Bring OS/2 MPM back from the dead.

Reverses r758899.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@804678 13f79535-47bb-0310-9956-ffa450edef68

16 files changed, 1412 insertions, 10 deletions

diff --git a/LAYOUT b/LAYOUT
index 7c4dada168..a89a7e6fde 100644
--- a/LAYOUT
+++ b/LAYOUT
@@ -153,6 +153,8 @@ server/ .................
 
     event/ .................. 
 
+    mpmt_os2/ ............... 
+
     netware/ ................ 
 
     prefork/ ................ 
diff --git a/docs/conf/extra/httpd-mpm.conf.in b/docs/conf/extra/httpd-mpm.conf.in
index 052be31e1b..5717754548 100644
--- a/docs/conf/extra/httpd-mpm.conf.in
+++ b/docs/conf/extra/httpd-mpm.conf.in
@@ -18,10 +18,12 @@
 <IfModule !mpm_simple_module>
 <IfModule !mpm_winnt_module>
 <IfModule !mpm_netware_module>
+<IfModule !mpm_mpmt_os2_module>
 LockFile "@rel_logfiledir@/accept.lock"
 </IfModule>
 </IfModule>
 </IfModule>
+</IfModule>
 
 
 #
@@ -88,6 +90,19 @@ LockFile "@rel_logfiledir@/accept.lock"
     MaxMemFree             100
 </IfModule>
 
+# OS/2 MPM
+# StartServers: Number of server processes to maintain
+# MinSpareThreads: Minimum number of idle threads per process, 
+#                  to handle request spikes
+# MaxSpareThreads: Maximum number of idle threads per process
+# MaxRequestsPerChild: Maximum number of connections per server process
+<IfModule mpm_mpmt_os2_module>
+    StartServers           2
+    MinSpareThreads        5
+    MaxSpareThreads       10
+    MaxRequestsPerChild    0
+</IfModule>
+
 # WinNT MPM
 # ThreadsPerChild: constant number of worker threads in the server process
 # MaxRequestsPerChild: maximum  number of requests a server process serves
diff --git a/docs/manual/misc/perf-tuning.xml b/docs/manual/misc/perf-tuning.xml
index 52895557c9..21605c184b 100644
--- a/docs/manual/misc/perf-tuning.xml
+++ b/docs/manual/misc/perf-tuning.xml
@@ -432,7 +432,8 @@
       <a href="../mpm.html">Multi-Processing Modules</a> (MPMs).
       When building Apache, you must choose an MPM to use.  There
       are platform-specific MPMs for some platforms:
-      <module>mpm_netware</module> and <module>mpm_winnt</module>.  For
+      <module>mpm_netware</module>,
+      <module>mpmt_os2</module>, and <module>mpm_winnt</module>.  For
       general Unix-type systems, there are several MPMs from which
       to choose.  The choice of MPM can affect the speed and scalability
       of the httpd:</p>
diff --git a/docs/manual/mod/mpm_common.xml b/docs/manual/mod/mpm_common.xml
index c717dd274b..66306c13c2 100644
--- a/docs/manual/mod/mpm_common.xml
+++ b/docs/manual/mod/mpm_common.xml
@@ -214,7 +214,7 @@ of the daemon</description>
 <syntax>PidFile <var>filename</var></syntax>
 <default>PidFile logs/httpd.pid</default>
 <contextlist><context>server config</context></contextlist>
-<modulelist><module>mpm_winnt</module>
+<modulelist><module>mpm_winnt</module><module>mpmt_os2</module>
 <module>prefork</module><module>worker</module></modulelist>
 
 <usage>
@@ -253,6 +253,7 @@ listens to</description>
 <syntax>Listen [<var>IP-address</var>:]<var>portnumber</var> [<var>protocol</var>]</syntax>
 <contextlist><context>server config</context></contextlist>
 <modulelist><module>mpm_netware</module><module>mpm_winnt</module>
+<module>mpmt_os2</module>
 <module>prefork</module><module>worker</module>
 <module>event</module>
 </modulelist>
@@ -335,7 +336,7 @@ The <var>protocol</var> argument was added in 2.1.5</compatibility>
 <contextlist><context>server config</context></contextlist>
 <modulelist>
 <module>mpm_netware</module><module>mpm_winnt</module>
-<module>prefork</module>
+<module>mpmt_os2</module><module>prefork</module>
 <module>worker</module></modulelist>
 
 <usage>
@@ -456,7 +457,7 @@ will handle during its life</description>
 <default>MaxRequestsPerChild 10000</default>
 <contextlist><context>server config</context></contextlist>
 <modulelist><module>mpm_netware</module>
-<module>mpm_winnt</module>
+<module>mpm_winnt</module><module>mpmt_os2</module>
 <module>prefork</module><module>worker</module></modulelist>
 
 <usage>
@@ -491,7 +492,7 @@ will handle during its life</description>
 <syntax>MaxSpareThreads <var>number</var></syntax>
 <default>See usage for details</default>
 <contextlist><context>server config</context></contextlist>
-<modulelist><module>mpm_netware</module>
+<modulelist><module>mpm_netware</module><module>mpmt_os2</module>
 <module>worker</module></modulelist>
 
 <usage>
@@ -508,6 +509,10 @@ will handle during its life</description>
     <code>MaxSpareThreads 100</code>. Since this MPM runs a
     single-process, the spare thread count is also server-wide.</p>
 
+    <p><module>mpmt_os2</module> works
+    similar to <module>mpm_netware</module>. For
+    <module>mpmt_os2</module> the default value is <code>10</code>.</p>
+
     <note><title>Restrictions</title>
       <p>The range of the <directive>MaxSpareThreads</directive> value
       is restricted. Apache will correct the given value automatically
@@ -533,7 +538,7 @@ spikes</description>
 <syntax>MinSpareThreads <var>number</var></syntax>
 <default>See usage for details</default>
 <contextlist><context>server config</context></contextlist>
-<modulelist><module>mpm_netware</module>
+<modulelist><module>mpm_netware</module><module>mpmt_os2</module>
 <module>worker</module></modulelist>
 
 <usage>
@@ -550,6 +555,10 @@ spikes</description>
     <p><module>mpm_netware</module> uses a default of
     <code>MinSpareThreads 10</code> and, since it is a single-process
     MPM, tracks this on a server-wide bases.</p>
+
+    <p><module>mpmt_os2</module> works
+    similar to <module>mpm_netware</module>.  For
+    <module>mpmt_os2</module> the default value is <code>5</code>.</p>
 </usage>
 <seealso><directive module="mpm_common">MaxSpareThreads</directive></seealso>
 <seealso><directive module="mpm_common">StartServers</directive></seealso>
@@ -597,7 +606,7 @@ Apache</a></seealso>
 <default>ReceiveBufferSize 0</default>
 <contextlist><context>server config</context></contextlist>
 <modulelist><module>mpm_netware</module><module>mpm_winnt</module>
-<module>prefork</module>
+<module>mpmt_os2</module><module>prefork</module>
 <module>worker</module></modulelist>
 
 <usage>
@@ -616,7 +625,7 @@ Apache</a></seealso>
 <default>SendBufferSize 0</default>
 <contextlist><context>server config</context></contextlist>
 <modulelist><module>mpm_netware</module><module>mpm_winnt</module>
-<module>prefork</module>
+<module>mpmt_os2</module><module>prefork</module>
 <module>worker</module></modulelist>
 
