Multipath TCP (MPTCP), standardized in RFC8684 [1],
is a TCP extension that enables a TCP connection to
use different paths.
Multipath TCP has been used for several use cases.
On smartphones, MPTCP enables seamless handovers between
cellular and Wi-Fi networks while preserving established
connections. This use-case is what pushed Apple to use
MPTCP since 2013 in multiple applications [2]. On dual-stack
hosts, Multipath TCP enables the TCP connection to
automatically use the best performing path, either IPv4
or IPv6. If one path fails, MPTCP automatically uses
the other path.
To benefit from MPTCP, both the client and the server
have to support it. Multipath TCP is a backward-compatible
TCP extension that is enabled by default on recent
Linux distributions (Debian, Ubuntu, Redhat, ...). Multipath
TCP is included in the Linux kernel since version 5.6 [3].
To use it on Linux, an application must explicitly enable
it when creating the socket. No need to change anything
else in the application.
Adding the possibility to create MPTCP sockets would thus
be a really fine addition to httpd, by allowing clients
to make use of their different interfaces.
This patch introduces the possibilty to connect to backend
servers using MPTCP. Note however that these changes are
only available on Linux, as IPPROTO_MPTCP is Linux specific
for the time being.
For proxies, we can connect using MPTCP by passing the
\"multipathtcp\" parameter:
ProxyPass \"/example\" \"http://backend.example.com\" multipathtcp=On
We then store this information in the worker and create sockets
appropriately according to this value.
Link: https://www.rfc-editor.org/rfc/rfc8684.html [1]
Link: https://www.tessares.net/apples-mptcp-story-so-far/ [2]
Link: https://www.mptcp.dev [3]
Add Multipath TCP (MPTCP) support (Core)
Multipath TCP (MPTCP), standardized in RFC8684 [1],
is a TCP extension that enables a TCP connection to
use different paths.
Multipath TCP has been used for several use cases.
On smartphones, MPTCP enables seamless handovers between
cellular and Wi-Fi networks while preserving established
connections. This use-case is what pushed Apple to use
MPTCP since 2013 in multiple applications [2]. On dual-stack
hosts, Multipath TCP enables the TCP connection to
automatically use the best performing path, either IPv4
or IPv6. If one path fails, MPTCP automatically uses
the other path.
To benefit from MPTCP, both the client and the server
have to support it. Multipath TCP is a backward-compatible
TCP extension that is enabled by default on recent
Linux distributions (Debian, Ubuntu, Redhat, ...). Multipath
TCP is included in the Linux kernel since version 5.6 [3].
To use it on Linux, an application must explicitly enable
it when creating the socket. No need to change anything
else in the application.
Adding the possibility to create MPTCP sockets would thus
be a really fine addition to httpd, by allowing clients
to make use of their different interfaces.
This patch introduces the possibility to listen with MPTCP
sockets. Note however that these changes are only available
on Linux, as IPPROTO_MPTCP is Linux specific for the time being.
To do so, we extended the Listen directive to include
a \"multipathtcp\" option, allowing to create MPTCP sockets
instead of regular TCP ones:
Listen 80 options=multipathtcp
We then store this information in flags for the listen directive
and create sockets appropriately according to this value.
Link: https://www.rfc-editor.org/rfc/rfc8684.html [1]
Link: https://www.tessares.net/apples-mptcp-story-so-far/ [2]
Link: https://www.mptcp.dev [3]
Submitted by: Aperence <anthony.doeraene hotmail.com>
Github: closes#476
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1920586 13f79535-47bb-0310-9956-ffa450edef68
With "ProxyPassMatch ^/([^/]+)/(.*)$ https://$1/$2", ap_proxy_get_worker_ex()
should not consider the length of scheme://host part of the given URL because
of the globbing match on the host part.
Fix it by setting worker->s>is_host_matchable when creating a worker with host
substitution and avoiding the min_match check in worker_matches() in this case.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1919617 13f79535-47bb-0310-9956-ffa450edef68
* modules/proxy/proxy_util.c:
Export ap_proxy_fixup_uds_filename() from fix_uds_filename.
Call it from ap_proxy_pre_request() even for rewritten balancer workers.
