diff options
Diffstat (limited to 'erts/emulator/beam/erl_threads.h')
| -rw-r--r-- | erts/emulator/beam/erl_threads.h | 319 |
1 files changed, 309 insertions, 10 deletions
diff --git a/erts/emulator/beam/erl_threads.h b/erts/emulator/beam/erl_threads.h index 065e7077c0..ee47c98009 100644 --- a/erts/emulator/beam/erl_threads.h +++ b/erts/emulator/beam/erl_threads.h @@ -1,7 +1,7 @@ /* * %CopyrightBegin% * - * Copyright Ericsson AB 2001-2011. All Rights Reserved. + * Copyright Ericsson AB 2001-2012. All Rights Reserved. * * The contents of this file are subject to the Erlang Public License, * Version 1.1, (the "License"); you may not use this file except in @@ -25,6 +25,235 @@ #ifndef ERL_THREAD_H__ #define ERL_THREAD_H__ +/* + * --- Documentation of atomics and memory barriers -------------------------- + * + * The following explicit memory barriers exist: + * + * - ERTS_THR_MEMORY_BARRIER + * Full memory barrier. Orders both loads, and stores. No + * load or store is allowed to be reordered over the + * barrier. + * - ERTS_THR_WRITE_MEMORY_BARRIER + * Write barrier. Orders *only* stores. These are not + * allowed to be reordered over the barrier. + * - ERTS_THR_READ_MEMORY_BARRIER + * Read barrier. Orders *only* loads. These are not + * allowed to be reordered over the barrier. + * - ERTS_THR_DATA_DEPENDENCY_READ_MEMORY_BARRIER + * Data dependency read barrier. Orders *only* loads + * according to data dependency across the barrier. + * + * If thread support has been disabled, these barriers will become no-ops. + * + * If the prefix ERTS_THR_ is replaced with ERTS_SMP_, the barriers will + * be enabled only in the SMP enabled runtime system. + * + * --- Atomic operations --- + * + * Atomics operations exist for 32-bit, word size, and double word size + * integers. Function prototypes are listed below. + * + * Each function implementing an atomic operation exist with the following + * implied memory barrier semantics. Not all combinations are useful, but + * all of them exist for simplicity. <B> is suffix in function name: + * + * - <B> - Description + * + * - mb - Full memory barrier. Orders both loads, and + * stores before, and after the atomic operation. + * No load or store is allowed to be reordered + * over the atomic operation. + * - relb - Release barrier. Orders both loads, and + * stores appearing *before* the atomic + * operation. These are not allowed to be + * reordered over the atomic operation. + * - acqb - Acquire barrier. Orders both loads, and stores + * appearing *after* the atomic operation. These + * are not allowed to be reordered over the + * atomic operation. + * - wb - Write barrier. Orders *only* stores. These are + * not allowed to be reordered over the barrier. + * Store in atomic operation is ordered *after* + * the barrier. + * - rb - Read barrier. Orders *only* loads. These are + * not allowed to be reordered over the barrier. + * Load in atomic operation is ordered *before* + * the barrier. + * - ddrb - Data dependency read barrier. Orders *only* + * loads according to data dependency across the + * barrier. Load in atomic operation is ordered + * before the barrier. + * + * If thread support has been disabled, these functions are mapped to + * functions that performs the same operation, but