GC_clear(volatile unsigned int *addr) { - __asm__ __volatile__("eieio" : : : "memory"); - *(addr) = 0; - } -# define GC_CLEAR_DEFINED -# endif -# if defined(ALPHA) - inline static int GC_test_and_set(volatile unsigned int * addr) - { - unsigned long oldvalue; - unsigned long temp; - - __asm__ __volatile__( - "1: ldl_l %0,%1\n" - " and %0,%3,%2\n" - " bne %2,2f\n" - " xor %0,%3,%0\n" - " stl_c %0,%1\n" - " beq %0,3f\n" - " mb\n" - "2:\n" - ".section .text2,\"ax\"\n" - "3: br 1b\n" - ".previous" - :"=&r" (temp), "=m" (*addr), "=&r" (oldvalue) - :"Ir" (1), "m" (*addr) - :"memory"); - - return oldvalue; - } -# define GC_TEST_AND_SET_DEFINED - /* Should probably also define GC_clear, since it needs */ - /* a memory barrier ?? */ -# endif /* ALPHA */ -# ifdef ARM32 - inline static int GC_test_and_set(volatile unsigned int *addr) { - int oldval; - /* SWP on ARM is very similar to XCHG on x86. Doesn't lock the - * bus because there are no SMP ARM machines. If/when there are, - * this code will likely need to be updated. */ - /* See linuxthreads/sysdeps/arm/pt-machine.h in glibc-2.1 */ - __asm__ __volatile__("swp %0, %1, [%2]" - : "=r"(oldval) - : "r"(1), "r"(addr) - : "memory"); - return oldval; - } -# define GC_TEST_AND_SET_DEFINED -# endif /* ARM32 */ -# endif /* __GNUC__ */ -# if (defined(ALPHA) && !defined(__GNUC__)) -# define GC_test_and_set(addr) __cxx_test_and_set_atomic(addr, 1) -# define GC_TEST_AND_SET_DEFINED -# endif -# if defined(MSWIN32) -# define GC_test_and_set(addr) InterlockedExchange((LPLONG)addr,1) -# define GC_TEST_AND_SET_DEFINED -# endif -# ifdef MIPS -# ifdef LINUX -# include <sys/tas.h> -# define GC_test_and_set(addr) _test_and_set((int *) addr,1) -# define GC_TEST_AND_SET_DEFINED -# elif __mips < 3 || !(defined (_ABIN32) || defined(_ABI64)) \ - || !defined(_COMPILER_VERSION) || _COMPILER_VERSION < 700 -# ifdef __GNUC__ -# define GC_test_and_set(addr) _test_and_set(addr,1) -# else -# define GC_test_and_set(addr) test_and_set(addr,1) -# endif -# else -# define GC_test_and_set(addr) __test_and_set(addr,1) -# define GC_clear(addr) __lock_release(addr); -# define GC_CLEAR_DEFINED -# endif -# define GC_TEST_AND_SET_DEFINED -# endif /* MIPS */ -# if 0 /* defined(HP_PA) */ - /* The official recommendation seems to be to not use ldcw from */ - /* user mode. Since multithreaded incremental collection doesn't */ - /* work anyway on HP_PA, this shouldn't be a major loss. */ - - /* "set" means 0 and "clear" means 1 here. */ -# define GC_test_and_set(addr) !GC_test_and_clear(addr); -# define GC_TEST_AND_SET_DEFINED -# define GC_clear(addr) GC_noop1((word)(addr)); *(volatile unsigned int *)addr = 1; - /* The above needs a memory barrier! */ -# define GC_CLEAR_DEFINED -# endif -# if defined(GC_TEST_AND_SET_DEFINED) && !defined(GC_CLEAR_DEFINED) -# ifdef __GNUC__ - inline static void GC_clear(volatile unsigned int *addr) { - /* Try to discourage gcc from moving anything past this. */ - __asm__ __volatile__(" " : : : "memory"); - *(addr) = 0; - } -# else - /* The function call in the following should prevent the */ - /* compiler from moving assignments to below the UNLOCK. */ -# define GC_clear(addr) GC_noop1((word)(addr)); \ - *((volatile unsigned int *)(addr)) = 0; -# endif -# define GC_CLEAR_DEFINED -# endif /* !GC_CLEAR_DEFINED */ - -# if !defined(GC_TEST_AND_SET_DEFINED) -# define USE_PTHREAD_LOCKS -# endif - -# if defined(GC_PTHREADS) && !defined(GC_SOLARIS_THREADS) \ - && !defined(GC_IRIX_THREADS) && !defined(GC_WIN32_THREADS) -# define NO_THREAD (pthread_t)(-1) -# include <pthread.h> -# if defined(PARALLEL_MARK) - /* We need compare-and-swap to update mark