harmony 鸿蒙使用JSVM-API接口创建多个引擎执行JS代码并销毁
使用JSVM-API接口创建多个引擎执行JS代码并销毁
场景介绍
开发者通过createJsCore方法来创建一个新的JS运行时环境，并通过该方法获得一个CoreID。然后，通过evaluateJS方法使用CoreID对应的运行环境来运行JS代码，在JS代码中创建promise并异步执行函数。最后，使用releaseJsCore方法来释放CoreID对应的运行环境。
使用示例
JSVM-API接口开发流程参考使用JSVM-API实现JS与C/C++语言交互开发流程，本文仅对接口对应C++相关代码进行展示。
新建多个JS运行时环境并运行JS代码
#include <map>
#include <mutex>
#include <deque>
using namespace std;
// 定义map管理每个独立vm环境
static map<int, JSVM_VM *> g_vmMap;
static map<int, JSVM_Env *> g_envMap;
static map<int, JSVM_CallbackStruct *> g_callBackStructMap;
static uint32_t ENVTAG_NUMBER = 0;
static std::mutex envMapLock;
#define CHECK_COND(cond) \
do { \
if (!(cond)) { \
OH_LOG_ERROR(LOG_APP, "jsvm fail file: %{public}s line: %{public}d ret = false", __FILE__, __LINE__); \
return -1; \
} \
} while (0)
class Task {
public:
virtual ~Task() = default;
virtual void Run() = 0;
};
static map<int, deque<Task *>> g_taskQueueMap;
// 自定义Consoleinfo方法
static JSVM_Value Consoleinfo(JSVM_Env env, JSVM_CallbackInfo info) {
size_t argc = 1;
JSVM_Value args[1];
char log[256] = "";
size_t log_length = 0;
JSVM_CALL(OH_JSVM_GetCbInfo(env, info, &argc, args, NULL, NULL));
JSVM_CALL(OH_JSVM_GetValueStringUtf8(env, args[0], log, 255, &log_length));
log[255] = 0;
OH_LOG_INFO(LOG_APP, "JSVM API TEST: %{public}s", log);
return nullptr;
}
// 自定义创建Promise方法用以在JS代码中创建Promise
static JSVM_Value CreatePromise(JSVM_Env env, JSVM_CallbackInfo info) {
OH_LOG_INFO(LOG_APP, "JSVM API TEST: CreatePromise start");
int envID = -1;
// 通过当前env获取envID
for (auto it = g_envMap.begin(); it != g_envMap.end(); ++it) {
if (*it->second == env) {
envID = it->first;
break;
}
}
if (envID == -1) {
OH_LOG_ERROR(LOG_APP, "JSVM API TEST: CreatePromise envID failed");
return nullptr;
}
JSVM_Value promise;
JSVM_Deferred deferred;
JSVM_CALL(OH_JSVM_CreatePromise(env, &deferred, &promise));
// 设计ReadTask类用以将promise对象的deferred加入执行队列
class ReadTask : public Task {
public:
ReadTask(JSVM_Env env, JSVM_Deferred deferred, int envNum) : env_(env), envID_(envNum), deferred_(deferred) {}
void Run() override {
// string str = "TEST RUN OH_JSVM_ResolveDeferred";
int envID = 0;
for (auto it = g_envMap.begin(); it != g_envMap.end(); ++it) {
if (*it->second == env_) {
envID = it->first;
break;
}
}
OH_LOG_INFO(LOG_APP, "JSVM API TEST: CreatePromise %{public}d", envID);
JSVM_Value result;
if (OH_JSVM_CreateInt32(env_, envID, &result) != JSVM_OK) {
return;
}
if (OH_JSVM_ResolveDeferred(env_, deferred_, result) != JSVM_OK) {
return;
}
}
private:
JSVM_Env env_;
int envID_;
JSVM_Deferred deferred_;
};
g_taskQueueMap[envID].push_back(new ReadTask(env, deferred, envID));
OH_LOG_INFO(LOG_APP, "JSVM API TEST: CreatePromise end");