* modules/proxy/mod_proxy.h:
Declare ap_proxy_fixup_uds_filename()
* modules/proxy/mod_proxy.c:
Fixup UDS filename from r->handler in proxy_handler().
* include/ap_mmn.h:
Bump MMN minor for ap_proxy_fixup_uds_filename()
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1918626 13f79535-47bb-0310-9956-ffa450edef68
Per discussion on PR #449, have a separate state for returning the connection
to the MPM to wait for an IO (namely CONN_STATE_ASYNC_WAITIO), rather than
(ab)using CONN_STATE_PROCESSING.
This removes the need for AGAIN added in r1918257 (for now), and AP_MPMQ_CAN_AGAIN
is renamed to AP_MPMQ_CAN_WAITIO.
This is also the state that mod_status accounts for, so rename ->processing
to ->wait_io in process_score (shows as "wait-io" in mod_status and mod_lua).
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1918482 13f79535-47bb-0310-9956-ffa450edef68
Before r1918022, returning OK with CONN_STATE_PROCESSING to mpm_event was
handled like/by CONN_STATE_LINGER "to not break old or third-party modules
which might return OK w/o touching the state and expect lingering close,
like with worker or prefork MPMs".
So we need a new return code to be allowed to apply the new POLLIN/POLLOUT
behaviour for CONN_STATE_PROCESSING, thus revive AGAIN as introduced by
Graham some times ago for a nonblocking WIP (moved to a branch/PR since then).
MPM event will advertise its ability to handle CONN_STATE_PROCESSING + AGAIN
with AP_MPMQ_CAN_AGAIN, and mod_http2 can use that to know how to return to
the MPM as expected. When !AP_MPMQ_CAN_AGAIN modules/mod_http2 can still use
CONN_STATE_WRITE_COMPLETION + CONN_SENSE_WANT_READ + c->clogging_input_filters
which will work in mpm_even-2.4.x still.
* include/ap_mmn.h:
Bump MMN minor for AP_MPMQ_CAN_AGAIN and AGAIN.
* include/ap_mpm.h:
Define AP_MPMQ_CAN_AGAIN.
* include/httpd.h:
Define AGAIN.
* modules/http2/h2.h:
No need for H2_USE_STATE_PROCESSING anymore with AP_MPMQ_CAN_AGAIN.
* modules/http2/h2_c1.c:
For !keepalive case return to the MPM using CONN_STATE_PROCESSING + AGAIN
or CONN_STATE_WRITE_COMPLETION + c->clogging_input_filters depending on
AP_MPMQ_CAN_AGAIN only.
* modules/http2/h2_session.c:
Can return to the MPM for h2_send_flow_blocked() provided it's async only.
* server/mpm/event/event.c:
Rework process_socket()'s CONN_STATE_PROCESSING to handle AGAIN and preserve
compatibility. Have a lingering_close label to goto there faster when
process_lingering_close() is to be called. Improve relevant comments.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1918257 13f79535-47bb-0310-9956-ffa450edef68
As a follow up to r1918022 which handled the new CONN_STATE_PROCESS(ing) and
existing CONN_STATE_WRITE_COMPLETION in the same async queue, let's now have
two separates ones which allows more relevant async accounting in mod_status.
Rename CONN_STATE_PROCESS to CONN_STATE_PROCESSING as it's how it will be
called in mod_status.
* include/ap_mmn.h:
MMN minor bump for process_score->processing counter.
* include/httpd.h:
Rename CONN_STATE_PROCESS to CONN_STATE_PROCESSING.
* include/scoreboard.h:
Add process_score->processing field.
* include/httpd.h, modules/http/http_core.c, modules/http2/h2_c1.c,
server/mpm/event/event.c, server/mpm/motorz/motorz.c,
server/mpm/simple/simple_io.c:
Rename CONN_STATE_PROCESS to CONN_STATE_PROCESSING.
* server/mpm/event/event.c:
Restore write_completion_q to handle connections in CONN_STATE_WRITE_COMPLETION.
Use processing_q (renamed from process_q) solely for CONN_STATE_PROCESSING.
Update process_score->processing according to the length of processing_q.
* modules/generators/mod_status.c:
Show the value of process_score->processing in the stats.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1918098 13f79535-47bb-0310-9956-ffa450edef68
* include/ap_mmn.h:
Bump MMN minor.