bits, where it's */ - /* performance critical. If USE_MARK_BYTES is defined, it is */ - /* no longer needed for this purpose. However we use it in */ - /* either case to implement atomic fetch-and-add, though that's */ - /* less performance critical, and could perhaps be done with */ - /* a lock. */ -# if defined(GENERIC_COMPARE_AND_SWAP) - /* Probably not useful, except for debugging. */ - /* We do use GENERIC_COMPARE_AND_SWAP on PA_RISC, but we */ - /* minimize its use. */ - extern pthread_mutex_t GC_compare_and_swap_lock; - - /* Note that if GC_word updates are not atomic, a concurrent */ - /* reader should acquire GC_compare_and_swap_lock. On */ - /* currently supported platforms, such updates are atomic. */ - extern GC_bool GC_compare_and_exchange(volatile GC_word *addr, - GC_word old, GC_word new_val); -# endif /* GENERIC_COMPARE_AND_SWAP */ -# if defined(I386) -# if !defined(GENERIC_COMPARE_AND_SWAP) - /* Returns TRUE if the comparison succeeded. */ - inline static GC_bool GC_compare_and_exchange(volatile GC_word *addr, - GC_word old, - GC_word new_val) - { - char result; - __asm__ __volatile__("lock; cmpxchgl %2, %0; setz %1" - : "=m"(*(addr)), "=r"(result) - : "r" (new_val), "0"(*(addr)), "a"(old) : "memory"); - return (GC_bool) result; - } -# endif /* !GENERIC_COMPARE_AND_SWAP */ - inline static void GC_memory_write_barrier() - { - /* We believe the processor ensures at least processor */ - /* consistent ordering. Thus a compiler barrier */ - /* should suffice. */ - __asm__ __volatile__("" : : : "memory"); - } -# endif /* I386 */ -# if defined(IA64) -# if !defined(GENERIC_COMPARE_AND_SWAP) - inline static GC_bool GC_compare_and_exchange(volatile GC_word *addr, - GC_word old, GC_word new_val) - { - unsigned long oldval; - __asm__ __volatile__("mov ar.ccv=%4 ;; cmpxchg8.rel %0=%1,%2,ar.ccv" - : "=r"(oldval), "=m"(*addr) - : "r"(new_val), "1"(*addr), "r"(old) : "memory"); - return (oldval == old); - } -# endif /* !GENERIC_COMPARE_AND_SWAP */ -# if 0 - /* Shouldn't be needed; we use volatile stores instead. */ - inline static void GC_memory_write_barrier() - { - __asm__ __volatile__("mf" : : : "memory"); - } -# endif /* 0 */ -# endif /* IA64 */ -# if !defined(GENERIC_COMPARE_AND_SWAP) - /* Returns the original value of *addr. */ - inline static GC_word GC_atomic_add(volatile GC_word *addr, - GC_word how_much) - { - GC_word old; - do { - old = *addr; - } while (!GC_compare_and_exchange(addr, old, old+how_much)); - return old; - } -# else /* GENERIC_COMPARE_AND_SWAP */ - /* So long as a GC_word can be atomically updated, it should */ - /* be OK to read *addr without a lock. */ - extern GC_word GC_atomic_add(volatile GC_word *addr, GC_word how_much); -# endif /* GENERIC_COMPARE_AND_SWAP */ - -# endif /* PARALLEL_MARK */ - -# 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 unsigned int 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 LOCK() \ - { if (GC_test_and_set(&GC_allocate_lock)) GC_lock(); \ - SET_LOCK_HOLDER(); } -# define UNLOCK() \ - { GC_ASSERT(I_HOLD_LOCK()); UNSET_LOCK_HOLDER(); \ - GC_clear(&GC_allocate_lock); } -# else -# define LOCK() \ - { if (GC_test_and_set(&GC_allocate_lock)) GC_lock(); } -# define UNLOCK() \ - GC_clear(&GC_allocate_lock) -# endif /* !GC_ASSERTIONS */ -# if 0 - /* Another alternative for OSF1 might be: */ -# include <sys/mman.h> - extern msemaphore GC_allocate_semaphore; -# define LOCK() { if (msem_lock(&GC_allocate_semaphore, MSEM_IF_NOWAIT) \ - != 0) GC_lock(); else GC_allocate_lock = 1; } - /* The following is INCORRECT, since the memory model is too weak. */ - /* Is this true? Presumably msem_unlock has the right