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-rw-r--r--ChangeLog10
-rw-r--r--generic/tclBasic.c27
-rw-r--r--generic/tclInt.h6
-rw-r--r--unix/tclUnixInit.c77
-rw-r--r--win/tclWin32Dll.c6
5 files changed, 70 insertions, 56 deletions
diff --git a/ChangeLog b/ChangeLog
index e7eb651..065efec 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2007-11-10 Miguel Sofer <msofer@users.sf.net>
+
+ * generic/tclBasic.c:
+ * generic/tclInt.h:
+ * unix/tclUnixInit.c:
+ * win/tclWin32Dll.c: restore simpler behaviour for stack checking,
+ not adaptive to stack size changes after a thread is
+ launched. Consensus is that "nobody does that", and so it is not
+ worth the cost.
+
2007-11-10 Kevin Kenny <kennykb@acm.org>
* win/tclWin32Dll.c: Rewrote the Windows stack checking algorithm
diff --git a/generic/tclBasic.c b/generic/tclBasic.c
index 2684986..53cd4fd 100644
--- a/generic/tclBasic.c
+++ b/generic/tclBasic.c
@@ -14,7 +14,7 @@
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
- * RCS: @(#) $Id: tclBasic.c,v 1.273 2007/11/10 16:08:09 msofer Exp $
+ * RCS: @(#) $Id: tclBasic.c,v 1.274 2007/11/10 19:01:34 msofer Exp $
*/
#include "tclInt.h"
@@ -338,15 +338,15 @@ static const OpCmdInfo mathOpCmds[] = {
static int stackGrowsDown = 1;
#define GetCStackParams(iPtr) \
- stackGrowsDown = TclpGetCStackParams(&((iPtr)->stackBoundPtr))
+ stackGrowsDown = TclpGetCStackParams(&((iPtr)->stackBound))
-#define CheckStackSpace(iPtr, localIntPtr) \
+#define StackOverflow(iPtr, localIntPtr) \
(stackGrowsDown \
- ? ((localIntPtr) > *((iPtr)->stackBoundPtr)) \
- : ((localIntPtr) < *((iPtr)->stackBoundPtr)) \
+ ? ((localIntPtr) < (iPtr)->stackBound) \
+ : ((localIntPtr) > (iPtr)->stackBound) \
)
#else /* stack check disabled: make them noops */
-#define CheckStackSpace(interp, localIntPtr) 1
+#define StackOverflow(interp, localIntPtr) 0
#define GetCStackParams(iPtr)
#endif
@@ -3407,7 +3407,7 @@ int
TclInterpReady(
Tcl_Interp *interp)
{
- int localInt, stackOverflow; /* used for checking the stack */
+ int localInt; /* used for checking the stack */
register Interp *iPtr = (Interp *) interp;
/*
@@ -3435,17 +3435,8 @@ TclInterpReady(
* probably because of an infinite loop somewhere.
*/
- stackOverflow = !CheckStackSpace(iPtr, &localInt);
- if (stackOverflow) {
- /*
- * Update the stack params in case the thread's stack was grown.
