Return-Path: <apache-cvs-owner-apache-cvs-archive=hyperreal.org@apache.org>
Delivered-To: apache-cvs-archive@hyperreal.org
Received: (qmail 9707 invoked by uid 6000); 25 Mar 1998 09:44:53 -0000
Received: (qmail 9701 invoked by alias); 25 Mar 1998 09:44:52 -0000
Delivered-To: apache-1.3-cvs@hyperreal.org
Received: (qmail 9698 invoked by uid 168); 25 Mar 1998 09:44:49 -0000
Date: 25 Mar 1998 09:44:49 -0000
Message-ID: <19980325094449.9697.qmail@hyperreal.org>
From: rse@hyperreal.org
To: apache-1.3-cvs@hyperreal.org
Subject: cvs commit: apache-1.3/src/modules/standard mod_so.c
Sender: apache-cvs-owner@apache.org
Precedence: bulk
Reply-To: new-httpd@apache.org

rse         98/03/25 01:44:49

  Modified:    .        STATUS
               src      CHANGES
               src/modules/standard mod_so.c
  Log:
  Make shared object loading work again (now that -DHIDE is the default).
  Distributed modules are loaded with AP_<name>_module and custom
  modules are now loaded with the fallback strategy via <name>_module
  (because their <name>_module is not and canno be hidden by hide.h).
  
  Revision  Changes    Path
  1.205     +2 -0      apache-1.3/STATUS
  
  Index: STATUS
  ===================================================================
  RCS file: /export/home/cvs/apache-1.3/STATUS,v
  retrieving revision 1.204
  retrieving revision 1.205
  diff -u -r1.204 -r1.205
  --- STATUS	1998/03/23 07:42:09	1.204
  +++ STATUS	1998/03/25 09:44:44	1.205
  @@ -102,6 +102,8 @@
       * Ralf's reanim. of undocum. directive: ProxyReceiveBufferSize, PR#1348
       * Ralf's mod_proxy fix to use FTP SIZE response for Content-Length, PR#1183
       * Ralf's change to make the shared object compilation command more portable
  +    * Dean's protect against FD_SETSIZE mismatches
  +    * Ralf's fallback stategy because of HIDE for loading shared object modules
   
   Available Patches:
   
  
  
  
  1.731     +5 -0      apache-1.3/src/CHANGES
  
  Index: CHANGES
  ===================================================================
  RCS file: /export/home/cvs/apache-1.3/src/CHANGES,v
  retrieving revision 1.730
  retrieving revision 1.731
  diff -u -r1.730 -r1.731
  --- CHANGES	1998/03/25 02:57:19	1.730
  +++ CHANGES	1998/03/25 09:44:46	1.731
  @@ -1,4 +1,9 @@
   Changes with Apache 1.3b6
  + 
  +  *) Finally fix the shared object loading by using a fallback strategy to
  +     overcome the HIDE feature problematic without loosing special cases. Also
  +     a huge comment was added to mod_so.c to make the situation more clear
  +     for the future. [Ralf S. Engelschall]
   
     *) Protect against FD_SETSIZE mismatches.  [Dean Gaudet]
   
  
  
  
  1.15      +66 -9     apache-1.3/src/modules/standard/mod_so.c
  
  Index: mod_so.c
  ===================================================================
  RCS file: /export/home/cvs/apache-1.3/src/modules/standard/mod_so.c,v
  retrieving revision 1.14
  retrieving revision 1.15
  diff -u -r1.14 -r1.15
  --- mod_so.c	1998/03/23 15:44:15	1.14
  +++ mod_so.c	1998/03/25 09:44:48	1.15
  @@ -222,6 +222,7 @@
       so_server_conf *sconf;
       moduleinfo *modi;
       moduleinfo *modie;
  +    char *modname_hidden;
       int i;
   
       /* 
  @@ -240,7 +241,53 @@
       modi->name = modname;
   
