/******************************************************************************/ #ifdef JEMALLOC_H_TYPES #endif /* JEMALLOC_H_TYPES */ /******************************************************************************/ #ifdef JEMALLOC_H_STRUCTS #endif /* JEMALLOC_H_STRUCTS */ /******************************************************************************/ #ifdef JEMALLOC_H_EXTERNS #endif /* JEMALLOC_H_EXTERNS */ /******************************************************************************/ #ifdef JEMALLOC_H_INLINES #ifndef JEMALLOC_ENABLE_INLINE void mb_write(void); #endif #if (defined(JEMALLOC_ENABLE_INLINE) || defined(JEMALLOC_MB_C_)) #ifdef __i386__ /* * According to the Intel Architecture Software Developer's Manual, current * processors execute instructions in order from the perspective of other * processors in a multiprocessor system, but 1) Intel reserves the right to * change that, and 2) the compiler's optimizer could re-order instructions if * there weren't some form of barrier. Therefore, even if running on an * architecture that does not need memory barriers (everything through at least * i686), an "optimizer barrier" is necessary. */ JEMALLOC_INLINE void mb_write(void) { # if 0 /* This is a true memory barrier. */ asm volatile ("pusha;" "xor %%eax,%%eax;" "cpuid;" "popa;" : /* Outputs. */ : /* Inputs. */ : "memory" /* Clobbers. */ ); # else /* * This is hopefully enough to keep the compiler from reordering * instructions around this one. */ asm volatile ("nop;" : /* Outputs. */ : /* Inputs. */ : "memory" /* Clobbers. */ ); # endif } #elif (defined(__amd64__) || defined(__x86_64__)) JEMALLOC_INLINE void mb_write(void) { asm volatile ("sfence" : /* Outputs. */ : /* Inputs. */ : "memory" /* Clobbers. */ ); } #elif defined(__powerpc__) JEMALLOC_INLINE void mb_write(void) { asm volatile ("eieio" : /* Outputs. */ : /* Inputs. */ : "memory" /* Clobbers. */ ); } #elif defined(__sparc__) && defined(__arch64__) JEMALLOC_INLINE void mb_write(void) { asm volatile ("membar #StoreStore" : /* Outputs. */ : /* Inputs. */ : "memory" /* Clobbers. */ ); } #elif defined(__tile__) JEMALLOC_INLINE void mb_write(void) { __sync_synchronize(); } #else /* * This is much slower than a simple memory barrier, but the semantics of mutex * unlock make this work. */ JEMALLOC_INLINE void mb_write(void) { malloc_mutex_t mtx; malloc_mutex_init(&mtx, "mb", WITNESS_RANK_OMIT); malloc_mutex_lock(TSDN_NULL, &mtx); malloc_mutex_unlock(TSDN_NULL, &mtx); } #endif #endif #endif /* JEMALLOC_H_INLINES */ /******************************************************************************/