Changeset 5716e9a in mainline

Timestamp:

2011-03-11T00:14:33Z (13 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

76b5a95c, c1a5d8d

Parents:

5ca5eaa7

Message:

Make sure that block_get() instantiates each block only once.

File:

• uspace/lib/block/libblock.c (modified) (2 diffs)

uspace/lib/block/libblock.c

@@ -411 +411 @@
         l = hash_table_find(&cache->block_hash, &key);
         if (l) {
+found:
                 /*
                  * We found the block in the cache.
@@ -493 +494 @@
                                         fibril_mutex_unlock(&b->lock);
                                         goto retry;
+                                }
+                                l = hash_table_find(&cache->block_hash, &key);
+                                if (l) {
+                                        /*
+                                         * Someone else must have already
+                                         * instantiated the block while we were
+                                         * not holding the cache lock.
+                                         * Leave the recycled block on the
+                                         * freelist and continue as if we
+                                         * found the block of interest during
+                                         * the first try.
+                                         */
+                                        fibril_mutex_unlock(&b->lock);
+                                        goto found;
                                 }