/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <assert.h>
#include <stddef.h>
#include <stdlib.h>
#include <apr_atomic.h>
#include <apr_thread_mutex.h>
#include <apr_thread_cond.h>
#include <apr_strings.h>
#include <apr_time.h>
#include <httpd.h>
#include <http_core.h>
#include <http_log.h>
#include <mpm_common.h>
#include "mod_http2.h"
#include "h2.h"
#include "h2_private.h"
#include "h2_bucket_beam.h"
#include "h2_config.h"
#include "h2_conn.h"
#include "h2_ctx.h"
#include "h2_h2.h"
#include "h2_mplx.h"
#include "h2_ngn_shed.h"
#include "h2_request.h"
#include "h2_stream.h"
#include "h2_session.h"
#include "h2_task.h"
#include "h2_workers.h"
#include "h2_util.h"
/* utility for iterating over ihash stream sets */
typedef struct {
h2_mplx *m;
h2_stream *stream;
apr_time_t now;
} stream_iter_ctx;
apr_status_t h2_mplx_child_init(apr_pool_t *pool, server_rec *s)
{
return APR_SUCCESS;
}
#define H2_MPLX_ENTER(m) \
do { apr_status_t rv; if ((rv = apr_thread_mutex_lock(m->lock)) != APR_SUCCESS) {\
return rv;\
} } while(0)
#define H2_MPLX_LEAVE(m) \
apr_thread_mutex_unlock(m->lock)
#define H2_MPLX_ENTER_ALWAYS(m) \
apr_thread_mutex_lock(m->lock)
#define H2_MPLX_ENTER_MAYBE(m, lock) \
if (lock) apr_thread_mutex_lock(m->lock)
#define H2_MPLX_LEAVE_MAYBE(m, lock) \
if (lock) apr_thread_mutex_unlock(m->lock)
static void check_data_for(h2_mplx *m, h2_stream *stream, int lock);
static void stream_output_consumed(void *ctx,
h2_bucket_beam *beam, apr_off_t length)
{
h2_stream *stream = ctx;
h2_task *task = stream->task;
if (length > 0 && task && task->assigned) {
h2_req_engine_out_consumed(task->assigned, task->c, length);
}
}
static void stream_input_ev(void *ctx, h2_bucket_beam *beam)
{
h2_stream *stream = ctx;
h2_mplx *m = stream->session->mplx;
apr_atomic_set32(&m->event_pending, 1);
}
static void stream_input_consumed(void *ctx, h2_bucket_beam *beam, apr_off_t length)
{
h2_stream_in_consumed(ctx, length);
}
static void stream_joined(h2_mplx *m, h2_stream *stream)
{
ap_assert(!stream->task || stream->task->worker_done);
h2_ihash_remove(m->shold, stream->id);
h2_ihash_add(m->spurge, stream);
}
static void stream_cleanup(h2_mplx *m, h2_stream *stream)
{
ap_assert(stream->state == H2_SS_CLEANUP);
if (stream->input) {
h2_beam_on_consumed(stream->input, NULL, NULL, NULL);
h2_beam_abort(stream->input);
}
if (stream->output) {
h2_beam_on_produced(stream->output, NULL, NULL);
h2_beam_leave(stream->output);
}
h2_stream_cleanup(stream);
h2_ihash_remove(m->streams, stream->id);
h2_iq_remove(m->q, stream->id);
h2_ififo_remove(m->readyq, stream->id);
h2_ihash_add(m->shold, stream);
if (!stream->task || stream->task->worker_done) {
stream_joined(m, stream);
}
else if (stream->task) {
stream->task->c->aborted = 1;
apr_thread_cond_broadcast(m->task_thawed);
}
}
/**
* A h2_mplx needs to be thread-safe *and* if will be called by
* the h2_session thread *and* the h2_worker threads. Therefore:
* - calls are protected by a mutex lock, m->lock
* - the pool needs its own allocator, since apr_allocator_t are
* not re-entrant. The separate allocator works without a
* separate lock since we already protect h2_mplx itself.
* Since HTTP/2 connections can be expected to live longer than
* their HTTP/1 cousins, the separate allocator seems to work better
* than protecting a shared h2_session one with an own lock.
*/
h2_mplx *h2_mplx_create(conn_rec *c, apr_pool_t *parent,
const h2_config *conf,
h2_workers *workers)
{
apr_status_t status = APR_SUCCESS;
apr_allocator_t *allocator;
apr_thread_mutex_t *mutex;
h2_mplx *m;
h2_ctx *ctx = h2_ctx_get(c, 0);
ap_assert(conf);
m = apr_pcalloc(parent, sizeof(h2_mplx));
if (m) {
m->id = c->id;
m->c = c;
m->s = (ctx? h2_ctx_server_get(ctx) : NULL);
if (!m->s) {
m->s = c->base_server;
}
/* We create a pool with its own allocator to be used for
* processing slave connections. This is the only way to have the
* processing independant of its parent pool in the sense that it
* can work in another thread. Also, the new allocator needs its own
* mutex to synchronize sub-pools.
