int main(int argc, char* argv[])
{
struct handler_threads_pool* handler_threads = NULL;
int socket_desc , client_sock , len, i;
struct sockaddr_in server, client;
socket_desc = socket(AF_INET , SOCK_STREAM , 0);
if (socket_desc == -1)
printf("Could not create socket");
server.sin_family = AF_INET;
server.sin_addr.s_addr = INADDR_ANY;
server.sin_port = htons( 8888 );
if( bind(socket_desc,(struct sockaddr *)&server , sizeof(server)) < 0)
{
perror("bind failed. Error");
return 1;
}
listen(socket_desc , 3);
len = sizeof(struct sockaddr_in);
Requests_queue* requests = new Requests_queue(&request_mutex, &got_request);
assert(requests);
handler_threads = init_handler_threads_pool(&request_mutex, &got_request, requests);
assert(handler_threads);
int num_requests; // количество запросов которых необходимо обработать
int num_threads; // количество активных потоков
//TODO: выделить отдельный поток под прослушивание сокета и не загружать основной,
//в мэин потоке будет выводить лишь статистика по подключениям.
//изменится основной цикл, будет использоваться epoll
while( (client_sock = accept(socket_desc, (struct sockaddr *)&client, (socklen_t*)&len)) )
{
requests->add_request(client_sock);
num_requests = requests->get_requests_number();
num_threads = get_handler_threads_number(handler_threads);
if (num_requests > HIGH_REQUESTS_WATERMARK &&
num_threads < MAX_NUM_HANDLER_THREADS)
{
printf("main: adding thread: '%d' requests, '%d' threads\n",
num_requests, num_threads);
add_handler_thread(handler_threads);
}
if (num_requests < LOW_REQUESTS_WATERMARK && num_threads > NUM_HANDLER_THREADS)
{
printf("main: deleting thread: '%d' requests, '%d' threads\n",
num_requests, num_threads);
delete_handler_thread(handler_threads);
}
}
delete_handler_threads_pool(handler_threads);
delete requests;
printf("we are done.\n");
return 0;
}
/* like any C program, program's execution begins in main */
int
main(int argc, char* argv[])
{
int i; /* loop counter */
struct timespec delay; /* used for wasting time */
struct requests_queue* requests = NULL; /* pointer to requests queue */
struct handler_threads_pool* handler_threads = NULL;
/* list of handler threads */
/* create the requests queue */
requests = init_requests_queue(&request_mutex, &got_request);
assert(requests);
/* create the handler threads list */
handler_threads =
init_handler_threads_pool(&request_mutex, &got_request, requests);
assert(handler_threads);
/* create the request-handling threads */
for (i=0; i<NUM_HANDLER_THREADS; i++) {
add_handler_thread(handler_threads);
}
/* run a loop that generates requests */
for (i=0; i<600; i++) {
int num_requests; // number of requests waiting to be handled.
int num_threads; // number of active handler threads.
add_request(requests, i);
num_requests = get_requests_number(requests);
num_threads = get_handler_threads_number(handler_threads);
/* if there are too many requests on the queue, spawn new threads */
/* if there are few requests and too many handler threads, cancel */
/* a handler thread. */
if (num_requests > HIGH_REQUESTS_WATERMARK &&
num_threads < MAX_NUM_HANDLER_THREADS) {
printf("main: adding thread: '%d' requests, '%d' threads\n",
num_requests, num_threads);
add_handler_thread(handler_threads);
}
if (num_requests < LOW_REQUESTS_WATERMARK &&
num_threads > NUM_HANDLER_THREADS) {
printf("main: deleting thread: '%d' requests, '%d' threads\n",
num_requests, num_threads);
delete_handler_thread(handler_threads);
}
/* pause execution for a little bit, to allow */
/* other threads to run and handle some requests. */
if (rand() > 3*(RAND_MAX/4)) { /* this is done about 25% of the time */
delay.tv_sec = 0;
delay.tv_nsec = 1;
nanosleep(&delay, NULL);
}
}
/* modify the flag to tell the handler threads no */
/* new requests will be generated. */
{
int rc;
rc = pthread_mutex_lock(&request_mutex);
done_creating_requests = 1;
rc = pthread_cond_broadcast(&got_request);
rc = pthread_mutex_unlock(&request_mutex);
}
/* cleanup */
delete_handler_threads_pool(handler_threads);
delete_requests_queue(requests);
printf("Glory, we are done.\n");
return 0;
}