Attachment "tcl.427196.0.diff.txt" to
ticket [427196ffff]
added by
andreas_kupries
2001-07-18 00:47:54.
? tools/man2tcl
? unix/linux-ix86
? unix/buffer.tcl
Index: ChangeLog
===================================================================
RCS file: /cvsroot/tcl/tcl/ChangeLog,v
retrieving revision 1.491
diff -u -r1.491 ChangeLog
--- ChangeLog 2001/07/06 22:03:11 1.491
+++ ChangeLog 2001/07/17 17:46:01
@@ -1,3 +1,13 @@
+2001-07-17 Andreas Kupries <[email protected]>
+
+ * generic/tclIO.c (GetInput): Fixed [SF #427196]. Memory was
+ overwritten because a buffer was used after a change of the
+ requested buffersize together with that requested buffersize and
+ not its actual size, which was smaller. Note that the continous
+ reuse of the smaller buffer negatively impacts performance. The
+ system never allocates a buffer with the newly requested bigger
+ buffersize.
+
2001-07-06 Mo DeJong <[email protected]>
* win/configure: Regen.
Index: generic/tclIO.c
===================================================================
RCS file: /cvsroot/tcl/tcl/generic/tclIO.c,v
retrieving revision 1.30
diff -u -r1.30 tclIO.c
--- generic/tclIO.c 2001/05/19 16:59:04 1.30
+++ generic/tclIO.c 2001/07/17 17:46:01
@@ -4999,7 +4999,21 @@
}
bufPtr->nextPtr = (ChannelBuffer *) NULL;
- toRead = statePtr->bufSize;
+ /* SF #427196: Use the actual size of the buffer to determine
+ * the number of bytes to read from the channel and not the
+ * size for new buffers. They can be different if the
+ * buffersize was changed between reads.
+ *
+ * Note: This affects performance negatively if the buffersize
+ * was extended but this small buffer is reused for all
+ * subsequent reads. The system never uses buffers with the
+ * requested bigger size in that case. An adjunct patch could
+ * try and delete all unused buffers it encounters and which
+ * are smaller than the formally requested buffersize.
+ */
+
+ toRead = bufPtr->bufLength - bufPtr->nextAdded;
+
if (statePtr->inQueueTail == NULL) {
statePtr->inQueueHead = bufPtr;
} else {