*/
status = apr_allocator_create(&allocator);
if (status != APR_SUCCESS) {
return NULL;
}
apr_allocator_max_free_set(allocator, ap_max_mem_free);
apr_pool_create_ex(&m->pool, parent, NULL, allocator);
if (!m->pool) {
apr_allocator_destroy(allocator);
return NULL;
}
apr_pool_tag(m->pool, "h2_mplx");
apr_allocator_owner_set(allocator, m->pool);
status = apr_thread_mutex_create(&mutex, APR_THREAD_MUTEX_DEFAULT,
m->pool);
if (status != APR_SUCCESS) {
apr_pool_destroy(m->pool);
return NULL;
}
apr_allocator_mutex_set(allocator, mutex);
status = apr_thread_mutex_create(&m->lock, APR_THREAD_MUTEX_DEFAULT,
m->pool);
if (status != APR_SUCCESS) {
apr_pool_destroy(m->pool);
return NULL;
}
status = apr_thread_cond_create(&m->task_thawed, m->pool);
if (status != APR_SUCCESS) {
apr_pool_destroy(m->pool);
return NULL;
}
m->max_streams = h2_config_geti(conf, H2_CONF_MAX_STREAMS);
m->stream_max_mem = h2_config_geti(conf, H2_CONF_STREAM_MAX_MEM);
m->streams = h2_ihash_create(m->pool, offsetof(h2_stream,id));
m->sredo = h2_ihash_create(m->pool, offsetof(h2_stream,id));
m->shold = h2_ihash_create(m->pool, offsetof(h2_stream,id));
m->spurge = h2_ihash_create(m->pool, offsetof(h2_stream,id));
m->q = h2_iq_create(m->pool, m->max_streams);
status = h2_ififo_set_create(&m->readyq, m->pool, m->max_streams);
if (status != APR_SUCCESS) {
apr_pool_destroy(m->pool);
return NULL;
}
m->workers = workers;
m->max_active = workers->max_workers;
m->limit_active = 6; /* the original h1 max parallel connections */
m->last_limit_change = m->last_idle_block = apr_time_now();
m->limit_change_interval = apr_time_from_msec(100);
m->spare_slaves = apr_array_make(m->pool, 10, sizeof(conn_rec*));
m->ngn_shed = h2_ngn_shed_create(m->pool, m->c, m->max_streams,
m->stream_max_mem);
h2_ngn_shed_set_ctx(m->ngn_shed , m);
}
return m;
}
int h2_mplx_shutdown(h2_mplx *m)
{
int max_stream_started = 0;
H2_MPLX_ENTER(m);
max_stream_started = m->max_stream_started;
/* Clear schedule queue, disabling existing streams from starting */
h2_iq_clear(m->q);
H2_MPLX_LEAVE(m);
return max_stream_started;
}
static int input_consumed_signal(h2_mplx *m, h2_stream *stream)
{
if (stream->input) {
return h2_beam_report_consumption(stream->input);
}
return 0;
}
static int report_consumption_iter(void *ctx, void *val)
{
h2_stream *stream = val;
h2_mplx *m = ctx;
input_consumed_signal(m, stream);
if (stream->state == H2_SS_CLOSED_L
&& (!stream->task || stream->task->worker_done)) {
ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, m->c,
H2_STRM_LOG(APLOGNO(10026), stream, "remote close missing"));
nghttp2_submit_rst_stream(stream->session->ngh2, NGHTTP2_FLAG_NONE,
stream->id, NGHTTP2_NO_ERROR);
}
return 1;
}
static int output_consumed_signal(h2_mplx *m, h2_task *task)
{
if (task->output.beam) {
return h2_beam_report_consumption(task->output.beam);
}
return 0;
}
static int stream_destroy_iter(void *ctx, void *val)
{
h2_mplx *m = ctx;
h2_stream *stream = val;
h2_ihash_remove(m->spurge, stream->id);
ap_assert(stream->state == H2_SS_CLEANUP);
if (stream->input) {
/* Process outstanding events before destruction */
input_consumed_signal(m, stream);
h2_beam_log(stream->input, m->c, APLOG_TRACE2, "stream_destroy");
h2_beam_destroy(stream->input);
stream->input = NULL;
}
if (stream->task) {
h2_task *task = stream->task;
conn_rec *slave;
int reuse_slave = 0;
stream->task = NULL;
slave = task->c;
if (slave) {
/* On non-serialized requests, the IO logging has not accounted for any
* meta data send over the network: response headers and h2 frame headers. we
* counted this on the stream and need to add this now.
