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Implement suspend flags as atomic variable (#2361)

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We have observed a significant performance degradation after merging
https://github.com/bytecodealliance/wasm-micro-runtime/pull/1991
Instead of protecting suspend flags with a mutex, we implement the flags
as atomic variable and only use mutex when atomics are not available
on a given platform.
This commit is contained in:
Marcin Kolny
2023-07-21 01:27:09 +01:00
committed by GitHub
parent fbe072c0d3
commit 0f4edf9735
8 changed files with 135 additions and 45 deletions
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45
core/iwasm/interpreter/wasm_interp_classic.c
View File

@ -1062,21 +1062,33 @@ wasm_interp_call_func_import(WASMModuleInstance *module_inst,
os_mutex_unlock(&exec_env->wait_lock); \
} while (0)
#else
#define CHECK_SUSPEND_FLAGS() \
do { \
os_mutex_lock(&exec_env->wait_lock); \
if (exec_env->suspend_flags.flags != 0) { \
if (exec_env->suspend_flags.flags & 0x01) { \
/* terminate current thread */ \
os_mutex_unlock(&exec_env->wait_lock); \
return; \
} \
while (exec_env->suspend_flags.flags & 0x02) { \
/* suspend current thread */ \
os_cond_wait(&exec_env->wait_cond, &exec_env->wait_lock); \
} \
} \
os_mutex_unlock(&exec_env->wait_lock); \
#if WASM_SUSPEND_FLAGS_IS_ATOMIC != 0
/* The lock is only needed when the suspend_flags is atomic; otherwise
the lock is already taken at the time when SUSPENSION_LOCK() is called. */
#define SUSPENSION_LOCK() os_mutex_lock(&exec_env->wait_lock);
#define SUSPENSION_UNLOCK() os_mutex_unlock(&exec_env->wait_lock);
#else
#define SUSPENSION_LOCK()
#define SUSPENSION_UNLOCK()
#endif
#define CHECK_SUSPEND_FLAGS() \
do { \
WASM_SUSPEND_FLAGS_LOCK(exec_env->wait_lock); \
if (WASM_SUSPEND_FLAGS_GET(exec_env->suspend_flags) \
& WASM_SUSPEND_FLAG_TERMINATE) { \
/* terminate current thread */ \
WASM_SUSPEND_FLAGS_UNLOCK(exec_env->wait_lock); \
return; \
} \
while (WASM_SUSPEND_FLAGS_GET(exec_env->suspend_flags) \
& WASM_SUSPEND_FLAG_SUSPEND) { \
/* suspend current thread */ \
SUSPENSION_LOCK() \
os_cond_wait(&exec_env->wait_cond, &exec_env->wait_lock); \
SUSPENSION_UNLOCK() \
} \
WASM_SUSPEND_FLAGS_UNLOCK(exec_env->wait_lock); \
} while (0)
#endif /* WASM_ENABLE_DEBUG_INTERP */
#endif /* WASM_ENABLE_THREAD_MGR */
@ -3783,7 +3795,8 @@ wasm_interp_call_func_bytecode(WASMModuleInstance *module,
HANDLE_OP(DEBUG_OP_BREAK)
{
wasm_cluster_thread_send_signal(exec_env, WAMR_SIG_TRAP);
exec_env->suspend_flags.flags |= 2;
WASM_SUSPEND_FLAGS_FETCH_OR(exec_env->suspend_flags,
WASM_SUSPEND_FLAG_SUSPEND);
frame_ip--;
SYNC_ALL_TO_FRAME();
CHECK_SUSPEND_FLAGS();

23
core/iwasm/interpreter/wasm_interp_fast.c
View File

@ -1065,18 +1065,17 @@ wasm_interp_call_func_import(WASMModuleInstance *module_inst,
#endif
#if WASM_ENABLE_THREAD_MGR != 0
#define CHECK_SUSPEND_FLAGS() \
do { \
os_mutex_lock(&exec_env->wait_lock); \
if (exec_env->suspend_flags.flags != 0) { \
if (exec_env->suspend_flags.flags & 0x01) { \
/* terminate current thread */ \
os_mutex_unlock(&exec_env->wait_lock); \
return; \
} \
/* TODO: support suspend and breakpoint */ \
} \
os_mutex_unlock(&exec_env->wait_lock); \
#define CHECK_SUSPEND_FLAGS() \
do { \
WASM_SUSPEND_FLAGS_LOCK(exec_env->wait_lock); \
if (WASM_SUSPEND_FLAGS_GET(exec_env->suspend_flags) \
& WASM_SUSPEND_FLAG_TERMINATE) { \
/* terminate current thread */ \
WASM_SUSPEND_FLAGS_UNLOCK(exec_env->wait_lock); \
return; \
} \
/* TODO: support suspend and breakpoint */ \
WASM_SUSPEND_FLAGS_UNLOCK(exec_env->wait_lock); \
} while (0)
#endif