 <usage>
@@ -692,7 +701,8 @@ Apache</a></seealso>
 <syntax>StartServers <var>number</var></syntax>
 <default>See usage for details</default>
 <contextlist><context>server config</context></contextlist>
-<modulelist><module>prefork</module><module>worker</module>
+<modulelist><module>mpmt_os2</module>
+<module>prefork</module><module>worker</module>
 </modulelist>
 
 <usage>
@@ -703,7 +713,8 @@ Apache</a></seealso>
 
     <p>The default value differs from MPM to MPM. <module>worker</module>
     defaults to <code>StartServers 3</code>; <module>prefork</module> 
-    defaults to <code>5</code>.</p>
+    defaults to <code>5</code>; <module>mpmt_os2</module> defaults to
+    <code>2</code>.</p>
 </usage>
 </directivesynopsis>
 
diff --git a/docs/manual/mod/mpmt_os2.html b/docs/manual/mod/mpmt_os2.html
new file mode 100644
index 0000000000..eb0b883e85
--- /dev/null
+++ b/docs/manual/mod/mpmt_os2.html
@@ -0,0 +1,5 @@
+# GENERATED FROM XML -- DO NOT EDIT
+
+URI: mpmt_os2.html.en
+Content-Language: en
+Content-type: text/html; charset=ISO-8859-1
diff --git a/docs/manual/mod/mpmt_os2.html.en b/docs/manual/mod/mpmt_os2.html.en
new file mode 100644
index 0000000000..7528697de1
--- /dev/null
+++ b/docs/manual/mod/mpmt_os2.html.en
@@ -0,0 +1,73 @@
+<?xml version="1.0" encoding="ISO-8859-1"?>
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
+        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
+              This file is generated from xml source: DO NOT EDIT
+        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
+      -->
+<title>mpmt_os2 - Apache HTTP Server</title>
+<link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
+<link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
+<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />
+<link href="../images/favicon.ico" rel="shortcut icon" /></head>
+<body>
+<div id="page-header">
+<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p>
+<p class="apache">Apache HTTP Server Version 2.3</p>
+<img alt="" src="../images/feather.gif" /></div>
+<div class="up"><a href="./"><img title="&lt;-" alt="&lt;-" src="../images/left.gif" /></a></div>
+<div id="path">
+<a href="http://www.apache.org/">Apache</a> &gt; <a href="http://httpd.apache.org/">HTTP Server</a> &gt; <a href="http://httpd.apache.org/docs/">Documentation</a> &gt; <a href="../">Version 2.3</a> &gt; <a href="./">Modules</a></div>
+<div id="page-content">
+<div id="preamble"><h1>Apache MPM os2</h1>
+<div class="toplang">
+<p><span>Available Languages: </span><a href="../en/mod/mpmt_os2.html" title="English">&nbsp;en&nbsp;</a></p>
+</div>
+<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Hybrid multi-process, multi-threaded MPM for OS/2</td></tr>
+<tr><th><a href="module-dict.html#Status">Status:</a></th><td>MPM</td></tr>
+<tr><th><a href="module-dict.html#ModuleIdentifier">Module Identifier:</a></th><td>mpm_mpmt_os2_module</td></tr>
+<tr><th><a href="module-dict.html#SourceFile">Source File:</a></th><td>mpmt_os2.c</td></tr></table>
+<h3>Summary</h3>
+
+    <p>The Server consists of a main, parent process and a small, static
+    number of child processes.</p>
+
+    <p>The parent process's job is to manage the child processes. This
+    involves spawning children as required to ensure there are always
+    <code class="directive"><a href="../mod/mpm_common.html#startservers">StartServers</a></code> processes
+    accepting connections.</p>
+    
+    <p>Each child process consists of a a pool of worker threads and a
+    main thread that accepts connections and passes them to the workers via
+    a work queue. The worker thread pool is dynamic, managed by a
+    maintenance thread so that the number of idle threads is kept between
+    <code class="directive"><a href="../mod/mpm_common.html#minsparethreads">MinSpareThreads</a></code> and
+    <code class="directive"><a href="../mod/mpm_common.html#maxsparethreads">MaxSpareThreads</a></code>.</p>
+</div>
+<div id="quickview"><h3 class="directives">Directives</h3>
+<ul id="toc">
+<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#group">Group</a></li>
+<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#listen">Listen</a></li>
+<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#listenbacklog">ListenBacklog</a></li>
+<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxrequestsperchild">MaxRequestsPerChild</a></li>
+<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxsparethreads">MaxSpareThreads</a></li>
+<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#minsparethreads">MinSpareThreads</a></li>
+<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#pidfile">PidFile</a></li>
+<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#receivebuffersize">ReceiveBufferSize</a></li>
+<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#sendbuffersize">SendBufferSize</a></li>
+<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#startservers">StartServers</a></li>
+<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#user">User</a></li>
+</ul>
+<h3>See also</h3>
+<ul class="seealso">
+<li><a href="../bind.html">Setting which addresses and ports Apache
+uses</a></li>
+</ul></div>
+
+</div>
+<div class="bottomlang">
+<p><span>Available Languages: </span><a href="../en/mod/mpmt_os2.html" title="English">&nbsp;en&nbsp;</a></p>
+</div><div id="footer">
+<p class="apache">Copyright 2009 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
+<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p></div>
+</body></html>
\ No newline at end of file
diff --git a/docs/manual/mod/mpmt_os2.xml b/docs/manual/mod/mpmt_os2.xml
new file mode 100644
index 0000000000..81b7fc9d62
--- /dev/null
+++ b/docs/manual/mod/mpmt_os2.xml
@@ -0,0 +1,73 @@
+<?xml version="1.0"?>
+<!DOCTYPE modulesynopsis SYSTEM "../style/modulesynopsis.dtd">
+<?xml-stylesheet type="text/xsl" href="../style/manual.en.xsl"?>
+<!-- $LastChangedRevision$ -->
+
+<!--
+ 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.
+-->
+
+<modulesynopsis metafile="mpmt_os2.xml.meta">
+
+<name>mpmt_os2</name>
+<description>Hybrid multi-process, multi-threaded MPM for OS/2</description>
+<status>MPM</status>
+<sourcefile>mpmt_os2.c</sourcefile>
+<identifier>mpm_mpmt_os2_module</identifier>
+
+<summary>
+    <p>The Server consists of a main, parent process and a small, static
+    number of child processes.</p>
+
+    <p>The parent process's job is to manage the child processes. This
+    involves spawning children as required to ensure there are always
+    <directive module="mpm_common">StartServers</directive> processes
