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[Emacs-diffs] Changes to emacs/gc/include/private/gc_locks.h [Boehm-ver
From: |
Dave Love |
Subject: |
[Emacs-diffs] Changes to emacs/gc/include/private/gc_locks.h [Boehm-versions] |
Date: |
Mon, 16 Jun 2003 11:19:59 -0400 |
Index: emacs/gc/include/private/gc_locks.h
diff -c /dev/null emacs/gc/include/private/gc_locks.h:1.2.2.1.2.1
*** /dev/null Mon Jun 16 11:19:59 2003
--- emacs/gc/include/private/gc_locks.h Mon Jun 16 11:19:53 2003
***************
*** 0 ****
--- 1,650 ----
+ /*
+ * 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 */
+ "\tsync\n" /* import barrier */
+ "2:\t\n" /* oldval is zero if we set */
+ : "=&r"(oldval), "=p"(addr)
+ : "r"(temp), "1"(addr)
+ : "cr0","memory");
+ return 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
+ inline static void GC_clear(volatile unsigned int *addr) {
+ __asm__ __volatile__("mb" : : : "memory");
+ *(addr) = 0;
+ }
+ # define GC_CLEAR_DEFINED
+ # 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 */
+ # ifdef S390
+ inline static int GC_test_and_set(volatile unsigned int *addr) {
+ int ret;
+ __asm__ __volatile__ (
+ " l %0,0(%2)\n"
+ "0: cs %0,%1,0(%2)\n"
+ " jl 0b"
+ : "=&d" (ret)
+ : "d" (1), "a" (addr)
+ : "cc", "memory");
+ return ret;
+ }
+ # endif
+ # endif /* __GNUC__ */
+ # if (defined(ALPHA) && !defined(__GNUC__))
+ # ifndef OSF1
+ --> We currently assume that if gcc is not used, we are
+ --> running under Tru64.
+ # endif
+ # include <machine/builtins.h>
+ # include <c_asm.h>
+ # define GC_test_and_set(addr) __ATOMIC_EXCH_LONG(addr, 1)
+ # define GC_TEST_AND_SET_DEFINED
+ # define GC_clear(addr) { asm("mb"); *(volatile unsigned *)addr = 0; }
+ # define GC_CLEAR_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((void *)addr,1)
+ # else
+ # define GC_test_and_set(addr) test_and_set((void *)addr,1)
+ # endif
+ # else
+ # define GC_test_and_set(addr) __test_and_set32((void *)addr,1)
+ # define GC_clear(addr) __lock_release(addr);
+ # define GC_CLEAR_DEFINED
+ # endif
+ # define GC_TEST_AND_SET_DEFINED
+ # endif /* MIPS */
+ # if defined(_AIX)
+ # include <sys/atomic_op.h>
+ # if (defined(_POWER) || defined(_POWERPC))
+ # if defined(__GNUC__)
+ inline static void GC_memsync() {
+ __asm__ __volatile__ ("sync" : : : "memory");
+ }
+ # else
+ # ifndef inline
+ # define inline __inline
+ # endif
+ # pragma mc_func GC_memsync { \
+ "7c0004ac" /* sync (same opcode used for dcs)*/ \
+ }
+ # endif
+ # else
+ # error dont know how to memsync
+ # endif
+ inline static int GC_test_and_set(volatile unsigned int * addr) {
+ int oldvalue = 0;
+ if (compare_and_swap((void *)addr, &oldvalue, 1)) {
+ GC_memsync();
+ return 0;
+ } else return 1;
+ }
+ # define GC_TEST_AND_SET_DEFINED
+ inline static void GC_clear(volatile unsigned int *addr) {
+ GC_memsync();
+ *(addr) = 0;
+ }
+ # define GC_CLEAR_DEFINED
+
+ # endif
+ # 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), "a"(old) : "memory");
+ return (GC_bool) result;
