core: Abort with sensible error message if no or more than one MPM is

loaded.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@987806 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 18 insertions, 0 deletions

diff --git a/server/config.c b/server/config.c
index b58f096939..ea54280ea4 100644
--- a/server/config.c
+++ b/server/config.c
@@ -49,6 +49,7 @@
 #include "http_main.h"
 #include "http_vhost.h"
 #include "util_cfgtree.h"
+#include "mpm_common.h"
 
 #define APLOG_UNSET   (APLOG_NO_MODULE - 1)
 APLOG_USE_MODULE(core);
@@ -2242,6 +2243,13 @@ AP_DECLARE(server_rec*) ap_read_config(process_rec *process, apr_pool_t *ptemp,
         return NULL;
     }
 
+    error = ap_check_mpm();
+    if (error) {
+        ap_log_error(APLOG_MARK, APLOG_STARTUP|APLOG_CRIT, 0, NULL,
+                     "%s: Configuration error: %s", ap_server_argv0, error);
+        return NULL;
+    }
+
     /*
      * We have loaded the dynamic modules. From now on we know exactly how
      * long the config vectors need to be.
diff --git a/server/mpm_common.c b/server/mpm_common.c
index 56bc70c875..e45a089447 100644
--- a/server/mpm_common.c
+++ b/server/mpm_common.c
@@ -375,3 +375,13 @@ AP_DECLARE(const char *)ap_show_mpm(void)
 
     return name;
 }
+
+AP_DECLARE(const char *)ap_check_mpm(void)
+{
+    if (!_hooks.link_mpm || _hooks.link_mpm->nelts == 0)
+        return "No MPM loaded.";
+    else if (_hooks.link_mpm->nelts > 1)
+        return "More than one MPM loaded.";
+    else
+        return NULL;
+}