Nginx源代码分析之初始化（三）

ngx_create_thread 有多个版本

类unix 下面的

ngx_err_t
ngx_create_thread(ngx_tid_t *tid, ngx_thread_value_t (*func)(void *arg),
    void *arg, ngx_log_t *log)
{
    int  err;


    if (nthreads >= max_threads) {
        ngx_log_error(NGX_LOG_CRIT, log, 0,
                      "no more than %ui threads can be created", max_threads);
        return NGX_ERROR;
    }


    err = pthread_create(tid, &thr_attr, func, arg);


    if (err != 0) {
        ngx_log_error(NGX_LOG_ALERT, log, err, "pthread_create() failed");
        return err;
    }


    ngx_log_debug1(NGX_LOG_DEBUG_CORE, log, 0,
                   "thread is created: " NGX_TID_T_FMT, *tid);


    nthreads++;


    return err;
}

bsd下面的

ngx_err_t
ngx_create_thread(ngx_tid_t *tid, ngx_thread_value_t (*func)(void *arg),
    void *arg, ngx_log_t *log)
{
    ngx_pid_t   id;
    ngx_err_t   err;
    char       *stack, *stack_top;


    if (nthreads >= max_threads) {
        ngx_log_error(NGX_LOG_CRIT, log, 0,
                      "no more than %ui threads can be created", max_threads);
        return NGX_ERROR;
    }


    last_stack -= ngx_thread_stack_size;


    stack = mmap(last_stack, usable_stack_size, PROT_READ|PROT_WRITE,
                 MAP_STACK, -1, 0);


    if (stack == MAP_FAILED) {
        ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
                      "mmap(%p:%uz, MAP_STACK) thread stack failed",
                      last_stack, usable_stack_size);
        return NGX_ERROR;
    }


    if (stack != last_stack) {
        ngx_log_error(NGX_LOG_ALERT, log, 0,
                      "stack %p address was changed to %p", last_stack, stack);
        return NGX_ERROR;
    }


    stack_top = stack + usable_stack_size;


    ngx_log_debug2(NGX_LOG_DEBUG_CORE, log, 0,
                   "thread stack: %p-%p", stack, stack_top);


    ngx_set_errno(0);


    id = rfork_thread(RFPROC|RFTHREAD|RFMEM, stack_top,
                      (ngx_rfork_thread_func_pt) func, arg);


    err = ngx_errno;


    if (id == -1) {
        ngx_log_error(NGX_LOG_ALERT, log, err, "rfork() failed");


    } else {
        *tid = id;
        nthreads = (ngx_freebsd_kern_usrstack - stack_top)
                                                       / ngx_thread_stack_size;
        tids[nthreads] = id;


        ngx_log_debug1(NGX_LOG_DEBUG_CORE, log, 0, "rfork()ed thread: %P", id);
    }


    return err;
}

windows 下面的

ngx_create_thread(ngx_tid_t *tid,
    ngx_thread_value_t (__stdcall *func)(void *arg), void *arg, ngx_log_t *log)
{
    u_long     id;
    ngx_err_t  err;


    *tid = CreateThread(NULL, stack_size, func, arg, 0, &id);


    if (*tid != NULL) {
        ngx_log_error(NGX_LOG_NOTICE, log, 0,
                      "create thread " NGX_TID_T_FMT, id);
        return 0;
    }


    err = ngx_errno;
    ngx_log_error(NGX_LOG_ALERT, log, err, "CreateThread() failed");
    return err;
}