Adding upstream version 2.4.38.upstream/2.4.38upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 330 insertions, 0 deletions

diff --git a/modules/http2/h2_mplx.h b/modules/http2/h2_mplx.h
new file mode 100644
index 0000000..2890b98
--- /dev/null
+++ b/modules/http2/h2_mplx.h
@@ -0,0 +1,330 @@
+/* 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.
+ */
+
+#ifndef __mod_h2__h2_mplx__
+#define __mod_h2__h2_mplx__
+
+/**
+ * The stream multiplexer. It pushes buckets from the connection
+ * thread to the stream threads and vice versa. It's thread-safe
+ * to use.
+ *
+ * There is one h2_mplx instance for each h2_session, which sits on top
+ * of a particular httpd conn_rec. Input goes from the connection to
+ * the stream tasks. Output goes from the stream tasks to the connection,
+ * e.g. the client.
+ *
+ * For each stream, there can be at most "H2StreamMaxMemSize" output bytes
+ * queued in the multiplexer. If a task thread tries to write more
+ * data, it is blocked until space becomes available.
+ *
+ * Writing input is never blocked. In order to use flow control on the input,
+ * the mplx can be polled for input data consumption.
+ */
+
+struct apr_pool_t;
+struct apr_thread_mutex_t;
+struct apr_thread_cond_t;
+struct h2_bucket_beam;
+struct h2_config;
+struct h2_ihash_t;
+struct h2_task;
+struct h2_stream;
+struct h2_request;
+struct apr_thread_cond_t;
+struct h2_workers;
+struct h2_iqueue;
+struct h2_ngn_shed;
+struct h2_req_engine;
+
+#include <apr_queue.h>
+
+typedef struct h2_mplx h2_mplx;
+
+struct h2_mplx {
+    long id;
+    conn_rec *c;
+    apr_pool_t *pool;
+    server_rec *s;                  /* server for master conn */
+
+    unsigned int event_pending;
+    unsigned int aborted;
+    unsigned int is_registered;     /* is registered at h2_workers */
+
+    struct h2_ihash_t *streams;     /* all streams currently processing */
+    struct h2_ihash_t *sredo;       /* all streams that need to be re-started */
+    struct h2_ihash_t *shold;       /* all streams done with task ongoing */
+    struct h2_ihash_t *spurge;      /* all streams done, ready for destroy */
+    
+    struct h2_iqueue *q;            /* all stream ids that need to be started */
+    struct h2_ififo *readyq;        /* all stream ids ready for output */
+        
+    struct h2_ihash_t *redo_tasks;  /* all tasks that need to be redone */
+    
+    int max_streams;        /* max # of concurrent streams */
+    int max_stream_started; /* highest stream id that started processing */
+    int tasks_active;       /* # of tasks being processed from this mplx */
+    int limit_active;       /* current limit on active tasks, dynamic */
+    int max_active;         /* max, hard limit # of active tasks in a process */
+    apr_time_t last_idle_block;      /* last time, this mplx entered IDLE while
+                                      * streams were ready */
+    apr_time_t last_limit_change;    /* last time, worker limit changed */
+    apr_interval_time_t limit_change_interval;
+
+    apr_thread_mutex_t *lock;
+    struct apr_thread_cond_t *added_output;
+    struct apr_thread_cond_t *task_thawed;
+    struct apr_thread_cond_t *join_wait;
+    
+    apr_size_t stream_max_mem;
+    
+    apr_pool_t *spare_io_pool;
+    apr_array_header_t *spare_slaves; /* spare slave connections */
+    
+    struct h2_workers *workers;
+    
+    struct h2_ngn_shed *ngn_shed;
+};
+
+
+
+/*******************************************************************************
+ * Object lifecycle and information.
+ ******************************************************************************/
+
+apr_status_t h2_mplx_child_init(apr_pool_t *pool, server_rec *s);
+
+/**
+ * Create the multiplexer for the given HTTP2 session. 
+ * Implicitly has reference count 1.
