/* * 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 # include 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 # include 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) # include inline static int GC_test_and_set(volatile unsigned int *addr) { return __sync_lock_test_and_set(addr, 1); } # define GC_TEST_AND_SET_DEFINED inline static void GC_clear(volatile unsigned int *addr) { *addr = 0; } # 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) # define GC_TEST_AND_SET_DEFINED # define GC_CLEAR_DEFINED # if (__GNUC__>4)||((__GNUC__==4)&&(__GNUC_MINOR__>=4)) # define GC_test_and_set(addr) __sync_lock_test_and_set (addr, 1) # define GC_clear(addr) __sync_lock_release (addr) # else inline static int GC_test_and_set(volatile unsigned int *addr) { int oldval; int temp = 1; /* locked value */ __asm__ __volatile__( "\n1:\n" "\tlwarx %0,%y3\n" /* load and reserve, 32-bits */ "\tcmpwi %0, 0\n" /* if load is */ "\tbne 2f\n" /* non-zero, return already set */ "\tstwcx. %2,%y3\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), "=m"(addr) : "r"(temp), "Z"(addr) : "cr0","memory"); return oldval; } inline static void GC_clear(volatile unsigned int *addr) { __asm__ __volatile__("lwsync" : : : "memory"); *(addr) = 0; } # endif # 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" # ifdef __ELF__ " beq %0,3f\n" # else " beq %0,1b\n" # endif " mb\n" "2:\n" # ifdef __ELF__ ".section .text2,\"ax\"\n" "3: br 1b\n" ".previous" # endif :"=&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 # define GC_TEST_AND_SET_DEFINED # if (__GNUC__>4)||((__GNUC__==4)&&(__GNUC_MINOR__>=5)) && defined(__ARM_EABI__) # define GC_CLEAR_DEFINED # define GC_test_and_set(addr) __sync_lock_test_and_set (addr, 1) # define GC_clear(addr) __sync_lock_release (addr) # else 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) : "0"(1), "r"(addr) : "memory"); return oldval; } # endif # endif /* ARM32 */ # ifdef CRIS inline static int GC_test_and_set(volatile unsigned int *addr) { /* Ripped from linuxthreads/sysdeps/cris/pt-machine.h. */ /* Included with Hans-Peter Nilsson's permission. */ register unsigned long int ret; /* Note the use of a dummy output of *addr to expose the write. * The memory barrier is to stop *other* writes being moved past * this code. */ __asm__ __volatile__("clearf\n" "0:\n\t" "movu.b [%2],%0\n\t" "ax\n\t" "move.b %3,[%2]\n\t" "bwf 0b\n\t" "clearf" : "=&r" (ret), "=m" (*addr) : "r" (addr), "r" ((int) 1), "m" (*addr) : "memory"); return ret; } # define GC_TEST_AND_SET_DEFINED # endif /* CRIS */ # 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 # include # 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 # 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 # include # include # 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 # 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_WIN32_THREADS) # define NO_THREAD (pthread_t)(-1) # include # 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) # if CPP_WORDSZ == 64 /* 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) { unsigned long result, dummy; __asm__ __volatile__( "1:\tldarx %0,0,%5\n" "\tcmpd %0,%4\n" "\tbne 2f\n" "\tstdcx. %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; } # else /* 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 # 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) { return __sync_bool_compare_and_swap (addr, old, new_val); } # endif /* !GENERIC_COMPARE_AND_SWAP */ # if 0 /* Shouldn't be needed; we use volatile stores instead. */ inline static void GC_memory_barrier() { __sync_synchronize (); } # 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 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 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_WIN32_THREADS) # if defined(GC_PTHREADS) # include 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 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 */