struct NextChannelHandler used only locally. Remove from tclIO.h.

1 files changed, 24 insertions, 0 deletions

diff --git a/generic/tclIO.c b/generic/tclIO.c
index ed08112..a944314 100644
--- a/generic/tclIO.c
+++ b/generic/tclIO.c
@@ -22,6 +22,30 @@
 
 
 /*
+ * This structure keeps track of the current ChannelHandler being invoked in
+ * the current invocation of ChannelHandlerEventProc. There is a potential
+ * problem if a ChannelHandler is deleted while it is the current one, since
+ * ChannelHandlerEventProc needs to look at the nextPtr field. To handle this
+ * problem, structures of the type below indicate the next handler to be
+ * processed for any (recursively nested) dispatches in progress. The
+ * nextHandlerPtr field is updated if the handler being pointed to is deleted.
+ * The nextPtr field is used to chain together all recursive invocations, so
+ * that Tcl_DeleteChannelHandler can find all the recursively nested
+ * invocations of ChannelHandlerEventProc and compare the handler being
+ * deleted against the NEXT handler to be invoked in that invocation; when it
+ * finds such a situation, Tcl_DeleteChannelHandler updates the nextHandlerPtr
+ * field of the structure to the next handler.
+ */
+
+typedef struct NextChannelHandler {
+    ChannelHandler *nextHandlerPtr;	/* The next handler to be invoked in
+					 * this invocation. */
+    struct NextChannelHandler *nestedHandlerPtr;
+					/* Next nested invocation of
+					 * ChannelHandlerEventProc. */
+} NextChannelHandler;
+
+/*
  * All static variables used in this file are collected into a single
  * instance of the following structure.  For multi-threaded implementations,
  * there is one instance of this structure for each thread.