From 1da12398f20df3780c9e7d34f0329f7d8cf8e2d1 Mon Sep 17 00:00:00 2001 From: pooryorick Date: Thu, 15 Feb 2018 06:35:02 +0000 Subject: Streamline TclOO object cleanup routines. --- generic/tclOO.c | 484 ++++++++++++++++++++++------------------------------- generic/tclOOInt.h | 4 + 2 files changed, 208 insertions(+), 280 deletions(-) diff --git a/generic/tclOO.c b/generic/tclOO.c index a27f92c..2a5d92c 100644 --- a/generic/tclOO.c +++ b/generic/tclOO.c @@ -4,6 +4,7 @@ * This file contains the object-system core (NB: not Tcl_Obj, but ::oo) * * Copyright (c) 2005-2012 by Donal K. Fellows + * Copyright (c) 2017 by Nathan Coulter * * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. @@ -81,7 +82,6 @@ static void ObjectRenamedTrace(ClientData clientData, const char *newName, int flags); static void ReleaseClassContents(Tcl_Interp *interp,Object *oPtr); static inline void SquelchCachedName(Object *oPtr); -static void SquelchedNsFirst(ClientData clientData); static int PublicObjectCmd(ClientData clientData, Tcl_Interp *interp, int objc, @@ -582,8 +582,7 @@ AllocObject( */ if (nsNameStr != NULL) { - oPtr->namespacePtr = Tcl_CreateNamespace(interp, nsNameStr, oPtr, - ObjectNamespaceDeleted); + oPtr->namespacePtr = Tcl_CreateNamespace(interp, nsNameStr, oPtr, NULL); if (oPtr->namespacePtr != NULL) { creationEpoch = ++fPtr->tsdPtr->nsCount; goto configNamespace; @@ -595,8 +594,7 @@ AllocObject( char objName[10 + TCL_INTEGER_SPACE]; sprintf(objName, "::oo::Obj%d", ++fPtr->tsdPtr->nsCount); - oPtr->namespacePtr = Tcl_CreateNamespace(interp, objName, oPtr, - ObjectNamespaceDeleted); + oPtr->namespacePtr = Tcl_CreateNamespace(interp, objName, oPtr, NULL); if (oPtr->namespacePtr != NULL) { creationEpoch = fPtr->tsdPtr->nsCount; break; @@ -636,7 +634,7 @@ AllocObject( * access variables in it. [Bug 2950259] */ - ((Namespace *) oPtr->namespacePtr)->earlyDeleteProc = SquelchedNsFirst; + ((Namespace *) oPtr->namespacePtr)->earlyDeleteProc = ObjectNamespaceDeleted; /* * Fill in the rest of the non-zero/NULL parts of the structure. @@ -751,30 +749,6 @@ MyDeleted( /* * ---------------------------------------------------------------------- * - * SquelchedNsFirst -- - * - * This callback is triggered when the object's namespace is deleted by - * any mechanism. It deletes the object's public command if it has not - * already been deleted, so ensuring that destructors get run at an - * appropriate time. [Bug 2950259] - * - * ---------------------------------------------------------------------- - */ - -static void -SquelchedNsFirst( - ClientData clientData) -{ - Object *oPtr = clientData; - - if (oPtr->command) { - Tcl_DeleteCommandFromToken(oPtr->fPtr->interp, oPtr->command); - } -} - -/* - * ---------------------------------------------------------------------- - * * ObjectRenamedTrace -- * * This callback is triggered when the object is deleted by any @@ -794,8 +768,6 @@ ObjectRenamedTrace( int flags) /* Why was the object deleted? */ { Object *oPtr = clientData; - Foundation *fPtr = oPtr->fPtr; - /* * If this is a rename and not a delete of the object, we just flush the * cache of the object name. @@ -807,87 +779,35 @@ ObjectRenamedTrace( } /* - * Oh dear, the object really is being deleted. Handle this by running the - * destructors and deleting the object's namespace, which in turn causes - * the real object structures to be