/boa-0.94.14rc21/src/queue.c

  1/*
  2 *  Boa, an http server
  3 *  Copyright (C) 1995 Paul Phillips <paulp@go2net.com>
  4 *  Copyright (C) 1997-2002 Jon Nelson <jnelson@boa.org>
  5 *
  6 *  This program is free software; you can redistribute it and/or modify
  7 *  it under the terms of the GNU General Public License as published by
  8 *  the Free Software Foundation; either version 1, or (at your option)
  9 *  any later version.
 10 *
 11 *  This program is distributed in the hope that it will be useful,
 12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 14 *  GNU General Public License for more details.
 15 *
 16 *  You should have received a copy of the GNU General Public License
 17 *  along with this program; if not, write to the Free Software
 18 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 19 *
 20 */
 21
 22/* $Id: queue.c,v 1.21.2.4 2005/02/22 14:11:29 jnelson Exp $*/
 23
 24#include "boa.h"
 25
 26request *request_ready = NULL;  /* ready list head */
 27request *request_block = NULL;  /* blocked list head */
 28request *request_free = NULL;   /* free list head */
 29
 30/*
 31 * Name: block_request
 32 *
 33 * Description: Moves a request from the ready queue to the blocked queue
 34 */
 35
 36void block_request(request * req)
 37{
 38    dequeue(&request_ready, req);
 39    enqueue(&request_block, req);
 40
 41    if (req->buffer_end) {
 42        BOA_FD_SET(req, req->fd, BOA_WRITE);
 43    } else {
 44        switch (req->status) {
 45        case IOSHUFFLE:
 46#ifndef HAVE_SENDFILE
 47            if (req->buffer_end - req->buffer_start == 0) {
 48                BOA_FD_SET(req, req->data_fd, BOA_READ);
 49                break;
 50            }
 51#endif
 52        case WRITE:
 53        case PIPE_WRITE:
 54        case DONE:
 55            BOA_FD_SET(req, req->fd, BOA_WRITE);
 56            break;
 57        case PIPE_READ:
 58            BOA_FD_SET(req, req->data_fd, BOA_READ);
 59            break;
 60        case BODY_WRITE:
 61            BOA_FD_SET(req, req->post_data_fd, BOA_WRITE);
 62            break;
 63        default:
 64            BOA_FD_SET(req, req->fd, BOA_READ);
 65            break;
 66        }
 67    }
 68}
 69
 70/*
 71 * Name: ready_request
 72 *
 73 * Description: Moves a request from the blocked queue to the ready queue
 74 */
 75
 76void ready_request(request * req)
 77{
 78    dequeue(&request_block, req);
 79    enqueue(&request_ready, req);
 80
 81    if (req->buffer_end) {
 82        BOA_FD_CLR(req, req->fd, BOA_WRITE);
 83    } else {
 84        switch (req->status) {
 85        case IOSHUFFLE:
 86#ifndef HAVE_SENDFILE
 87            if (req->buffer_end - req->buffer_start == 0) {
 88                BOA_FD_CLR(req, req->data_fd, BOA_READ);
 89                break;
 90            }
 91#endif
 92        case WRITE:
 93        case PIPE_WRITE:
 94        case DONE:
 95            BOA_FD_CLR(req, req->fd, BOA_WRITE);
 96            break;
 97        case PIPE_READ:
 98            BOA_FD_CLR(req, req->data_fd, BOA_READ);
 99            break;
100        case BODY_WRITE:
101            BOA_FD_CLR(req, req->post_data_fd, BOA_WRITE);
102            break;
103        default:
104            BOA_FD_CLR(req, req->fd, BOA_READ);
105        }
106    }
107}
108
109
110/*
111 * Name: dequeue
112 *
113 * Description: Removes a request from its current queue
114 */
115
116void dequeue(request ** head, request * req)
117{
118    if (*head == req)
119        *head = req->next;
120
121    if (req->prev)
122        req->prev->next = req->next;
123    if (req->next)
124        req->next->prev = req->prev;
125
126    req->next = NULL;
127    req->prev = NULL;
128}
129
130/*
131 * Name: enqueue
132 *
133 * Description: Adds a request to the head of a queue
134 */
135
136void enqueue(request ** head, request * req)
137{
138    if (*head)
139        (*head)->prev = req;    /* previous head's prev is us */
140
141    req->next = *head;          /* our next is previous head */
142    req->prev = NULL;           /* first in list */
143
144    *head = req;                /* now we are head */
145}