diff options
Diffstat (limited to 'deps/jemalloc/include/jemalloc/internal/mb.h')
-rw-r--r-- | deps/jemalloc/include/jemalloc/internal/mb.h | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/deps/jemalloc/include/jemalloc/internal/mb.h b/deps/jemalloc/include/jemalloc/internal/mb.h new file mode 100644 index 000000000..dc9f2a542 --- /dev/null +++ b/deps/jemalloc/include/jemalloc/internal/mb.h @@ -0,0 +1,108 @@ +/******************************************************************************/ +#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(__sparc64__) +JEMALLOC_INLINE void +mb_write(void) +{ + + asm volatile ("membar #StoreStore" + : /* Outputs. */ + : /* Inputs. */ + : "memory" /* Clobbers. */ + ); +} +#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); + malloc_mutex_lock(&mtx); + malloc_mutex_unlock(&mtx); +} +#endif +#endif + +#endif /* JEMALLOC_H_INLINES */ +/******************************************************************************/ |