* This is supposed to happen before the EOR bucket triggers the
* logging of the transaction. *fingers crossed* */
if (task->request && !task->request->serialize && h2_task_logio_add_bytes_out) {
apr_off_t unaccounted = stream->out_frame_octets - stream->out_data_octets;
if (unaccounted > 0) {
h2_task_logio_add_bytes_out(slave, unaccounted);
}
}
if (m->s->keep_alive_max == 0 || slave->keepalives < m->s->keep_alive_max) {
reuse_slave = ((m->spare_slaves->nelts < (m->limit_active * 3 / 2))
&& !task->rst_error);
}
if (reuse_slave && slave->keepalive == AP_CONN_KEEPALIVE) {
h2_beam_log(task->output.beam, m->c, APLOG_DEBUG,
APLOGNO(03385) "h2_task_destroy, reuse slave");
h2_task_destroy(task);
APR_ARRAY_PUSH(m->spare_slaves, conn_rec*) = slave;
}
else {
h2_beam_log(task->output.beam, m->c, APLOG_TRACE1,
"h2_task_destroy, destroy slave");
h2_slave_destroy(slave);
}
}
}
h2_stream_destroy(stream);
return 0;
}
static void purge_streams(h2_mplx *m, int lock)
{
if (!h2_ihash_empty(m->spurge)) {
H2_MPLX_ENTER_MAYBE(m, lock);
while (!h2_ihash_iter(m->spurge, stream_destroy_iter, m)) {
/* repeat until empty */
}
H2_MPLX_LEAVE_MAYBE(m, lock);
}
}
typedef struct {
h2_mplx_stream_cb *cb;
void *ctx;
} stream_iter_ctx_t;
static int stream_iter_wrap(void *ctx, void *stream)
{
stream_iter_ctx_t *x = ctx;
return x->cb(stream, x->ctx);
}
apr_status_t h2_mplx_stream_do(h2_mplx *m, h2_mplx_stream_cb *cb, void *ctx)
{
stream_iter_ctx_t x;
H2_MPLX_ENTER(m);
x.cb = cb;
x.ctx = ctx;
h2_ihash_iter(m->streams, stream_iter_wrap, &x);
H2_MPLX_LEAVE(m);
return APR_SUCCESS;
}
static int report_stream_iter(void *ctx, void *val) {
h2_mplx *m = ctx;
h2_stream *stream = val;
h2_task *task = stream->task;
if (APLOGctrace1(m->c)) {
ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, m->c,
H2_STRM_MSG(stream, "started=%d, scheduled=%d, ready=%d, out_buffer=%ld"),
!!stream->task, stream->scheduled, h2_stream_is_ready(stream),
(long)h2_beam_get_buffered(stream->output));
}
if (task) {
ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, m->c, /* NO APLOGNO */
H2_STRM_MSG(stream, "->03198: %s %s %s"
"[started=%d/done=%d/frozen=%d]"),
task->request->method, task->request->authority,
task->request->path, task->worker_started,
task->worker_done, task->frozen);
}
else {
ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, m->c, /* NO APLOGNO */
H2_STRM_MSG(stream, "->03198: no task"));
}
return 1;
}
static int unexpected_stream_iter(void *ctx, void *val) {
h2_mplx *m = ctx;
h2_stream *stream = val;
ap_log_cerror(APLOG_MARK, APLOG_WARNING, 0, m->c, /* NO APLOGNO */
H2_STRM_MSG(stream, "unexpected, started=%d, scheduled=%d, ready=%d"),
!!stream->task, stream->scheduled, h2_stream_is_ready(stream));
return 1;
}
static int stream_cancel_iter(void *ctx, void *val) {
h2_mplx *m = ctx;
h2_stream *stream = val;
/* disabled input consumed reporting */
if (stream->input) {
h2_beam_on_consumed(stream->input, NULL, NULL, NULL);
}
/* take over event monitoring */
h2_stream_set_monitor(stream, NULL);
/* Reset, should transit to CLOSED state */
h2_stream_rst(stream, H2_ERR_NO_ERROR);
/* All connection data has been sent, simulate cleanup */
h2_stream_dispatch(stream, H2_SEV_EOS_SENT);
stream_cleanup(m, stream);
return 0;
}
void h2_mplx_release_and_join(h2_mplx *m, apr_thread_cond_t *wait)
{
apr_status_t status;
int i, wait_secs = 60;
/* How to shut down a h2 connection:
* 0. abort and tell the workers that no more tasks will come from us */
m->aborted = 1;
h2_workers_unregister(m->workers, m);
H2_MPLX_ENTER_ALWAYS(m);
/* How to shut down a h2 connection:
* 1. cancel all streams still active */
while (!h2_ihash_iter(m->streams, stream_cancel_iter, m)) {
/* until empty */
}
/* 2. terminate ngn_shed, no more streams
* should be scheduled or in the active set */
h2_ngn_shed_abort(m->ngn_shed);
ap_assert(h2_ihash_empty(m->streams));
ap_assert(h2_iq_empty(m->q));
/* 3. while workers are busy on this connection, meaning they
* are processing tasks from this connection, wait on them finishing
* in order to wake us and let us check again.