* include/ap_regex.h:
Declare ap_regexec_ex().
* server/util_pcre.c(ap_regexec, ap_regexec_len, ap_regexec_ex):
Reuse existing ap_regexec_len() code to implement ap_regexec_ex() where the
offset is given instead of zero, then implement ap_regexec{,len}() in terms
of ap_regexec_ex().
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1915267 13f79535-47bb-0310-9956-ffa450edef68
The latter requires a pool and returns a non constant string although it may
return worker shared data.
By computing the worker "UDS" name at init time we can return a constant name
in any case with no need for a pool, that's the new ap_proxy_worker_get_name().
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1912461 13f79535-47bb-0310-9956-ffa450edef68
Define a new proxy_address struct holding the current/latest sockaddr in use
by each proxy worker and conn. Since backend addresses can be updated when
their TTL expires and while connections are being processed, each address is
refcounted and freed only when the last worker (or conn) using it grabs the
new one.
The lifetime of the addresses is handled at a single place by the new
ap_proxy_determine_address() function. It guarantees to bind the current/latest
backend address to the passed in conn (or do nothing if it's up to date already).
The function is called indirectly by ap_proxy_determine_connection() for the
proxy modules that use it, or directly by mod_proxy_ftp and mod_proxy_hcheck.
It also is called eventually by ap_proxy_connect_backend() when connect()ing all
the current addresses fails, to check (PROXY_DETERMINE_ADDRESS_CHECK) if some
new addrs are available.
This commit is also a rework of the lifetime of conn->addr, conn->hostname
and conn->forward, using the conn->uds_pool and conn->fwd_pool for the cases
where the backend is connected through a UDS socket and a remote CONNECT proxy
respectively.
* include/ap_mmn.h:
Minor bump for new function/fields.
* modules/proxy/mod_proxy.h (struct proxy_address,
ap_proxy_determine_addresss()):
Declare ap_proxy_determine_addresss() and opaque struct proxy_address,
new fields to structs proxy_conn_rec/proxy_worker_shared/proxy_worker.
* modules/proxy/mod_proxy.c (set_worker_param):
Parse/set the new worker->address_ttl parameter.
* modules/proxy/proxy_util.c (proxy_util_register_hooks(),
ap_proxy_initialize_worker(),
ap_proxy_connection_reusable(),
ap_proxyerror(), proxyerror_core(),
init_conn_pool(), make_conn_subpool(),
connection_make(), connection_cleanup(),
connection_constructor()):
Initialize *proxy_start_time in proxy_util_register_hooks() as the epoch
from which expiration times are relative (i.e. seconds stored in an uint32_t
for atomic changes).
Make sure worker->s->is_address_reusable and worker->s->disablereuse are
consistant in ap_proxy_initialize_worker(), thus no need to check for both
in ap_proxy_connection_reusable().
New proxyerror_core() helper taking an apr_status_t to log, wrap in
ap_proxyerror().
New make_conn_subpool() to create worker->cp->{pool,dns} with their own
allocator.
New connection_make() helper to factorize code in connection_cleanup() and
connection_constructor().
* modules/proxy/proxy_util.c (proxy_address_inc(), proxy_address_dec(),
proxy_address_cleanup(), proxy_address_set_expired(),
worker_address_get(), worker_address_set(),
worker_address_resolve(), proxy_addrs_equal(),
ap_proxy_determine_address(),
ap_proxy_determine_connection(),
ap_proxy_connect_backend()):
Implement ap_proxy_determine_address() using the above helpers for atomic changes,
and call it from ap_proxy_determine_connection() and ap_proxy_connect_backend().
* modules/proxy/mod_proxy_ftp.c (proxy_ftp_handler):
Use ap_proxy_determine_address() and use the returned backend->addr.
* modules/proxy/mod_proxy_hcheck.c (hc_determine_connection, hc_get_backend,
hc_init_worker, hc_watchdog_callback):
Use ap_proxy_determine_address() in hc_determine_connection() and call the
latter from hc_get_backend(), replace hc_init_worker() by hc_init_baton()
which now calls hc_get_hcworker() and hc_get_backend() to resolve the first
address at init time.
* modules/proxy/mod_proxy_http.c (proxy_http_handler):
Use backend->addr and ->hostname instead of worker->cp->addr and
worker->s->hostname_ex respectively.
