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authordgp <dgp@users.sourceforge.net>2016-07-18 16:46:34 (GMT)
committerdgp <dgp@users.sourceforge.net>2016-07-18 16:46:34 (GMT)
commit3766e26550a1315f09945ab1162d78d0143d32a2 (patch)
tree542c90fa64596001e6147e5f9b5d2e9145eeb38f /generic/tclIO.c
parentc95dfd2ed336a593d21fa9098b5c82a8761b02d7 (diff)
parenta127a9e4aa8b2a9a386cd7fe694bfef8f1cf5264 (diff)
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[104f2885bb] Rework the "chan" Tcl_ObjType to properly validate cached channel name lookups.
Diffstat (limited to 'generic/tclIO.c')
-rw-r--r--generic/tclIO.c159
1 files changed, 73 insertions, 86 deletions
diff --git a/generic/tclIO.c b/generic/tclIO.c
index f93d00d..80f6fa4 100644
--- a/generic/tclIO.c
+++ b/generic/tclIO.c
@@ -313,15 +313,20 @@ static int WillRead(Channel *chanPtr);
&& (strncmp(optionName, (nameString), len) == 0))
/*
- * The ChannelObjType type. We actually store the ChannelState structure
- * as that lives longest and we want to return the bottomChanPtr when
- * requested (consistent with Tcl_GetChannel). The setFromAny and
- * updateString can be NULL as they should not be called.
+ * The ChannelObjType type. Used to store the result of looking up
+ * a channel name in the context of an interp. Saves the lookup
+ * result and values needed to check its continued validity.
*/
+typedef struct ResolvedChanName {
+ ChannelState *statePtr; /* The saved lookup result */
+ Tcl_Interp *interp; /* The interp in which the lookup was done. */
+ int epoch; /* The epoch of the channel when the lookup
+ * was done. Use to verify validity. */
+ int refCount; /* Share this struct among many Tcl_Obj. */
+} ResolvedChanName;
+
static void DupChannelIntRep(Tcl_Obj *objPtr, Tcl_Obj *copyPtr);
-static int SetChannelFromAny(Tcl_Interp *interp,
- Tcl_Obj *objPtr);
static void FreeChannelIntRep(Tcl_Obj *objPtr);
static const Tcl_ObjType chanObjType = {
@@ -329,18 +334,9 @@ static const Tcl_ObjType chanObjType = {
FreeChannelIntRep, /* freeIntRepProc */
DupChannelIntRep, /* dupIntRepProc */
NULL, /* updateStringProc */
- NULL /* setFromAnyProc SetChannelFromAny */
+ NULL /* setFromAnyProc */
};
-#define GET_CHANNELSTATE(objPtr) \
- ((ChannelState *) (objPtr)->internalRep.twoPtrValue.ptr1)
-#define SET_CHANNELSTATE(objPtr, storePtr) \
- ((objPtr)->internalRep.twoPtrValue.ptr1 = (void *) (storePtr))
-#define GET_CHANNELINTERP(objPtr) \
- ((Tcl_Interp *) (objPtr)->internalRep.twoPtrValue.ptr2)
-#define SET_CHANNELINTERP(objPtr, storePtr) \
- ((objPtr)->internalRep.twoPtrValue.ptr2 = (void *) (storePtr))
-
#define BUSY_STATE(st, fl) \
((((st)->csPtrR) && ((fl) & TCL_READABLE)) || \
(((st)->csPtrW) && ((fl) & TCL_WRITABLE)))
@@ -1021,7 +1017,7 @@ DeleteChannelTable(
*/
Tcl_DeleteHashEntry(hPtr);
- SetFlag(statePtr, CHANNEL_TAINTED);
+ statePtr->epoch++;
if (statePtr->refCount-- <= 1) {
if (!GotFlag(statePtr, BG_FLUSH_SCHEDULED)) {
(void) Tcl_Close(interp, (Tcl_Channel) chanPtr);
@@ -1365,7 +1361,7 @@ DetachChannel(
return TCL_ERROR;
}
Tcl_DeleteHashEntry(hPtr);
- SetFlag(statePtr, CHANNEL_TAINTED);
+ statePtr->epoch++;
/*
* Remove channel handlers that refer to this interpreter, so that
@@ -1498,12 +1494,57 @@ TclGetChannelFromObj(
int flags)
{
ChannelState *statePtr;
+ ResolvedChanName *resPtr = NULL;
+ Tcl_Channel chan;
+
+ if (interp == NULL) {
+ return TCL_ERROR;
+ }
+
+ if (objPtr->typePtr == &chanObjType) {
+ /*
+ * Confirm validity of saved lookup results.