+    accepting connections.</p>
+    
+    <p>Each child process consists of a a pool of worker threads and a
+    main thread that accepts connections and passes them to the workers via
+    a work queue. The worker thread pool is dynamic, managed by a
+    maintenance thread so that the number of idle threads is kept between
+    <directive module="mpm_common">MinSpareThreads</directive> and
+    <directive module="mpm_common">MaxSpareThreads</directive>.</p>
+</summary>
+<seealso><a href="../bind.html">Setting which addresses and ports Apache
+uses</a></seealso>
+
+<directivesynopsis location="mpm_common"><name>User</name>
+</directivesynopsis>
+<directivesynopsis location="mpm_common"><name>Group</name>
+</directivesynopsis>
+<directivesynopsis location="mpm_common"><name>Listen</name>
+</directivesynopsis>
+<directivesynopsis location="mpm_common"><name>ListenBacklog</name>
+</directivesynopsis>
+<directivesynopsis location="mpm_common"><name>ReceiveBufferSize</name>
+</directivesynopsis>
+<directivesynopsis location="mpm_common"><name>SendBufferSize</name>
+</directivesynopsis>
+<directivesynopsis location="mpm_common"><name>MaxRequestsPerChild</name>
+</directivesynopsis>
+<directivesynopsis location="mpm_common"><name>MaxSpareThreads</name>
+</directivesynopsis>
+<directivesynopsis location="mpm_common"><name>MinSpareThreads</name>
+</directivesynopsis>
+<directivesynopsis location="mpm_common"><name>PidFile</name>
+</directivesynopsis>
+<directivesynopsis location="mpm_common"><name>StartServers</name>
+</directivesynopsis>
+
+</modulesynopsis>
diff --git a/docs/manual/mod/mpmt_os2.xml.meta b/docs/manual/mod/mpmt_os2.xml.meta
new file mode 100644
index 0000000000..ef1089b78b
--- /dev/null
+++ b/docs/manual/mod/mpmt_os2.xml.meta
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!-- GENERATED FROM XML: DO NOT EDIT -->
+
+<metafile>
+  <basename>mpmt_os2</basename>
+  <path>/mod/</path>
+  <relpath>..</relpath>
+
+  <variants>
+    <variant>en</variant>
+  </variants>
+</metafile>
diff --git a/docs/manual/mpm.xml b/docs/manual/mpm.xml
index a4b5cec50d..1043894c74 100644
--- a/docs/manual/mpm.xml
+++ b/docs/manual/mpm.xml
@@ -102,6 +102,7 @@ choice at compile-time.</p>
 <table>
 <columnspec><column width=".2"/><column width=".2"/></columnspec>
 <tr><td>Netware</td><td><module>mpm_netware</module></td></tr>
+<tr><td>OS/2</td><td><module>mpmt_os2</module></td></tr>
 <tr><td>Unix</td><td><module>prefork</module></td></tr>
 <tr><td>Windows</td><td><module>mpm_winnt</module></td></tr>
 </table>
diff --git a/server/mpm/MPM.NAMING b/server/mpm/MPM.NAMING
index ad6d49947c..1cc0c7c4ff 100644
--- a/server/mpm/MPM.NAMING
+++ b/server/mpm/MPM.NAMING
@@ -5,6 +5,9 @@ The following MPMs currently exist:
                   depending on configuration and operating systems.  Should
                   be able to run on all modern operating systems.
   prefork ....... Multi  Process Model with Preforking (Apache 1.3)
+  mpmt_os2 ...... Multi Process Model with Threading on OS/2
+                  Constant number of processes, variable number of threads.
+                  One acceptor thread per process, multiple workers threads.
   winnt ......... Single Process Model with Threading on Windows NT
   worker ........ Multi Process model with threads.  One acceptor thread,
                   multiple worker threads.
diff --git a/server/mpm/mpmt_os2/Makefile.in b/server/mpm/mpmt_os2/Makefile.in
new file mode 100644
index 0000000000..38e598edf3
--- /dev/null
+++ b/server/mpm/mpmt_os2/Makefile.in
@@ -0,0 +1,5 @@
+
+LTLIBRARY_NAME    = libmpmt_os2.la
+LTLIBRARY_SOURCES = mpmt_os2.c mpmt_os2_child.c
+
+include $(top_srcdir)/build/ltlib.mk
diff --git a/server/mpm/mpmt_os2/config5.m4 b/server/mpm/mpmt_os2/config5.m4
new file mode 100644
index 0000000000..b27c296d2a
--- /dev/null
+++ b/server/mpm/mpmt_os2/config5.m4
@@ -0,0 +1,5 @@
+if test "$MPM_NAME" = "mpmt_os2" ; then
+    AC_CACHE_SAVE
+    APACHE_FAST_OUTPUT(server/mpm/$MPM_NAME/Makefile)
+    APR_ADDTO(CFLAGS,-Zmt)
+fi
diff --git a/server/mpm/mpmt_os2/mpm.h b/server/mpm/mpmt_os2/mpm.h
new file mode 100644
index 0000000000..f8bbc30eb3
--- /dev/null
+++ b/server/mpm/mpmt_os2/mpm.h
@@ -0,0 +1,43 @@
+/* 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  mpmt_os2/mpm.h
+ * @brief MPM for os2
+ *
+ * @defgroup APACHE_MPM_OS2 os2 MPM
+ * @ingroup  APACHE_OS_OS2 APACHE_MPM
+ */
+ 
+#ifndef APACHE_MPM_MPMT_OS2_H
+#define APACHE_MPM_MPMT_OS2_H
+
+#define MPMT_OS2_MPM
+
+#include "httpd.h"
+#include "mpm_default.h"
+#include "scoreboard.h"
+
+#define MPM_NAME "MPMT_OS2"
+
+extern server_rec *ap_server_conf;
+#define AP_MPM_WANT_SET_PIDFILE
+#define AP_MPM_WANT_SET_MAX_REQUESTS
+#define AP_MPM_DISABLE_NAGLE_ACCEPTED_SOCK
+#define AP_MPM_WANT_SET_MAX_MEM_FREE
+
+#endif /* APACHE_MPM_MPMT_OS2_H */
+/** @} */
diff --git a/server/mpm/mpmt_os2/mpm_default.h b/server/mpm/mpmt_os2/mpm_default.h
new file mode 100644
index 0000000000..2a21cd5088
--- /dev/null
+++ b/server/mpm/mpmt_os2/mpm_default.h
@@ -0,0 +1,68 @@
+/* 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  mpmt_os2/mpm_default.h
+ * @brief os2 MPM defaults
+ * 
+ * @addtogroup APACHE_MPM_OS2
+ * @{
+ */
+
+#ifndef APACHE_MPM_DEFAULT_H
+#define APACHE_MPM_DEFAULT_H
+
+/* Number of servers processes to spawn off by default
+ */
+#ifndef DEFAULT_START_DAEMON
+#define DEFAULT_START_DAEMON 2
+#endif
+
+/* Maximum number of *free* server threads --- more than this, and
+ * they will die off.
+ */
+
+#ifndef DEFAULT_MAX_SPARE_THREAD
+#define DEFAULT_MAX_SPARE_THREAD 10
+#endif
+
+/* Minimum --- fewer than this, and more will be created */
+
+#ifndef DEFAULT_MIN_SPARE_THREAD
+#define DEFAULT_MIN_SPARE_THREAD 5
+#endif
+
+/* Where the main/parent process's pid is logged */
+#ifndef DEFAULT_PIDLOG
+#define DEFAULT_PIDLOG DEFAULT_REL_RUNTIMEDIR "/httpd.pid"
+#endif
+
+/*
+ * Interval, in microseconds, between scoreboard maintenance.
+ */
+#ifndef SCOREBOARD_MAINTENANCE_INTERVAL
+#define SCOREBOARD_MAINTENANCE_INTERVAL 1000000
+#endif
+
+/* Number of requests to try to handle in a single process.  If <= 0,
+ * the children don't die off.
+ */
+#ifndef DEFAULT_MAX_REQUESTS_PER_CHILD
+#define DEFAULT_MAX_REQUESTS_PER_CHILD 10000
+#endif
+
+#endif /* AP_MPM_DEFAULT_H */
+/** @} */
diff --git a/server/mpm/mpmt_os2/mpmt_os2.c b/server/mpm/mpmt_os2/mpmt_os2.c
new file mode 100644
index 0000000000..32b8e1e79d
--- /dev/null
+++ b/server/mpm/mpmt_os2/mpmt_os2.c
@@ -0,0 +1,606 @@
+/* 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.
+ */
+
+/* Multi-process, multi-threaded MPM for OS/2
+ *
+ * Server consists of