* modules/proxy/mod_proxy_ajp.c (ap_proxy_ajp_request):
Use backend->addr and ->hostname instead of worker->cp->addr and
worker->s->hostname_ex respectively.
Closes#367
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1912459 13f79535-47bb-0310-9956-ffa450edef68
described in RFC 8441. A new directive 'H2WebSockets on|off' has been
added. The feature is by default not enabled.
As also discussed in the manual, this feature should work for setups
using "ProxyPass backend-url upgrade=websocket" without further changes.
Special server modules for WebSockets will have to be adapted,
most likely, as the handling if IO events is different with HTTP/2.
HTTP/2 WebSockets are supported on platforms with native pipes. This
excludes Windows.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1910507 13f79535-47bb-0310-9956-ffa450edef68
ap_die() to judge if it can send out a response. Bump mmn.
Enable test cases that check errors during response body to
appear as error on client side.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1910161 13f79535-47bb-0310-9956-ffa450edef68
In case that AllowEncodedSlashes is set to NoDecode do not double encode
encoded slashes in the URL sent by the reverse proxy to the backend.
* include/ap_mmn.h: Document the addition of ap_proxy_canonenc_ex to the API.
* modules/proxy/mod_proxy.h: Declare ap_proxy_canonenc_ex and define flag
values.
* modules/proxy/proxy_util.c: Implement ap_proxy_canonenc_ex by modifying
ap_proxy_canonenc accordingly and reimplement ap_proxy_canonenc to
use ap_proxy_canonenc_ex with the appropriate flag.
* modules/http2/mod_proxy_http2.c, modules/proxy/mod_proxy_*.c: Set the
correct flag based on the AllowEncodedSlashes configuration and use
ap_proxy_canonenc_ex instead of ap_proxy_canonenc.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1908341 13f79535-47bb-0310-9956-ffa450edef68
*) core/mod_http: use REQUEST meta buckets and a new HTTP/1.x specific
input filter to separate the handling for HTTP requests from the
handling of HTTP/1.x request parsing and checks.
A new HTTP1_REQUEST_IN filter installs itself on http/1.1 connections
before a request is being read. It generates either a REQUEST meta
bucket on success or an ERROR bucket with the proposed response status.
The core connection processing, relying on ap_read_request(), now expects
a REQUEST or ERROR bucket from the input filters and is agnostic to
specific HTTP versions and how they bring requests into the server.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1899799 13f79535-47bb-0310-9956-ffa450edef68
- adds new meta bucket types REQUEST, RESPONSE and HEADERS to the API.
- adds a new method for setting standard response headers Date and Server
- adds helper methods for formatting parts of HTTP/1.x, like headers and
end chunks for use in non-core parts of the server, e.g. mod_proxy
- splits the HTTP_IN filter into a "generic HTTP" and "specific HTTP/1.x"
filter. The latter one named HTTP1_BODY_IN.
- Uses HTTP1_BODY_IN only for requests with HTTP version <= 1.1
- Removes the chunked input simulation from mod_http2
- adds body_indeterminate flag to request_rec that indicates that a request
body may be present and needs to be read/discarded. This replaces logic
that thinks without Content-Length and Transfer-Encoding, no request
body can exist.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1899547 13f79535-47bb-0310-9956-ffa450edef68
create_secondary_connection and ap_create_secondary_connection()
to setup connections related to a "master" one, as used in
the HTTP/2 protocol implementation.
*) mod_http2: using the new API calls to get rid of knowledge
about how the core handles conn_rec specifics.
Improvements in pollset stream handling to use less sets.
Using atomic read/writes instead of volatiles now.
Keeping a reserve of "transit" pools and bucket_allocs for
use on secondary connections to avoid repeated setup/teardowns.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1899032 13f79535-47bb-0310-9956-ffa450edef68
to stabilize CI tests again. Previous revision of trunk has been copied
to branches/trunk-ssl-handshake-unblocking to make those into a PR where
changes can be discussed and tested separately.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1897760 13f79535-47bb-0310-9956-ffa450edef68
Replace ap_thread_current_create() by ap_thread_main_create() which is how
it's used by httpd. The former is now a local helper only to implement the
latter.