+ */
+h2_mplx *h2_mplx_create(conn_rec *c, apr_pool_t *master, 
+                        const struct h2_config *conf, 
+                        struct h2_workers *workers);
+
+/**
+ * Decreases the reference counter of this mplx and waits for it
+ * to reached 0, destroy the mplx afterwards.
+ * This is to be called from the thread that created the mplx in
+ * the first place.
+ * @param m the mplx to be released and destroyed
+ * @param wait condition var to wait on for ref counter == 0
+ */ 
+void h2_mplx_release_and_join(h2_mplx *m, struct apr_thread_cond_t *wait);
+
+apr_status_t h2_mplx_pop_task(h2_mplx *m, struct h2_task **ptask);
+
+void h2_mplx_task_done(h2_mplx *m, struct h2_task *task, struct h2_task **ptask);
+
+/**
+ * Shut down the multiplexer gracefully. Will no longer schedule new streams
+ * but let the ongoing ones finish normally.
+ * @return the highest stream id being/been processed
+ */
+int h2_mplx_shutdown(h2_mplx *m);
+
+int h2_mplx_is_busy(h2_mplx *m);
+
+/*******************************************************************************
+ * IO lifetime of streams.
+ ******************************************************************************/
+
+struct h2_stream *h2_mplx_stream_get(h2_mplx *m, int id);
+
+/**
+ * Notifies mplx that a stream has been completely handled on the main
+ * connection and is ready for cleanup.
+ * 
+ * @param m the mplx itself
+ * @param stream the stream ready for cleanup
+ */
+apr_status_t h2_mplx_stream_cleanup(h2_mplx *m, struct h2_stream *stream);
+
+/**
+ * Waits on output data from any stream in this session to become available. 
+ * Returns APR_TIMEUP if no data arrived in the given time.
+ */
+apr_status_t h2_mplx_out_trywait(h2_mplx *m, apr_interval_time_t timeout,
+                                 struct apr_thread_cond_t *iowait);
+
+apr_status_t h2_mplx_keep_active(h2_mplx *m, struct h2_stream *stream);
+
+/*******************************************************************************
+ * Stream processing.
+ ******************************************************************************/
+
+/**
+ * Process a stream request.
+ * 
+ * @param m the multiplexer
+ * @param stream the identifier of the stream
+ * @param r the request to be processed
+ * @param cmp the stream priority compare function
+ * @param ctx context data for the compare function
+ */
+apr_status_t h2_mplx_process(h2_mplx *m, struct h2_stream *stream, 
+                             h2_stream_pri_cmp *cmp, void *ctx);
+
+/**
+ * Stream priorities have changed, reschedule pending requests.
+ * 
+ * @param m the multiplexer
+ * @param cmp the stream priority compare function
+ * @param ctx context data for the compare function
+ */
+apr_status_t h2_mplx_reprioritize(h2_mplx *m, h2_stream_pri_cmp *cmp, void *ctx);
+
+typedef apr_status_t stream_ev_callback(void *ctx, struct h2_stream *stream);
+
+/**
+ * Check if the multiplexer has events for the master connection pending.
+ * @return != 0 iff there are events pending
+ */
+int h2_mplx_has_master_events(h2_mplx *m);
+
+/**
+ * Dispatch events for the master connection, such as
+ ± @param m the multiplexer
+ * @param on_resume new output data has arrived for a suspended stream 
+ * @param ctx user supplied argument to invocation.
+ */
+apr_status_t h2_mplx_dispatch_master_events(h2_mplx *m, 
+                                            stream_ev_callback *on_resume, 
+                                            void *ctx);
+
+int h2_mplx_awaits_data(h2_mplx *m);
+
+typedef int h2_mplx_stream_cb(struct h2_stream *s, void *ctx);
+
+apr_status_t h2_mplx_stream_do(h2_mplx *m, h2_mplx_stream_cb *cb, void *ctx);
+
+/*******************************************************************************
+ * Output handling of streams.
+ ******************************************************************************/
+
+/**
+ * Opens the output for the given stream with the specified response.