* Eventually, this has to succeed. */
m->join_wait = wait;
for (i = 0; h2_ihash_count(m->shold) > 0; ++i) {
status = apr_thread_cond_timedwait(wait, m->lock, apr_time_from_sec(wait_secs));
if (APR_STATUS_IS_TIMEUP(status)) {
/* This can happen if we have very long running requests
* that do not time out on IO. */
ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, m->c, APLOGNO(03198)
"h2_mplx(%ld): waited %d sec for %d tasks",
m->id, i*wait_secs, (int)h2_ihash_count(m->shold));
h2_ihash_iter(m->shold, report_stream_iter, m);
}
}
ap_assert(m->tasks_active == 0);
m->join_wait = NULL;
/* 4. close the h2_req_enginge shed */
h2_ngn_shed_destroy(m->ngn_shed);
m->ngn_shed = NULL;
/* 4. With all workers done, all streams should be in spurge */
if (!h2_ihash_empty(m->shold)) {
ap_log_cerror(APLOG_MARK, APLOG_WARNING, 0, m->c, APLOGNO(03516)
"h2_mplx(%ld): unexpected %d streams in hold",
m->id, (int)h2_ihash_count(m->shold));
h2_ihash_iter(m->shold, unexpected_stream_iter, m);
}
H2_MPLX_LEAVE(m);
ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, m->c,
"h2_mplx(%ld): released", m->id);
}
apr_status_t h2_mplx_stream_cleanup(h2_mplx *m, h2_stream *stream)
{
H2_MPLX_ENTER(m);
ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, m->c,
H2_STRM_MSG(stream, "cleanup"));
stream_cleanup(m, stream);
H2_MPLX_LEAVE(m);
return APR_SUCCESS;
}
h2_stream *h2_mplx_stream_get(h2_mplx *m, int id)
{
h2_stream *s = NULL;
H2_MPLX_ENTER_ALWAYS(m);
s = h2_ihash_get(m->streams, id);
H2_MPLX_LEAVE(m);
return s;
}
static void output_produced(void *ctx, h2_bucket_beam *beam, apr_off_t bytes)
{
h2_stream *stream = ctx;
h2_mplx *m = stream->session->mplx;
check_data_for(m, stream, 1);
}
static apr_status_t out_open(h2_mplx *m, int stream_id, h2_bucket_beam *beam)
{
apr_status_t status = APR_SUCCESS;
h2_stream *stream = h2_ihash_get(m->streams, stream_id);
if (!stream || !stream->task || m->aborted) {
return APR_ECONNABORTED;
}
ap_assert(stream->output == NULL);
stream->output = beam;
if (APLOGctrace2(m->c)) {
h2_beam_log(beam, m->c, APLOG_TRACE2, "out_open");
}
else {
ap_log_cerror(APLOG_MARK, APLOG_TRACE1, status, m->c,
"h2_mplx(%s): out open", stream->task->id);
}
h2_beam_on_consumed(stream->output, NULL, stream_output_consumed, stream);
h2_beam_on_produced(stream->output, output_produced, stream);
if (stream->task->output.copy_files) {
h2_beam_on_file_beam(stream->output, h2_beam_no_files, NULL);
}
/* we might see some file buckets in the output, see
* if we have enough handles reserved. */
check_data_for(m, stream, 0);
return status;
}
apr_status_t h2_mplx_out_open(h2_mplx *m, int stream_id, h2_bucket_beam *beam)
{
apr_status_t status;
H2_MPLX_ENTER(m);
if (m->aborted) {
status = APR_ECONNABORTED;
}
else {
status = out_open(m, stream_id, beam);
}
H2_MPLX_LEAVE(m);
return status;
}
static apr_status_t out_close(h2_mplx *m, h2_task *task)
{
apr_status_t status = APR_SUCCESS;
h2_stream *stream;
if (!task) {
return APR_ECONNABORTED;
}
if (task->c) {
++task->c->keepalives;
}
stream = h2_ihash_get(m->streams, task->stream_id);
if (!stream) {
return APR_ECONNABORTED;
}
ap_log_cerror(APLOG_MARK, APLOG_TRACE2, status, m->c,
"h2_mplx(%s): close", task->id);
status = h2_beam_close(task->output.beam);
h2_beam_log(task->output.beam, m->c, APLOG_TRACE2, "out_close");
output_consumed_signal(m, task);
check_data_for(m, stream, 0);
return status;
}
apr_status_t h2_mplx_out_trywait(h2_mplx *m, apr_interval_time_t timeout,
apr_thread_cond_t *iowait)
{
apr_status_t status;
H2_MPLX_ENTER(m);
if (m->aborted) {
status = APR_ECONNABORTED;
}
else if (h2_mplx_has_master_events(m)) {
status = APR_SUCCESS;
}
else {
purge_streams(m, 0);
h2_ihash_iter(m->streams, report_consumption_iter, m);
m->added_output = iowait;
status = apr_thread_cond_timedwait(m->added_output, m->lock, timeout);
if (APLOGctrace2(m->c)) {
ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, m->c,
"h2_mplx(%ld): trywait on data for %f ms)",
m->id, timeout/1000.0);
}
m->added_output = NULL;
}
H2_MPLX_LEAVE(m);
return status;
}
static void check_data_for(h2_mplx *m, h2_stream *stream, int lock)
{
if (h2_ififo_push(m->readyq, stream->id) == APR_SUCCESS) {
apr_atomic_set32(&m->event_pending, 1);
H2_MPLX_ENTER_MAYBE(m, lock);
if (m->added_output) {
apr_thread_cond_signal(m->added_output);
}
H2_MPLX_LEAVE_MAYBE(m, lock);
}
}