+ * - a main, parent process
+ * - a small, static number of child processes
+ *
+ * The parent process's job is to manage the child processes. This involves
+ * spawning children as required to ensure there are always ap_daemons_to_start
+ * processes accepting connections.
+ *
+ * Each child process consists of a a pool of worker threads and a
+ * main thread that accepts connections & passes them to the workers via
+ * a work queue. The worker thread pool is dynamic, managed by a maintanence
+ * thread so that the number of idle threads is kept between
+ * min_spare_threads & max_spare_threads.
+ *
+ */
+
+/*
+ Todo list
+ - Enforce MaxClients somehow
+*/
+#define INCL_NOPMAPI
+#define INCL_DOS
+#define INCL_DOSERRORS
+
+#include "ap_config.h"
+#include "httpd.h"
+#include "mpm_default.h"
+#include "http_main.h"
+#include "http_log.h"
+#include "http_config.h"
+#include "http_core.h"  /* for get_remote_host */
+#include "http_connection.h"
+#include "mpm.h"
+#include "ap_mpm.h"
+#include "ap_listen.h"
+#include "apr_portable.h"
+#include "mpm_common.h"
+#include "apr_strings.h"
+#include <os2.h>
+#include <process.h>
+
+/* We don't need many processes,
+ * they're only for redundancy in the event of a crash
+ */
+#define HARD_SERVER_LIMIT 10
+
+/* Limit on the total number of threads per process
+ */
+#ifndef HARD_THREAD_LIMIT
+#define HARD_THREAD_LIMIT 256
+#endif
+
+server_rec *ap_server_conf;
+static apr_pool_t *pconf = NULL;  /* Pool for config stuff */
+static const char *ap_pid_fname=NULL;
+
+/* Config globals */
+static int one_process = 0;
+static int ap_daemons_to_start = 0;
+static int ap_thread_limit = 0;
+static int ap_max_requests_per_child = 0;
+int ap_min_spare_threads = 0;
+int ap_max_spare_threads = 0;
+
+/* Keep track of a few interesting statistics */
+int ap_max_daemons_limit = -1;
+
+/* volatile just in case */
+static int volatile shutdown_pending;
+static int volatile restart_pending;
+static int volatile is_graceful = 0;
+ap_generation_t volatile ap_my_generation=0; /* Used by the scoreboard */
+static int is_parent_process=TRUE;
+HMTX ap_mpm_accept_mutex = 0;
+
+/* An array of these is stored in a shared memory area for passing
+ * sockets from the parent to child processes
+ */
+typedef struct {
+    struct sockaddr_in name;
+    apr_os_sock_t listen_fd;
+} listen_socket_t;
+
+typedef struct {
+    HMTX accept_mutex;
+    listen_socket_t listeners[1];
+} parent_info_t;
+
+static char master_main();
+static void spawn_child(int slot);
+void ap_mpm_child_main(apr_pool_t *pconf);
+static void set_signals();
+
+
+int ap_mpm_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s )
+{
+    char *listener_shm_name;
+    parent_info_t *parent_info;
+    ULONG rc;
+    pconf = _pconf;
+    ap_server_conf = s;
+    restart_pending = 0;
+
+    DosSetMaxFH(ap_thread_limit * 2);
+    listener_shm_name = apr_psprintf(pconf, "/sharemem/httpd/parent_info.%d", getppid());
+    rc = DosGetNamedSharedMem((PPVOID)&parent_info, listener_shm_name, PAG_READ);
+    is_parent_process = rc != 0;
+    ap_scoreboard_fname = apr_psprintf(pconf, "/sharemem/httpd/scoreboard.%d", is_parent_process ? getpid() : getppid());
+
+    if (rc == 0) {
+        /* Child process */
+        ap_listen_rec *lr;
+        int num_listeners = 0;
+
+        ap_mpm_accept_mutex = parent_info->accept_mutex;
+
+        /* Set up a default listener if necessary */
+        if (ap_listeners == NULL) {
+            ap_listen_rec *lr = apr_pcalloc(s->process->pool, sizeof(ap_listen_rec));
+            ap_listeners = lr;
+            apr_sockaddr_info_get(&lr->bind_addr, "0.0.0.0", APR_UNSPEC,
+                                  DEFAULT_HTTP_PORT, 0, s->process->pool);
+            apr_socket_create(&lr->sd, lr->bind_addr->family,
+                              SOCK_STREAM, 0, s->process->pool);
+        }
+
+        for (lr = ap_listeners; lr; lr = lr->next) {
+            apr_sockaddr_t *sa;
+            apr_os_sock_put(&lr->sd, &parent_info->listeners[num_listeners].listen_fd, pconf);
+            apr_socket_addr_get(&sa, APR_LOCAL, lr->sd);
+            num_listeners++;
+        }
+
+        DosFreeMem(parent_info);
+
+        /* Do the work */
+        ap_mpm_child_main(pconf);
+
+        /* Outta here */
+        return 1;
+    }
+    else {
+        /* Parent process */
+        char restart;
+        is_parent_process = TRUE;
+
+        if (ap_setup_listeners(ap_server_conf) < 1) {
+            ap_log_error(APLOG_MARK, APLOG_ALERT, 0, s,
+                         "no listening sockets available, shutting down");
+            return 1;
+        }
+
+        ap_log_pid(pconf, ap_pid_fname);
+
+        restart = master_main();
+        ++ap_my_generation;
+        ap_scoreboard_image->global->running_generation = ap_my_generation;
+
+        if (!restart) {
+            const char *pidfile = ap_server_root_relative(pconf, ap_pid_fname);
+
+            if (pidfile != NULL && remove(pidfile) == 0) {
+                ap_log_error(APLOG_MARK, APLOG_INFO, APR_SUCCESS,
+                             ap_server_conf, "removed PID file %s (pid=%d)",
+                             pidfile, getpid());
+            }
+
+            ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,
+                         "caught SIGTERM, shutting down");
+            return 1;
+        }
+    }  /* Parent process */
+
+    return 0; /* Restart */
+}
+
+
+
+/* Main processing of the parent process
+ * returns TRUE if restarting
+ */
+static char master_main()
+{
+    server_rec *s = ap_server_conf;
+    ap_listen_rec *lr;
+    parent_info_t *parent_info;
+    char *listener_shm_name;
+    int listener_num, num_listeners, slot;
+    ULONG rc;
+
+    printf("%s \n", ap_get_server_description());
+    set_signals();
+
+    if (ap_setup_listeners(ap_server_conf) < 1) {
+        ap_log_error(APLOG_MARK, APLOG_ALERT, 0, s,
+                     "no listening sockets available, shutting down");
+        return FALSE;
+    }
+
+    /* Allocate a shared memory block for the array of listeners */
+    for (num_listeners = 0, lr = ap_listeners; lr; lr = lr->next) {
+        num_listeners++;
+    }
+
+    listener_shm_name = apr_psprintf(pconf, "/sharemem/httpd/parent_info.%d", getpid());
+    rc = DosAllocSharedMem((PPVOID)&parent_info, listener_shm_name,
+                           sizeof(parent_info_t) + num_listeners * sizeof(listen_socket_t),
+                           PAG_READ|PAG_WRITE|PAG_COMMIT);
+
+    if (rc) {
+        ap_log_error(APLOG_MARK, APLOG_ALERT, APR_FROM_OS_ERROR(rc), s,
