Nginx + fastcgi multithreading

Hello i'v been trying to make fastcgi application, and i want it to be multithreaded so it can handle a lot of request at one time. I found the code, and modified it a bit

FCGX_InitRequest(&request, 0, FCGI_FAIL_ACCEPT_ON_INTR);

for (;;)
{
    static pthread_mutex_t accept_mutex = PTHREAD_MUTEX_INITIALIZER;
    static pthread_mutex_t counts_mutex = PTHREAD_MUTEX_INITIALIZER;
    pthread_mutex_lock(&accept_mutex);
    rc = FCGX_Accept_r(&request);
    pthread_mutex_unlock(&accept_mutex);

    ... ... ...


    FCGX_FPrintF(request.out,"%s",test_stream.str().c_str());

    FCGX_Finish_r(&request);
}

The code is keep stucking on accept so actually it waits, until request is fully done.

I tried spawning fastcgi like this

spawn-fcgi -p 8001 -U www-data -n handler.cgi -F 32
spawn-fcgi -p 8001 -U www-data -n handler.cgi -- /usr/bin/multiwatch -F 32

Solution

The problem is solved. Use FCGX_OpenSocket and umask(0) in order to let socket accept. This will give you real multithreaded application.

#include <pthread.h> 
#include <sys/types.h> 
#include <stdio.h> 

#include "fcgi_config.h" 
#include "fcgiapp.h" 


#define THREAD_COUNT 8 
#define SOCKET_PATH "/var/run/myfcgiserver.sock" // your unix socket file

static int socketId; 

static void *doit(void *a) 
{ 
    int rc, i; 
    FCGX_Request request; 
    char *server_name; 

    if(FCGX_InitRequest(&request, socketId, 0) != 0) 
    { 
        printf("Can not init request\n"); 
        return NULL; 
    } 
    printf("Request is inited\n"); 

    for(;;) 
    { 
        static pthread_mutex_t accept_mutex = PTHREAD_MUTEX_INITIALIZER; 

        printf("Try to accept new request\n"); 
        pthread_mutex_lock(&accept_mutex); 
        rc = FCGX_Accept_r(&request); 
        pthread_mutex_unlock(&accept_mutex); 

        if(rc < 0) 
        { 
            printf("Can not accept new request\n"); 
            break; 
        } 
        printf("request is accepted\n"); 

        server_name = FCGX_GetParam("SERVER_NAME", request.envp); 

        FCGX_PutS("Content-type: text/html\r\n", request.out); 
        FCGX_PutS("\r\n", request.out); 
        FCGX_PutS("<html>\r\n", request.out); 
        FCGX_PutS("<head>\r\n", request.out); 
        FCGX_PutS("<title>FastCGI Hello! (multi-threaded C, fcgiapp library)</title>\r\n", request.out); 
        FCGX_PutS("</head>\r\n", request.out); 
        FCGX_PutS("<body>\r\n", request.out); 
        FCGX_PutS("<h1>FastCGI Hello! (multi-threaded C, fcgiapp library)</h1>\r\n", request.out); 
        FCGX_PutS("<p>Request accepted from host <i>", request.out); 
        FCGX_PutS(server_name ? server_name : "?", request.out); 
        FCGX_PutS("</i></p>\r\n", request.out); 
        FCGX_PutS("</body>\r\n", request.out); 
        FCGX_PutS("</html>\r\n", request.out); 

        FCGX_Finish_r(&request); 

    } 

    return NULL; 
} 

int main(void) 
{ 
    int i; 
    pthread_t id[THREAD_COUNT]; 

    FCGX_Init(); 
    printf("Lib is inited\n"); 
    umask(0);   
    socketId = FCGX_OpenSocket(SOCKET_PATH, 2000); 
    if(socketId < 0) 
    { 
           return 1; 
    } 
    printf("Socket is opened\n"); 


    for(i = 0; i < THREAD_COUNT; i++) 
    { 
        pthread_create(&id[i], NULL, doit, NULL); 
    } 

    for(i = 0; i < THREAD_COUNT; i++) 
    { 
        pthread_join(id[i], NULL); 
    } 

    return 0; 
}