aren't atomic + * and don't imply any memory barriers. + * + * If the atomic operations are prefixed with erts_smp_ instead of only + * erts_ the atomic operations will only be atomic in the SMP enabled + * runtime system, and will be mapped to non-atomic operations without + * memory barriers in the runtime system without SMP support. Atomic + * operations with erts_smp_ prefix should use the atomic types + * erts_smp_atomic32_t, erts_smp_atomic_t, and erts_smp_dw_atomic_t + * instead of erts_atomic32_t, erts_atomic_t, and erts_dw_atomic_t. The + * integer data types erts_aint32_t, erts_aint_t, and erts_dw_atomic_t + * are the same. + * + * --- 32-bit atomic operations --- + * + * The following 32-bit atomic operations exist. <B> should be + * replaced with a supported memory barrier (see above). Note + * that sizeof(erts_atomic32_t) might be larger than 4! + * + * + * Initialize (not necessarily the same as the set operation): + * void erts_atomic32_init_<B>(erts_atomic32_t *atmc, + * erts_aint32_t val); + * + * Set value: + * void erts_atomic32_set_<B>(erts_atomic32_t *atmc, + * erts_aint32_t val); + * + * Read; returns current value: + * erts_aint32_t erts_atomic32_read_<B>(erts_atomic32_t *atmc); + * + * Increment; returns resulting value: + * erts_aint32_t erts_atomic32_inc_read_<B>(erts_atomic32_t *atmc); + * + * Decrement; returns resulting value: + * erts_aint32_t erts_atomic32_dec_read_<B>(erts_atomic32_t *atmc); + * + * Increment: + * void erts_atomic32_inc_<B>(erts_atomic32_t *atmc); + * + * Decrement: + * void erts_atomic32_dec_<B>(erts_atomic32_t *atmc); + * + * Add value; returns resulting value: + * erts_aint32_t erts_atomic32_add_read_<B>(erts_atomic32_t *atmc, + * erts_aint32_t val); + * + * Add value: + * void erts_atomic32_add_<B>(erts_atomic32_t *atmc, + * erts_aint32_t val); + * + * Bitwise-or; returns previous value: + * erts_aint32_t erts_atomic32_read_bor_<B>(erts_atomic32_t *atmc, + * erts_aint32_t val); + * + * Bitwise-and; returns previous value: + * erts_aint32_t erts_atomic32_read_band_<B>(erts_atomic32_t *atmc, + * erts_aint32_t val); + * + * Exchange; returns previous value: + * erts_aint32_t erts_atomic32_xchg_<B>(erts_atomic32_t *atmc, + * erts_aint32_t val); + * + * Compare and exchange; returns previous or current value. If + * returned value equals 'exp' the value was changed to 'new'; + * otherwise not: + * erts_aint32_t erts_atomic32_cmpxchg_<B>(erts_atomic32_t *a, + * erts_aint32_t new, + * erts_aint32_t exp); + * + * --- Word size atomic operations --- + * + * The following word size (same size as sizeof(void *)) atomic + * operations exist. <B> should be replaced with a supported + * memory barrier (see above). Note that sizeof(erts_atomic_t) + * might be larger than sizeof(void *)! + * + * Initialize (not necessarily the same as the set operation): + * void erts_atomic_init_<B>(erts_atomic_t *atmc, + * erts_aint_t val); + * + * Set value; + * void erts_atomic_set_<B>(erts_atomic_t *atmc, + * erts_aint_t val); + * + * Read; returns current value: + * erts_aint_t erts_atomic_read_<B>(erts_atomic_t *atmc); + * + * Increment; returns resulting value: + * erts_aint_t erts_atomic_inc_read_<B>(erts_atomic_t *atmc); + * + * Decrement; returns resulting value: + * erts_aint_t