C++ 如何在整个程序中访问有关线程的信息_C++_C_Multithreading

C++ 如何在整个程序中访问有关线程的信息

c++ c multithreading

C++ 如何在整个程序中访问有关线程的信息,c++,c,multithreading,C++,C,Multithreading,问题1：我试图为每个线程命名，以便它可以在整个程序中使用，但收到错误，如“请求“planes[t]”中的成员“fid”，这是非类类型“pthread\u t”。它指的是使用planes[t].tid或使用planes[t].startState。我不确定如何获取/保存每个线程的这些值问题2：一旦我有了一个线程的startState，我如何将该线程发送到takeoff（）函数（一系列开关状态和printfs）问题3：应该向StartState函数传递什么？我试图让每个线程记住它的开始状态，以便

问题1：我试图为每个线程命名，以便它可以在整个程序中使用，但收到错误，如“请求“planes[t]”中的成员“fid”，这是非类类型“pthread\u t”。它指的是使用planes[t].tid或使用planes[t].startState。我不确定如何获取/保存每个线程的这些值

问题2：一旦我有了一个线程的startState，我如何将该线程发送到takeoff（）函数（一系列开关状态和printfs）

问题3：应该向StartState函数传递什么？我试图让每个线程记住它的开始状态，以便在代码的后面我可以让航班“着陆”或“起飞”

以下是相关代码：于2006年10月22:37更新

#include <pthread.h> #include <stdio.h> #include <cstdlib> #include <iostream> #include <queue> #include <unistd.h> #include <algorithm> #include <time.h> #include <ctime> #define NUM_THREADS 3 //3 flights using std::queue; using std::vector; pthread_mutex_t runway1lock; pthread_mutex_t runway2lock; bool run1occupied; bool run2occupied; struct flight_data{ //each plane has these characteristics //void *FlightID; long fid; int startState; // if start=1 ==> taking off ::: if start=2 ==> landing int flyTime; //fly == randomly generated time (order) of takeoff/land }; struct flight_data flightinfo[NUM_THREADS]; void *FlightID(void *flightid){ struct flight_data *my_flights; my_flights = (struct flight_data*)flightid; int taskid; taskid = my_flights->fid; // long fid; // fid = (long)flightid; // printf("Flight #%1d\n", tid); pthread_exit(NULL); } void Start(struct flight_data my_flights){ my_flights = (struct flight_data)my_flights; int startState; srand(time(0)); my_flights.startState = rand() % 2+1; std::string startstring; if(my_flights.startState == 1){ startstring = "Taking off"; } if(my_flights.startState == 2){ startstring = "Landing"; } for(int i = 1; i<NUM_THREADS+1; i++){ std::cout << "Start state for Flight # " << i << " is " << startstring << std::endl; } } void takeoff(struct flight_data my_flights){ my_flights = (struct flight_data)my_flights; for(int i = 1; i<NUM_THREADS+1; i++){ int state = my_flights.startState; switch(state){ case 1:{ //G (GATE) std::cout << "Flight # " << flightinfo[i].fid << " is listed as waiting at the gate." << std::endl; std::cout << "Flight # " << flightinfo[i].fid << "'s position in queue for runway: " << flightinfo[i].flyTime << std::endl; sleep(3); state = 2; break; } case 2: { //Q (queue) -- sets order for use of runway queue<pthread_t> queue; vector<int> flightTimes; int soonestFlightTime = 10; flightTimes.push_back(flightinfo[i].flyTime); //put all flight times into a vector called flightTimes std::sort(flightTimes.begin(), flightTimes.end()); //sort the vector of flightTimes low to high std::reverse(flightTimes.begin(), flightTimes.end()); //flips vector -- high(front) to low(back) while(!flightTimes.empty()){ if (flightinfo[i].flyTime == flightTimes.back()){ //if a thread has the soonest flight time queue.push(i); //then put the flight in the runway queue flightTimes.pop_back(); //pop off the soonest flight time } } while(!queue.empty()){ if(flightinfo[i].fid == queue.front()){ state = 3; queue.pop(); sleep(3); } } break; } case 3: { //CLR (clearance for runway) std::cout << "Flight # " << flightinfo[i].fid << " has clearance to move to the runway." << std::endl; //will go in order of queue if(run1occupied){ sleep(3); } // else if(collide){ // state = 7; // } else{ state = 4; } break; } case 4: { //RTO (runway takeoff) pthread_mutex_lock(&runway1lock); run1occupied = true; std::cout << "Flight # " << flightinfo[i].fid << " is taking off. Runway occupied. Stand by." << std::endl; sleep(3); pthread_mutex_unlock(&runway1lock); run1occupied = false; state = 5; break; } case 5: { //CZ (cruise) std::cout << "Flight # " << flightinfo[i].fid << " is reaching proper altitude and cruising toward destination." << std::endl; sleep(3); // if(!collide){ state = 6; // } // else{ // state = 7; //collision!!! // } break; } case 6: { //RMV (remove from monitoring list) std::cout << "Flight # " << flightinfo[i].fid << " has been removed from the monitoring list." << std::endl; break; } case 7:{ //COLL (collision) std::cout << "Collision in the air. There were many casualties." << std::endl; break; } } } } void landing(struct flight_data my_flights){ my_flights = (struct flight_data)my_flights; for (int i = 0; i<NUM_THREADS; i++){ int state = my_flights.startState; switch(state){ case 1:{ //ENTR (enter monitoring list) state = 2; break; } case 2:{ //Q (queue) //if not the first thing in the queue then state = 4; //otherwise state = 3; } case 3:{ //RWL (runway land) state = 5; break; } case 4:{ //HVR (hover) //if first in queue then state = 3; //otherwise stay here //if collision state = 7; } case 5:{ //CLR (clearance to move to gate) //if collision state = 7 //otherwise state = 6; } case 6:{ //G (gate) } case 7:{ //COLL (collision) } } } } /* bool collision(){ bool collide; //random if(){ collide = true; } else{ collide = false; } return collide; }*/ int main(int argc, char *argv[]){ pthread_t flights[NUM_THREADS]; //pthread_t keeps a thread ID after the thread is created with pthread_create() //it's like an index on a vector of threads int *taskids[NUM_THREADS]; int rc; long t; for (t=1; t<=NUM_THREADS; t++){ //loop creates threads(flights) printf("In main: Creating flight %1d\n", t); flightinfo[t].fid= t; rc = pthread_create(&flights[t], NULL, FlightID, (void *)&flights[t]); if (rc){ printf("ERROR: return code from pthread_create() is %d\n", rc); return (-1); } printf("Created flight %1d\n", t); // Start(flightinfo[t]); flightinfo[t].startState = rand() % 2+1; std::cout << flightinfo[t].startState << std::endl; if((flightinfo[t].startState)==1){ std::cout << "Flight # " << flightinfo[t].fid << " is listed with start state as " << flightinfo[t].startState << std::endl; takeoff(flightinfo[t]); //go to takeoff function and go through switch case } if((flightinfo[t].startState)==2){ std::cout << "Flight # " << flightinfo[t].fid << " is listed with start state as " << flightinfo[t].startState << std::endl; landing(flightinfo[t]); //go to landing function and go through switch case } } pthread_exit(NULL); }

