view src/event/ngx_event_busy_lock.c @ 4192:61e4af19df9f

Autoindex: escape '?' in file names. For files with '?' in their names autoindex generated links with '?' not escaped. This resulted in effectively truncated links as '?' indicates query string start. This is an updated version of the patch originally posted at [1]. It introduces generic NGX_ESCAPE_URI_COMPONENT which escapes everything but unreserved characters as per RFC 3986. This approach also renders unneeded special colon processing (as colon is percent-encoded now), it's dropped accordingly. [1] http://nginx.org/pipermail/nginx-devel/2010-February/000112.html Reported by Konstantin Leonov.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 11 Oct 2011 17:56:51 +0000
parents 4c43e25d11ea
children d620f497c50f
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>


static ngx_int_t ngx_event_busy_lock_look_cacheable(ngx_event_busy_lock_t *bl,
    ngx_event_busy_lock_ctx_t *ctx);
static void ngx_event_busy_lock_handler(ngx_event_t *ev);
static void ngx_event_busy_lock_posted_handler(ngx_event_t *ev);


/*
 * NGX_OK:     the busy lock is held
 * NGX_AGAIN:  the all busy locks are held but we will wait the specified time
 * NGX_BUSY:   ctx->timer == 0: there are many the busy locks
 *             ctx->timer != 0: there are many the waiting locks
 */

ngx_int_t
ngx_event_busy_lock(ngx_event_busy_lock_t *bl, ngx_event_busy_lock_ctx_t *ctx)
{
    ngx_int_t  rc;

    ngx_mutex_lock(bl->mutex);

    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ctx->event->log, 0,
                   "event busy lock: b:%d mb:%d",
                   bl->busy, bl->max_busy);

    if (bl->busy < bl->max_busy) {
        bl->busy++;

        rc = NGX_OK;

    } else if (ctx->timer && bl->waiting < bl->max_waiting) {
        bl->waiting++;
        ngx_add_timer(ctx->event, ctx->timer);
        ctx->event->handler = ngx_event_busy_lock_handler;

        if (bl->events) {
            bl->last->next = ctx;

        } else {
            bl->events = ctx;
        }

        bl->last = ctx;

        rc = NGX_AGAIN;

    } else {
        rc = NGX_BUSY;
    }

    ngx_mutex_unlock(bl->mutex);

    return rc;
}


ngx_int_t
ngx_event_busy_lock_cacheable(ngx_event_busy_lock_t *bl,
    ngx_event_busy_lock_ctx_t *ctx)
{
    ngx_int_t  rc;

    ngx_mutex_lock(bl->mutex);

    rc = ngx_event_busy_lock_look_cacheable(bl, ctx);

    ngx_log_debug3(NGX_LOG_DEBUG_EVENT, ctx->event->log, 0,
                   "event busy lock: %d w:%d mw:%d",
                   rc, bl->waiting, bl->max_waiting);

    /*
     * NGX_OK:     no the same request, there is free slot and we locked it
     * NGX_BUSY:   no the same request and there is no free slot
     * NGX_AGAIN:  the same request is processing
     */

    if (rc == NGX_AGAIN) {

        if (ctx->timer && bl->waiting < bl->max_waiting) {
            bl->waiting++;
            ngx_add_timer(ctx->event, ctx->timer);
            ctx->event->handler = ngx_event_busy_lock_handler;

            if (bl->events == NULL) {
                bl->events = ctx;
            } else {
                bl->last->next = ctx;
            }
            bl->last = ctx;

        } else {
            rc = NGX_BUSY;
        }
    }

    ngx_mutex_unlock(bl->mutex);

    return rc;
}


void
ngx_event_busy_unlock(ngx_event_busy_lock_t *bl,
    ngx_event_busy_lock_ctx_t *ctx)
{
    ngx_event_t                *ev;
    ngx_event_busy_lock_ctx_t  *wakeup;

    ngx_mutex_lock(bl->mutex);

    if (bl->events) {
        wakeup = bl->events;
        bl->events = bl->events->next;

    } else {
        wakeup = NULL;
        bl->busy--;
    }

    /*
     * MP: all ctx's and their queue must be in shared memory,
     *     each ctx has pid to wake up
     */

    if (wakeup == NULL) {
        ngx_mutex_unlock(bl->mutex);
        return;
    }

    if (ctx->md5) {
        for (wakeup = bl->events; wakeup; wakeup = wakeup->next) {
            if (wakeup->md5 == NULL || wakeup->slot != ctx->slot) {
                continue;
            }

            wakeup->handler = ngx_event_busy_lock_posted_handler;
            wakeup->cache_updated = 1;

            ev = wakeup->event;

            ngx_post_event(ev, &ngx_posted_events);
        }

        ngx_mutex_unlock(bl->mutex);

    } else {
        bl->waiting--;

        ngx_mutex_unlock(bl->mutex);

        wakeup->handler = ngx_event_busy_lock_posted_handler;
        wakeup->locked = 1;

        ev = wakeup->event;

        if (ev->timer_set) {
            ngx_del_timer(ev);
        }

        ngx_post_event(ev, &ngx_posted_events);
    }
}


void
ngx_event_busy_lock_cancel(ngx_event_busy_lock_t *bl,
    ngx_event_busy_lock_ctx_t *ctx)
{
    ngx_event_busy_lock_ctx_t  *c, *p;

    ngx_mutex_lock(bl->mutex);

    bl->waiting--;

    if (ctx == bl->events) {
        bl->events = ctx->next;

    } else {
        p = bl->events;
        for (c = bl->events->next; c; c = c->next) {
            if (c == ctx) {
                p->next = ctx->next;
                break;
            }
            p = c;
        }
    }

    ngx_mutex_unlock(bl->mutex);
}


static ngx_int_t
ngx_event_busy_lock_look_cacheable(ngx_event_busy_lock_t *bl,
    ngx_event_busy_lock_ctx_t *ctx)
{
    ngx_int_t    free;
    ngx_uint_t   i, bit, cacheable, mask;

    bit = 0;
    cacheable = 0;
    free = -1;

#if (NGX_SUPPRESS_WARN)
    mask = 0;
#endif

    for (i = 0; i < bl->max_busy; i++) {

        if ((bit & 7) == 0) {
            mask = bl->md5_mask[i / 8];
        }

        if (mask & 1) {
            if (ngx_memcmp(&bl->md5[i * 16], ctx->md5, 16) == 0) {
                ctx->waiting = 1;
                ctx->slot = i;
                return NGX_AGAIN;
            }
            cacheable++;

        } else if (free == -1) {
            free = i;
        }

        if (cacheable == bl->cacheable) {
            if (free == -1 && cacheable < bl->max_busy) {
                free = i + 1;
            }

            break;
        }

        mask >>= 1;
        bit++;
    }

    if (free == -1) {
        return NGX_BUSY;
    }

#if 0
    if (bl->busy == bl->max_busy) {
        return NGX_BUSY;
    }
#endif

    ngx_memcpy(&bl->md5[free * 16], ctx->md5, 16);
    bl->md5_mask[free / 8] |= 1 << (free & 7);
    ctx->slot = free;

    bl->cacheable++;
    bl->busy++;

    return NGX_OK;
}


static void
ngx_event_busy_lock_handler(ngx_event_t *ev)
{
    ev->handler = ngx_event_busy_lock_posted_handler;

    ngx_post_event(ev, &ngx_posted_events);
}


static void
ngx_event_busy_lock_posted_handler(ngx_event_t *ev)
{
    ngx_event_busy_lock_ctx_t  *ctx;

    ctx = ev->data;
    ctx->handler(ev);
}