Adding upstream version 2.4.56.upstream/2.4.56

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

1 files changed, 280 insertions, 0 deletions

diff --git a/include/ap_mpm.h b/include/ap_mpm.h
new file mode 100644
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--- /dev/null
+++ b/include/ap_mpm.h
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+/* 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.
+ */
+
+/**
+ * @file  ap_mpm.h
+ * @brief Apache Multi-Processing Module library
+ *
+ * @defgroup APACHE_CORE_MPM Multi-Processing Module library
+ * @ingroup  APACHE_CORE
+ * @{
+ */
+
+#ifndef AP_MPM_H
+#define AP_MPM_H
+
+#include "apr_thread_proc.h"
+#include "httpd.h"
+#include "scoreboard.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+    The MPM, "multi-processing model" provides an abstraction of the
+    interface with the OS for distributing incoming connections to
+    threads/process for processing.  http_main invokes the MPM, and
+    the MPM runs until a shutdown/restart has been indicated.
+    The MPM calls out to the apache core via the ap_process_connection
+    function when a connection arrives.
+
+    The MPM may or may not be multithreaded.  In the event that it is
+    multithreaded, at any instant it guarantees a 1:1 mapping of threads
+    ap_process_connection invocations.
+
+    Note: In the future it will be possible for ap_process_connection
+    to return to the MPM prior to finishing the entire connection; and
+    the MPM will proceed with asynchronous handling for the connection;
+    in the future the MPM may call ap_process_connection again -- but
+    does not guarantee it will occur on the same thread as the first call.
+
+    The MPM further guarantees that no asynchronous behaviour such as
+    longjmps and signals will interfere with the user code that is
+    invoked through ap_process_connection.  The MPM may reserve some
+    signals for its use (i.e. SIGUSR1), but guarantees that these signals
+    are ignored when executing outside the MPM code itself.  (This
+    allows broken user code that does not handle EINTR to function
+    properly.)
+
+    The suggested server restart and stop behaviour will be "graceful".
+    However the MPM may choose to terminate processes when the user
+    requests a non-graceful restart/stop.  When this occurs, the MPM kills
+    all threads with extreme prejudice, and destroys the pchild pool.
+    User cleanups registered in the pchild apr_pool_t will be invoked at
+    this point.  (This can pose some complications, the user cleanups
+    are asynchronous behaviour not unlike longjmp/signal... but if the
+    admin is asking for a non-graceful shutdown, how much effort should
+    we put into doing it in a nice way?)
+
+    unix/posix notes:
+    - The MPM does not set a SIGALRM handler, user code may use SIGALRM.
+        But the preferred method of handling timeouts is to use the
+        timeouts provided by the BUFF abstraction.
+    - The proper setting for SIGPIPE is SIG_IGN, if user code changes it
+        for any of their own processing, it must be restored to SIG_IGN
+        prior to executing or returning to any apache code.
+    TODO: add SIGPIPE debugging check somewhere to make sure it's SIG_IGN
+*/
+
+/**
+ * Pass control to the MPM for steady-state processing.  It is responsible
+ * for controlling the parent and child processes.  It will run until a
+ * restart/shutdown is indicated.
+ * @param pconf the configuration pool, reset before the config file is read
+ * @param plog the log pool, reset after the config file is read
+ * @param server_conf the global server config.
+ * @return DONE for shutdown OK otherwise.
+ * @ingroup hooks
+ */
+AP_DECLARE_HOOK(int, mpm, (apr_pool_t *pconf, apr_pool_t *plog, server_rec *server_conf))
+
+/**
+ * Spawn a process with privileges that another module has requested
+ * @param r The request_rec of the current request
+ * @param newproc The resulting process handle.
+ * @param progname The program to run
+ * @param args the arguments to pass to the new program.  The first
+ *                   one should be the program name.
+ * @param env The new environment apr_table_t for the new process.  This
+ *            should be a list of NULL-terminated strings.
+ * @param attr the procattr we should use to determine how to create the new
+ *         process
+ * @param p The pool to use.
+ */
+AP_DECLARE(apr_status_t) ap_os_create_privileged_process(
+    const request_rec *r,
+    apr_proc_t *newproc,
+    const char *progname,
+    const char * const *args,
+    const char * const *env,
+    apr_procattr_t *attr,
+    apr_pool_t *p);
+
+/** @defgroup mpmq MPM query
+ * @{
+ */
+
+/** @defgroup thrdfrk Subtypes/Values returned for AP_MPMQ_IS_THREADED and AP_MPMQ_IS_FORKED
+ *  @ingroup mpmq
+ *  @{
+ */
+#define AP_MPMQ_NOT_SUPPORTED      0  /**< This value specifies that an
+                                       * MPM is not capable of
+                                       * threading or forking.        */
+#define AP_MPMQ_STATIC             1  /**< This value specifies that
+                                       * an MPM is using a static
+                                       * number of threads or daemons */