return promise;
}
// 自定义Add方法
static JSVM_Value Add(JSVM_Env env, JSVM_CallbackInfo info) {
size_t argc = 2;
JSVM_Value args[2];
JSVM_CALL(OH_JSVM_GetCbInfo(env, info, &argc, args, NULL, NULL));
double num1 = 0, num2 = 0;
JSVM_CALL(OH_JSVM_GetValueDouble(env, args[0], &num1));
JSVM_CALL(OH_JSVM_GetValueDouble(env, args[1], &num2));
JSVM_Value sum = nullptr;
JSVM_CALL(OH_JSVM_CreateDouble(env, num1 + num2, &sum));
return sum;
}
// 自定义AssertEqual方法
static JSVM_Value AssertEqual(JSVM_Env env, JSVM_CallbackInfo info) {
size_t argc = 2;
JSVM_Value args[2];
JSVM_CALL(OH_JSVM_GetCbInfo(env, info, &argc, args, NULL, NULL));
bool isStrictEquals = false;
JSVM_CALL(OH_JSVM_StrictEquals(env, args[0], args[1], &isStrictEquals));
if (isStrictEquals) {
OH_LOG_INFO(LOG_APP, "JSVM API TEST RESULT: PASS");
} else {
OH_LOG_INFO(LOG_APP, "JSVM API TEST RESULT: FAILED");
}
return nullptr;
}
static int fromOHStringValue(JSVM_Env &env, JSVM_Value &value, std::string &result) {
size_t size = 0;
CHECK_RET(OH_JSVM_GetValueStringUtf8(env, value, nullptr, 0, &size));
char resultStr[size + 1];
CHECK_RET(OH_JSVM_GetValueStringUtf8(env, value, resultStr, size + 1, &size));
result = resultStr;
return 0;
}
// 提供创建JSVM运行环境的对外接口并返回对应唯一ID
static int CreateJsCore(uint32_t *result) {
OH_LOG_INFO(LOG_APP, "JSVM CreateJsCore START");
g_taskQueueMap[ENVTAG_NUMBER] = deque<Task *>{};
if (g_aa == 0) {
JSVM_InitOptions init_options;
memset(&init_options, 0, sizeof(init_options));
CHECK(OH_JSVM_Init(&init_options));
g_aa++;
}
std::lock_guard<std::mutex> lock_guard(envMapLock);
// 虚拟机实例
g_vmMap[ENVTAG_NUMBER] = new JSVM_VM;
JSVM_CreateVMOptions options;
JSVM_VMScope vmScope;
memset(&options, 0, sizeof(options));
CHECK(OH_JSVM_CreateVM(&options, g_vmMap[ENVTAG_NUMBER]));
CHECK(OH_JSVM_OpenVMScope(*g_vmMap[ENVTAG_NUMBER], &vmScope));
// 新环境
g_envMap[ENVTAG_NUMBER] = new JSVM_Env;
g_callBackStructMap[ENVTAG_NUMBER] = new JSVM_CallbackStruct[4];
// 注册用户提供的本地函数的回调函数指针和数据，通过JSVM-API暴露给js
for (int i = 0; i < 4; i++) {
g_callBackStructMap[ENVTAG_NUMBER][i].data = nullptr;
}
g_callBackStructMap[ENVTAG_NUMBER][0].callback = Consoleinfo;
g_callBackStructMap[ENVTAG_NUMBER][1].callback = Add;
g_callBackStructMap[ENVTAG_NUMBER][2].callback = AssertEqual;
g_callBackStructMap[ENVTAG_NUMBER][3].callback = CreatePromise;
JSVM_PropertyDescriptor descriptors[] = {
{"consoleinfo", NULL, &g_callBackStructMap[ENVTAG_NUMBER][0], NULL, NULL, NULL, JSVM_DEFAULT},
{"add", NULL, &g_callBackStructMap[ENVTAG_NUMBER][1], NULL, NULL, NULL, JSVM_DEFAULT},
{"assertEqual", NULL, &g_callBackStructMap[ENVTAG_NUMBER][2], NULL, NULL, NULL, JSVM_DEFAULT},
