From: Alex Rousskov <rousskov@measurement-factory.com>
Date: Sun, 20 Jan 2013 01:50:52 +0000 (-0700)
Subject: Use signed type for StoreMapSliceId because we use -1 as an "unset" value.
X-Git-Tag: SQUID_3_5_0_1~444^2~77
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f13833e94e7f85c3a3271dd2bdefe6f1d4050732;p=thirdparty%2Fsquid.git

Use signed type for StoreMapSliceId because we use -1 as an "unset" value.

Initialize slice.next to be "unset". This should not be necessary in most
cases, but reduces the probability that a half-made writeable entry cannot be
freed properly because it contains an invalid slice.next value.

Losing the bit to store ID sign is not a big deal: Since slices always contain
non-trivial number of bytes for metadata, it is unlikely that all 32 (but less
than 33) bits would be required to store slice IDs in the future.
---

diff --git a/src/ipc/StoreMap.h b/src/ipc/StoreMap.h
index a8975301fb..19c6990761 100644
--- a/src/ipc/StoreMap.h
+++ b/src/ipc/StoreMap.h
@@ -9,13 +9,13 @@
 namespace Ipc
 {
 
-typedef uint32_t StoreMapSliceId;
+typedef int32_t StoreMapSliceId;
 
 /// a piece of Store entry, linked to other pieces, forming a chain
 class StoreMapSlice
 {
 public:
-    StoreMapSlice(): next(0), size(0) {}
+    StoreMapSlice(): next(-1), size(0) {}
 
     StoreMapSliceId next; ///< ID of the next slice occupied by the entry
     uint32_t size; ///< slice contents size