Add wasm_module_obtain() to clone wasm_module_t (#1660)

Also add support for wasm_shared_module_t, and add lock for
wasm_module_t related operations.

And add wasm-c-api sample threads, update sample clone.

samples/wasm-c-api/CMakeLists.txt

@@ -134,6 +134,7 @@ set(EXAMPLES
   memory
   reflect
   table
+  threads
   trap
 )
 

samples/wasm-c-api/src/clone.c

@@ -20,6 +20,7 @@ typedef struct _vm {
     wasm_engine_t *engine;
     wasm_store_t *store;
     wasm_module_t *module;
+    wasm_shared_module_t *shared_module;
     wasm_instance_t *instance;
     wasm_func_t **function_list;
     wasm_memory_t *memory;
@@ -72,10 +73,49 @@ fail:
     return NULL;
 }
 
+wasm_vm_t *
+vm_release(wasm_vm_t *vm)
+{
+    if (!vm)
+        return NULL;
+
+    if (vm->function_list) {
+        free(vm->function_list);
+        vm->function_list = NULL;
+    }
+
+    vm->memory = NULL;
+
+    if (vm->exports) {
+        wasm_extern_vec_delete(vm->exports);
+        free(vm->exports);
+        vm->exports = NULL;
+    }
+
+    wasm_instance_delete(vm->instance);
+    vm->instance = NULL;
+
+    wasm_shared_module_delete(vm->shared_module);
+    vm->shared_module = NULL;
+
+    wasm_module_delete(vm->module);
+    vm->module = NULL;
+
+    wasm_store_delete(vm->store);
+    vm->store = NULL;
+
+    wasm_engine_delete(vm->engine);
+    vm->engine = NULL;
+
+    free(vm);
+    return NULL;
+}
+
 bool
 vm_load(wasm_vm_t *vm, const wasm_byte_vec_t *binary)
 {
     vm->module = wasm_module_new(vm->store, binary);
+    vm->shared_module = wasm_module_share(vm->module);
     return vm->module != NULL;
 }
 
@@ -127,7 +167,10 @@ vm_clone_from_module(const wasm_vm_t *base)
     secondary = vm_new();
     if (secondary) {
         printf("Reuse module and bypass vm_load()...");
-        secondary->module = base->module;
+        secondary->module =
+            wasm_module_obtain(base->store, base->shared_module);
+        if (!secondary->module)
+            secondary = vm_release(secondary);
     }
 
     return secondary;
@@ -163,39 +206,6 @@ vm_clone(const wasm_vm_t *base, clone_level level)
         return vm_clone_from_instance(base);
 }
 
-wasm_vm_t *
-vm_release(wasm_vm_t *vm)
-{
-    if (!vm)
-        return NULL;
-
-    if (vm->function_list) {
-        free(vm->function_list);
-        vm->function_list = NULL;
-    }
-
-    if (vm->exports) {
-        wasm_extern_vec_delete(vm->exports);
-        free(vm->exports);
-        vm->exports = NULL;
-    }
-
-    wasm_instance_delete(vm->instance);
-    vm->instance = NULL;
-
-    wasm_module_delete(vm->module);
-    vm->module = NULL;
-
-    wasm_store_delete(vm->store);
-    vm->store = NULL;
-
-    wasm_engine_delete(vm->engine);
-    vm->engine = NULL;
-
-    free(vm);
-    return NULL;
-}
-
 bool
 vm_memory_set_byte(const wasm_vm_t *vm, uint32_t offset, uint8_t byte)
 {
@@ -444,6 +454,8 @@ static void *
 thrd_func(void *arg)
 {
     thread_arg_t *thrd_arg = (thread_arg_t *)arg;
+
+    sleep(rand() % 5);
     printf("Running warm start at %s...\n", thrd_arg->name);
 
     pthread_setspecific(name_key, thrd_arg->name);
@@ -483,7 +495,6 @@ main()
     run_test(base_vm);
 
     printf("Running warm start at other threads...\n");
-    pthread_mutex_trylock(&ready_go_lock);
 
     pthread_t tids[WORKER_NUMBER] = { 0 };
     thread_arg_t thrd_args[WORKER_NUMBER] = { 0 };
@@ -501,8 +512,8 @@ main()
             break;
     }
 
-    sleep(5);
-
+    sleep(1);
+    pthread_mutex_trylock(&ready_go_lock);
     ready_go_flag = true;
     pthread_mutex_unlock(&ready_go_lock);
     pthread_cond_broadcast(&ready_go_cond);
@@ -511,6 +522,7 @@ main()
         if (tids[i] != 0)
             pthread_join(tids[i], NULL);
     }
+
     vm_release(base_vm);
     ret = EXIT_SUCCESS;
 quit:

samples/wasm-c-api/src/threads.c

@@ -0,0 +1,185 @@
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include <unistd.h>
+
+#include "wasm_c_api.h"
+
+#define own
+
+const int N_THREADS = 10;
+const int N_REPS = 3;
+
+// A function to be called from Wasm code.
+own wasm_trap_t *
+callback(const wasm_val_vec_t *args, wasm_val_vec_t *results)
+{
+    assert(args->data[0].kind == WASM_I32);
+    printf("> Thread %d running\n", args->data[0].of.i32);
+    return NULL;
+}
+
+typedef struct {
+    wasm_engine_t *engine;
+    wasm_shared_module_t *module;
+    int id;
+} thread_args;
+
+void *
+run(void *args_abs)
+{
+    thread_args *args = (thread_args *)args_abs;
+
+    // Rereate store and module.
+    own wasm_store_t *store = wasm_store_new(args->engine);
+    own wasm_module_t *module = wasm_module_obtain(store, args->module);
+
+    // Run the example N times.
+    for (int i = 0; i < N_REPS; ++i) {
+        usleep(100000);
+
+        // Create imports.
+        own wasm_functype_t *func_type =
+            wasm_functype_new_1_0(wasm_valtype_new_i32());
+        own wasm_func_t *func = wasm_func_new(store, func_type, callback);
+        wasm_functype_delete(func_type);
+
+        wasm_val_t val = WASM_I32_VAL((int32_t)args->id);
+        own wasm_globaltype_t *global_type =
+            wasm_globaltype_new(wasm_valtype_new_i32(), WASM_CONST);
+        own wasm_global_t *global = wasm_global_new(store, global_type, &val);
+        wasm_globaltype_delete(global_type);
+
+        // Instantiate.
+        wasm_extern_t *externs[] = {
+            wasm_func_as_extern(func),
+            wasm_global_as_extern(global),
+        };
+        wasm_extern_vec_t imports = WASM_ARRAY_VEC(externs);
+        own wasm_instance_t *instance =
+            wasm_instance_new(store, module, &imports, NULL);
+        if (!instance) {
+            printf("> Error instantiating module!\n");
+            return NULL;
+        }
+
+        wasm_func_delete(func);
+        wasm_global_delete(global);
+
+        // Extract export.
+        own wasm_extern_vec_t exports;
+        wasm_instance_exports(instance, &exports);
+        if (exports.size == 0) {
+            printf("> Error accessing exports!\n");
+            return NULL;
+        }
+        const wasm_func_t *run_func = wasm_extern_as_func(exports.data[0]);
+        if (run_func == NULL) {
+            printf("> Error accessing export!\n");
+            return NULL;
+        }
+
+        wasm_instance_delete(instance);
+
+        // Call.
+        wasm_val_vec_t empty = WASM_EMPTY_VEC;
+        if (wasm_func_call(run_func, &empty, &empty)) {
+            printf("> Error calling function!\n");
+            return NULL;
+        }
+
+        wasm_extern_vec_delete(&exports);
+    }
+
+    wasm_module_delete(module);
+    wasm_store_delete(store);
+
+    free(args_abs);
+
+    return NULL;
+}
+
+int
+main(int argc, const char *argv[])
+{
+    // Initialize.
+    wasm_engine_t *engine = wasm_engine_new();
+
+    // Load binary.
+#if WASM_ENABLE_AOT != 0 && WASM_ENABLE_INTERP == 0
+    FILE *file = fopen("threads.aot", "rb");
+#else
+    FILE *file = fopen("threads.wasm", "rb");
+#endif
+    if (!file) {
+        printf("> Error loading module!\n");
+        return 1;
+    }
+
+    int ret = fseek(file, 0L, SEEK_END);
+    if (ret == -1) {
+        printf("> Error loading module!\n");
+        fclose(file);
+        return 1;
+    }
+
+    long file_size = ftell(file);
+    if (file_size == -1) {
+        printf("> Error loading module!\n");
+        fclose(file);
+        return 1;
+    }
+
+    ret = fseek(file, 0L, SEEK_SET);
+    if (ret == -1) {
+        printf("> Error loading module!\n");
+        fclose(file);
+        return 1;
+    }
+
+    wasm_byte_vec_t binary;
+    wasm_byte_vec_new_uninitialized(&binary, file_size);
+    if (fread(binary.data, file_size, 1, file) != 1) {
+        printf("> Error loading module!\n");
+        return 1;
+    }
+    fclose(file);
+
+    // Compile and share.
+    own wasm_store_t *store = wasm_store_new(engine);
+    own wasm_module_t *module = wasm_module_new(store, &binary);
+    if (!module) {
+        printf("> Error compiling module!\n");
+        return 1;
+    }
+
+    wasm_byte_vec_delete(&binary);
+
+    own wasm_shared_module_t *shared = wasm_module_share(module);
+
+    wasm_module_delete(module);
+    wasm_store_delete(store);
+
+    // Spawn threads.
+    pthread_t threads[N_THREADS];
+    for (int i = 0; i < N_THREADS; i++) {
+        thread_args *args = malloc(sizeof(thread_args));
+        args->id = i;
+        args->engine = engine;
+        args->module = shared;
+        printf("Initializing thread %d...\n", i);
+        pthread_create(&threads[i], NULL, &run, args);
+    }
+
+    for (int i = 0; i < N_THREADS; i++) {
+        printf("Waiting for thread: %d\n", i);
+        pthread_join(threads[i], NULL);
+    }
+
+    wasm_shared_module_delete(shared);
+    wasm_engine_delete(engine);
+
+    return 0;
+}

samples/wasm-c-api/src/threads.wat

@@ -0,0 +1,5 @@
+(module
+  (func $message (import "" "hello") (param i32))
+  (global $id (import "" "id") i32)
+  (func (export "run") (call $message (global.get $id)))
+)