{"createPromise", NULL, &g_callBackStructMap[ENVTAG_NUMBER][3], NULL, NULL, NULL, JSVM_DEFAULT},
};
CHECK(OH_JSVM_CreateEnv(*g_vmMap[ENVTAG_NUMBER], sizeof(descriptors) / sizeof(descriptors[0]), descriptors,
g_envMap[ENVTAG_NUMBER]));
CHECK(OH_JSVM_CloseVMScope(*g_vmMap[ENVTAG_NUMBER], vmScope));
OH_LOG_INFO(LOG_APP, "JSVM CreateJsCore END");
*result = ENVTAG_NUMBER;
ENVTAG_NUMBER++;
return 0;
}
// 对外提供释放JSVM环境接口，通过envId释放对应环境
static int ReleaseJsCore(uint32_t coreEnvId) {
std::lock_guard<std::mutex> lock_guard(envMapLock);
OH_LOG_INFO(LOG_APP, "JSVM ReleaseJsCore START");
CHECK_COND(g_envMap.count(coreEnvId) != 0 && g_envMap[coreEnvId] != nullptr);
CHECK(OH_JSVM_DestroyEnv(*g_envMap[coreEnvId]));
g_envMap[coreEnvId] = nullptr;
g_envMap.erase(coreEnvId);
CHECK(OH_JSVM_DestroyVM(*g_vmMap[coreEnvId]));
g_vmMap[coreEnvId] = nullptr;
g_vmMap.erase(coreEnvId);
delete[] g_callBackStructMap[coreEnvId];
g_callBackStructMap[coreEnvId] = nullptr;
g_callBackStructMap.erase(coreEnvId);
g_taskQueueMap.erase(coreEnvId);
OH_LOG_INFO(LOG_APP, "JSVM ReleaseJsCore END");
return 0;
}
static std::mutex mutexLock;
// 对外提供执行JS代码接口，通过coreID在对应的JSVN环境中执行JS代码
static int EvaluateJS(uint32_t envId, const char *source, std::string &res) {
OH_LOG_INFO(LOG_APP, "JSVM EvaluateJS START");
CHECK_COND(g_envMap.count(envId) != 0 && g_envMap[envId] != nullptr);
JSVM_Env env = *g_envMap[envId];
JSVM_VM vm = *g_vmMap[envId];
JSVM_VMScope vmScope;
JSVM_EnvScope envScope;
JSVM_HandleScope handleScope;
JSVM_Value result;
std::lock_guard<std::mutex> lock_guard(mutexLock);
{
// 创建JSVM环境
CHECK_RET(OH_JSVM_OpenVMScope(vm, &vmScope));
CHECK_RET(OH_JSVM_OpenEnvScope(*g_envMap[envId], &envScope));
CHECK_RET(OH_JSVM_OpenHandleScope(*g_envMap[envId], &handleScope));
// 通过script调用测试函数
JSVM_Script script;
JSVM_Value jsSrc;
CHECK_RET(OH_JSVM_CreateStringUtf8(env, source, JSVM_AUTO_LENGTH, &jsSrc));
CHECK_RET(OH_JSVM_CompileScript(env, jsSrc, nullptr, 0, true, nullptr, &script));
CHECK_RET(OH_JSVM_RunScript(env, script, &result));
JSVM_ValueType type;
CHECK_RET(OH_JSVM_Typeof(env, result, &type));
OH_LOG_INFO(LOG_APP, "JSVM API TEST type: %{public}d", type);
// Execute tasks in the current env event queue
while (!g_taskQueueMap[envId].empty()) {
auto task = g_taskQueueMap[envId].front();
g_taskQueueMap[envId].pop_front();
task->Run();
delete task;
}
if (type == JSVM_STRING) {
CHECK_COND(fromOHStringValue(env, result, res) != -1);
} else if (type == JSVM_BOOLEAN) {
bool ret = false;
CHECK_RET(OH_JSVM_GetValueBool(env, result, &ret));
ret ? res = "true" : res = "false";
} else if (type == JSVM_NUMBER) {
int32_t num;
CHECK_RET(OH_JSVM_GetValueInt32(env, result, &num));