semantics? */ - /* - HB */ -# define UNLOCK() { GC_allocate_lock = 0; \ - msem_unlock(&GC_allocate_semaphore, 0); } -# endif /* 0 */ -# else /* THREAD_LOCAL_ALLOC || USE_PTHREAD_LOCKS */ -# ifndef USE_PTHREAD_LOCKS -# define USE_PTHREAD_LOCKS -# endif -# endif /* THREAD_LOCAL_ALLOC */ -# ifdef USE_PTHREAD_LOCKS -# include <pthread.h> - extern pthread_mutex_t GC_allocate_ml; -# ifdef GC_ASSERTIONS -# define LOCK() \ - { GC_lock(); \ - SET_LOCK_HOLDER(); } -# define UNLOCK() \ - { GC_ASSERT(I_HOLD_LOCK()); UNSET_LOCK_HOLDER(); \ - pthread_mutex_unlock(&GC_allocate_ml); } -# else /* !GC_ASSERTIONS */ -# define LOCK() \ - { if (0 != pthread_mutex_trylock(&GC_allocate_ml)) GC_lock(); } -# define UNLOCK() pthread_mutex_unlock(&GC_allocate_ml) -# endif /* !GC_ASSERTIONS */ -# endif /* USE_PTHREAD_LOCKS */ -# define SET_LOCK_HOLDER() GC_lock_holder = pthread_self() -# define UNSET_LOCK_HOLDER() GC_lock_holder = NO_THREAD -# define I_HOLD_LOCK() (pthread_equal(GC_lock_holder, pthread_self())) - extern VOLATILE GC_bool GC_collecting; -# define ENTER_GC() GC_collecting = 1; -# define EXIT_GC() GC_collecting = 0; - extern void GC_lock(void); - extern pthread_t GC_lock_holder; -# ifdef GC_ASSERTIONS - extern pthread_t GC_mark_lock_holder; -# endif -# endif /* GC_PTHREADS with linux_threads.c implementation */ -# if defined(GC_IRIX_THREADS) -# include <pthread.h> - /* This probably should never be included, but I can't test */ - /* on Irix anymore. */ -# include <mutex.h> - - extern unsigned long GC_allocate_lock; - /* This is not a mutex because mutexes that obey the (optional) */ - /* POSIX scheduling rules are subject to convoys in high contention */ - /* applications. This is basically a spin lock. */ - extern pthread_t GC_lock_holder; - extern void GC_lock(void); - /* Allocation lock holder. Only set if acquired by client through */ - /* GC_call_with_alloc_lock. */ -# define SET_LOCK_HOLDER() GC_lock_holder = pthread_self() -# define NO_THREAD (pthread_t)(-1) -# define UNSET_LOCK_HOLDER() GC_lock_holder = NO_THREAD -# define I_HOLD_LOCK() (pthread_equal(GC_lock_holder, pthread_self())) -# define LOCK() { if (GC_test_and_set(&GC_allocate_lock)) GC_lock(); } -# define UNLOCK() GC_clear(&GC_allocate_lock); - extern VOLATILE GC_bool GC_collecting; -# define ENTER_GC() \ - { \ - GC_collecting = 1; \ - } -# define EXIT_GC() GC_collecting = 0; -# endif /* GC_IRIX_THREADS */ -# if defined(GC_WIN32_THREADS) -# if defined(GC_PTHREADS) -# include <pthread.h> - extern pthread_mutex_t GC_allocate_ml; -# define LOCK() pthread_mutex_lock(&GC_allocate_ml) -# define UNLOCK() pthread_mutex_unlock(&GC_allocate_ml) -# else -# include <windows.h> - GC_API CRITICAL_SECTION GC_allocate_ml; -# define LOCK() EnterCriticalSection(&GC_allocate_ml); -# define UNLOCK() LeaveCriticalSection(&GC_allocate_ml); -# endif -# endif -# ifndef SET_LOCK_HOLDER -# define SET_LOCK_HOLDER() -# define UNSET_LOCK_HOLDER() -# define I_HOLD_LOCK() FALSE - /* Used on platforms were locks can be reacquired, */ - /* so it doesn't matter if we lie. */ -# endif -# else /* !THREADS */ -# define LOCK() -# define UNLOCK() -# endif /* !THREADS */ -# ifndef SET_LOCK_HOLDER -# define SET_LOCK_HOLDER() -# define UNSET_LOCK_HOLDER() -# define I_HOLD_LOCK() FALSE - /* Used on platforms were locks can be reacquired, */ - /* so it doesn't matter if we lie. */ -# endif -# ifndef ENTER_GC -# define ENTER_GC() -# define EXIT_GC() -# endif - -# ifndef DCL_LOCK_STATE -# define DCL_LOCK_STATE -# endif -# ifndef FASTLOCK -# define FASTLOCK() LOCK() -# define FASTLOCK_SUCCEEDED() TRUE -# define FASTUNLOCK() UNLOCK() -# endif - -#endif /* GC_LOCKS_H */ |