+#define AP_MPMQ_DYNAMIC            2  /**< This value specifies that
+                                       * an MPM is using a dynamic
+                                       * number of threads or daemons */
+/** @} */
+
+/** @defgroup qstate Values returned for AP_MPMQ_MPM_STATE
+ *  @ingroup mpmq
+ *  @{
+ */
+#define AP_MPMQ_STARTING              0
+#define AP_MPMQ_RUNNING               1
+#define AP_MPMQ_STOPPING              2
+/** @} */
+
+/** @defgroup qcodes Query codes for ap_mpm_query()
+ *  @ingroup mpmq
+ *  @{
+ */
+/** Max # of daemons used so far */
+#define AP_MPMQ_MAX_DAEMON_USED       1
+/** MPM can do threading         */
+#define AP_MPMQ_IS_THREADED           2
+/** MPM can do forking           */
+#define AP_MPMQ_IS_FORKED             3
+/** The compiled max # daemons   */
+#define AP_MPMQ_HARD_LIMIT_DAEMONS    4
+/** The compiled max # threads   */
+#define AP_MPMQ_HARD_LIMIT_THREADS    5
+/** \# of threads/child by config */
+#define AP_MPMQ_MAX_THREADS           6
+/** Min # of spare daemons       */
+#define AP_MPMQ_MIN_SPARE_DAEMONS     7
+/** Min # of spare threads       */
+#define AP_MPMQ_MIN_SPARE_THREADS     8
+/** Max # of spare daemons       */
+#define AP_MPMQ_MAX_SPARE_DAEMONS     9
+/** Max # of spare threads       */
+#define AP_MPMQ_MAX_SPARE_THREADS    10
+/** Max # of requests per daemon */
+#define AP_MPMQ_MAX_REQUESTS_DAEMON  11
+/** Max # of daemons by config   */
+#define AP_MPMQ_MAX_DAEMONS          12
+/** starting, running, stopping  */
+#define AP_MPMQ_MPM_STATE            13
+/** MPM can process async connections  */
+#define AP_MPMQ_IS_ASYNC             14
+/** MPM generation */
+#define AP_MPMQ_GENERATION           15
+/** MPM can drive serf internally  */
+#define AP_MPMQ_HAS_SERF             16
+/** @} */
+
+/**
+ * Query a property of the current MPM.
+ * @param query_code One of AP_MPMQ_*
+ * @param result A location to place the result of the query
+ * @return APR_EGENERAL if an mpm-query hook has not been registered;
+ * APR_SUCCESS or APR_ENOTIMPL otherwise
+ * @remark The MPM doesn't register the implementing hook until the
+ * register_hooks hook is called, so modules cannot use ap_mpm_query()
+ * until after that point.
+ * @fn int ap_mpm_query(int query_code, int *result)
+ */
+AP_DECLARE(apr_status_t) ap_mpm_query(int query_code, int *result);
+
+/** @} */
+
+typedef void (ap_mpm_callback_fn_t)(void *baton);
+
+/* only added support in the Event MPM....  check for APR_ENOTIMPL */
+AP_DECLARE(apr_status_t) ap_mpm_register_timed_callback(apr_time_t t,
+                                                       ap_mpm_callback_fn_t *cbfn,
+                                                       void *baton);
+
+typedef enum mpm_child_status {
+    MPM_CHILD_STARTED,
+    MPM_CHILD_EXITED,
+    MPM_CHILD_LOST_SLOT
+} mpm_child_status;
+
+/**
+ * Allow a module to remain aware of MPM child process state changes,
+ * along with the generation and scoreboard slot of the process changing
+ * state.
+ *
+ * With some MPMs (event and worker), an active MPM child process may lose
+ * its scoreboard slot if the child process is exiting and the scoreboard
+ * slot is needed by other processes.  When this occurs, the hook will be
+ * called with the MPM_CHILD_LOST_SLOT state.
+ *
+ * @param s The main server_rec.
+ * @param pid The id of the MPM child process.
+ * @param gen The server generation of that child process.
+ * @param slot The scoreboard slot number, or -1.  It will be -1 when an
+ * MPM child process exits, and that child had previously lost its
+ * scoreboard slot.
+ * @param state One of the mpm_child_status values.  Modules should ignore
+ * unrecognized values.
+ * @ingroup hooks
+ */
+AP_DECLARE_HOOK(void,child_status,(server_rec *s, pid_t pid, ap_generation_t gen,
+                                   int slot, mpm_child_status state))
+
+/**
+ * Allow a module to be notified when the last child process of a generation
+ * exits.
+ *
+ * @param s The main server_rec.
+ * @param gen The server generation which is now completely finished.
+ * @ingroup hooks
+ */
+AP_DECLARE_HOOK(void,end_generation,(server_rec *s, ap_generation_t gen))
+
+/* Defining GPROF when compiling uses the moncontrol() function to
+ * disable gprof profiling in the parent, and enable it only for
+ * request processing in children (or in one_process mode).  It's
+ * absolutely required to get useful gprof results under linux
+ * because the profile itimers and such are disabled across a
+ * fork().  It's probably useful elsewhere as well.
+ */
+#ifdef GPROF
+extern void moncontrol(int);
+#define AP_MONCONTROL(x) moncontrol(x)
+#else
+#define AP_MONCONTROL(x)
+#endif
+
+#ifdef AP_ENABLE_EXCEPTION_HOOK
+typedef struct ap_exception_info_t {
+    int sig;
+    pid_t pid;
+} ap_exception_info_t;
+
+/**
+ * Run the fatal_exception hook for each module; this hook is run
+ * from some MPMs in the event of a child process crash, if the
+ * server was built with --enable-exception-hook and the
+ * EnableExceptionHook directive is On.
+ * @param ei information about the exception
+ * @ingroup hooks
+ */
+AP_DECLARE_HOOK(int,fatal_exception,(ap_exception_info_t *ei))
+#endif /*AP_ENABLE_EXCEPTION_HOOK*/
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+/** @} */