- */
-
- GetCStackParams(iPtr);
- stackOverflow = !CheckStackSpace(iPtr, &localInt);
- }
-
- if (stackOverflow || ((iPtr->numLevels) > iPtr->maxNestingDepth)) {
+ if (((iPtr->numLevels) > iPtr->maxNestingDepth)
+ || StackOverflow(iPtr, &localInt)) {
Tcl_AppendResult(interp,
"too many nested evaluations (infinite loop?)", NULL);
return TCL_ERROR;
diff --git a/generic/tclInt.h b/generic/tclInt.h
index 1dc744c..6a72767 100644
--- a/generic/tclInt.h
+++ b/generic/tclInt.h
@@ -13,7 +13,7 @@
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
- * RCS: @(#) $Id: tclInt.h,v 1.339 2007/11/10 16:08:10 msofer Exp $
+ * RCS: @(#) $Id: tclInt.h,v 1.340 2007/11/10 19:01:35 msofer Exp $
*/
#ifndef _TCLINT
@@ -1855,7 +1855,7 @@ typedef struct Interp {
* tclObj.c and tclThreadAlloc.c */
int *asyncReadyPtr; /* Pointer to the asyncReady indicator for
* this interp's thread; see tclAsync.c */
- int **stackBoundPtr; /* Pointer to the limit stack address
+ int *stackBound; /* Pointer to the limit stack address
* allowable for invoking a new command
* without "risking" a C-stack overflow;
* see TclpCheckStackSpace in the
@@ -2502,7 +2502,7 @@ MODULE_SCOPE int TclParseAllWhiteSpace(CONST char *src, int numBytes);
MODULE_SCOPE int TclProcessReturn(Tcl_Interp *interp,
int code, int level, Tcl_Obj *returnOpts);
#ifndef TCL_NO_STACK_CHECK
-MODULE_SCOPE int TclpGetCStackParams(int ***stackBound);
+MODULE_SCOPE int TclpGetCStackParams(int **stackBoundPtr);
#endif
MODULE_SCOPE int TclpObjLstat(Tcl_Obj *pathPtr, Tcl_StatBuf *buf);
MODULE_SCOPE Tcl_Obj * TclpTempFileName(void);
diff --git a/unix/tclUnixInit.c b/unix/tclUnixInit.c
index 4ae061c..86edc38 100644
--- a/unix/tclUnixInit.c
+++ b/unix/tclUnixInit.c
@@ -7,7 +7,7 @@
* Copyright (c) 1999 by Scriptics Corporation.
* All rights reserved.
*
- * RCS: @(#) $Id: tclUnixInit.c,v 1.75 2007/11/10 16:08:10 msofer Exp $
+ * RCS: @(#) $Id: tclUnixInit.c,v 1.76 2007/11/10 19:01:35 msofer Exp $
*/
#include "tclInt.h"
@@ -78,7 +78,6 @@
typedef struct ThreadSpecificData {
int *outerVarPtr; /* The "outermost" stack frame pointer for
* this thread. */
- int stackDetermineResult; /* What happened when we did that? */
int *stackBound; /* The current stack boundary */
} ThreadSpecificData;
static Tcl_ThreadDataKey dataKey;
@@ -1028,21 +1027,21 @@ TclpFindVariable(
#ifndef TCL_NO_STACK_CHECK
int
TclpGetCStackParams(
- int ***stackBoundPtr)
+ int **stackBoundPtr)
{
- int localVar;
- size_t stackSize; /* The size of the current stack. */
+ int result = TCL_OK;
+ size_t stackSize = 0; /* The size of the current stack. */
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
/* Most variables are actually in a
* thread-specific data block to minimise the
* impact on the stack. */
-
+
if (stackGrowsDown == -1) {
/*
* Not initialised!
*/
- stackGrowsDown = StackGrowsDown(&localVar);
+ stackGrowsDown = StackGrowsDown(&result);
}
/*
@@ -1051,37 +1050,47 @@ TclpGetCStackParams(
*/
if (tsdPtr->outerVarPtr == NULL) {
- tsdPtr->outerVarPtr = &localVar;
- tsdPtr->stackDetermineResult = GetStackSize(&stackSize);
+ tsdPtr->outerVarPtr = &result;
+ result = GetStackSize(&stackSize);
+ if (result != TCL_OK) {
+ /* Can't check, assume it always succeeds */
+ stackGrowsDown = 1;
+ tsdPtr->stackBound = NULL;
+ goto done;
+ }
}
- if ((stackGrowsDown && (&localVar < tsdPtr->stackBound))
- || (!stackGrowsDown && (&localVar > tsdPtr->stackBound))) {
- /*
- * Stack failure - if we didn't already blow up, we are within the
- * safety area. Recheck with the OS in case the stack was grown.
