New APR function apr_mmap_dup.

this is used in the MMAP bucket setaside function for a performance win. Mod_file_cache will also use this Submitted by: Brian Pane <[email protected]> git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@62536 13f79535-47bb-0310-9956-ffa450edef68
notroj · Nov 21, 2001 · 1594bc7 · 1594bc7
1 parent c267c38
commit 1594bc7
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diff --git a/CHANGES b/CHANGES
@@ -1,4 +1,9 @@
 Changes with APR b1  
+  *)  New function apr_mmap_dup. This is called in the mmap_setaside 
+      [Brain Pane <[email protected]>]
+
+  *)  speed up the apr_hash_t implementation's handling of APR_HASH_KEY_STRING.
+      [Brain Pane <[email protected]>]
 
   *) Tweak apr_gethostname() so that it detects truncation of the
      name and returns an error.  [Jeff Trawick]

diff --git a/include/apr_mmap.h b/include/apr_mmap.h
@@ -111,6 +111,8 @@ struct apr_mmap_t {
     void *mm;
     /** The amount of data in the mmap */
     apr_size_t size;
+    /** Whether this object is reponsible for doing the munmap */
+    int is_owner;
 };
 
 #if APR_HAS_MMAP || defined(DOXYGEN)
@@ -135,6 +137,19 @@ APR_DECLARE(apr_status_t) apr_mmap_create(apr_mmap_t **newmmap,
                                           apr_size_t size, apr_int32_t flag,
                                           apr_pool_t *cntxt);
 
+/**
+ * Duplicate the specified MMAP.
+ * @param new_mmap The structure to duplicate into. 
+ * @param old_mmap The file to duplicate.
+ * @param p The pool to use for the new file.
+ * @param transfer_ownership  Whether responsibility for destroying
+ *  the memory-mapped segment is transferred from old_mmap to new_mmap
+ */         
+APR_DECLARE(apr_status_t) apr_mmap_dup(apr_mmap_t **new_mmap,
+                                       apr_mmap_t *old_mmap,
+                                       apr_pool_t *p,
+                                       int transfer_ownership);
+
 /**
  * Remove a mmap'ed.
  * @param mmap The mmap'ed file.

diff --git a/mmap/unix/mmap.c b/mmap/unix/mmap.c
@@ -83,6 +83,11 @@ static apr_status_t mmap_cleanup(void *themmap)
 {
     apr_mmap_t *mm = themmap;
     int rv;
+
+    if (!mm->is_owner) {
+        return APR_SUCCESS;
+    }
+
 #ifdef BEOS
     rv = delete_area(mm->area);
 
@@ -159,13 +164,40 @@ APR_DECLARE(apr_status_t) apr_mmap_create(apr_mmap_t **new,
     (*new)->mm = mm;
     (*new)->size = size;
     (*new)->cntxt = cont;
+    (*new)->is_owner = 1;
 
     /* register the cleanup... */
     apr_pool_cleanup_register((*new)->cntxt, (void*)(*new), mmap_cleanup,
              apr_pool_cleanup_null);
     return APR_SUCCESS;
 }
 
+APR_DECLARE(apr_status_t) apr_mmap_dup(apr_mmap_t **new_mmap,
+                                       apr_mmap_t *old_mmap,
+                                       apr_pool_t *p,
+                                       int transfer_ownership)
+{
+    *new_mmap = (apr_mmap_t *)apr_pmemdup(p, old_mmap, sizeof(apr_mmap_t));
+    (*new_mmap)->cntxt = p;
+
+    /* The old_mmap can transfer ownership only if the old_mmap itself
+     * is an owner of the mmap'ed segment.
+     */
+    if (old_mmap->is_owner) {
+        if (transfer_ownership) {
+            (*new_mmap)->is_owner = 1;
+            old_mmap->is_owner = 0;
+            apr_pool_cleanup_kill(old_mmap->cntxt, old_mmap, mmap_cleanup);
+        }
+        else {
+            (*new_mmap)->is_owner = 0;
+        }
+        apr_pool_cleanup_register(p, *new_mmap, mmap_cleanup,
+                                  apr_pool_cleanup_null);
+    }
+    return APR_SUCCESS;
+}
+
 APR_DECLARE(apr_status_t) apr_mmap_delete(apr_mmap_t *mmap)
 {
     apr_status_t rv;

diff --git a/mmap/win32/mmap.c b/mmap/win32/mmap.c
@@ -66,6 +66,11 @@ static apr_status_t mmap_cleanup(void *themmap)
 {
     apr_mmap_t *mm = themmap;
     apr_status_t rv = 0;
+
+    if (!mm->is_owner) {
+        return APR_SUCCESS;
+    }
+
     if (mm->mv) {
         if (!UnmapViewOfFile(mm->mv))
         {
@@ -155,13 +160,40 @@ APR_DECLARE(apr_status_t) apr_mmap_create(apr_mmap_t **new, apr_file_t *file,
     (*new)->mm = (char*)((*new)->mv) + offset;
     (*new)->size = size;
     (*new)->cntxt = cont;
+    (*new)->is_owner = 1;
 
     /* register the cleanup... */
     apr_pool_cleanup_register((*new)->cntxt, (void*)(*new), mmap_cleanup,
                          apr_pool_cleanup_null);
     return APR_SUCCESS;
 }
 
+APR_DECLARE(apr_status_t) apr_mmap_dup(apr_mmap_t **new_mmap,
+                                       apr_mmap_t *old_mmap,
+                                       apr_pool_t *p,
+                                       int transfer_ownership)
+{
+    *new_mmap = (apr_mmap_t *)apr_pmemdup(p, old_mmap, sizeof(apr_mmap_t));
+    (*new_mmap)->cntxt = p;
+
+    /* The old_mmap can transfer ownership only if the old_mmap itself
+     * is an owner of the mmap'ed segment.
+     */
+    if (old_mmap->is_owner) {
+        if (transfer_ownership) {
+            (*new_mmap)->is_owner = 1;
+            old_mmap->is_owner = 0;
+            apr_pool_cleanup_kill(old_mmap->cntxt, old_mmap, mmap_cleanup);
+        }
+        else {
+            (*new_mmap)->is_owner = 0;
+        }
+        apr_pool_cleanup_register(p, *new_mmap, mmap_cleanup,
+                                  apr_pool_cleanup_null);
+    }
+    return APR_SUCCESS;
+}
+
 APR_DECLARE(apr_status_t) apr_mmap_delete(apr_mmap_t *mmap)
 {
     apr_status_t rv;