+                     "failure allocating shared memory, shutting down");
+        return FALSE;
+    }
+
+    /* Store the listener sockets in the shared memory area for our children to see */
+    for (listener_num = 0, lr = ap_listeners; lr; lr = lr->next, listener_num++) {
+        apr_os_sock_get(&parent_info->listeners[listener_num].listen_fd, lr->sd);
+    }
+
+    /* Create mutex to prevent multiple child processes from detecting
+     * a connection with apr_poll()
+     */
+
+    rc = DosCreateMutexSem(NULL, &ap_mpm_accept_mutex, DC_SEM_SHARED, FALSE);
+
+    if (rc) {
+        ap_log_error(APLOG_MARK, APLOG_ALERT, APR_FROM_OS_ERROR(rc), s,
+                     "failure creating accept mutex, shutting down");
+        return FALSE;
+    }
+
+    parent_info->accept_mutex = ap_mpm_accept_mutex;
+
+    /* Allocate shared memory for scoreboard */
+    if (ap_scoreboard_image == NULL) {
+        void *sb_mem;
+        rc = DosAllocSharedMem(&sb_mem, ap_scoreboard_fname,
+                               ap_calc_scoreboard_size(),
+                               PAG_COMMIT|PAG_READ|PAG_WRITE);
+
+        if (rc) {
+            ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
+                         "unable to allocate shared memory for scoreboard , exiting");
+            return FALSE;
+        }
+
+        ap_init_scoreboard(sb_mem);
+    }
+
+    ap_scoreboard_image->global->restart_time = apr_time_now();
+    ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,
+                "%s configured -- resuming normal operations",
+                ap_get_server_description());
+    ap_log_error(APLOG_MARK, APLOG_INFO, 0, ap_server_conf,
+                "Server built: %s", ap_get_server_built());
+#ifdef AP_MPM_WANT_SET_ACCEPT_LOCK_MECH
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf,
+                "AcceptMutex: %s (default: %s)",
+                apr_proc_mutex_name(accept_mutex),
+                apr_proc_mutex_defname());
+#endif
+    if (one_process) {
+        ap_scoreboard_image->parent[0].pid = getpid();
+        ap_mpm_child_main(pconf);
+        return FALSE;
+    }
+
+    while (!restart_pending && !shutdown_pending) {
+        RESULTCODES proc_rc;
+        PID child_pid;
+        int active_children = 0;
+
+        /* Count number of active children */
+        for (slot=0; slot < HARD_SERVER_LIMIT; slot++) {
+            active_children += ap_scoreboard_image->parent[slot].pid != 0 &&
+                !ap_scoreboard_image->parent[slot].quiescing;
+        }
+
+        /* Spawn children if needed */
+        for (slot=0; slot < HARD_SERVER_LIMIT && active_children < ap_daemons_to_start; slot++) {
+            if (ap_scoreboard_image->parent[slot].pid == 0) {
+                spawn_child(slot);
+                active_children++;
+            }
+        }
+
+        rc = DosWaitChild(DCWA_PROCESSTREE, DCWW_NOWAIT, &proc_rc, &child_pid, 0);
+
+        if (rc == 0) {
+            /* A child has terminated, remove its scoreboard entry & terminate if necessary */
+            for (slot=0; ap_scoreboard_image->parent[slot].pid != child_pid && slot < HARD_SERVER_LIMIT; slot++);
+
+            if (slot < HARD_SERVER_LIMIT) {
+                ap_scoreboard_image->parent[slot].pid = 0;
+                ap_scoreboard_image->parent[slot].quiescing = 0;
+
+                if (proc_rc.codeTerminate == TC_EXIT) {
+                    /* Child terminated normally, check its exit code and
+                     * terminate server if child indicates a fatal error
+                     */
+                    if (proc_rc.codeResult == APEXIT_CHILDFATAL)
+                        break;
+                }
+            }
+        } else if (rc == ERROR_CHILD_NOT_COMPLETE) {
+            /* No child exited, lets sleep for a while.... */
+            apr_sleep(SCOREBOARD_MAINTENANCE_INTERVAL);
+        }
+    }
+
+    /* Signal children to shut down, either gracefully or immediately */
+    for (slot=0; slot<HARD_SERVER_LIMIT; slot++) {
+      kill(ap_scoreboard_image->parent[slot].pid, is_graceful ? SIGHUP : SIGTERM);
+    }
+
+    DosFreeMem(parent_info);
+    return restart_pending;
+}
+
+
+
+static void spawn_child(int slot)
+{
+    PPIB ppib;
+    PTIB ptib;
+    char fail_module[100];
+    char progname[CCHMAXPATH];
+    RESULTCODES proc_rc;
+    ULONG rc;
+
+    ap_scoreboard_image->parent[slot].generation = ap_my_generation;
+    DosGetInfoBlocks(&ptib, &ppib);
+    DosQueryModuleName(ppib->pib_hmte, sizeof(progname), progname);
+    rc = DosExecPgm(fail_module, sizeof(fail_module), EXEC_ASYNCRESULT,
+                    ppib->pib_pchcmd, NULL, &proc_rc, progname);
+
+    if (rc) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
+                     "error spawning child, slot %d", slot);
+    }
+
+    if (ap_max_daemons_limit < slot) {
+        ap_max_daemons_limit = slot;
+    }
+
+    ap_scoreboard_image->parent[slot].pid = proc_rc.codeTerminate;
+}
+
+
+
+/* Signal handling routines */
+
+static void sig_term(int sig)
+{
+    shutdown_pending = 1;
+    signal(SIGTERM, SIG_DFL);
+}
+
+
+
+static void sig_restart(int sig)
+{
+    if (sig == SIGUSR1) {
+        is_graceful = 1;
+    }
+
+    restart_pending = 1;
+}
+
+
+
+static void set_signals()
+{
+    struct sigaction sa;
+
+    sigemptyset(&sa.sa_mask);
+    sa.sa_flags = 0;
+    sa.sa_handler = sig_term;
+
+    if (sigaction(SIGTERM, &sa, NULL) < 0)
+        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGTERM)");
+
+    if (sigaction(SIGINT, &sa, NULL) < 0)
+        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGINT)");
+
+    sa.sa_handler = sig_restart;
+
+    if (sigaction(SIGHUP, &sa, NULL) < 0)
+        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGHUP)");
+    if (sigaction(SIGUSR1, &sa, NULL) < 0)
+        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGUSR1)");
+}
+
+
+
+/* Enquiry functions used get MPM status info */
+
+AP_DECLARE(apr_status_t) ap_mpm_query(int query_code, int *result)
+{
+    switch (query_code) {
+        case AP_MPMQ_MAX_DAEMON_USED:
+            *result = ap_max_daemons_limit;
+            return APR_SUCCESS;
+        case AP_MPMQ_IS_THREADED:
+            *result = AP_MPMQ_DYNAMIC;
+            return APR_SUCCESS;
+        case AP_MPMQ_IS_FORKED:
+            *result = AP_MPMQ_NOT_SUPPORTED;
+            return APR_SUCCESS;
+        case AP_MPMQ_HARD_LIMIT_DAEMONS:
+            *result = HARD_SERVER_LIMIT;
+            return APR_SUCCESS;
+        case AP_MPMQ_HARD_LIMIT_THREADS:
+            *result = HARD_THREAD_LIMIT;
+            return APR_SUCCESS;