+ */
+
+ resPtr = (ResolvedChanName *) objPtr->internalRep.twoPtrValue.ptr1;
+ statePtr = resPtr->statePtr;
+ if ((resPtr->interp == interp) /* Same interp context */
+ /* No epoch change in channel since lookup */
+ && (resPtr->epoch == statePtr->epoch)) {
+
+ /* Have a valid saved lookup. Jump to end to return it. */
+ goto valid;
+ }
+ }
+
+ chan = Tcl_GetChannel(interp, TclGetString(objPtr), NULL);
- if (SetChannelFromAny(interp, objPtr) != TCL_OK) {
+ if (chan == NULL) {
+ if (resPtr) {
+ FreeChannelIntRep(objPtr);
+ }
return TCL_ERROR;
}
- statePtr = GET_CHANNELSTATE(objPtr);
+ if (resPtr && resPtr->refCount == 1) {
+ /* Re-use the ResolvedCmdName struct */
+ Tcl_Release((ClientData) resPtr->statePtr);
+
+ } else {
+ TclFreeIntRep(objPtr);
+
+ resPtr = (ResolvedChanName *) ckalloc(sizeof(ResolvedChanName));
+ resPtr->refCount = 1;
+ objPtr->internalRep.twoPtrValue.ptr1 = (ClientData) resPtr;
+ objPtr->typePtr = &chanObjType;
+ }
+ statePtr = ((Channel *)chan)->state;
+ resPtr->statePtr = statePtr;
+ Tcl_Preserve((ClientData) statePtr);
+ resPtr->interp = interp;
+ resPtr->epoch = statePtr->epoch;
+
+ valid:
*channelPtr = (Tcl_Channel) statePtr->bottomChanPtr;
if (modePtr != NULL) {
@@ -1676,6 +1717,8 @@ Tcl_CreateChannel(
statePtr->chanMsg = NULL;
statePtr->unreportedMsg = NULL;
+ statePtr->epoch = 0;
+
/*
* Link the channel into the list of all channels; create an on-exit
* handler if there is not one already, to close off all the channels in
@@ -11121,78 +11164,16 @@ DupChannelIntRep(
register Tcl_Obj *copyPtr) /* Object with internal rep to set. Must not
* currently have an internal rep.*/
{
- ChannelState *statePtr = GET_CHANNELSTATE(srcPtr);
+ ResolvedChanName *resPtr = srcPtr->internalRep.twoPtrValue.ptr1;
- SET_CHANNELSTATE(copyPtr, statePtr);
- SET_CHANNELINTERP(copyPtr, GET_CHANNELINTERP(srcPtr));
- Tcl_Preserve(statePtr);
+ resPtr->refCount++;
+ copyPtr->internalRep.twoPtrValue.ptr1 = resPtr;
copyPtr->typePtr = srcPtr->typePtr;
}
/*
*----------------------------------------------------------------------
*
- * SetChannelFromAny --
- *
- * Create an internal representation of type "Channel" for an object.
- *
- * Results:
- * This operation always succeeds and returns TCL_OK.
- *
- * Side effects:
- * Any old internal reputation for objPtr is freed and the internal
- * representation is set to "Channel".
- *
- *----------------------------------------------------------------------
- */
-
-static int
-SetChannelFromAny(
- Tcl_Interp *interp, /* Used for error reporting if not NULL. */
- register Tcl_Obj *objPtr) /* The object to convert. */
-{
- ChannelState *statePtr;
-
- if (interp == NULL) {
- return TCL_ERROR;
- }
- if (objPtr->typePtr == &chanObjType) {
- /*
- * TODO: TAINT Flag and dup'd channel values?
- * The channel is valid until any call to DetachChannel occurs.
- * Ensure consistency checks are done.
- */
-
- statePtr = GET_CHANNELSTATE(objPtr);
- if (GotFlag(statePtr, CHANNEL_TAINTED|CHANNEL_CLOSED)) {
- ResetFlag(statePtr, CHANNEL_TAINTED);
- Tcl_Release(statePtr);
- objPtr->typePtr = NULL;
- } else if (interp != GET_CHANNELINTERP(objPtr)) {
- Tcl_Release(statePtr);
- objPtr->typePtr = NULL;
- }
- }
- if (objPtr->typePtr != &chanObjType) {
- Tcl_Channel chan = Tcl_GetChannel(interp, TclGetString(objPtr), NULL);
-
- if (chan == NULL) {
- return TCL_ERROR;
- }
-
- TclFreeIntRep(objPtr);
- statePtr = ((Channel *) chan)->state;
- Tcl_Preserve(statePtr);
- SET_CHANNELSTATE(objPtr, statePtr);
- SET_CHANNELINTERP(objPtr, interp);
- objPtr->typePtr = &chanObjType;
- }
- return TCL_OK;
-}
-
-/*
- *----------------------------------------------------------------------
- *
* FreeChannelIntRep --
*
* Release statePtr storage.
@@ -11210,8 +11191,14 @@ static void
FreeChannelIntRep(
Tcl_Obj *objPtr) /* Object with internal rep to free. */
{
- Tcl_Release(GET_CHANNELSTATE(objPtr));
+ ResolvedChanName *resPtr = objPtr->internalRep.twoPtrValue.ptr1;
+
objPtr->typePtr = NULL;
+ if (--resPtr->refCount) {
+ return;
+ }
+ Tcl_Release(resPtr->statePtr);
+ ckfree(resPtr);
}
#if 0