FastCGI的并发处理

FastCGI的并发处理

我还没找到异步处理的方式。如果有异步的实现方式，那就可以单线程异步处理多个并发请求了。

不过我在FastCGI的sample里面找到了多线程的方式，多线程的方式封装一下应该也可以达到异步的效果的。比如，doit()线程把FCGX_Request request丢给另一个线程A处理，然后doit()线程阻塞的等待线程A的返回结果。那么线程A实际上就可以采取异步的方式来处理请求了。

以下是FastCGI的sample里面的多线程实现：

/*
 * threaded.c -- A simple multi-threaded FastCGI application.
 */

#ifndef lint
static const char rcsid[] = "$Id: threaded.c,v 1.9 2001/11/20 03:23:21 robs Exp $";
#endif /* not lint */

#include "fcgi_config.h"

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

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include "fcgiapp.h"


#define THREAD_COUNT 20

static int counts[THREAD_COUNT];

static void *doit(void *a)
{
    int rc, i, thread_id = (int)a;
    pid_t pid = getpid();
    FCGX_Request request;
    char *server_name;

    FCGX_InitRequest(&request, 0, 0);

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

        /* Some platforms require accept() serialization, some don't.. */
        pthread_mutex_lock(&accept_mutex);
        rc = FCGX_Accept_r(&request);
        pthread_mutex_unlock(&accept_mutex);

        if (rc < 0)
            break;

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

        FCGX_FPrintF(request.out,
            "Content-type: text/html "
            " "
            "<title>FastCGI Hello! (multi-threaded C, fcgiapp library)</title>"
            "<h1>FastCGI Hello! (multi-threaded C, fcgiapp library)</h1>"
            "Thread %d, Process %ld<p>"
            "Request counts for %d threads running on host <i>%s</i><p><code>",
            thread_id, pid, THREAD_COUNT, server_name ? server_name : "?");

        sleep(2);

        pthread_mutex_lock(&counts_mutex);
        ++counts[thread_id];
        for (i = 0; i < THREAD_COUNT; i++)
            FCGX_FPrintF(request.out, "%5d " , counts[i]);
        pthread_mutex_unlock(&counts_mutex);

        FCGX_Finish_r(&request);
    }

    return NULL;
}

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

    FCGX_Init();

    for (i = 1; i < THREAD_COUNT; i++)
        pthread_create(&id[i], NULL, doit, (void*)i);

    doit(0);

    return 0;
}

 

另外，FCGX_Accept_r()可以在FCGX_Finish_r()之前连续accept多个request，这应该也代表着一种异步的方法。不过需要构造多个request对象给FCGX_Accept_r()。