Commit 866965e
src: fix race on modpending
Fixes a rare race condition on modpending when two native modules are
loaded simultaneously on different threads by storing it thread-
locally.
PR-URL: #21611
Reviewed-By: Gabriel Schulhof <gabriel.schulhof@intel.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>1 parent c894145 commit 866965e
1 file changed
Lines changed: 12 additions & 5 deletions
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
@@ -187,7 +187,8 @@ static int v8_thread_pool_size = v8_default_thread_pool_size; | |||
| 187 | 187 | static bool prof_process = false; | |
| 188 | 188 | static bool v8_is_profiling = false; | |
| 189 | 189 | static bool node_is_initialized = false; | |
| 190 | - static node_module* modpending; | ||
| 190 | + static uv_once_t init_modpending_once = UV_ONCE_INIT; | ||
| 191 | + static uv_key_t thread_local_modpending; | ||
| 191 | 192 | static node_module* modlist_builtin; | |
| 192 | 193 | static node_module* modlist_internal; | |
| 193 | 194 | static node_module* modlist_linked; | |
@@ -1254,7 +1255,7 @@ extern "C" void node_module_register(void* m) { | |||
| 1254 | 1255 | mp->nm_link = modlist_linked; | |
| 1255 | 1256 | modlist_linked = mp; | |
| 1256 | 1257 | } else { | |
| 1257 | - modpending = mp; | ||
| 1258 | + uv_key_set(&thread_local_modpending, mp); | ||
| 1258 | 1259 | } | |
| 1259 | 1260 | } | |
| 1260 | 1261 | ||
@@ -1368,6 +1369,10 @@ inline napi_addon_register_func GetNapiInitializerCallback(DLib* dlib) { | |||
| 1368 | 1369 | reinterpret_cast<napi_addon_register_func>(dlib->GetSymbolAddress(name)); | |
| 1369 | 1370 | } | |
| 1370 | 1371 | ||
| 1372 | + void InitModpendingOnce() { | ||
| 1373 | + CHECK_EQ(0, uv_key_create(&thread_local_modpending)); | ||
| 1374 | + } | ||
| 1375 | + | ||
| 1371 | 1376 | // DLOpen is process.dlopen(module, filename, flags). | |
| 1372 | 1377 | // Used to load 'module.node' dynamically shared objects. | |
| 1373 | 1378 | // | |
@@ -1378,7 +1383,8 @@ static void DLOpen(const FunctionCallbackInfo<Value>& args) { | |||
| 1378 | 1383 | Environment* env = Environment::GetCurrent(args); | |
| 1379 | 1384 | auto context = env->context(); | |
| 1380 | 1385 | ||
| 1381 | - CHECK_NULL(modpending); | ||
| 1386 | + uv_once(&init_modpending_once, InitModpendingOnce); | ||
| 1387 | + CHECK_NULL(uv_key_get(&thread_local_modpending)); | ||
| 1382 | 1388 | ||
| 1383 | 1389 | if (args.Length() < 2) { | |
| 1384 | 1390 | env->ThrowError("process.dlopen needs at least 2 arguments."); | |
@@ -1406,8 +1412,9 @@ static void DLOpen(const FunctionCallbackInfo<Value>& args) { | |||
| 1406 | 1412 | // Objects containing v14 or later modules will have registered themselves | |
| 1407 | 1413 | // on the pending list. Activate all of them now. At present, only one | |
| 1408 | 1414 | // module per object is supported. | |
| 1409 | - node_module* const mp = modpending; | ||
| 1410 | - modpending = nullptr; | ||
| 1415 | + node_module* const mp = static_cast<node_module*>( | ||
| 1416 | + uv_key_get(&thread_local_modpending)); | ||
| 1417 | + uv_key_set(&thread_local_modpending, nullptr); | ||
| 1411 | 1418 | ||
| 1412 | 1419 | if (!is_opened) { | |
| 1413 | 1420 | Local<String> errmsg = OneByteString(env->isolate(), dlib.errmsg_.c_str()); | |
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