apr_status_t h2_mplx_reprioritize(h2_mplx *m, h2_stream_pri_cmp *cmp, void *ctx)
{
apr_status_t status;
H2_MPLX_ENTER(m);
if (m->aborted) {
status = APR_ECONNABORTED;
}
else {
h2_iq_sort(m->q, cmp, ctx);
ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, m->c,
"h2_mplx(%ld): reprioritize tasks", m->id);
status = APR_SUCCESS;
}
H2_MPLX_LEAVE(m);
return status;
}
static void register_if_needed(h2_mplx *m)
{
if (!m->aborted && !m->is_registered && !h2_iq_empty(m->q)) {
apr_status_t status = h2_workers_register(m->workers, m);
if (status == APR_SUCCESS) {
m->is_registered = 1;
}
else {
ap_log_cerror(APLOG_MARK, APLOG_ERR, status, m->c, APLOGNO(10021)
"h2_mplx(%ld): register at workers", m->id);
}
}
}
apr_status_t h2_mplx_process(h2_mplx *m, struct h2_stream *stream,
h2_stream_pri_cmp *cmp, void *ctx)
{
apr_status_t status;
H2_MPLX_ENTER(m);
if (m->aborted) {
status = APR_ECONNABORTED;
}
else {
status = APR_SUCCESS;
h2_ihash_add(m->streams, stream);
if (h2_stream_is_ready(stream)) {
/* already have a response */
check_data_for(m, stream, 0);
ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, m->c,
H2_STRM_MSG(stream, "process, add to readyq"));
}
else {
h2_iq_add(m->q, stream->id, cmp, ctx);
register_if_needed(m);
ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, m->c,
H2_STRM_MSG(stream, "process, added to q"));
}
}
H2_MPLX_LEAVE(m);
return status;
}
static h2_task *next_stream_task(h2_mplx *m)
{
h2_stream *stream;
int sid;
while (!m->aborted && (m->tasks_active < m->limit_active)
&& (sid = h2_iq_shift(m->q)) > 0) {
stream = h2_ihash_get(m->streams, sid);
if (stream) {
conn_rec *slave, **pslave;
pslave = (conn_rec **)apr_array_pop(m->spare_slaves);
if (pslave) {
slave = *pslave;
slave->aborted = 0;
}
else {
slave = h2_slave_create(m->c, stream->id, m->pool);
}
if (!stream->task) {
if (sid > m->max_stream_started) {
m->max_stream_started = sid;
}
if (stream->input) {
h2_beam_on_consumed(stream->input, stream_input_ev,
stream_input_consumed, stream);
}
stream->task = h2_task_create(slave, stream->id,
stream->request, m, stream->input,
stream->session->s->timeout,
m->stream_max_mem);
if (!stream->task) {
ap_log_cerror(APLOG_MARK, APLOG_ERR, APR_ENOMEM, slave,
H2_STRM_LOG(APLOGNO(02941), stream,
"create task"));
return NULL;
}
}
++m->tasks_active;
return stream->task;
}
}
return NULL;
}
apr_status_t h2_mplx_pop_task(h2_mplx *m, h2_task **ptask)
{
apr_status_t rv = APR_EOF;
*ptask = NULL;
ap_assert(m);
ap_assert(m->lock);
if (APR_SUCCESS != (rv = apr_thread_mutex_lock(m->lock))) {
return rv;
}
if (m->aborted) {
rv = APR_EOF;
}
else {
*ptask = next_stream_task(m);
rv = (*ptask != NULL && !h2_iq_empty(m->q))? APR_EAGAIN : APR_SUCCESS;
}
if (APR_EAGAIN != rv) {
m->is_registered = 0; /* h2_workers will discard this mplx */
}
H2_MPLX_LEAVE(m);
return rv;
}
static void task_done(h2_mplx *m, h2_task *task, h2_req_engine *ngn)
{
h2_stream *stream;
if (task->frozen) {
/* this task was handed over to an engine for processing
* and the original worker has finished. That means the
* engine may start processing now. */
h2_task_thaw(task);
apr_thread_cond_broadcast(m->task_thawed);
return;
}
ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, m->c,
"h2_mplx(%ld): task(%s) done", m->id, task->id);
out_close(m, task);
if (ngn) {
apr_off_t bytes = 0;
h2_beam_send(task->output.beam, NULL, APR_NONBLOCK_READ);
bytes += h2_beam_get_buffered(task->output.beam);
if (bytes > 0) {
/* we need to report consumed and current buffered output
* to the engine. The request will be streamed out or cancelled,
* no more data is coming from it and the engine should update
* its calculations before we destroy this information. */
h2_req_engine_out_consumed(ngn, task->c, bytes);
}
}
if (task->engine) {
if (!m->aborted && !task->c->aborted
&& !h2_req_engine_is_shutdown(task->engine)) {
ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, m->c, APLOGNO(10022)
"h2_mplx(%ld): task(%s) has not-shutdown "
"engine(%s)", m->id, task->id,
h2_req_engine_get_id(task->engine));
}
h2_ngn_shed_done_ngn(m->ngn_shed, task->engine);
}
task->worker_done = 1;
task->done_at = apr_time_now();
ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, m->c,
"h2_mplx(%s): request done, %f ms elapsed", task->id,
(task->done_at - task->started_at) / 1000.0);
if (task->started_at > m->last_idle_block) {
/* this task finished without causing an 'idle block', e.g.
