diff options
| -rw-r--r-- | ChangeLog | 5 | ||||
| -rw-r--r-- | generic/tclInt.h | 128 | ||||
| -rw-r--r-- | generic/tclObj.c | 4 |
3 files changed, 74 insertions, 63 deletions
@@ -1,5 +1,10 @@ 2004-06-18 Donal K. Fellows <donal.k.fellows@man.ac.uk> + * generic/tclInt.h (PendingObjData,TclFreeObjMacro,etc): + * generic/tclObj.c (TclFreeObj): Added scheme for making TclFreeObj() + avoid blowing up the C stack when freeing up very large object + trees. [Bug 886231] + * win/tclWinInit.c (SetDefaultLibraryDir): Fix logic, simplify and add comments. diff --git a/generic/tclInt.h b/generic/tclInt.h index 8dbecfa..e96b5a8 100644 --- a/generic/tclInt.h +++ b/generic/tclInt.h @@ -12,7 +12,7 @@ * 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 1.163 2004/06/18 13:42:41 dkf Exp $ + * RCS: @(#) $Id: tclInt.h,v 1.164 2004/06/18 15:12:39 dkf Exp $ */ #ifndef _TCLINT @@ -2198,66 +2198,12 @@ EXTERN Tcl_Obj *TclPtrIncrWideVar _ANSI_ARGS_((Tcl_Interp *interp, Var *varPtr, # define TclIncrObjsFreed() #endif /* TCL_COMPILE_STATS */ -#ifndef TCL_MEM_DEBUG -# define TclNewObj(objPtr) \ - TclIncrObjsAllocated(); \ - TclAllocObjStorage(objPtr); \ - (objPtr)->refCount = 0; \ - (objPtr)->bytes = tclEmptyStringRep; \ - (objPtr)->length = 0; \ - (objPtr)->typePtr = NULL - -# define TclDecrRefCount(objPtr) \ - if (--(objPtr)->refCount <= 0) { \ - TclObjInitDeletionContext(contextPtr); \ - if (TclObjDeletePending(contextPtr)) { \ - TclPushObjToDelete(contextPtr,objPtr); \ - } else { \ - TclFreeObjMacro(contextPtr,objPtr); \ - } \ - } - /* - * Note that the contents of the while loop assume that the string rep - * has already been freed and we don't want to do anything fancy with - * adding to the queue inside ourselves. Must take care to unstack the - * object first since freeing the internal rep can add further objects - * to the stack. The code assumes that it is the first thing in a - * block; all current usages in the core satisfy this. - * - * Optimization opportunity: Allocate the context once in a large - * function (e.g. TclExecuteByteCode) and use it directly instead of - * looking it up each time. - */ -#define TclFreeObjMacro(contextPtr,objPtr) \ - if (((objPtr)->typePtr != NULL) \ - && ((objPtr)->typePtr->freeIntRepProc != NULL)) { \ - TclObjDeletionLock(contextPtr); \ - (objPtr)->typePtr->freeIntRepProc(objPtr); \ - TclObjDeletionUnlock(contextPtr); \ - } \ - if (((objPtr)->bytes != NULL) \ - && ((objPtr)->bytes != tclEmptyStringRep)) { \ - ckfree((char *) (objPtr)->bytes); \ - } \ - TclFreeObjStorage(objPtr); \ - TclIncrObjsFreed(); \ - TclObjDeletionLock(contextPtr); \ - while (TclObjOnStack(contextPtr)) { \ - Tcl_Obj *objToFree; \ - TclPopObjToDelete(contextPtr,objToFree); \ - if ((objToFre->typePtr != NULL) \ - && (objToFree->typePtr->freeIntRepProc != NULL)) { \ - objToFree->typePtr->freeIntRepProc(objToFree); \ - } \ - TclFreeObjStorage(objToFree); \ - TclIncrObjsFreed(); \ - } \ - TclObjDeletionUnlock(contextPtr) - -/* - * All context references are pointers to this structure; every thread - * will have its own reference. + * All context references used in the object freeing code are pointers + * to this structure; every thread will have its own structure + * instance. The purpose of this structure is to allow deeply nested + * collections of Tcl_Objs to be freed without taking