erts_atomic_dec_read_<B>(erts_atomic_t *atmc); + * + * Increment: + * void erts_atomic_inc_<B>(erts_atomic_t *atmc); + * + * Decrement: + * void erts_atomic_dec_<B>(erts_atomic_t *atmc); + * + * Add value; returns resulting value: + * erts_aint_t erts_atomic_add_read_<B>(erts_atomic_t *atmc, + * erts_aint_t val); + * + * Add value: + * void erts_atomic_add_<B>(erts_atomic_t *atmc, + * erts_aint_t val); + * + * Bitwise-or; returns previous value: + * erts_aint_t erts_atomic_read_bor_<B>(erts_atomic_t *atmc, + * erts_aint_t val); + * + * Bitwise-and; returns previous value: + * erts_aint_t erts_atomic_read_band_<B>(erts_atomic_t *atmc, + * erts_aint_t val); + * + * Exchange; returns previous value: + * erts_aint_t erts_atomic_xchg_<B>(erts_atomic_t *atmc, + * erts_aint_t val); + * + * Compare and exchange; returns previous or current value. If + * returned value equals 'exp' the value was changed to 'new'; + * otherwise not: + * erts_aint_t erts_atomic_cmpxchg_<B>(erts_atomic_t *a, + * erts_aint_t new, + * erts_aint_t exp); + * + * --- Double word size atomic operations --- + * + * The following double word atomic operations exist. <B> should be + * replaced with a supported memory barrier (see above). + * + * Note that sizeof(erts_dw_atomic_t) usually is larger than + * 2*sizeof(void *)! + * + * The erts_dw_aint_t data type should be accessed as if it was defined + * like this: + * + * typedef struct { + * erts_aint_t sint[2]; + * } erts_dw_aint_t; + * + * Most significant word is 'sint[ERTS_DW_AINT_HIGH_WORD]' and least + * significant word is 'sint[ERTS_DW_AINT_LOW_WORD]'. + * + * + * Initialize (not necessarily the same as the set operation): + * void erts_dw_atomic_init_<B>(erts_dw_atomic_t *var, + * erts_dw_aint_t *val); + * + * Set; value is written into 'val': + * void erts_dw_atomic_set_<B>(erts_dw_atomic_t *var, + * erts_dw_aint_t *val); + * + * Read; value is written into 'val': + * void erts_dw_atomic_read_<B>(erts_dw_atomic_t *var, + * erts_dw_aint_t *val); + * + * Compare and exchange; returns a value != 0 if exchange was + * made; otherwise 0. 'new_val' contains new value to set. If 'exp_act' + * contains the same value as in memory when the function is called, + * 'new' is written to memory; otherwise, not. If exchange was not + * made, 'exp_act' contains the actual value in memory: + * int erts_dw_atomic_cmpxchg_<B>(erts_dw_atomic_t *var, + * erts_dw_aint_t *new, + * erts_dw_aint_t *exp_act); + */ + #define ERTS_SPIN_BODY ETHR_SPIN_BODY #include "sys.h" @@ -52,6 +281,9 @@ typedef Sint32 erts_no_atomic32_t; #endif #define ERTS_THR_MEMORY_BARRIER ETHR_MEMORY_BARRIER +#define ERTS_THR_WRITE_MEMORY_BARRIER ETHR_WRITE_MEMORY_BARRIER +#define ERTS_THR_READ_MEMORY_BARRIER ETHR_READ_MEMORY_BARRIER +#define ERTS_THR_DATA_DEPENDENCY_READ_MEMORY_BARRIER ETHR_READ_DEPEND_MEMORY_BARRIER #ifdef ERTS_ENABLE_LOCK_COUNT #define erts_mtx_lock(L) erts_mtx_lock_x(L, __FILE__, __LINE__) @@ -113,6 +345,9 @@ typedef ethr_ts_event erts_tse_t; #define erts_aint32_t ethr_sint32_t #define erts_atomic32_t ethr_atomic32_t +#define ERTS_DW_AINT_HIGH_WORD ETHR_DW_SINT_HIGH_WORD +#define ERTS_DW_AINT_LOW_WORD ETHR_DW_SINT_LOW_WORD + /* spinlock */ typedef struct { ethr_spinlock_t slck; @@ -149,6 +384,9 @@ __decl_noreturn void __noreturn