#包括 #包括 #包括 #包括 #包括 #包括 #包括 #包括 #包括 #定义NUM_线程3//3个航班使用std：：queue；使用std：：vector； pthread_mutex_t runway1锁； pthread_mutex_t runway2lock；有人占了便宜；被占用的bool run2； struct flight_data{//每架飞机都有这些特征 //void*FlightID；长fid； int startState；//如果开始=1==>起飞：：：如果开始=2==>着陆 int flyTime；//fly==随机生成的起飞/着陆时间（顺序） }; struct flight_data flightinfo[NUM_THREADS]； void*FlightID（void*FlightID）{ 结构航班数据*我的航班；我的航班=（结构航班数据*）航班ID； int taskid； taskid=我的航班->fid； //长fid； //fid=（长）flightid； //printf（“航班#%1d\n”，tid）； pthread_exit（NULL）； } 无效启动（结构航班数据我的航班）{ 我的航班=（结构航班数据）我的航班； int startState； srand（时间（0））； my_flights.startState=rand（）%2+1； std：：字符串开始字符串；如果（my_flights.startState==1）{ startstring=“起飞”； } 如果（my_flights.startState==2）{ startstring=“着陆”； } 对于（int i=1；i所有这些变量似乎都存储在flights 数组中，而不是planes 数组中。您似乎混淆了pthread\u t管理变量planes 与包含飞行数据的变量flights pthread_t管理变量planes ，由pthread库使用，您实际上应该只将其用作pthread库调用的参数，否则就不用管它了，不用担心它。将变量planes 视为您创建的存储区域，然后将其交给pthread库使用nd通过这样做，您将该变量的所有权授予pthread库因此，第一个任务是分离并区分pthread管理和线程正在操作的实际数据之间的差异您在多个地方使用pthread管理变量planes ，就好像它是一个飞行数据变量一样。它不是。请将planes 替换为flights if((flights[t].startState)==1){ std::cout << "Flight # " << flights[t].fid << " is listed as waiting at the gate." << std::endl; void takeoff(); //go to takeoff function and go through switch case } if((flights[t].startState)==2){ std::cout << "Flight # " << flights[t].fid << " is listed as waiting to land." << std::endl; //go to landing function and go through switch case } 我假设您想用一些随机启动状态设置特定航班的启动状态。因此，我希望源代码如下所示，因为我假设您对设置特定航班的启动状态感兴趣，并且循环除了运行随机数生成器NUM_THREADS 但是我没有检查你的逻辑，范围是否正确 my_flights->startState = rand() % 1+2; 建议的行动方案你应该把线程看作是一个小程序或应用程序。对于这个简单的例子，我建议你首先编写飞行逻辑，而不必担心线程。因此，如果你从一个函数开始，比如说flyplanefright（）向其传递一个flight变量，然后此函数调用其他函数来执行各种操作，当flight结束时，它返回给调用者，您可能会处于线程的良好位置。在为单个flight设置好逻辑后，您可以使用pthread库通过初始化飞行数据，然后创建一个线程，该线程使用FlyPlaneFlight（）
你还需要考虑时间和交互。对于这种模拟，我怀疑你会想要拥有<代码> FrimePrimeFlash（）。
函数，在其中更改飞行数据，然后线程将休眠一两秒钟。作为开始测试，使用迭代次数确定的for循环，然后退出，例如：