res = std::to_string(num);
} else if (type == JSVM_OBJECT) {
JSVM_Value objResult;
CHECK_RET(OH_JSVM_JsonStringify(env, result, &objResult));
CHECK_COND(fromOHStringValue(env, objResult, res) != -1);
}
}
{
bool aal = false;
CHECK_RET(OH_JSVM_PumpMessageLoop(*g_vmMap[envId], &aal));
CHECK_RET(OH_JSVM_PerformMicrotaskCheckpoint(*g_vmMap[envId]));
CHECK_RET(OH_JSVM_CloseHandleScope(*g_envMap[envId], handleScope));
CHECK_RET(OH_JSVM_CloseEnvScope(*g_envMap[envId], envScope));
CHECK_RET(OH_JSVM_CloseVMScope(*g_vmMap[envId], vmScope));
}
OH_LOG_INFO(LOG_APP, "JSVM EvaluateJS END");
return 0;
}
static int32_t TestJSVM() {
const char source1[] = "{\
let a = \"hello World\";\
consoleinfo(a);\
const mPromise = createPromise();\
mPromise.then((result) => {\
assertEqual(result, 0);\
});\
a;\
};";
const char source2[] = "{\
let a = \"second hello\";\
consoleinfo(a);\
let b = add(99, 1);\
assertEqual(100, b);\
assertEqual(add(99, 1), 100);\
createPromise().then((result) => {\
assertEqual(result, 1);\
});\
a;\
};";
// 创建首个运行环境，并绑定TS回调
uint32_t coreId1 = 0;
CHECK_COND(CreateJsCore(&coreId1) == 0);
OH_LOG_INFO(LOG_APP, "TEST coreId: %{public}d", coreId1);
// 在首个运行环境中执行JS代码
std::string result1;
CHECK_COND(EvaluateJS(coreId1, source1, result1) == 0);
OH_LOG_INFO(LOG_APP, "TEST evaluateJS: %{public}s", result1.c_str());
// 创建第二个运行环境，并绑定TS回调
uint32_t coreId2 = 0;
CHECK_COND(CreateJsCore(&coreId2) == 0);
OH_LOG_INFO(LOG_APP, "TEST coreId: %{public}d", coreId2);
// 在第二个运行环境中执行JS代码
std::string result2;
CHECK_COND(EvaluateJS(coreId2, source2, result2) == 0);
OH_LOG_INFO(LOG_APP, "TEST evaluateJS: %{public}s", result2.c_str());
// 释放首个运行环境
CHECK_COND(ReleaseJsCore(coreId1) == 0);
// 释放第二个运行环境
CHECK_COND(ReleaseJsCore(coreId2) == 0);
OH_LOG_INFO(LOG_APP, "Test NAPI end");
return 0;
}
预计的输出结果：
JSVM CreateJsCore START
JSVM CreateJsCore END
TEST coreId: 0
JSVM EvaluateJS START
JSVM API TEST: hello World
JSVM API TEST: CreatePromise start
JSVM API TEST: CreatePromise end
JSVM API TEST type: 4
JSVM API TEST: CreatePromise 0
JSVM API TEST RESULT: PASS
JSVM EvaluateJS END
TEST evaluateJS: hello World
JSVM CreateJsCore START
JSVM CreateJsCore END
TEST coreId: 1
JSVM EvaluateJS START
JSVM API TEST: second hello
JSVM API TEST RESULT: PASS
JSVM API TEST RESULT: PASS
JSVM API TEST: CreatePromise start
JSVM API TEST: CreatePromise end
JSVM API TEST type: 4
JSVM API TEST: CreatePromise 1
JSVM API TEST RESULT: PASS
JSVM EvaluateJS END
TEST evaluateJS: second hello
JSVM ReleaseJsCore START
JSVM ReleaseJsCore END
JSVM ReleaseJsCore START
JSVM ReleaseJsCore END
Test NAPI end
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