erts_thr_fatal_error(int, char *); #else /* #ifdef USE_THREADS */ #define ERTS_THR_MEMORY_BARRIER +#define ERTS_THR_WRITE_MEMORY_BARRIER +#define ERTS_THR_READ_MEMORY_BARRIER +#define ERTS_THR_DATA_DEPENDENCY_READ_MEMORY_BARRIER #define ERTS_THR_OPTS_DEFAULT_INITER 0 typedef int erts_thr_opts_t; @@ -361,18 +599,13 @@ ERTS_GLB_INLINE void erts_thr_sigmask(int how, const sigset_t *set, ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig); #endif /* #ifdef HAVE_ETHR_SIG_FUNCS */ +#ifdef USE_THREADS + /* - * Functions implementing atomic operations with with no (nob), - * full (mb), acquire (acqb), release (relb), read (rb), and - * write (wb) memory barriers. - * - * If thread support has been disabled, they are mapped to - * functions that performs the same operation, but aren't atomic - * and don't imply memory barriers. + * See "Documentation of atomics and memory barriers" at the top + * of this file for info on atomics. */ -#ifdef USE_THREADS - /* Double word size atomics */ #define erts_dw_atomic_init_nob ethr_dw_atomic_init @@ -395,6 +628,11 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig); #define erts_dw_atomic_read_relb ethr_dw_atomic_read_relb #define erts_dw_atomic_cmpxchg_relb ethr_dw_atomic_cmpxchg_relb +#define erts_dw_atomic_init_ddrb ethr_dw_atomic_init_ddrb +#define erts_dw_atomic_set_ddrb ethr_dw_atomic_set_ddrb +#define erts_dw_atomic_read_ddrb ethr_dw_atomic_read_ddrb +#define erts_dw_atomic_cmpxchg_ddrb ethr_dw_atomic_cmpxchg_ddrb + #define erts_dw_atomic_init_rb ethr_dw_atomic_init_rb #define erts_dw_atomic_set_rb ethr_dw_atomic_set_rb #define erts_dw_atomic_read_rb ethr_dw_atomic_read_rb @@ -463,6 +701,20 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig); #define erts_atomic_xchg_relb ethr_atomic_xchg_relb #define erts_atomic_cmpxchg_relb ethr_atomic_cmpxchg_relb +#define erts_atomic_init_ddrb ethr_atomic_init_ddrb +#define erts_atomic_set_ddrb ethr_atomic_set_ddrb +#define erts_atomic_read_ddrb ethr_atomic_read_ddrb +#define erts_atomic_inc_read_ddrb ethr_atomic_inc_read_ddrb +#define erts_atomic_dec_read_ddrb ethr_atomic_dec_read_ddrb +#define erts_atomic_inc_ddrb ethr_atomic_inc_ddrb +#define erts_atomic_dec_ddrb ethr_atomic_dec_ddrb +#define erts_atomic_add_read_ddrb ethr_atomic_add_read_ddrb +#define erts_atomic_add_ddrb ethr_atomic_add_ddrb +#define erts_atomic_read_bor_ddrb ethr_atomic_read_bor_ddrb +#define erts_atomic_read_band_ddrb ethr_atomic_read_band_ddrb +#define erts_atomic_xchg_ddrb ethr_atomic_xchg_ddrb +#define erts_atomic_cmpxchg_ddrb ethr_atomic_cmpxchg_ddrb + #define erts_atomic_init_rb ethr_atomic_init_rb #define erts_atomic_set_rb ethr_atomic_set_rb #define erts_atomic_read_rb ethr_atomic_read_rb @@ -549,6 +801,20 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig); #define erts_atomic32_xchg_relb ethr_atomic32_xchg_relb #define erts_atomic32_cmpxchg_relb ethr_atomic32_cmpxchg_relb +#define erts_atomic32_init_ddrb ethr_atomic32_init_ddrb +#define erts_atomic32_set_ddrb ethr_atomic32_set_ddrb +#define erts_atomic32_read_ddrb ethr_atomic32_read_ddrb +#define erts_atomic32_inc_read_ddrb ethr_atomic32_inc_read_ddrb +#define erts_atomic32_dec_read_ddrb ethr_atomic32_dec_read_ddrb +#define erts_atomic32_inc_ddrb ethr_atomic32_inc_ddrb +#define erts_atomic32_dec_ddrb