* a block by flow control.
*/
if (task->done_at- m->last_limit_change >= m->limit_change_interval
&& m->limit_active < m->max_active) {
/* Well behaving stream, allow it more workers */
m->limit_active = H2MIN(m->limit_active * 2,
m->max_active);
m->last_limit_change = task->done_at;
ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, m->c,
"h2_mplx(%ld): increase worker limit to %d",
m->id, m->limit_active);
}
}
stream = h2_ihash_get(m->streams, task->stream_id);
if (stream) {
/* stream not done yet. */
if (!m->aborted && h2_ihash_get(m->sredo, stream->id)) {
/* reset and schedule again */
h2_task_redo(task);
h2_ihash_remove(m->sredo, stream->id);
h2_iq_add(m->q, stream->id, NULL, NULL);
}
else {
/* stream not cleaned up, stay around */
ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, m->c,
H2_STRM_MSG(stream, "task_done, stream open"));
if (stream->input) {
h2_beam_leave(stream->input);
}
/* more data will not arrive, resume the stream */
check_data_for(m, stream, 0);
}
}
else if ((stream = h2_ihash_get(m->shold, task->stream_id)) != NULL) {
/* stream is done, was just waiting for this. */
ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, m->c,
H2_STRM_MSG(stream, "task_done, in hold"));
if (stream->input) {
h2_beam_leave(stream->input);
}
stream_joined(m, stream);
}
else if ((stream = h2_ihash_get(m->spurge, task->stream_id)) != NULL) {
ap_log_cerror(APLOG_MARK, APLOG_WARNING, 0, m->c,
H2_STRM_LOG(APLOGNO(03517), stream, "already in spurge"));
ap_assert("stream should not be in spurge" == NULL);
}
else {
ap_log_cerror(APLOG_MARK, APLOG_WARNING, 0, m->c, APLOGNO(03518)
"h2_mplx(%s): task_done, stream not found",
task->id);
ap_assert("stream should still be available" == NULL);
}
}
void h2_mplx_task_done(h2_mplx *m, h2_task *task, h2_task **ptask)
{
H2_MPLX_ENTER_ALWAYS(m);
task_done(m, task, NULL);
--m->tasks_active;
if (m->join_wait) {
apr_thread_cond_signal(m->join_wait);
}
if (ptask) {
/* caller wants another task */
*ptask = next_stream_task(m);
}
register_if_needed(m);
H2_MPLX_LEAVE(m);
}
/*******************************************************************************
* h2_mplx DoS protection
******************************************************************************/
static int latest_repeatable_unsubmitted_iter(void *data, void *val)
{
stream_iter_ctx *ctx = data;
h2_stream *stream = val;
if (stream->task && !stream->task->worker_done
&& h2_task_can_redo(stream->task)
&& !h2_ihash_get(ctx->m->sredo, stream->id)) {
if (!h2_stream_is_ready(stream)) {
/* this task occupies a worker, the response has not been submitted
* yet, not been cancelled and it is a repeatable request
* -> it can be re-scheduled later */
if (!ctx->stream
|| (ctx->stream->task->started_at < stream->task->started_at)) {
/* we did not have one or this one was started later */
ctx->stream = stream;
}
}
}
return 1;
}
static h2_stream *get_latest_repeatable_unsubmitted_stream(h2_mplx *m)
{
stream_iter_ctx ctx;
ctx.m = m;
ctx.stream = NULL;
h2_ihash_iter(m->streams, latest_repeatable_unsubmitted_iter, &ctx);
return ctx.stream;
}
static int timed_out_busy_iter(void *data, void *val)
{
stream_iter_ctx *ctx = data;
h2_stream *stream = val;
if (stream->task && !stream->task->worker_done
&& (ctx->now - stream->task->started_at) > stream->task->timeout) {
/* timed out stream occupying a worker, found */
ctx->stream = stream;
return 0;
}
return 1;
}
static h2_stream *get_timed_out_busy_stream(h2_mplx *m)
{
stream_iter_ctx ctx;
ctx.m = m;
ctx.stream = NULL;
ctx.now = apr_time_now();
h2_ihash_iter(m->streams, timed_out_busy_iter, &ctx);
return ctx.stream;
}
static apr_status_t unschedule_slow_tasks(h2_mplx *m)
{
h2_stream *stream;
int n;
/* Try to get rid of streams that occupy workers. Look for safe requests
* that are repeatable. If none found, fail the connection.