for (int i = 0; i < 100; i++) { // modify the flight data sleep(1000); // sleep for a second (1000 milliseconds) then repeat }
其思想是将飞机飞行视为一个对象，飞行所需的所有数据都在
struct flight\u data
struct中，并且在大多数情况下，您可以忽略pthread库，该库不涉及实际飞行模拟，而是用于允许模拟多个飞行对象。因此，您可以创建e多个线程，每个线程都有自己的飞行数据，然后使用相同的代码来处理飞行数据。你做一些随机化，这样所有不同的飞行都会有不同的历史，它们会做不同的事情
编辑
您的main将有一个如下所示的循环

for (t=0; t<NUM_THREADS; t++){ //loop creates threads(flights) std::cout << "In main: Creating flight " << t+1 << std::endl; flights[t].fid= t+1; rc = pthread_create(&planes[t], NULL, FlightID, (void *)&flights[t]); if (rc){ std::cout << "ERROR: return code from pthread_create() is " << rc << std::endl; return (-1); } std::cout << "Created flight " << t << std::endl; } pthread_exit(NULL); // exit the main thread and allow remaining threads to complete
根据2006年10月10日22:37的源代码更新编辑#2

#include <pthread.h> #include <stdio.h> #include <cstdlib> #include <iostream> #include <queue> #include <unistd.h> #include <algorithm> #include <time.h> #include <ctime> #define NUM_THREADS 3 //3 flights using std::queue; using std::vector; pthread_mutex_t runway1lock; pthread_mutex_t runway2lock; bool run1occupied; bool run2occupied; struct flight_data{ //each plane has these characteristics //void *FlightID; long fid; int startState; // if start=1 ==> taking off ::: if start=2 ==> landing int flyTime; //fly == randomly generated time (order) of takeoff/land }; struct flight_data flightinfo[NUM_THREADS]; void *FlightID(void *flightid){ struct flight_data *my_flights; my_flights = (struct flight_data*)flightid; int taskid; taskid = my_flights->fid; // long fid; // fid = (long)flightid; // printf("Flight #%1d\n", tid); pthread_exit(NULL); } void Start(struct flight_data my_flights){ my_flights = (struct flight_data)my_flights; int startState; srand(time(0)); my_flights.startState = rand() % 2+1; std::string startstring; if(my_flights.startState == 1){ startstring = "Taking off"; } if(my_flights.startState == 2){ startstring = "Landing"; } for(int i = 1; i<NUM_THREADS+1; i++){ std::cout << "Start state for Flight # " << i << " is " << startstring << std::endl; } } void takeoff(struct flight_data my_flights){ my_flights = (struct flight_data)my_flights; for(int i = 1; i<NUM_THREADS+1; i++){ int state = my_flights.startState; switch(state){ case 1:{ //G (GATE) std::cout << "Flight # " << flightinfo[i].fid << " is listed as waiting at the gate." << std::endl; std::cout << "Flight # " << flightinfo[i].fid << "'s position in queue for runway: " << flightinfo[i].flyTime << std::endl; sleep(3); state = 2; break; } case 2: { //Q (queue) -- sets order for use of runway queue<pthread_t> queue; vector<int> flightTimes; int soonestFlightTime = 10; flightTimes.push_back(flightinfo[i].flyTime); //put all flight times into a vector called flightTimes std::sort(flightTimes.begin(), flightTimes.end()); //sort the vector of flightTimes low to high std::reverse(flightTimes.begin(), flightTimes.end()); //flips vector -- high(front) to low(back) while(!flightTimes.empty()){ if (flightinfo[i].flyTime == flightTimes.back()){ //if a thread has the soonest flight time queue.push(i); //then put the flight in the runway queue flightTimes.pop_back(); //pop off the soonest flight time } } while(!queue.empty()){ if(flightinfo[i].fid == queue.front()){ state = 3; queue.pop(); sleep(3); } } break; } case 3: { //CLR (clearance for runway) std::cout << "Flight # " << flightinfo[i].fid << " has clearance to move to the runway." << std::endl; //will go in order of queue if(run1occupied){ sleep(3); } // else if(collide){ // state = 7; // } else{ state = 4; } break; } case 4: { //RTO (runway takeoff) pthread_mutex_lock(&runway1lock); run1occupied = true; std::cout << "Flight # " << flightinfo[i].fid << " is taking off. Runway occupied. Stand