This allows to consolidate/factorize common code in the main() of httpd and
the unix MPMs.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1897543 13f79535-47bb-0310-9956-ffa450edef68
#define ap_thread_create, ap_thread_current_create and ap_thread_current to
their apr-1.8+ equivalent if available, or implement them using the compiler's
thread_local mechanism if available, or finally provide stubs otherwise.
#define AP_HAS_THREAD_LOCAL to 1 in the two former case or 0 otherwise, while
AP_THREAD_LOCAL is defined to the compiler's keyword iff AP_HAS_THREAD_LOCAL.
Replace all apr_thread_create() calls with ap_thread_create() so that httpd
threads can use ap_thread_current()'s pool data as Thread Local Storage.
Bump MMN minor.
* include/httpd.h():
Define AP_HAS_THREAD_LOCAL, AP_THREAD_LOCAL (eventually), ap_thread_create(),
ap_thread_current_create() and ap_thread_current().
* server/util.c:
Implement ap_thread_create(), ap_thread_current_create() and
ap_thread_current() when APR < 1.8.
* modules/core/mod_watchdog.c, modules/http2/h2_workers.c,
modules/ssl/mod_ssl_ct.c:
Use ap_thread_create() instead of apr_thread_create.
* server/main.c:
Use AP_HAS_THREAD_LOCAL and ap_thread_current_create instead of APR's.
* server/util_pcre.c:
Use AP_HAS_THREAD_LOCAL and ap_thread_current instead of APR's.
* server/mpm/event/event.c, server/mpm/worker/worker.c,
server/mpm/prefork/prefork.c:
Use ap_thread_create() instead of apr_thread_create.
Create an apr_thread_t/ap_thread_current() for the main chaild thread usable
at child_init().
* server/mpm/winnt/child.c:
Use ap_thread_create() instead of CreateThread().
Create an apr_thread_t/ap_thread_current() for the main chaild thread usable
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1897460 13f79535-47bb-0310-9956-ffa450edef68
CONN_STATE_READ_REQUEST_LINE phase, in addition to the existing
CONN_STATE_WRITE_COMPLETION phase. Update mod_ssl to perform non blocking
TLS handshakes.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1897281 13f79535-47bb-0310-9956-ffa450edef68
The worker name is a fully qualified URI while the hostname's limit is 256
already, so potentially more than 256 are needed to store the name. Let's
use 384.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1896253 13f79535-47bb-0310-9956-ffa450edef68
have an http(s) scheme, and that the ones to be forward proxied have a
hostname, per HTTP specifications.
The early checks avoid failing the request later on and thus save cycles
for those invalid cases.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1895921 13f79535-47bb-0310-9956-ffa450edef68
* modules/proxy/mod_proxy.h,modules/proxy/proxy_util.c:
Add ap_proxy_fill_error_brigade() to factorize proxy error handling
on the client connection side.
* modules/proxy/mod_proxy_{http,ajp,uwsgi}.c:
Use ap_proxy_fill_error_brigade() where needed, including when an
empty brigade is returned on the backend side or when calling
ap_proxy_buckets_lifetime_transform fails.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1893595 13f79535-47bb-0310-9956-ffa450edef68
* modules/proxy/mod_proxy.h:
Restore the interface of ap_proxy_transfer_between_connections() back to
before MMN 20210506.0.
Add ap_proxy_tunnel_conn_bytes_in() and ap_proxy_tunnel_conn_bytes_out().
New proxy_tunnel_conn_t typedef'ed from opaque struct proxy_tunnel_conn.
* modules/proxy/mod_proxy.h(ap_proxy_tunnel_conn_get_read,
ap_proxy_tunnel_conn_get_transferred):
Axed/replaced by ap_proxy_tunnel_conn_bytes_in() and
ap_proxy_tunnel_conn_bytes_out().
* modules/proxy/proxy_util.c(struct proxy_tunnel_conn):
Replace "exchanged" by "bytes_in" and "bytes_out".
* modules/proxy/proxy_util.c(proxy_transfer):
New helper implementing ap_proxy_transfer_between_connections() and
returning both &bytes_in and &bytes_out.
* modules/proxy/proxy_util.c(ap_proxy_transfer_between_connections):
Now calls proxy_transfer().
