HarmonyOS Next开发学习手册——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基础运行时环境，并通过该方法获得一个CoreID，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并异步调取TS侧设定的callback函数，最后使用releaseJsCore方法来释放CoreID对应的运行环境。

使用示例

1. 接口声明和编译配置

接口声明

// index.d.ts
export const createJsCore: (fun: Function) => number;
export const releaseJsCore: (a: number) => void;
export const evalUateJS: (a: number, str: string) => string;

编译配置

// CMakeLists.txt
# the minimum version of CMake.
cmake_minimum_required(VERSION 3.4.1)
project(MyApplication)

set(NATIVERENDER_ROOT_PATH ${CMAKE_CURRENT_SOURCE_DIR})

if(DEFINED PACKAGE_FIND_FILE)
include(${PACKAGE_FIND_FILE})
endif()

include_directories(${NATIVERENDER_ROOT_PATH}
                    ${NATIVERENDER_ROOT_PATH}/include)

add_library(entry SHARED create_jsvm_runtime.cpp)
target_link_libraries(entry PUBLIC libace_napi.z.so libjsvm.so libhilog_ndk.z.so)

2.新建多个JS运行时环境并运行JS代码

// create_jsvm_runtime.cpp
#include "napi/native_api.h"
#include "ark_runtime/jsvm.h"
#include "common.h"

#include <bits/alltypes.h>
#include <deque>
#include <map>
#include <unistd.h>
#include <hilog/log.h>

#include <cstring>
#include <string>
#include <vector>
#include <sstream>

#define LOG_TAG "TEST_TAG"
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_VMScope> g_vmScopeMap;
static map<int, JSVM_Env*> g_envMap;
static map<int, napi_env> g_napiEnvMap;
static map<int, JSVM_EnvScope> g_envScopeMap;
static map<int, napi_ref> g_callBackMap;
static map<int, JSVM_CallbackStruct*> g_callBackStructMap;
static uint32_t ENVTAG_NUMBER = 0;
static std::mutex envMapLock;
static int aa = 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;
    OH_JSVM_GetCbInfo(env, info, &argc, args, NULL, NULL);

    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 = 0;
    // 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_INFO(LOG_APP, "JSVM API TEST: CreatePromise envID faild");
        return nullptr;
    }
    JSVM_Value promise;
    JSVM_Deferred deferred;
    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;
            OH_JSVM_CreateInt32(env_, envID, &result);
            OH_JSVM_ResolveDeferred(env_, deferred_, result);
        }
    private:
        JSVM_Env env_;
        int envID_;
        JSVM_Deferred deferred_;
    };
    g_taskQueueMap[envID].push_back(new ReadTask(env, deferred, envID));
    OH_LOG_INFO(