a vast depth of + * C stack (which could cause all sorts of breakage.) */ typedef struct PendingObjData { @@ -2308,6 +2254,9 @@ typedef struct PendingObjData { (objPtrVar) = (contextPtr)->deletionStack; \ (contextPtr)->deletionStack = (Tcl_Obj *) (objPtrVar)->bytes +/* + * Macro to set up the local reference to the deletion context. + */ #ifndef TCL_THREADS extern PendingObjData tclPendingObjData; #define TclObjInitDeletionContext(contextPtr) \ @@ -2316,9 +2265,66 @@ extern PendingObjData tclPendingObjData; extern Tcl_ThreadDataKey tclPendingObjDataKey; #define TclObjInitDeletionContext(contextPtr) \ PendingObjData *CONST contextPtr = (PendingObjData *) \ - Tcl_GetThreadData(&pendingObjDataKey, sizeof(PendingObjData)) + Tcl_GetThreadData(&tclPendingObjDataKey, sizeof(PendingObjData)) #endif +#ifndef TCL_MEM_DEBUG +# define TclNewObj(objPtr) \ + TclIncrObjsAllocated(); \ + TclAllocObjStorage(objPtr); \ + (objPtr)->refCount = 0; \ + (objPtr)->bytes = tclEmptyStringRep; \ + (objPtr)->length = 0; \ + (objPtr)->typePtr = NULL + +# define TclDecrRefCount(objPtr) \ + if (--(objPtr)->refCount <= 0) { \ + TclObjInitDeletionContext(contextPtr); \ + if (TclObjDeletePending(contextPtr)) { \ + TclPushObjToDelete(contextPtr,objPtr); \ + } else { \ + TclFreeObjMacro(contextPtr,objPtr); \ + } \ + } + +/* + * Note that the contents of the while loop assume that the string rep + * has already been freed and we don't want to do anything fancy with + * adding to the queue inside ourselves. Must take care to unstack the + * object first since freeing the internal rep can add further objects + * to the stack. The code assumes that it is the first thing in a + * block; all current usages in the core satisfy this. + * + * Optimization opportunity: Allocate the context once in a large + * function (e.g. TclExecuteByteCode) and use it directly instead of + * looking it up each time. + */ +#define TclFreeObjMacro(contextPtr,objPtr) \ + if (((objPtr)->typePtr != NULL) \ + && ((objPtr)->typePtr->freeIntRepProc != NULL)) { \ + TclObjDeletionLock(contextPtr); \ + (objPtr)->typePtr->freeIntRepProc(objPtr); \ + TclObjDeletionUnlock(contextPtr); \ + } \ + if (((objPtr)->bytes != NULL) \ + && ((objPtr)->bytes != tclEmptyStringRep)) { \ + ckfree((char *) (objPtr)->bytes); \ + } \ + TclFreeObjStorage(objPtr); \ + TclIncrObjsFreed(); \ + TclObjDeletionLock(contextPtr); \ + while (TclObjOnStack(contextPtr)) { \ + Tcl_Obj *objToFree; \ + TclPopObjToDelete(contextPtr,objToFree); \ + if ((objToFree->typePtr != NULL) \ + && (objToFree->typePtr->freeIntRepProc != NULL)) { \ + objToFree->typePtr->freeIntRepProc(objToFree); \ + } \ + TclFreeObjStorage(objToFree); \ + TclIncrObjsFreed(); \ + } \ + TclObjDeletionUnlock(contextPtr) + #if defined(PURIFY) /* diff --git a/generic/tclObj.c b/generic/tclObj.c index ba617cf..ec3eeb5 100644 --- a/generic/tclObj.c +++ b/generic/tclObj.c @@ -11,7 +11,7 @@ * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclObj.c,v 1.61 2004/06/18 13:42:41 dkf Exp $ + * RCS: @(#) $Id: tclObj.c,v 1.62 2004/06/18 15:12:39 dkf Exp $ */ #include "tclInt.h" @@ -793,7 +793,7 @@ TclFreeObj(objPtr) TclPopObjToDelete(context,objToFree); - if ((objToFre->typePtr != NULL) + if ((objToFree->typePtr != NULL) && (objToFree->typePtr->freeIntRepProc != NULL)) { objToFree->typePtr->freeIntRepProc(objToFree); } |