* modules/proxy/proxy_util.c(ap_proxy_tunnel_conn_bytes_in,
ap_proxy_tunnel_conn_bytes_out):
Return tc->bytes_in and tc->bytes_out respectively.
* modules/proxy/proxy_util.c(proxy_tunnel_forward):
Use proxy_transfer() which updates in->bytes_in, &out->bytes_out.
tunnel->replied will be updated in proxy_tunnel_run().
* modules/proxy/proxy_util.c(proxy_tunnel_forward):
Fall through the "done" label in any case to set tunnel->replied based
on tunnel->client->bytes_out > 0.
* modules/proxy/mod_proxy_http.c(ap_proxy_http_process_response):
Use ap_proxy_tunnel_conn_bytes_{in,out}() for worker->s->{read,transferred}
accounting.
* modules/proxy/mod_proxy_http.c(proxy_http_async_finish):
Update worker->s->{read,transferred} when async too.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1893594 13f79535-47bb-0310-9956-ffa450edef68
the pre_connection hook of the core module maybe did not run
(it is APR_HOOK_REALLY_LAST) and hence we missed to
- Put the socket in c->conn_config
- Setup core output and input filters
- Set socket options and timeouts
For calls of ap_run_pre_connection where this matters create a wrapper named
ap_pre_connection that ensures that this happens.
* include/ap_mmn.h: Bump minor version as we added new ap_pre_connection
function.
* include/http_connection.h: Declare ap_pre_connection prototype.
* server/connection.c: Make use of ap_pre_connection in ap_process_connection.
* server/core.c: Implement ap_pre_connection.
* server/mpm/event/event.c: Make use of ap_pre_connection.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1893497 13f79535-47bb-0310-9956-ffa450edef68
c->outgoing shouldn't be set by mod_ssl, ap_create_connection() allows that
and this commit also replaces all the calls to ap_run_create_connection() in
mod_proxy modules (not in the MPMs which create incoming connections only).
* include/http_connection.h, server/connection.c:
Declare and implement ap_create_connection().
* modules/proxy/proxy_util.c, modules/proxy/mod_proxy_connect.c,
modules/proxy/mod_proxy_ftp.c:
Use ap_create_connection() instead of ap_run_create_connection(), and don't
provide a connection_id a scoreboard handle for outgoing connection.
* server/log.c(do_errorlog_default):
Use c->outgoing instead of c->sbh to determine if it's a "client" or "remote"
connection.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1893184 13f79535-47bb-0310-9956-ffa450edef68
Define WC bucket semantics as:
/**
* @brief Write Completion (WC) bucket
*
* A WC bucket is a FLUSH bucket with special ->data == &ap_bucket_wc_data,
* still both AP_BUCKET_IS_WC() and APR_BUCKET_IS_FLUSH() hold for them so
* they have the same semantics for most filters, namely:
* Everything produced before shall be passed to the next filter, including
* the WC/FLUSH bucket itself.
* The distinction between WC and FLUSH buckets is only for filters that care
* about write completion (calling ap_filter_reinstate_brigade() with non-NULL
* flush_upto), those can setaside WC buckets and the preceding data provided
* they have first determined that the next filter(s) have pending data
* already, usually by calling ap_filter_should_yield(f->next).
*/
The only filters that care about write completion for now are
ap_core_output_filter() and ssl_io_filter_output(), which try to fill
in the pipe as much as possible, using ap_filter_reinstate_brigade(&flush_upto)
to determine whether they should flush (blocking) or setaside their remaining
data.
So ap_filter_reinstate_brigade() is made to not treat WC as FLUSH buckets and
keep the above filters working as before (and correctly w.r.t. above WC bucket
semantics).
* include/ap_mmn.h, include/util_filter.h:
Axe specific ap_bucket_type_wc and define global &ap_bucket_wc_data address to
mark WC buckets checked by AP_BUCKET_IS_WC().
* server/util_filter.c (ap_filter_reinstate_brigade):
Don't treat WC buckets as FLUSH buckets.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1892468 13f79535-47bb-0310-9956-ffa450edef68
stopping a child process. The additional `graceful` parameter allows
registered hooks to free resources early during a graceful shutdown.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1891919 13f79535-47bb-0310-9956-ffa450edef68