+        case AP_MPMQ_MIN_SPARE_DAEMONS:
+            *result = 0;
+            return APR_SUCCESS;
+        case AP_MPMQ_MAX_SPARE_DAEMONS:
+            *result = 0;
+            return APR_SUCCESS;
+        case AP_MPMQ_MAX_REQUESTS_DAEMON:
+            *result = ap_max_requests_per_child;
+            return APR_SUCCESS;
+    }
+    return APR_ENOTIMPL;
+}
+
+
+
+
+/* Configuration handling stuff */
+
+static int mpmt_os2_pre_config(apr_pool_t *pconf, apr_pool_t *plog, apr_pool_t *ptemp)
+{
+    one_process = ap_exists_config_define("ONE_PROCESS") ||
+                  ap_exists_config_define("DEBUG");
+    is_graceful = 0;
+    ap_listen_pre_config();
+    ap_daemons_to_start = DEFAULT_START_DAEMON;
+    ap_thread_limit = HARD_THREAD_LIMIT;
+    ap_pid_fname = DEFAULT_PIDLOG;
+    ap_max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD;
+    ap_extended_status = 0;
+    ap_min_spare_threads = DEFAULT_MIN_SPARE_THREAD;
+    ap_max_spare_threads = DEFAULT_MAX_SPARE_THREAD;
+#ifdef AP_MPM_WANT_SET_MAX_MEM_FREE
+        ap_max_mem_free = APR_ALLOCATOR_MAX_FREE_UNLIMITED;
+#endif
+
+    return OK;
+}
+
+
+
+static int mpmt_os2_check_config(apr_pool_t *p, apr_pool_t *plog,
+                                 apr_pool_t *ptemp, server_rec *s)
+{
+    static int restart_num = 0;
+    int startup = 0;
+
+    /* we want this only the first time around */
+    if (restart_num++ == 0) {
+        startup = 1;
+    }
+
+    if (ap_daemons_to_start < 0) {
+        if (startup) {
+            ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL,
+                         "WARNING: StartServers of %d not allowed, "
+                         "increasing to 1.", ap_daemons_to_start);
+        } else {
+            ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s,
+                         "StartServers of %d not allowed, increasing to 1",
+                         ap_daemons_to_start);
+        }
+        ap_daemons_to_start = 1;
+    }
+
+    if (ap_min_spare_threads < 1) {
+        if (startup) {
+            ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL,
+                         "WARNING: MinSpareThreads of %d not allowed, "
+                         "increasing to 1", ap_min_spare_threads);
+            ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL,
+                         " to avoid almost certain server failure.");
+            ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_STARTUP, 0, NULL,
+                         " Please read the documentation.");
+        } else {
+            ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s,
+                         "MinSpareThreads of %d not allowed, increasing to 1",
+                         ap_min_spare_threads);
+        }
+        ap_min_spare_threads = 1;
+    }
+
+    return OK;
+}
+
+
+
+static void mpmt_os2_hooks(apr_pool_t *p)
+{
+    ap_hook_pre_config(mpmt_os2_pre_config, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_check_config(mpmt_os2_check_config, NULL, NULL, APR_HOOK_MIDDLE);
+}
+
+
+
+static const char *set_daemons_to_start(cmd_parms *cmd, void *dummy, const char *arg)
+{
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+    if (err != NULL) {
+        return err;
+    }
+
+    ap_daemons_to_start = atoi(arg);
+    return NULL;
+}
+
+
+
+static const char *set_min_spare_threads(cmd_parms *cmd, void *dummy,
+                                         const char *arg)
+{
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+    if (err != NULL) {
+        return err;
+    }
+
+    ap_min_spare_threads = atoi(arg);
+    return NULL;
+}
+
+
+
+static const char *set_max_spare_threads(cmd_parms *cmd, void *dummy,
+                                         const char *arg)
+{
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+    if (err != NULL) {
+        return err;
+    }
+
+    ap_max_spare_threads = atoi(arg);
+    return NULL;
+}
+
+
+
+static const char *ignore_cmd(cmd_parms *cmd, void *dummy, const char *arg)
+{
+    return NULL;
+}
+
+
+
+static const command_rec mpmt_os2_cmds[] = {
+LISTEN_COMMANDS,
+AP_INIT_TAKE1( "StartServers", set_daemons_to_start, NULL, RSRC_CONF,
+  "Number of child processes launched at server startup" ),
+AP_INIT_TAKE1("MinSpareThreads", set_min_spare_threads, NULL, RSRC_CONF,
+  "Minimum number of idle children, to handle request spikes"),
+AP_INIT_TAKE1("MaxSpareThreads", set_max_spare_threads, NULL, RSRC_CONF,
+  "Maximum number of idle children"),
+AP_INIT_TAKE1("User", ignore_cmd, NULL, RSRC_CONF,
+  "Not applicable on this platform"),
+AP_INIT_TAKE1("Group", ignore_cmd, NULL, RSRC_CONF,
+  "Not applicable on this platform"),
+AP_INIT_TAKE1("ScoreBoardFile", ignore_cmd, NULL, RSRC_CONF, \
+  "Not applicable on this platform"),
+{ NULL }
+};
+
+module AP_MODULE_DECLARE_DATA mpm_mpmt_os2_module = {
+    MPM20_MODULE_STUFF,
+    NULL,            /* hook to run before apache parses args */
+    NULL,            /* create per-directory config structure */
+    NULL,            /* merge per-directory config structures */
+    NULL,            /* create per-server config structure */
+    NULL,            /* merge per-server config structures */
+    mpmt_os2_cmds,   /* command apr_table_t */
+    mpmt_os2_hooks,  /* register_hooks */
+};
diff --git a/server/mpm/mpmt_os2/mpmt_os2_child.c b/server/mpm/mpmt_os2/mpmt_os2_child.c
new file mode 100644
index 0000000000..51c85644ce
--- /dev/null
+++ b/server/mpm/mpmt_os2/mpmt_os2_child.c
@@ -0,0 +1,479 @@
+/* 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.
+ */
+
+#define INCL_NOPMAPI
+#define INCL_DOS
+#define INCL_DOSERRORS
+
+#include "ap_config.h"
+#include "httpd.h"
+#include "mpm_default.h"
+#include "http_main.h"
+#include "http_log.h"
+#include "http_config.h"
+#include "http_core.h"  /* for get_remote_host */
+#include "http_connection.h"
+#include "mpm.h"
+#include "ap_mpm.h"
+#include "ap_listen.h"
+#include "apr_portable.h"
+#include "apr_poll.h"
+#include "mpm_common.h"
+#include "apr_strings.h"
+#include <os2.h>
+#include <process.h>
+
+/* XXXXXX move these to header file private to this MPM */
+
+/* We don't need many processes,
+ * they're only for redundancy in the event of a crash
+ */
+#define HARD_SERVER_LIMIT 10
+
+/* Limit on the total number of threads per process
+ */
+#ifndef HARD_THREAD_LIMIT
+#define HARD_THREAD_LIMIT 256
+#endif
+
+#define ID_FROM_CHILD_THREAD(c, t)    ((c * HARD_THREAD_LIMIT) + t)
+
+typedef struct {
+    apr_pool_t *pconn;
+    apr_socket_t *conn_sd;
+} worker_args_t;
+
+#define WORKTYPE_CONN 0
+#define WORKTYPE_EXIT 1
+
+static apr_pool_t *pchild = NULL;