by." << std::endl; sleep(3); pthread_mutex_unlock(&runway1lock); run1occupied = false; state = 5; break; } case 5: { //CZ (cruise) std::cout << "Flight # " << flightinfo[i].fid << " is reaching proper altitude and cruising toward destination." << std::endl; sleep(3); // if(!collide){ state = 6; // } // else{ // state = 7; //collision!!! // } break; } case 6: { //RMV (remove from monitoring list) std::cout << "Flight # " << flightinfo[i].fid << " has been removed from the monitoring list." << std::endl; break; } case 7:{ //COLL (collision) std::cout << "Collision in the air. There were many casualties." << std::endl; break; } } } } void landing(struct flight_data my_flights){ my_flights = (struct flight_data)my_flights; for (int i = 0; i<NUM_THREADS; i++){ int state = my_flights.startState; switch(state){ case 1:{ //ENTR (enter monitoring list) state = 2; break; } case 2:{ //Q (queue) //if not the first thing in the queue then state = 4; //otherwise state = 3; } case 3:{ //RWL (runway land) state = 5; break; } case 4:{ //HVR (hover) //if first in queue then state = 3; //otherwise stay here //if collision state = 7; } case 5:{ //CLR (clearance to move to gate) //if collision state = 7 //otherwise state = 6; } case 6:{ //G (gate) } case 7:{ //COLL (collision) } } } } /* bool collision(){ bool collide; //random if(){ collide = true; } else{ collide = false; } return collide; }*/ int main(int argc, char *argv[]){ pthread_t flights[NUM_THREADS]; //pthread_t keeps a thread ID after the thread is created with pthread_create() //it's like an index on a vector of threads int *taskids[NUM_THREADS]; int rc; long t; for (t=1; t<=NUM_THREADS; t++){ //loop creates threads(flights) printf("In main: Creating flight %1d\n", t); flightinfo[t].fid= t; rc = pthread_create(&flights[t], NULL, FlightID, (void *)&flights[t]); if (rc){ printf("ERROR: return code from pthread_create() is %d\n", rc); return (-1); } printf("Created flight %1d\n", t); // Start(flightinfo[t]); flightinfo[t].startState = rand() % 2+1; std::cout << flightinfo[t].startState << std::endl; if((flightinfo[t].startState)==1){ std::cout << "Flight # " << flightinfo[t].fid << " is listed with start state as " << flightinfo[t].startState << std::endl; takeoff(flightinfo[t]); //go to takeoff function and go through switch case } if((flightinfo[t].startState)==2){ std::cout << "Flight # " << flightinfo[t].fid << " is listed with start state as " << flightinfo[t].startState << std::endl; landing(flightinfo[t]); //go to landing function and go through switch case } } pthread_exit(NULL); }
在源代码中，您有一个全局数组变量，
flights
，您正试图通过源代码直接访问该变量。这是一个导致问题的错误。您需要做的是让线程创建调用将flights的特定数组元素分配给t
for (t=0; t<NUM_THREADS; t++){ //loop creates threads(flights) std::cout << "In main: Creating flight " << t+1 << std::endl; flights[t].fid= t+1; rc = pthread_create(&planes[t], NULL, FlightID, (void *)&flights[t]); if (rc){ std::cout << "ERROR: return code from pthread_create() is " << rc << std::endl; return (-1); } std::cout << "Created flight " << t << std::endl; } pthread_exit(NULL); // exit the main thread and allow remaining threads to complete

void FlyPlaneFlight (struct flight_data *my_flights) { for (int i = 0; i < 100; i++) { switch (my_flights->startState) { case 1: std::cout << "Flight # " << my_flights->fid << " is listed as waiting at the gate." << std::endl; // now move the flight state to the next state. break; case 2: std::cout << "Flight # " << my_flights->fid << " is listed as waiting to land." << std::endl; // now move the flight state to the next state. break; // other case statements for other flight states and moving between the // various flight states. } sleep (1000); // sleep this thread for one second (1000 milliseconds) then repeat } }

rc = pthread_create(&planes[t], NULL, FlightID, (void *)&flights[t]);