       /*
  -     * Actually load the file into the address space 
  +     * NOW COMES THE PROBLEMATIC PART:
  +     *
  +     * Because of the -DHIDE/hide.h feature of Apache 1.3 we have eight
  +     * situations from which four doesn't work at all and four are a bit
  +     * different because of the AP_ hiding stuff and the fact that this symbol
  +     * hiding applies only to distributed modules.
  +     *
  +     * Apache ...... means the Apache code itself
  +     * S-Module .... means a standard module which is distributed with Apache
  +     * C-Module .... means a custom module which is not distributed with Apache
  +     * HIDE ........ means -DHIDE was used when compiling
  +     * !HIDE ....... means -DHIDE was not used when compiling
  +     * xxx ......... means the symbol "<name>_module" of the module structure
  +     *
  +     *                      Resolving| dlopen()     dlsym()
  +     *                               | (implicit)   (explicit)
  +     * Situation                     | core->module core<-module
  +     * ------------------------------+-----------------------------------
  +     * The compatible variants:      |
  +     * Apache+!HIDE & S-Module+!HIDE | succeeds     succeeds only w/ xxx
  +     * Apache+ HIDE & S-Module+ HIDE | succeeds     succeeds only w/ AP_xxx
  +     * Apache+!HIDE & C-Module+!HIDE | succeeds     succeeds only w/ xxx
  +     * Apache+ HIDE & C-Module+ HIDE | succeeds     succeeds only w/ xxx  <<==
  +     * The incompatible variants:    |
  +     * Apache+!HIDE & S-Module+ HIDE | fails        would succeed w/ AP_xxx
  +     * Apache+ HIDE & S-Module+!HIDE | fails        would succeed w/ xxx
  +     * Apache+!HIDE & C-Module+ HIDE | fails        would succeed w/ xxx
  +     * Apache+ HIDE & C-Module+!HIDE | fails        would succeed w/ xxx
  +     *
  +     * In other words: For the incompatible variants where the Apache core was
  +     * built with a different setting than the ones the module was compiled
  +     * with, we have no chance at all because the implicit resolving of
  +     * Apache's core symbols in dlopen() already fails for the module (because
  +     * for instance the module needs palloc while Apache exports AP_palloc).
  +     *
  +     * So, only for the compatible variants we have a chance. And here we
  +     * succeed by always trying to resolve the plain xxx symbol and only for
  +     * the case of a distributed standard module we have to resolve via the
  +     * AP_xxx variant. Because we cannot decide if the module to be loaded is
  +     * a distributed one or a custom one we really have to try both: First for
  +     * AP_xxx and if this fails additionally for xxx.
  +     *
  +     *                                                        -- rse
  +     */
  +
  +    /*
  +     * Load the file into the Apache address space
        */
       if (!(modhandle = os_dl_load(szModuleFile))) {
   	const char *my_error = os_dl_error();
  @@ -252,21 +299,31 @@
       aplog_error(APLOG_MARK, APLOG_DEBUG|APLOG_NOERRNO, NULL,
   		"loaded module %s", modname);
   
  -#ifdef HIDE
  -    modname = pstrcat(cmd->pool, "AP_", modname, NULL);
  -#endif
  +    /*
  +     * Create the symbol variant for the case where
  +     * we have to load a distributed module compiled with -DHIDE
  +     */
  +    modname_hidden = pstrcat(cmd->pool, "AP_", modname, NULL);
   
  +    /*
  +     * Optionally prefix the symbol with an underscore
  +     * for some platforms.
  +     */
   #ifdef NEED_UNDERSCORE_SYM
  +    modname_hidden = pstrcat(cmd->pool, "_", modname_hidden, NULL);
       modname = pstrcat(cmd->pool, "_", modname, NULL);
   #endif
   
       /*
  -     * Retrieve the pointer to the module structure 
  -     * through the module name
  +     * Retrieve the pointer to the module structure through the module name:
  +     * First with the hidden variant (prefix `AP_') and then with the plain
  +     * symbol name.
        */
  -    if (!(modp = (module *)(os_dl_sym (modhandle, modname)))) {
  -	return pstrcat(cmd->pool, "Can't find module ", modname,
  -		       " in file ", filename, ":", os_dl_error(), NULL);
  +    if (!(modp = (module *)(os_dl_sym (modhandle, modname_hidden)))) {
  +	if (!(modp = (module *)(os_dl_sym (modhandle, modname)))) {
  +	    return pstrcat(cmd->pool, "Can't find module ", modname,
  +			   " in file ", filename, ":", os_dl_error(), NULL);
  +	}
       }
       modi->modp = modp;
       modp->dynamic_load_handle = modhandle;