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Add/reorganize locks for thread synchronization (#1995)

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Attempt to fix data races when using threads.
- Protect access (from multiple threads) to exception and memory
- Fix shared memory lock usage
This commit is contained in:
Enrico Loparco
2023-03-04 01:15:26 +01:00
committed by GitHub
parent 1c44411a97
commit e8d718096d
9 changed files with 274 additions and 81 deletions
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30
core/iwasm/libraries/thread-mgr/thread_manager.c
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@ -16,6 +16,10 @@
#include "debug_engine.h"
#endif
#if WASM_ENABLE_SHARED_MEMORY != 0
#include "wasm_shared_memory.h"
#endif
typedef struct {
bh_list_link l;
void (*destroy_cb)(WASMCluster *);
@ -826,15 +830,18 @@ clusters_have_exec_env(WASMExecEnv *exec_env)
WASMExecEnv *node;
while (cluster) {
os_mutex_lock(&cluster->lock);
node = bh_list_first_elem(&cluster->exec_env_list);
while (node) {
if (node == exec_env) {
bh_assert(exec_env->cluster == cluster);
os_mutex_unlock(&cluster->lock);
return true;
}
node = bh_list_elem_next(node);
}
os_mutex_unlock(&cluster->lock);
cluster = bh_list_elem_next(cluster);
}
@ -848,13 +855,11 @@ wasm_cluster_join_thread(WASMExecEnv *exec_env, void **ret_val)
korp_tid handle;
os_mutex_lock(&cluster_list_lock);
os_mutex_lock(&exec_env->cluster->lock);
if (!clusters_have_exec_env(exec_env) || exec_env->thread_is_detached) {
/* Invalid thread, thread has exited or thread has been detached */
if (ret_val)
*ret_val = NULL;
os_mutex_unlock(&exec_env->cluster->lock);
os_mutex_unlock(&cluster_list_lock);
return 0;
}
@ -864,7 +869,6 @@ wasm_cluster_join_thread(WASMExecEnv *exec_env, void **ret_val)
handle = exec_env->handle;
os_mutex_unlock(&exec_env->wait_lock);
os_mutex_unlock(&exec_env->cluster->lock);
os_mutex_unlock(&cluster_list_lock);
return os_thread_join(handle, ret_val);
@ -1146,12 +1150,22 @@ set_exception_visitor(void *node, void *user_data)
(WASMModuleInstance *)get_module_inst(curr_exec_env);
/* Only spread non "wasi proc exit" exception */
#if WASM_ENABLE_SHARED_MEMORY != 0
WASMSharedMemNode *shared_mem_node = wasm_module_get_shared_memory(
(WASMModuleCommon *)curr_wasm_inst->module);
if (shared_mem_node)
os_mutex_lock(&shared_mem_node->shared_mem_lock);
#endif
if (!strstr(wasm_inst->cur_exception, "wasi proc exit")) {
bh_memcpy_s(curr_wasm_inst->cur_exception,
sizeof(curr_wasm_inst->cur_exception),
wasm_inst->cur_exception,
sizeof(wasm_inst->cur_exception));
}
#if WASM_ENABLE_SHARED_MEMORY != 0
if (shared_mem_node)
os_mutex_unlock(&shared_mem_node->shared_mem_lock);
#endif
/* Terminate the thread so it can exit from dead loops */
set_thread_cancel_flags(curr_exec_env);
@ -1168,7 +1182,17 @@ clear_exception_visitor(void *node, void *user_data)
WASMModuleInstance *curr_wasm_inst =
(WASMModuleInstance *)get_module_inst(curr_exec_env);
#if WASM_ENABLE_SHARED_MEMORY != 0
WASMSharedMemNode *shared_mem_node = wasm_module_get_shared_memory(
(WASMModuleCommon *)curr_wasm_inst->module);
if (shared_mem_node)
os_mutex_lock(&shared_mem_node->shared_mem_lock);
#endif
curr_wasm_inst->cur_exception[0] = '\0';
#if WASM_ENABLE_SHARED_MEMORY != 0
if (shared_mem_node)
os_mutex_unlock(&shared_mem_node->shared_mem_lock);
#endif
}
}