+static int child_slot;
+static int shutdown_pending = 0;
+extern int ap_my_generation;
+static int volatile is_graceful = 1;
+HEV shutdown_event; /* signaled when this child is shutting down */
+
+/* grab some MPM globals */
+extern int ap_min_spare_threads;
+extern int ap_max_spare_threads;
+extern HMTX ap_mpm_accept_mutex;
+
+static void worker_main(void *vpArg);
+static void clean_child_exit(int code);
+static void set_signals();
+static void server_maintenance(void *vpArg);
+
+
+static void clean_child_exit(int code)
+{
+    if (pchild) {
+        apr_pool_destroy(pchild);
+    }
+
+    exit(code);
+}
+
+
+
+void ap_mpm_child_main(apr_pool_t *pconf)
+{
+    ap_listen_rec *lr = NULL;
+    int requests_this_child = 0;
+    int rv = 0;
+    unsigned long ulTimes;
+    int my_pid = getpid();
+    ULONG rc, c;
+    HQUEUE workq;
+    apr_pollset_t *pollset;
+    int num_listeners;
+    TID server_maint_tid;
+    void *sb_mem;
+
+    /* Stop Ctrl-C/Ctrl-Break signals going to child processes */
+    DosSetSignalExceptionFocus(0, &ulTimes);
+    set_signals();
+
+    /* Create pool for child */
+    apr_pool_create(&pchild, pconf);
+
+    ap_run_child_init(pchild, ap_server_conf);
+
+    /* Create an event semaphore used to trigger other threads to shutdown */
+    rc = DosCreateEventSem(NULL, &shutdown_event, 0, FALSE);
+
+    if (rc) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
+                     "unable to create shutdown semaphore, exiting");
+        clean_child_exit(APEXIT_CHILDFATAL);
+    }
+
+    /* Gain access to the scoreboard. */
+    rc = DosGetNamedSharedMem(&sb_mem, ap_scoreboard_fname,
+                              PAG_READ|PAG_WRITE);
+
+    if (rc) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
+                     "scoreboard not readable in child, exiting");
+        clean_child_exit(APEXIT_CHILDFATAL);
+    }
+
+    ap_calc_scoreboard_size();
+    ap_init_scoreboard(sb_mem);
+
+    /* Gain access to the accpet mutex */
+    rc = DosOpenMutexSem(NULL, &ap_mpm_accept_mutex);
+
+    if (rc) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
+                     "accept mutex couldn't be accessed in child, exiting");
+        clean_child_exit(APEXIT_CHILDFATAL);
+    }
+
+    /* Find our pid in the scoreboard so we know what slot our parent allocated us */
+    for (child_slot = 0; ap_scoreboard_image->parent[child_slot].pid != my_pid && child_slot < HARD_SERVER_LIMIT; child_slot++);
+
+    if (child_slot == HARD_SERVER_LIMIT) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf,
+                     "child pid not found in scoreboard, exiting");
+        clean_child_exit(APEXIT_CHILDFATAL);
+    }
+
+    ap_my_generation = ap_scoreboard_image->parent[child_slot].generation;
+    memset(ap_scoreboard_image->servers[child_slot], 0, sizeof(worker_score) * HARD_THREAD_LIMIT);
+
+    /* Set up an OS/2 queue for passing connections & termination requests
+     * to worker threads
+     */
+    rc = DosCreateQueue(&workq, QUE_FIFO, apr_psprintf(pchild, "/queues/httpd/work.%d", my_pid));
+
+    if (rc) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
+                     "unable to create work queue, exiting");
+        clean_child_exit(APEXIT_CHILDFATAL);
+    }
+
+    /* Create initial pool of worker threads */
+    for (c = 0; c < ap_min_spare_threads; c++) {
+//        ap_scoreboard_image->servers[child_slot][c].tid = _beginthread(worker_main, NULL, 128*1024, (void *)c);
+    }
+
+    /* Start maintenance thread */
+    server_maint_tid = _beginthread(server_maintenance, NULL, 32768, NULL);
+
+    /* Set up poll */
+    for (num_listeners = 0, lr = ap_listeners; lr; lr = lr->next) {
+        num_listeners++;
+    }
+
+    apr_pollset_create(&pollset, num_listeners, pchild, 0);
+
+    for (lr = ap_listeners; lr != NULL; lr = lr->next) {
+        apr_pollfd_t pfd = { 0 };
+
+        pfd.desc_type = APR_POLL_SOCKET;
+        pfd.desc.s = lr->sd;
+        pfd.reqevents = APR_POLLIN;
+        pfd.client_data = lr;
+        apr_pollset_add(pollset, &pfd);
+    }
+
+    /* Main connection accept loop */
+    do {
+        apr_pool_t *pconn;
+        worker_args_t *worker_args;
+        int last_poll_idx = 0;
+
+        apr_pool_create(&pconn, pchild);
+        worker_args = apr_palloc(pconn, sizeof(worker_args_t));
+        worker_args->pconn = pconn;
+
+        if (num_listeners == 1) {
+            rv = apr_socket_accept(&worker_args->conn_sd, ap_listeners->sd, pconn);
+        } else {
+            const apr_pollfd_t *poll_results;
+            apr_int32_t num_poll_results;
+
+            rc = DosRequestMutexSem(ap_mpm_accept_mutex, SEM_INDEFINITE_WAIT);
+
+            if (shutdown_pending) {
+                DosReleaseMutexSem(ap_mpm_accept_mutex);
+                break;
+            }
+
+            rv = APR_FROM_OS_ERROR(rc);
+
+            if (rv == APR_SUCCESS) {
+                rv = apr_pollset_poll(pollset, -1, &num_poll_results, &poll_results);
+                DosReleaseMutexSem(ap_mpm_accept_mutex);
+            }
+
+            if (rv == APR_SUCCESS) {
+                if (last_poll_idx >= num_listeners) {
+                    last_poll_idx = 0;
+                }
+
+                lr = poll_results[last_poll_idx++].client_data;
+                rv = apr_socket_accept(&worker_args->conn_sd, lr->sd, pconn);
+                last_poll_idx++;
+            }
+        }
+
+        if (rv != APR_SUCCESS) {
+            if (!APR_STATUS_IS_EINTR(rv)) {
+                ap_log_error(APLOG_MARK, APLOG_ERR, rv, ap_server_conf,
+                             "apr_socket_accept");
+                clean_child_exit(APEXIT_CHILDFATAL);
+            }
+        } else {
+            DosWriteQueue(workq, WORKTYPE_CONN, sizeof(worker_args_t), worker_args, 0);
+            requests_this_child++;
+        }
+
+        if (ap_max_requests_per_child != 0 && requests_this_child >= ap_max_requests_per_child)
+            break;
+    } while (!shutdown_pending && ap_my_generation == ap_scoreboard_image->global->running_generation);
+
+    ap_scoreboard_image->parent[child_slot].quiescing = 1;
+    DosPostEventSem(shutdown_event);
+    DosWaitThread(&server_maint_tid, DCWW_WAIT);
+
+    if (is_graceful) {
+        char someleft;
+
+        /* tell our worker threads to exit */
+        for (c=0; c<HARD_THREAD_LIMIT; c++) {
+            if (ap_scoreboard_image->servers[child_slot][c].status != SERVER_DEAD) {
+                DosWriteQueue(workq, WORKTYPE_EXIT, 0, NULL, 0);
+            }
+        }
+
+        do {
+            someleft = 0;
