Commit b156c592 authored by Yann Ylavic's avatar Yann Ylavic
Browse files

core: always allocate filters (ap_filter_t) on f->c->pool. 

When filters are allocated on f->r->pool, they may be destroyed any time
underneath themselves which makes it hard for them to be passed the EOR and
forward it (*f can't be dereferenced anymore when the EOR is destroyed, thus
before request filters return).

On the util_filter side, it also makes it impossible to flush pending request
filters when they have set aside the EOR, since f->bb can't be accessed after
it's passed to the f->next.

So we always use f->c->pool to allocate filters and pending brigades, and to
avoid leaks with keepalive requests (long living connections handling multiple
requests), filters and brigades are recycled with a cleanup on f->r->pool.

Recycling is done (generically) with a spare data ring (void pointers), and a
filter(s) context struct is associated with the conn_rec to maintain the rings
by connection, that is:

    struct ap_filter_conn_ctx {
        struct ap_filter_ring *pending_input_filters;
        struct ap_filter_ring *pending_output_filters;

        struct ap_filter_spare_ring *spare_containers,
                                    *spare_brigades,
                                    *spare_filters,
                                    *spare_flushes;
        int flushing;
    };

MMN major bumped (again).


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1839997 13f79535-47bb-0310-9956-ffa450edef68
parent c1b278a3

include/ap_mmn.h

+4 −2
Changes for include/ap_mmn.h: 4 added lines, 2 removed lines.
Original line number Diff line number Diff line
@@ -598,13 +598,15 @@ 
 * 20180720.7 (2.5.1-dev)  worker_share struct re-organized

 * 20180902.1 (2.5.1-dev)  Split conn_rec pending_filters in two rings,

 *                         pending_input_filters and pending_output_filters

 *

 * 20180903.1 (2.5.1-dev)  Replace conn_rec pending_{in,out}put_filters by

 *                         filter_conn_ctx, remove argument pool from

 *                         ap_filter_prepare_brigade()

 */



#define MODULE_MAGIC_COOKIE 0x41503235UL /* "AP25" */



#ifndef MODULE_MAGIC_NUMBER_MAJOR

#define MODULE_MAGIC_NUMBER_MAJOR 20180902

#define MODULE_MAGIC_NUMBER_MAJOR 20180903

#endif

#define MODULE_MAGIC_NUMBER_MINOR 1                 /* 0...n */

include/httpd.h

+3 −5
Changes for include/httpd.h: 3 added lines, 5 removed lines.
Original line number Diff line number Diff line
@@ -1111,7 +1111,7 @@ typedef enum { 
    AP_CONN_KEEPALIVE

} ap_conn_keepalive_e;



/* For struct ap_filter and ap_filter_ring */

/* For struct ap_filter_conn_ctx */

#include "util_filter.h"



/**
@@ -1224,10 +1224,8 @@ struct conn_rec { 
    /** Array of requests being handled under this connection. */

    apr_array_header_t *requests;



    /** Ring of pending input filters (with setaside buckets) */

    struct ap_filter_ring *pending_input_filters;

    /** Ring of pending output filters (with setaside buckets) */

    struct ap_filter_ring *pending_output_filters;

    /** Filters' context for this connection */

    struct ap_filter_conn_ctx *filter_conn_ctx;



    /** The minimum level of filter type to allow setaside buckets */

    int async_filter;

include/util_filter.h

+3 −6
Changes for include/util_filter.h: 3 added lines, 6 removed lines.
Original line number Diff line number Diff line
@@ -304,9 +304,9 @@ struct ap_filter_t { 
};



/**

 * @brief The type of a filters' ring (opaque).

 * @brief The filters' context in conn_rec (opaque).

 */

typedef struct ap_filter_ring ap_filter_ring_t;

struct ap_filter_conn_ctx;



/**

 * Get the current bucket brigade from the next filter on the filter
@@ -569,12 +569,9 @@ AP_DECLARE(apr_status_t) ap_save_brigade(ap_filter_t *f, 
 * filters, or can be used within an output filter by being called via

 * ap_filter_setaside_brigade().

 * @param f The current filter

 * @param p The pool that was used to create the brigade. In a request

 * filter this will be the request pool, in a connection filter this will

 * be the connection pool.

 * @returns OK if a brigade was created, DECLINED otherwise.

 */

AP_DECLARE(int) ap_filter_prepare_brigade(ap_filter_t *f, apr_pool_t **p);

AP_DECLARE(int) ap_filter_prepare_brigade(ap_filter_t *f);



/**

 * Prepare a bucket brigade to be setaside, creating a dedicated pool if

modules/http2/h2_conn.c

+1 −0
Changes for modules/http2/h2_conn.c: 1 added line, 0 removed lines.
Original line number Diff line number Diff line
@@ -313,6 +313,7 @@ conn_rec *h2_slave_create(conn_rec *master, int slave_id, apr_pool_t *parent) 
    c->notes                  = apr_table_make(pool, 5);

    c->input_filters          = NULL;

    c->output_filters         = NULL;

    c->filter_conn_ctx        = NULL;

    c->bucket_alloc           = apr_bucket_alloc_create(pool);

    /* prevent mpm_event from making wrong assumptions about this connection,

     * like e.g. using its socket for an async read check. */

modules/ssl/ssl_engine_io.c

+3 −4
Changes for modules/ssl/ssl_engine_io.c: 3 added lines, 4 removed lines.
Original line number Diff line number Diff line
@@ -1813,7 +1813,7 @@ static apr_status_t ssl_io_filter_output(ap_filter_t *f, 


        /* if the core has set aside data, back off and try later */

        if (!flush_upto) {

            if (ap_filter_should_yield(f)) {

            if (ap_filter_should_yield(f->next)) {

                break;

            }

        }
@@ -1869,10 +1869,9 @@ static apr_status_t ssl_io_filter_output(ap_filter_t *f, 


    }



    if (APR_STATUS_IS_EOF(status) || (status == APR_SUCCESS)) {

        return ap_filter_setaside_brigade(f, bb);

    if (status == APR_SUCCESS) {

        status = ap_filter_setaside_brigade(f, bb);

    }



    return status;

}