- */
+ if (stackSize || (stackGrowsDown && (&result < tsdPtr->stackBound))
+ || (!stackGrowsDown && (&result > tsdPtr->stackBound))) {
+ /*
+ * Either the thread's first pass or stack failure: set the params
+ */
- tsdPtr->stackDetermineResult = GetStackSize(&stackSize);
- }
+ if (!stackSize) {
+ /*
+ * Stack failure: if we didn't already blow up, we are within the
+ * safety area. Recheck with the OS in case the stack was grown.
+ */
+ result = GetStackSize(&stackSize);
+ if (result != TCL_OK) {
+ /* Can't check, assume it always succeeds */
+ stackGrowsDown = 1;
+ tsdPtr->stackBound = NULL;
+ goto done;
+ }
+ }
- if (tsdPtr->stackDetermineResult != TCL_OK) {
- switch (tsdPtr->stackDetermineResult) {
- case TCL_BREAK:
- STACK_DEBUG(("skipping stack checks with failure\n"));
- case TCL_CONTINUE:
- STACK_DEBUG(("skipping stack checks with success\n"));
+ if (stackGrowsDown) {
+ tsdPtr->stackBound = (int *) ((char *)tsdPtr->outerVarPtr -
+ stackSize);
+ } else {
+ tsdPtr->stackBound = (int *) ((char *)tsdPtr->outerVarPtr +
+ stackSize);
}
- stackGrowsDown = 1;
- tsdPtr->stackBound = NULL;
- } else if (stackGrowsDown) {
- tsdPtr->stackBound = (int *) ((char *)tsdPtr->outerVarPtr -
- stackSize);
- } else {
- tsdPtr->stackBound = (int *) ((char *)tsdPtr->outerVarPtr +
- stackSize);
}
- *stackBoundPtr = &(tsdPtr->stackBound);
+
+ done:
+ *stackBoundPtr = tsdPtr->stackBound;
return stackGrowsDown;
}
@@ -1132,6 +1141,7 @@ GetStackSize(
/*
* Some kind of confirmed error?!
*/
+ STACK_DEBUG(("skipping stack checks with failure\n"));
return TCL_BREAK;
}
if (rawStackSize > 0) {
@@ -1149,12 +1159,14 @@ GetStackSize(
/*
* getrlimit() failed, just fail the whole thing.
*/
+ STACK_DEBUG(("skipping stack checks with failure: getrlimit failed\n"));
return TCL_BREAK;
}
if (rLimit.rlim_cur == RLIM_INFINITY) {
/*
* Limit is "infinite"; there is no stack limit.
*/
+ STACK_DEBUG(("skipping stack checks with success: infinite limit\n"));
return TCL_CONTINUE;
}
rawStackSize = rLimit.rlim_cur;
@@ -1169,6 +1181,7 @@ GetStackSize(
finalSanityCheck:
#endif
if (rawStackSize <= 0) {
+ STACK_DEBUG(("skipping stack checks with success\n"));
return TCL_CONTINUE;
}
diff --git a/win/tclWin32Dll.c b/win/tclWin32Dll.c
index 0ad344e..e7d20f5 100644
--- a/win/tclWin32Dll.c
+++ b/win/tclWin32Dll.c
@@ -10,7 +10,7 @@
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
- * RCS: @(#) $Id: tclWin32Dll.c,v 1.51 2007/11/10 17:40:35 kennykb Exp $
+ * RCS: @(#) $Id: tclWin32Dll.c,v 1.52 2007/11/10 19:01:35 msofer Exp $
*/
#include "tclWinInt.h"
@@ -544,7 +544,7 @@ TclWinNoBackslash(
#ifndef TCL_NO_STACK_CHECK
int
TclpGetCStackParams(
- int ***stackBoundPtr)
+ int **stackBoundPtr)
{
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
SYSTEM_INFO si; /* The system information, used to
@@ -592,7 +592,7 @@ TclpGetCStackParams(
+ TCL_WIN_STACK_THRESHOLD);
}
}
- *stackBoundPtr = &(tsdPtr->stackBound);
+ *stackBoundPtr = tsdPtr->stackBound;
return 1;
}
#endif