+
+            for (c=0; c<HARD_THREAD_LIMIT; c++) {
+                if (ap_scoreboard_image->servers[child_slot][c].status != SERVER_DEAD) {
+                    someleft = 1;
+                    DosSleep(1000);
+                    break;
+                }
+            }
+        } while (someleft);
+    } else {
+        DosPurgeQueue(workq);
+
+        for (c=0; c<HARD_THREAD_LIMIT; c++) {
+            if (ap_scoreboard_image->servers[child_slot][c].status != SERVER_DEAD) {
+                DosKillThread(ap_scoreboard_image->servers[child_slot][c].tid);
+            }
+        }
+    }
+
+    apr_pool_destroy(pchild);
+}
+
+
+
+void add_worker()
+{
+    int thread_slot;
+
+    /* Find a free thread slot */
+    for (thread_slot=0; thread_slot < HARD_THREAD_LIMIT; thread_slot++) {
+        if (ap_scoreboard_image->servers[child_slot][thread_slot].status == SERVER_DEAD) {
+            ap_scoreboard_image->servers[child_slot][thread_slot].status = SERVER_STARTING;
+            ap_scoreboard_image->servers[child_slot][thread_slot].tid =
+                _beginthread(worker_main, NULL, 128*1024, (void *)thread_slot);
+            break;
+        }
+    }
+}
+
+
+
+ULONG APIENTRY thread_exception_handler(EXCEPTIONREPORTRECORD *pReportRec,
+                                        EXCEPTIONREGISTRATIONRECORD *pRegRec,
+                                        CONTEXTRECORD *pContext,
+                                        PVOID p)
+{
+    int c;
+
+    if (pReportRec->fHandlerFlags & EH_NESTED_CALL) {
+        return XCPT_CONTINUE_SEARCH;
+    }
+
+    if (pReportRec->ExceptionNum == XCPT_ACCESS_VIOLATION ||
+        pReportRec->ExceptionNum == XCPT_INTEGER_DIVIDE_BY_ZERO) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf,
+                     "caught exception in worker thread, initiating child shutdown pid=%d", getpid());
+        for (c=0; c<HARD_THREAD_LIMIT; c++) {
+            if (ap_scoreboard_image->servers[child_slot][c].tid == _gettid()) {
+                ap_scoreboard_image->servers[child_slot][c].status = SERVER_DEAD;
+                break;
+            }
+        }
+
+        /* Shut down process ASAP, it could be quite unhealthy & leaking resources */
+        shutdown_pending = 1;
+        ap_scoreboard_image->parent[child_slot].quiescing = 1;
+        kill(getpid(), SIGHUP);
+        DosUnwindException(UNWIND_ALL, 0, 0);
+    }
+
+    return XCPT_CONTINUE_SEARCH;
+}
+
+
+
+static void worker_main(void *vpArg)
+{
+    long conn_id;
+    conn_rec *current_conn;
+    apr_pool_t *pconn;
+    apr_allocator_t *allocator;
+    apr_bucket_alloc_t *bucket_alloc;
+    worker_args_t *worker_args;
+    HQUEUE workq;
+    PID owner;
+    int rc;
+    REQUESTDATA rd;
+    ULONG len;
+    BYTE priority;
+    int thread_slot = (int)vpArg;
+    EXCEPTIONREGISTRATIONRECORD reg_rec = { NULL, thread_exception_handler };
+    ap_sb_handle_t *sbh;
+
+    /* Trap exceptions in this thread so we don't take down the whole process */
+    DosSetExceptionHandler( &reg_rec );
+
+    rc = DosOpenQueue(&owner, &workq,
+                      apr_psprintf(pchild, "/queues/httpd/work.%d", getpid()));
+
+    if (rc) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
+                     "unable to open work queue, exiting");
+        ap_scoreboard_image->servers[child_slot][thread_slot].tid = 0;
+    }
+
+    conn_id = ID_FROM_CHILD_THREAD(child_slot, thread_slot);
+    ap_update_child_status_from_indexes(child_slot, thread_slot, SERVER_READY,
+                                        NULL);
+
+    apr_allocator_create(&allocator);
+    apr_allocator_max_free_set(allocator, ap_max_mem_free);
+    bucket_alloc = apr_bucket_alloc_create_ex(allocator);
+
+    while (rc = DosReadQueue(workq, &rd, &len, (PPVOID)&worker_args, 0, DCWW_WAIT, &priority, NULLHANDLE),
+           rc == 0 && rd.ulData != WORKTYPE_EXIT) {
+        pconn = worker_args->pconn;
+        ap_create_sb_handle(&sbh, pconn, child_slot, thread_slot);
+        current_conn = ap_run_create_connection(pconn, ap_server_conf,
+                                                worker_args->conn_sd, conn_id,
+                                                sbh, bucket_alloc);
+
+        if (current_conn) {
+            ap_process_connection(current_conn, worker_args->conn_sd);
+            ap_lingering_close(current_conn);
+        }
+
+        apr_pool_destroy(pconn);
+        ap_update_child_status_from_indexes(child_slot, thread_slot,
+                                            SERVER_READY, NULL);
+    }
+
+    ap_update_child_status_from_indexes(child_slot, thread_slot, SERVER_DEAD,
+                                        NULL);
+
+    apr_bucket_alloc_destroy(bucket_alloc);
+    apr_allocator_destroy(allocator);
+}
+
+
+
+static void server_maintenance(void *vpArg)
+{
+    int num_idle, num_needed;
+    ULONG num_pending = 0;
+    int threadnum;
+    HQUEUE workq;
+    ULONG rc;
+    PID owner;
+
+    rc = DosOpenQueue(&owner, &workq,
+                      apr_psprintf(pchild, "/queues/httpd/work.%d", getpid()));
+
+    if (rc) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
+                     "unable to open work queue in maintenance thread");
+        return;
+    }
+
+    do {
+        for (num_idle=0, threadnum=0; threadnum < HARD_THREAD_LIMIT; threadnum++) {
+            num_idle += ap_scoreboard_image->servers[child_slot][threadnum].status == SERVER_READY;
+        }
+
+        DosQueryQueue(workq, &num_pending);
+        num_needed = ap_min_spare_threads - num_idle + num_pending;
+
+        if (num_needed > 0) {
+            for (threadnum=0; threadnum < num_needed; threadnum++) {
+                add_worker();
+            }
+        }
+
+        if (num_idle - num_pending > ap_max_spare_threads) {
+            DosWriteQueue(workq, WORKTYPE_EXIT, 0, NULL, 0);
+        }
+    } while (DosWaitEventSem(shutdown_event, 500) == ERROR_TIMEOUT);
+}
+
+
+
+/* Signal handling routines */
+
+static void sig_term(int sig)
+{
+    shutdown_pending = 1;
+    is_graceful = 0;
+    signal(SIGTERM, SIG_DFL);
+}
+
+
+
+static void sig_hup(int sig)
+{
+    shutdown_pending = 1;
+    is_graceful = 1;
+}
+
+
+
+static void set_signals()
+{
+    struct sigaction sa;
+
+    sigemptyset(&sa.sa_mask);
+    sa.sa_flags = 0;
+    sa.sa_handler = sig_term;
+
+    if (sigaction(SIGTERM, &sa, NULL) < 0)
+        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGTERM)");
+
+    sa.sa_handler = sig_hup;
+
+    if (sigaction(SIGHUP, &sa, NULL) < 0)
+        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGHUP)");
+}