diff options
-rw-r--r-- | ChangeLog | 5 | ||||
-rw-r--r-- | generic/tclExecute.c | 92 |
2 files changed, 78 insertions, 19 deletions
@@ -1,3 +1,8 @@ +2002-08-01 Miguel Sofer <msofer@users.sourceforge.net> + + * generic/tclExecute.c: added a reference count for the complete + execution stack, instead of Tcl_Preserve/Tcl_Release. + 2002-08-01 Mo DeJong <mdejong@users.sourceforge.net> * generic/tclCkalloc.c (TclFinalizeMemorySubsystem): diff --git a/generic/tclExecute.c b/generic/tclExecute.c index a1ba0cb..24613aa 100644 --- a/generic/tclExecute.c +++ b/generic/tclExecute.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: tclExecute.c,v 1.86 2002/07/31 09:57:34 dkf Exp $ + * RCS: @(#) $Id: tclExecute.c,v 1.87 2002/08/01 20:02:11 msofer Exp $ */ #include "tclInt.h" @@ -513,11 +513,22 @@ TclCreateExecEnv(interp) * environment is being created. */ { ExecEnv *eePtr = (ExecEnv *) ckalloc(sizeof(ExecEnv)); + Tcl_Obj **stackPtr; + + stackPtr = (Tcl_Obj **) + ckalloc((size_t) (TCL_STACK_INITIAL_SIZE * sizeof(Tcl_Obj *))); + + /* + * Use the bottom pointer to keep a reference count; the + * execution environment holds a reference. + */ + + stackPtr++; + eePtr->stackPtr = stackPtr; + stackPtr[-1] = (Tcl_Obj *) ((char *) 1); - eePtr->stackPtr = (Tcl_Obj **) - ckalloc((unsigned) (TCL_STACK_INITIAL_SIZE * sizeof(Tcl_Obj *))); eePtr->stackTop = -1; - eePtr->stackEnd = (TCL_STACK_INITIAL_SIZE - 1); + eePtr->stackEnd = (TCL_STACK_INITIAL_SIZE - 2); eePtr->errorInfo = Tcl_NewStringObj("::errorInfo", -1); Tcl_IncrRefCount(eePtr->errorInfo); @@ -558,7 +569,11 @@ void TclDeleteExecEnv(eePtr) ExecEnv *eePtr; /* Execution environment to free. */ { - Tcl_EventuallyFree((ClientData)eePtr->stackPtr, TCL_DYNAMIC); + if (eePtr->stackPtr[-1] == (Tcl_Obj *) ((char *) 1)) { + ckfree((char *) (eePtr->stackPtr-1)); + } else { + panic("ERROR: freeing an execEnv whose stack is still in use.\n"); + } TclDecrRefCount(eePtr->errorInfo); TclDecrRefCount(eePtr->errorCode); ckfree((char *) eePtr); @@ -621,18 +636,44 @@ GrowEvaluationStack(eePtr) int newElems = 2*currElems; int currBytes = currElems * sizeof(Tcl_Obj *); int newBytes = 2*currBytes; - Tcl_Obj **newStackPtr = (Tcl_Obj **) ckalloc((unsigned) newBytes); + Tcl_Obj **newStackPtr; + Tcl_Obj **oldStackPtr = eePtr->stackPtr; /* - * Copy the existing stack items to the new stack space, free the old - * storage if appropriate, and mark new space as malloc'ed. + * We keep the stack reference count as a (char *), as that + * works nicely as a portable pointer-sized counter. + */ + + char *refCount = (char *) oldStackPtr[-1]; + + /* + * Realloc the stack: copy existing stack items to the new stack + * space, free the old storage if appropriate. */ - memcpy((VOID *) newStackPtr, (VOID *) eePtr->stackPtr, - (size_t) currBytes); - Tcl_EventuallyFree((ClientData)eePtr->stackPtr, TCL_DYNAMIC); + newStackPtr = (Tcl_Obj **) ckrealloc((VOID *) (oldStackPtr-1), + (unsigned) newBytes); + newStackPtr++; eePtr->stackPtr = newStackPtr; - eePtr->stackEnd = (newElems - 1); /* i.e. index of last usable item */ + eePtr->stackEnd = (newElems - 2); /* index of last usable item */ + + if (newStackPtr != oldStackPtr) { + /* + * The stack was moved; update the refCounts. + */ + + newStackPtr[-1] = (Tcl_Obj *) ((char *) 1); + if (refCount == (char *) 1) { + ckfree((VOID *) (oldStackPtr-1)); + } else { + /* + * Remove the reference corresponding to the + * environment pointer. + */ + + oldStackPtr[-1] = (Tcl_Obj *) (refCount-1); + } + } } /* @@ -1304,10 +1345,20 @@ TclExecuteByteCode(interp, codePtr) { int objc = opnd; /* The number of arguments. */ Tcl_Obj **objv; /* The array of argument objects. */ - Tcl_Obj **preservedStack; - /* Reference to memory block containing + + /* + * We keep the stack reference count as a (char *), as that + * works nicely as a portable pointer-sized counter. + */ + + char **preservedStackRefCountPtr; + + /* + * Reference to memory block containing * objv array (must be kept live throughout - * trace and command invokations.) */ + * trace and command invokations.) + */ + objv = &(stackPtr[stackTop - (objc-1)]); #ifdef TCL_COMPILE_DEBUG @@ -1364,15 +1415,15 @@ TclExecuteByteCode(interp, codePtr) /* * A reference to part of the stack vector itself - * escapes our control, so must use preserve/release + * escapes our control: increase its refCount * to stop it from being deallocated by a recursive * call to ourselves. The extra variable is needed * because all others are liable to change due to the * trace procedures. */ - Tcl_Preserve((ClientData)stackPtr); - preservedStack = stackPtr; + preservedStackRefCountPtr = (char **) (stackPtr-1); + ++*preservedStackRefCountPtr; /* * Finally, let TclEvalObjvInternal handle the command. @@ -1389,7 +1440,10 @@ TclExecuteByteCode(interp, codePtr) * going to be used from now on. */ - Tcl_Release((ClientData) preservedStack); + --*preservedStackRefCountPtr; + if (*preservedStackRefCountPtr == (char *) 0) { + ckfree((VOID *) preservedStackRefCountPtr); + } if (result == TCL_OK) { /* |