From bbc1e878f5029246c02d893921f05975e49de026 Mon Sep 17 00:00:00 2001
From: Jim Jagielski <jim@apache.org>
Date: Tue, 18 Sep 2012 10:59:20 +0000
Subject: [PATCH] Add in new type CLEARINUSE which allows the inuse table to be
 cleared upon storage. This may be expected/wanted/required by some
 applications

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1387088 13f79535-47bb-0310-9956-ffa450edef68
---
 docs/manual/mod/mod_slotmem_shm.xml |  6 +++---
 include/ap_slotmem.h                | 10 +++++++---
 modules/slotmem/mod_slotmem_shm.c   | 27 +++++++++++++++++++++++++--
 3 files changed, 35 insertions(+), 8 deletions(-)

diff --git a/docs/manual/mod/mod_slotmem_shm.xml b/docs/manual/mod/mod_slotmem_shm.xml
index e129970f16..f27d156ba9 100644
--- a/docs/manual/mod/mod_slotmem_shm.xml
+++ b/docs/manual/mod/mod_slotmem_shm.xml
@@ -51,11 +51,11 @@
       <dd>call the callback on all worker slots</dd>
 
       <dt>apr_status_t create(ap_slotmem_instance_t **new, const char *name, apr_size_t item_size, unsigned int item_num, ap_slotmem_type_t type, apr_pool_t *pool)</dt>
-      <dd>create a new slotmem with each item size is item_size. <code>name</code> is the filename for the persistent store of
-      the shared memory. Values are:
+      <dd>create a new slotmem with each item size is item_size. <code>name</code> is used to generate a filename for the persistent store of
+      the shared memory if configured. Values are:
        <dl>
          <dt><code>"none"</code></dt>
-         <dd><code>Does not persist shared memory in file.</code></dd>
+         <dd><code>Anonymous shared memory and no persistent store</code></dd>
          <dt><code>"file-name"</code></dt>
          <dd><code>[DefaultRuntimeDir]/file-name</code></dd>
          <dt><code>"/absolute-file-name"</code></dt>
diff --git a/include/ap_slotmem.h b/include/ap_slotmem.h
index 229aa713f4..b9c810366d 100644
--- a/include/ap_slotmem.h
+++ b/include/ap_slotmem.h
@@ -62,10 +62,14 @@ typedef unsigned int ap_slotmem_type_t;
  * AP_SLOTMEM_TYPE_NOTMPSAFE:
  *
  * AP_SLOTMEM_TYPE_PREALLOC: Access to slots require they be grabbed 1st
+ *
+ * AP_SLOTMEM_TYPE_CLEARINUSE: If persisting, clear 'inuse' array before
+ *    storing
  */
-#define AP_SLOTMEM_TYPE_PERSIST   (1 << 0)
-#define AP_SLOTMEM_TYPE_NOTMPSAFE (1 << 1)
-#define AP_SLOTMEM_TYPE_PREGRAB   (1 << 2)
+#define AP_SLOTMEM_TYPE_PERSIST      (1 << 0)
+#define AP_SLOTMEM_TYPE_NOTMPSAFE    (1 << 1)
+#define AP_SLOTMEM_TYPE_PREGRAB      (1 << 2)
+#define AP_SLOTMEM_TYPE_CLEARINUSE   (1 << 3)
 
 typedef struct ap_slotmem_instance_t ap_slotmem_instance_t;
 
diff --git a/modules/slotmem/mod_slotmem_shm.c b/modules/slotmem/mod_slotmem_shm.c
index f29aefad2d..e5be2448c4 100644
--- a/modules/slotmem/mod_slotmem_shm.c
+++ b/modules/slotmem/mod_slotmem_shm.c
@@ -43,8 +43,9 @@
 #endif
 #endif
 
-#define AP_SLOTMEM_IS_PREGRAB(t) (t->desc.type & AP_SLOTMEM_TYPE_PREGRAB)
-#define AP_SLOTMEM_IS_PERSIST(t) (t->desc.type & AP_SLOTMEM_TYPE_PERSIST)
+#define AP_SLOTMEM_IS_PREGRAB(t)    (t->desc.type & AP_SLOTMEM_TYPE_PREGRAB)
+#define AP_SLOTMEM_IS_PERSIST(t)    (t->desc.type & AP_SLOTMEM_TYPE_PERSIST)
+#define AP_SLOTMEM_IS_CLEARINUSE(t) (t->desc.type & AP_SLOTMEM_TYPE_CLEARINUSE)
 
 /* The description of the slots to reuse the slotmem */
 typedef struct {
@@ -152,6 +153,25 @@ static const char *slotmem_filename(apr_pool_t *pool, const char *slotmemname,
     return fname;
 }
 
+static void slotmem_clearinuse(ap_slotmem_instance_t *slot)
+{
+    unsigned int i;
+    char *inuse;
+    
+    if (!slot) {
+        return;
+    }
+    
+    inuse = slot->inuse;
+    
+    for (i = 0; i < slot->desc.num; i++, inuse++) {
+        if (*inuse) {
+            *inuse = 0;
+            (*slot->num_free)++;
+        }
+    }
+}
+
 static void store_slotmem(ap_slotmem_instance_t *slotmem)
 {
     apr_file_t *fp;
@@ -175,6 +195,9 @@ static void store_slotmem(ap_slotmem_instance_t *slotmem)
         if (rv != APR_SUCCESS) {
             return;
         }
+        if (AP_SLOTMEM_IS_CLEARINUSE(slotmem)) {
+            slotmem_clearinuse(slotmem);
+        }
         nbytes = (slotmem->desc.size * slotmem->desc.num) +
                  (slotmem->desc.num * sizeof(char)) + AP_UNSIGNEDINT_OFFSET;
         /* XXX: Error handling */
-- 
2.40.0