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authorEric Wong <normalperson@yhbt.net>2008-09-07 19:14:45 +0200
committerMax Kellermann <max@duempel.org>2008-09-07 19:14:45 +0200
commit3c4de5b560691bb877d47f475932b3c8f5751b93 (patch)
treeed688ef3f13c12d9c4a4b54c0592b873c92d2b48
parent194c8c3c0fc92e5d781a6cc23252a701c84bb380 (diff)
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tag: lock all accesses to tag_pool
The tag pool is a shared global resource that is infrequently modified. However, it can occasionally be modified by several threads, especially by the metadata_pipe for streaming metadata (both reading/writing). The bulk tag_item pool is NOT locked as currently only the update thread uses it.
-rw-r--r--src/tag.c16
-rw-r--r--src/tag_pool.c2
-rw-r--r--src/tag_pool.h3
3 files changed, 15 insertions, 6 deletions
diff --git a/src/tag.c b/src/tag.c
index 45a2687cb..35835f1a1 100644
--- a/src/tag.c
+++ b/src/tag.c
@@ -244,8 +244,9 @@ static void deleteItem(struct tag *tag, int idx)
assert(idx < tag->numOfItems);
tag->numOfItems--;
+ pthread_mutex_lock(&tag_pool_lock);
tag_pool_put_item(tag->items[idx]);
- /* free(tag->items[idx].value); */
+ pthread_mutex_unlock(&tag_pool_lock);
if (tag->numOfItems - idx > 0) {
memmove(tag->items + idx, tag->items + idx + 1,
@@ -277,10 +278,10 @@ static void clearMpdTag(struct tag *tag)
{
int i;
- for (i = 0; i < tag->numOfItems; i++) {
- /* free(tag->items[i].value); */
+ pthread_mutex_lock(&tag_pool_lock);
+ for (i = 0; i < tag->numOfItems; i++)
tag_pool_put_item(tag->items[i]);
- }
+ pthread_mutex_unlock(&tag_pool_lock);
if (tag->items == bulk.items) {
#ifndef NDEBUG
@@ -317,9 +318,10 @@ struct tag *tag_dup(const struct tag *tag)
ret->numOfItems = tag->numOfItems;
ret->items = ret->numOfItems > 0 ? xmalloc(items_size(tag)) : NULL;
- for (i = 0; i < tag->numOfItems; i++) {
+ pthread_mutex_lock(&tag_pool_lock);
+ for (i = 0; i < tag->numOfItems; i++)
ret->items[i] = tag_pool_dup_item(tag->items[i]);
- }
+ pthread_mutex_unlock(&tag_pool_lock);
return ret;
}
@@ -428,7 +430,9 @@ static void appendToTagItems(struct tag *tag, enum tag_type type,
items_size(tag) - sizeof(struct tag_item));
}
+ pthread_mutex_lock(&tag_pool_lock);
tag->items[i] = tag_pool_get_item(type, p, len);
+ pthread_mutex_unlock(&tag_pool_lock);
if (p != value)
xfree(p);
diff --git a/src/tag_pool.c b/src/tag_pool.c
index 89efef1fc..d227a2988 100644
--- a/src/tag_pool.c
+++ b/src/tag_pool.c
@@ -19,6 +19,8 @@
#include "tag_pool.h"
#include "utils.h"
+pthread_mutex_t tag_pool_lock = PTHREAD_MUTEX_INITIALIZER;
+
#define NUM_SLOTS 4096
struct slot {
diff --git a/src/tag_pool.h b/src/tag_pool.h
index e19b2f4b4..d837d4446 100644
--- a/src/tag_pool.h
+++ b/src/tag_pool.h
@@ -20,6 +20,9 @@
#define TAG_POOL_H
#include "tag.h"
+#include "os_compat.h"
+
+extern pthread_mutex_t tag_pool_lock;
struct tag_item;