ethr_atomic32_dec_ddrb +#define erts_atomic32_add_read_ddrb ethr_atomic32_add_read_ddrb +#define erts_atomic32_add_ddrb ethr_atomic32_add_ddrb +#define erts_atomic32_read_bor_ddrb ethr_atomic32_read_bor_ddrb +#define erts_atomic32_read_band_ddrb ethr_atomic32_read_band_ddrb +#define erts_atomic32_xchg_ddrb ethr_atomic32_xchg_ddrb +#define erts_atomic32_cmpxchg_ddrb ethr_atomic32_cmpxchg_ddrb + #define erts_atomic32_init_rb ethr_atomic32_init_rb #define erts_atomic32_set_rb ethr_atomic32_set_rb #define erts_atomic32_read_rb ethr_atomic32_read_rb @@ -601,6 +867,11 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig); #define erts_dw_atomic_read_relb erts_no_dw_atomic_read #define erts_dw_atomic_cmpxchg_relb erts_no_dw_atomic_cmpxchg +#define erts_dw_atomic_init_ddrb erts_no_dw_atomic_init +#define erts_dw_atomic_set_ddrb erts_no_dw_atomic_set +#define erts_dw_atomic_read_ddrb erts_no_dw_atomic_read +#define erts_dw_atomic_cmpxchg_ddrb erts_no_dw_atomic_cmpxchg + #define erts_dw_atomic_init_rb erts_no_dw_atomic_init #define erts_dw_atomic_set_rb erts_no_dw_atomic_set #define erts_dw_atomic_read_rb erts_no_dw_atomic_read @@ -669,6 +940,20 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig); #define erts_atomic_xchg_relb erts_no_atomic_xchg #define erts_atomic_cmpxchg_relb erts_no_atomic_cmpxchg +#define erts_atomic_init_ddrb erts_no_atomic_set +#define erts_atomic_set_ddrb erts_no_atomic_set +#define erts_atomic_read_ddrb erts_no_atomic_read +#define erts_atomic_inc_read_ddrb erts_no_atomic_inc_read +#define erts_atomic_dec_read_ddrb erts_no_atomic_dec_read +#define erts_atomic_inc_ddrb erts_no_atomic_inc +#define erts_atomic_dec_ddrb erts_no_atomic_dec +#define erts_atomic_add_read_ddrb erts_no_atomic_add_read +#define erts_atomic_add_ddrb erts_no_atomic_add +#define erts_atomic_read_bor_ddrb erts_no_atomic_read_bor +#define erts_atomic_read_band_ddrb erts_no_atomic_read_band +#define erts_atomic_xchg_ddrb erts_no_atomic_xchg +#define erts_atomic_cmpxchg_ddrb erts_no_atomic_cmpxchg + #define erts_atomic_init_rb erts_no_atomic_set #define erts_atomic_set_rb erts_no_atomic_set #define erts_atomic_read_rb erts_no_atomic_read @@ -755,6 +1040,20 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig); #define erts_atomic32_xchg_relb erts_no_atomic32_xchg #define erts_atomic32_cmpxchg_relb erts_no_atomic32_cmpxchg +#define erts_atomic32_init_ddrb erts_no_atomic32_set +#define erts_atomic32_set_ddrb erts_no_atomic32_set +#define erts_atomic32_read_ddrb erts_no_atomic32_read +#define erts_atomic32_inc_read_ddrb erts_no_atomic32_inc_read +#define erts_atomic32_dec_read_ddrb erts_no_atomic32_dec_read +#define erts_atomic32_inc_ddrb erts_no_atomic32_inc +#define erts_atomic32_dec_ddrb erts_no_atomic32_dec +#define erts_atomic32_add_read_ddrb erts_no_atomic32_add_read +#define erts_atomic32_add_ddrb erts_no_atomic32_add +#define erts_atomic32_read_bor_ddrb erts_no_atomic32_read_bor +#define erts_atomic32_read_band_ddrb erts_no_atomic32_read_band +#define erts_atomic32_xchg_ddrb erts_no_atomic32_xchg +#define erts_atomic32_cmpxchg_ddrb erts_no_atomic32_cmpxchg + #define erts_atomic32_init_rb erts_no_atomic32_set #define erts_atomic32_set_rb erts_no_atomic32_set #define erts_atomic32_read_rb erts_no_atomic32_read |