*/
n = (m->tasks_active - m->limit_active - (int)h2_ihash_count(m->sredo));
while (n > 0 && (stream = get_latest_repeatable_unsubmitted_stream(m))) {
h2_task_rst(stream->task, H2_ERR_CANCEL);
h2_ihash_add(m->sredo, stream);
--n;
}
if ((m->tasks_active - h2_ihash_count(m->sredo)) > m->limit_active) {
h2_stream *stream = get_timed_out_busy_stream(m);
if (stream) {
/* Too many busy workers, unable to cancel enough streams
* and with a busy, timed out stream, we tell the client
* to go away... */
return APR_TIMEUP;
}
}
return APR_SUCCESS;
}
apr_status_t h2_mplx_idle(h2_mplx *m)
{
apr_status_t status = APR_SUCCESS;
apr_time_t now;
apr_size_t scount;
H2_MPLX_ENTER(m);
scount = h2_ihash_count(m->streams);
if (scount > 0) {
if (m->tasks_active) {
/* If we have streams in connection state 'IDLE', meaning
* all streams are ready to sent data out, but lack
* WINDOW_UPDATEs.
*
* This is ok, unless we have streams that still occupy
* h2 workers. As worker threads are a scarce resource,
* we need to take measures that we do not get DoSed.
*
* This is what we call an 'idle block'. Limit the amount
* of busy workers we allow for this connection until it
* well behaves.
*/
now = apr_time_now();
m->last_idle_block = now;
if (m->limit_active > 2
&& now - m->last_limit_change >= m->limit_change_interval) {
if (m->limit_active > 16) {
m->limit_active = 16;
}
else if (m->limit_active > 8) {
m->limit_active = 8;
}
else if (m->limit_active > 4) {
m->limit_active = 4;
}
else if (m->limit_active > 2) {
m->limit_active = 2;
}
m->last_limit_change = now;
ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, m->c,
"h2_mplx(%ld): decrease worker limit to %d",
m->id, m->limit_active);
}
if (m->tasks_active > m->limit_active) {
status = unschedule_slow_tasks(m);
}
}
else if (!h2_iq_empty(m->q)) {
ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, m->c,
"h2_mplx(%ld): idle, but %d streams to process",
m->id, (int)h2_iq_count(m->q));
status = APR_EAGAIN;
}
else {
/* idle, have streams, but no tasks active. what are we waiting for?
* WINDOW_UPDATEs from client? */
h2_stream *stream = NULL;
ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, m->c,
"h2_mplx(%ld): idle, no tasks ongoing, %d streams",
m->id, (int)h2_ihash_count(m->streams));
h2_ihash_shift(m->streams, (void**)&stream, 1);
if (stream) {
h2_ihash_add(m->streams, stream);
if (stream->output && !stream->out_checked) {
/* FIXME: this looks like a race between the session thinking
* it is idle and the EOF on a stream not being sent.
* Signal to caller to leave IDLE state.