+ }
+ # endif /* !GENERIC_COMPARE_AND_SWAP */
+ inline static void GC_memory_barrier()
+ {
+ /* We believe the processor ensures at least processor */
+ /* consistent ordering. Thus a compiler barrier */
+ /* should suffice. */
+ __asm__ __volatile__("" : : : "memory");
+ }
+ # endif /* I386 */
+
+ # if defined(POWERPC)
+ # 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)
+ {
+ int result, dummy;
+ __asm__ __volatile__(
+ "1:\tlwarx %0,0,%5\n"
+ "\tcmpw %0,%4\n"
+ "\tbne 2f\n"
+ "\tstwcx. %3,0,%2\n"
+ "\tbne- 1b\n"
+ "\tsync\n"
+ "\tli %1, 1\n"
+ "\tb 3f\n"
+ "2:\tli %1, 0\n"
+ "3:\t\n"
+ : "=&r" (dummy), "=r" (result), "=p" (addr)
+ : "r" (new_val), "r" (old), "2"(addr)
+ : "cr0","memory");
+ return (GC_bool) result;
+ }
+ # endif /* !GENERIC_COMPARE_AND_SWAP */
+ inline static void GC_memory_barrier()
+ {
+ __asm__ __volatile__("sync" : : : "memory");
+ }
+ # endif /* POWERPC */
+
+ # 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_barrier()
+ {
+ __asm__ __volatile__("mf" : : : "memory");
+ }
+ # endif /* 0 */
+ # endif /* IA64 */
+ # if defined(ALPHA)
+ # if !defined(GENERIC_COMPARE_AND_SWAP)
+ # if defined(__GNUC__)
+ inline static GC_bool GC_compare_and_exchange(volatile GC_word
*addr,
+ GC_word old, GC_word
new_val)
+ {
+ unsigned long was_equal;
+ unsigned long temp;
+
+ __asm__ __volatile__(
+ "1: ldq_l %0,%1\n"
+ " cmpeq %0,%4,%2\n"
+ " mov %3,%0\n"
+ " beq %2,2f\n"
+ " stq_c %0,%1\n"
+ " beq %0,1b\n"
+ "2:\n"
+ " mb\n"
+ :"=&r" (temp), "=m" (*addr), "=&r" (was_equal)
+ : "r" (new_val), "Ir" (old)
+ :"memory");
+ return was_equal;
+ }
+ # else /* !__GNUC__ */
+ inline static GC_bool GC_compare_and_exchange(volatile GC_word
*addr,
+ GC_word old, GC_word
new_val)
+ {
+ return __CMP_STORE_QUAD(addr, old, new_val, addr);
+ }
+ # endif /* !__GNUC__ */
+ # endif /* !GENERIC_COMPARE_AND_SWAP */
+ # ifdef __GNUC__
+ inline static void GC_memory_barrier()
+ {
+ __asm__ __volatile__("mb" : : : "memory");
+ }
+ # else
+ # define GC_memory_barrier() asm("mb")
+ # endif /* !__GNUC__ */
+ # endif /* ALPHA */
+ # if defined(S390)
+ # if !defined(GENERIC_COMPARE_AND_SWAP)
+ inline static GC_bool GC_compare_and_exchange(volatile C_word *addr,
+ GC_word old, GC_word new_val)
+ {
+ int retval;
+ __asm__ __volatile__ (
+ # ifndef __s390x__
+ " cs %1,%2,0(%3)\n"
+ # else
+ " csg %1,%2,0(%3)\n"
+ # endif
+ " ipm %0\n"
+ " srl %0,28\n"
+ : "=&d" (retval), "+d" (old)
+ : "d" (new_val), "a" (addr)
+ : "cc", "memory");
+ return retval == 0;
+ }
+ # endif
+ # endif
+ # 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 */
+ # if defined(NO_PTHREAD_TRYLOCK)
+ # define LOCK() GC_lock();
+ # else /* !defined(NO_PTHREAD_TRYLOCK) */
+ # define LOCK() \
+ { if (0 != pthread_mutex_trylock(&GC_allocate_ml)) GC_lock(); }
+ # endif
+ # 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 volatile unsigned int 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 */
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