+ */
+apr_status_t h2_mplx_out_open(h2_mplx *mplx, int stream_id,
+                              struct h2_bucket_beam *beam);
+
+/*******************************************************************************
+ * h2_mplx list Manipulation.
+ ******************************************************************************/
+
+/**
+ * The magic pointer value that indicates the head of a h2_mplx list
+ * @param  b The mplx list
+ * @return The magic pointer value
+ */
+#define H2_MPLX_LIST_SENTINEL(b)	APR_RING_SENTINEL((b), h2_mplx, link)
+
+/**
+ * Determine if the mplx list is empty
+ * @param b The list to check
+ * @return true or false
+ */
+#define H2_MPLX_LIST_EMPTY(b)	APR_RING_EMPTY((b), h2_mplx, link)
+
+/**
+ * Return the first mplx in a list
+ * @param b The list to query
+ * @return The first mplx in the list
+ */
+#define H2_MPLX_LIST_FIRST(b)	APR_RING_FIRST(b)
+
+/**
+ * Return the last mplx in a list
+ * @param b The list to query
+ * @return The last mplx int he list
+ */
+#define H2_MPLX_LIST_LAST(b)	APR_RING_LAST(b)
+
+/**
+ * Insert a single mplx at the front of a list
+ * @param b The list to add to
+ * @param e The mplx to insert
+ */
+#define H2_MPLX_LIST_INSERT_HEAD(b, e) do {				\
+h2_mplx *ap__b = (e);                                        \
+APR_RING_INSERT_HEAD((b), ap__b, h2_mplx, link);	\
+} while (0)
+
+/**
+ * Insert a single mplx at the end of a list
+ * @param b The list to add to
+ * @param e The mplx to insert
+ */
+#define H2_MPLX_LIST_INSERT_TAIL(b, e) do {				\
+h2_mplx *ap__b = (e);					\
+APR_RING_INSERT_TAIL((b), ap__b, h2_mplx, link);	\
+} while (0)
+
+/**
+ * Get the next mplx in the list
+ * @param e The current mplx
+ * @return The next mplx
+ */
+#define H2_MPLX_NEXT(e)	APR_RING_NEXT((e), link)
+/**
+ * Get the previous mplx in the list
+ * @param e The current mplx
+ * @return The previous mplx
+ */
+#define H2_MPLX_PREV(e)	APR_RING_PREV((e), link)
+
+/**
+ * Remove a mplx from its list
+ * @param e The mplx to remove
+ */
+#define H2_MPLX_REMOVE(e)	APR_RING_REMOVE((e), link)
+
+/*******************************************************************************
+ * h2_mplx DoS protection
+ ******************************************************************************/
+
+/**
+ * Master connection has entered idle mode.
+ * @param m the mplx instance of the master connection
+ * @return != SUCCESS iff connection should be terminated
+ */
+apr_status_t h2_mplx_idle(h2_mplx *m);
+
+/*******************************************************************************
+ * h2_req_engine handling
+ ******************************************************************************/
+
+typedef void h2_output_consumed(void *ctx, conn_rec *c, apr_off_t consumed);
+typedef apr_status_t h2_mplx_req_engine_init(struct h2_req_engine *engine, 
+                                             const char *id, 
+                                             const char *type,
+                                             apr_pool_t *pool, 
+                                             apr_size_t req_buffer_size,
+                                             request_rec *r,
+                                             h2_output_consumed **pconsumed,
+                                             void **pbaton);
+
+apr_status_t h2_mplx_req_engine_push(const char *ngn_type, 
+                                     request_rec *r, 
+                                     h2_mplx_req_engine_init *einit);
+apr_status_t h2_mplx_req_engine_pull(struct h2_req_engine *ngn, 
+                                     apr_read_type_e block, 
+                                     int capacity, 
+                                     request_rec **pr);
+void h2_mplx_req_engine_done(struct h2_req_engine *ngn, conn_rec *r_conn,
+                             apr_status_t status);
+
+#endif /* defined(__mod_h2__h2_mplx__) */