*/
ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, m->c,
H2_STRM_MSG(stream, "output closed=%d, mplx idle"
", out has %ld bytes buffered"),
h2_beam_is_closed(stream->output),
(long)h2_beam_get_buffered(stream->output));
h2_ihash_add(m->streams, stream);
check_data_for(m, stream, 0);
stream->out_checked = 1;
status = APR_EAGAIN;
}
}
}
}
register_if_needed(m);
H2_MPLX_LEAVE(m);
return status;
}
/*******************************************************************************
* HTTP/2 request engines
******************************************************************************/
typedef struct {
h2_mplx * m;
h2_req_engine *ngn;
int streams_updated;
} ngn_update_ctx;
static int ngn_update_window(void *ctx, void *val)
{
ngn_update_ctx *uctx = ctx;
h2_stream *stream = val;
if (stream->task && stream->task->assigned == uctx->ngn
&& output_consumed_signal(uctx->m, stream->task)) {
++uctx->streams_updated;
}
return 1;
}
static apr_status_t ngn_out_update_windows(h2_mplx *m, h2_req_engine *ngn)
{
ngn_update_ctx ctx;
ctx.m = m;
ctx.ngn = ngn;
ctx.streams_updated = 0;
h2_ihash_iter(m->streams, ngn_update_window, &ctx);
return ctx.streams_updated? APR_SUCCESS : APR_EAGAIN;
}
apr_status_t h2_mplx_req_engine_push(const char *ngn_type,
request_rec *r,
http2_req_engine_init *einit)
{
apr_status_t status;
h2_mplx *m;
h2_task *task;
h2_stream *stream;
task = h2_ctx_rget_task(r);
if (!task) {
return APR_ECONNABORTED;
}
m = task->mplx;
H2_MPLX_ENTER(m);
stream = h2_ihash_get(m->streams, task->stream_id);
if (stream) {
status = h2_ngn_shed_push_request(m->ngn_shed, ngn_type, r, einit);
}
else {
status = APR_ECONNABORTED;
}
H2_MPLX_LEAVE(m);
return status;
}
apr_status_t h2_mplx_req_engine_pull(h2_req_engine *ngn,
apr_read_type_e block,
int capacity,
request_rec **pr)
{
h2_ngn_shed *shed = h2_ngn_shed_get_shed(ngn);
h2_mplx *m = h2_ngn_shed_get_ctx(shed);
apr_status_t status;
int want_shutdown;
H2_MPLX_ENTER(m);
want_shutdown = (block == APR_BLOCK_READ);
/* Take this opportunity to update output consummation
* for this engine */
ngn_out_update_windows(m, ngn);
if (want_shutdown && !h2_iq_empty(m->q)) {
/* For a blocking read, check first if requests are to be
* had and, if not, wait a short while before doing the
* blocking, and if unsuccessful, terminating read.
*/
status = h2_ngn_shed_pull_request(shed, ngn, capacity, 1, pr);
if (APR_STATUS_IS_EAGAIN(status)) {
ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, m->c,
"h2_mplx(%ld): start block engine pull", m->id);
apr_thread_cond_timedwait(m->task_thawed, m->lock,
apr_time_from_msec(20));
status = h2_ngn_shed_pull_request(shed, ngn, capacity, 1, pr);
}
}
else {
status = h2_ngn_shed_pull_request(shed, ngn, capacity,
want_shutdown, pr);
}
H2_MPLX_LEAVE(m);
return status;
}
void h2_mplx_req_engine_done(h2_req_engine *ngn, conn_rec *r_conn,
apr_status_t status)
{
h2_task *task = h2_ctx_cget_task(r_conn);
if (task) {
h2_mplx *m = task->mplx;
h2_stream *stream;
H2_MPLX_ENTER_ALWAYS(m);
stream = h2_ihash_get(m->streams, task->stream_id);
ngn_out_update_windows(m, ngn);
h2_ngn_shed_done_task(m->ngn_shed, ngn, task);
if (status != APR_SUCCESS && stream
&& h2_task_can_redo(task)
&& !h2_ihash_get(m->sredo, stream->id)) {
h2_ihash_add(m->sredo, stream);
}
if (task->engine) {
/* cannot report that as done until engine returns */
}
else {
task_done(m, task, ngn);
}
H2_MPLX_LEAVE(m);
}
}
/*******************************************************************************
* mplx master events dispatching
******************************************************************************/
int h2_mplx_has_master_events(h2_mplx *m)
{
return apr_atomic_read32(&m->event_pending) > 0;
}
apr_status_t h2_mplx_dispatch_master_events(h2_mplx *m,
stream_ev_callback *on_resume,
void *on_ctx)
{
h2_stream *stream;
int n, id;
ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, m->c,
"h2_mplx(%ld): dispatch events", m->id);
apr_atomic_set32(&m->event_pending, 0);
/* update input windows for streams */
h2_ihash_iter(m->streams, report_consumption_iter, m);
purge_streams(m, 1);
n = h2_ififo_count(m->readyq);
while (n > 0
&& (h2_ififo_try_pull(m->readyq, &id) == APR_SUCCESS)) {
--n;
stream = h2_ihash_get(m->streams, id);
if (stream) {
on_resume(on_ctx, stream);
}
}
return APR_SUCCESS;
}
apr_status_t h2_mplx_keep_active(h2_mplx *m, h2_stream *stream)
{
check_data_for(m, stream, 1);
return APR_SUCCESS;
}
int h2_mplx_awaits_data(h2_mplx *m)
{
int waiting = 1;
H2_MPLX_ENTER_ALWAYS(m);
if (h2_ihash_empty(m->streams)) {
waiting = 0;
}
else if (!m->tasks_active && !h2_ififo_count(m->readyq)
&& h2_iq_empty(m->q)) {
waiting = 0;
}
H2_MPLX_LEAVE(m);
return waiting;
}