pthread使用实例

在cocos2d-x里面用多线程还是乖乖的用pthread吧。应用一启动时创建线程作为逻辑线程。

创建方法如下：

extern ResourcePool logicThreadResource;
void *test(void *param){
    while (true) {
        if (logicThreadResource.peekNextDataLength()) {
            printf("有数据需要处理");
            int datasize = 0;
            char *receiveData = new char[512];
            logicThreadResource.popData(receiveData, datasize, 512);
            
            int sigal = *((int32_t *) receiveData);
            printf("the sigal is %d\n", sigal);
            if (sigal == 100) {
                CalWinRate(receiveData+4);
            }
            delete[] receiveData;
            
        }else{
            pthread_mutex_lock(&locklogicthread);
            pthread_cond_wait(&cond, &locklogicthread);
            pthread_mutex_unlock(&locklogicthread);
        }
    }
    
    return NULL;
}

void create_pthread(){
    //    启动两个测试的主线程
    pthread_t tid;
    pthread_create(&tid, NULL, test, NULL);
}

pthread_create原型为:PTW32_DLLPORT int PTW32_CDECL pthread_create(pthread_t *tid, const pthread_attr_t *attr, void*(*start)(void *), void *arg)。create有四个参数，第一个是pthread_t，第二个是创建线程的参数，第三个是线程的入口函数，第四个为入口函数参数。这里需要注意的是设置pthread_cond_wait即唤醒函数的时候一定要加锁。启动函数如下：

bool ResourcePool::pushData(const char *data, int size){
    AutoReleaseLock myLock = AutoReleaseLock();

//    deal
    int realSize = size + sizeof(int32_t);
    int needMemory = bufferLength + realSize;
    if (needMemory > bufferCapacity) {
//        需要重新分配内存
        if (reMollocMemory(needMemory)) {
        }else{
            return false;
        }
    }
//
    char *pWriteBuff = resPool + bufferLength;
    
    *((int32_t *)pWriteBuff) = size;
    
    pWriteBuff += sizeof(int32_t);
    bufferLength += sizeof(int32_t);
    
    memmove(pWriteBuff, data, size);
    bufferLength += size;
    
//    缓冲区有数据的话就激活线程
    pthread_cond_signal(&cond);
    
    return true;
}

思路还是采用的是我上篇博客的思路，至于cocos2d-x里面的调用我是这样的：

local handler
local scheduler = CCDirector:sharedDirector():getScheduler()
handler = scheduler:scheduleScriptFunc(function()
                                -- 每帧检测一下数据，看看是否是合理的
                                BookUtils:parsePackageToLua()
                                if GLOABLEPACKAGE ~= "" then
                                    -- 解析数据
                                    local package = json.decode(GLOABLEPACKAGE)
                                    print("the GLOABLEPACKAGE is " .. GLOABLEPACKAGE)
                                    GLOABLEPACKAGE = ""

                                    local dataTable = {}
                                    table.walk(package, function(val, key)
                                            if tonumber(key) ~= 1 then
                                                dataTable[#dataTable+1] = val   
                                            end
                                        end)
                                    
                                    if tonumber(package[1]) == 100 then
                                        -- 胜率计算器，更新胜率
                                        CCNotificationCenter:sharedNotificationCenter():postNotification("CAL_WIN_RATE_UPDATE", CCString:create(json.encode(dataTable)))
                                    elseif tonumber(package[1]) == 101 then
                                        -- 胜率计算完毕
                                        CCNotificationCenter:sharedNotificationCenter():postNotification("CAL_WIN_RATE_UPDATE_END")
                                    end

                                end
                                
                            end, 0, false)

即主线程每一帧去检测缓冲区，如果有数据，则发送消息。