deleted. - * - * Note that it is possible for the namespace to be deleted before the - * command. Because of that case, we must take care here to mark the - * command as being deleted so that if we return here we don't run into - * reentrancy problems. - * - * We also do not run destructors on the core class objects when the - * interpreter is being deleted; their incestuous nature causes problems - * in that case when the destructor is partially deleted before the uses - * of it have gone. [Bug 2949397] - */ - - AddRef(oPtr); - AddRef(fPtr->classCls); - AddRef(fPtr->objectCls); - AddRef(fPtr->classCls->thisPtr); - AddRef(fPtr->objectCls->thisPtr); - oPtr->command = NULL; - - if (!(oPtr->flags & DESTRUCTOR_CALLED) && !Tcl_InterpDeleted(interp)) { - CallContext *contextPtr = - TclOOGetCallContext(oPtr, NULL, DESTRUCTOR, NULL); - int result; - Tcl_InterpState state; - - oPtr->flags |= DESTRUCTOR_CALLED; - if (contextPtr != NULL) { - contextPtr->callPtr->flags |= DESTRUCTOR; - contextPtr->skip = 0; - state = Tcl_SaveInterpState(interp, TCL_OK); - result = Tcl_NRCallObjProc(interp, TclOOInvokeContext, - contextPtr, 0, NULL); - if (result != TCL_OK) { - Tcl_BackgroundException(interp, result); - } - Tcl_RestoreInterpState(interp, state); - TclOODeleteContext(contextPtr); - } - } - - /* - * OK, the destructor's been run. Time to splat the class data (if any) - * and nuke the namespace (which triggers the final crushing of the object - * structure itself). - * - * The class of objects needs some special care; if it is deleted (and - * we're not killing the whole interpreter) we force the delete of the - * class of classes now as well. Due to the incestuous nature of those two - * classes, if one goes the other must too and yet the tangle can - * sometimes not go away automatically; we force it here. [Bug 2962664] - */ - - if (!Tcl_InterpDeleted(interp) && IsRootObject(oPtr) - && !Deleted(fPtr->classCls->thisPtr)) { - Tcl_DeleteCommandFromToken(interp, fPtr->classCls->thisPtr->command); - } - - if (oPtr->classPtr != NULL) { - AddRef(oPtr->classPtr); - ReleaseClassContents(interp, oPtr); - } - - /* * The namespace is only deleted if it hasn't already been deleted. [Bug - * 2950259] + * 2950259]. If the namespace has already been deleted, then + * ObjectNamespaceDeleted() has already cleaned up this command. */ - if (oPtr->namespacePtr && ((Namespace *) oPtr->namespacePtr)->earlyDeleteProc != NULL) { - Tcl_DeleteNamespace(oPtr->namespacePtr); - } - if (oPtr->classPtr) { - DelRef(oPtr->classPtr); + if (oPtr->namespacePtr == NULL) { + /* + * ObjectNamespaceDeleted() has already done all the cleanup, but + * detected that the command was in the process of being deleted, and + * left the pointer allocated for us. + */ + DelRef(oPtr); + } else { + if (((Namespace *) oPtr->namespacePtr)->earlyDeleteProc == NULL) { + /* + * ObjectNamespaceDeleted() called us, and still has some work to + * do, so we leave the pointer allocated for it to finish, and then + * it will deallocate the pointer. + */ + } else { + Tcl_DeleteNamespace(oPtr->namespacePtr); + /* + * ObjectNamespaceDeleted() doesn't know it was us that just + * called, so it left the pointer allocated. + */ + DelRef(oPtr); + } } - DelRef(fPtr->classCls->thisPtr); - DelRef(fPtr->objectCls->thisPtr); - DelRef(fPtr->classCls); - DelRef(fPtr->objectCls); - DelRef(oPtr); + return; } /* @@ -959,7 +879,9 @@ ReleaseClassContents( int i; Class *clsPtr = oPtr->classPtr, *mixinSubclassPtr, *subclassPtr; Object *instancePtr; + Method *mPtr; Foundation *fPtr = oPtr->fPtr; + Tcl_Obj *variableObj; /* * Sanity check! @@ -1150,6 +1072,26 @@ ReleaseClassContents( ckfree(clsPtr->metadataPtr); clsPtr->metadataPtr = NULL; } + + ClearMixins(clsPtr); + ClearSuperclasses(clsPtr); + + FOREACH_HASH_VALUE(mPtr, &clsPtr->classMethods) { + TclOODelMethodRef(mPtr); + } + Tcl_DeleteHashTable(&clsPtr->classMethods); + TclOODelMethodRef(clsPtr->constructorPtr); + TclOODelMethodRef(clsPtr->destructorPtr); + + FOREACH(variableObj, clsPtr->variables) { + TclDecrRefCount(variableObj); + } + if (i) { + ckfree(clsPtr->variables.list); + } + + DelRef(clsPtr); + } /* @@ -1171,36 +1113,92 @@ ObjectNamespaceDeleted( * being deleted. */ { Object *oPtr = clientData; + Foundation *fPtr = oPtr->fPtr; FOREACH_HASH_DECLS; - Class *clsPtr = oPtr->classPtr, *mixinPtr; + Class *mixinPtr; Method *mPtr; Tcl_Obj *filterObj, *variableObj; - int deleteAlreadyInProgress = 0, i; + Tcl_Interp *interp = oPtr->fPtr->interp; + int finished = 0, i; + + + AddRef(fPtr->classCls); + AddRef(fPtr->objectCls); + AddRef(fPtr->classCls->thisPtr); + AddRef(fPtr->objectCls->thisPtr); /* - * Instruct everyone to no longer use any allocated fields of the object. - * Also delete the commands that refer to the object at this point (if - * they still exist) because otherwise their references to the object - * point into freed memory, allowing crashes. + * We do not run destructors on the core class objects when the + * interpreter is being deleted; their incestuous nature causes problems + * in that case when the destructor is partially deleted before the uses + * of it have gone. [Bug 2949397] */ - if (oPtr->command) { - if ((((Command *)oPtr->command)->flags && CMD_IS_DELETED)) { - /* - * Namespace deletion must have been triggered by a trace on command - * deletion , meaning that ObjectRenamedTrace() is eventually going - * to be called . - */ - deleteAlreadyInProgress = 1; + if (!(oPtr->flags & DESTRUCTOR_CALLED) && !Tcl_InterpDeleted(interp)) { + CallContext *contextPtr = + TclOOGetCallContext(oPtr, NULL, DESTRUCTOR, NULL); + int result; + + Tcl_InterpState state; + + oPtr->flags |= DESTRUCTOR_CALLED; + if (contextPtr != NULL) { + contextPtr->callPtr->flags |= DESTRUCTOR; + contextPtr->skip = 0; + state = Tcl_SaveInterpState(interp, TCL_OK); + result = Tcl_NRCallObjProc(interp, TclOOInvokeContext, + contextPtr, 0, NULL); + if (result != TCL_OK) { + Tcl_BackgroundException(interp, result); + } + Tcl_RestoreInterpState(interp, state); + TclOODeleteContext(contextPtr); } + } + /* + * Instruct everyone to no longer use any allocated fields of the object. + * Also delete the command that refers to the object at this point (if + * it still exists) because otherwise its pointer to the object + * points into freed memory. + */ + + if ((((Command *)oPtr->command)->flags && CMD_IS_DELETED)) { + /* + * Something has already started the command deletion process. We can + * go ahead and clean up the the namespace, + */ + } else { + /* + * The namespace must have been deleted directly. Delete the command + * as well. + */ Tcl_DeleteCommandFromToken(oPtr->fPtr->interp, oPtr->command); + finished = 1; } + oPtr->command = NULL; + if (oPtr->myCommand) { Tcl_DeleteCommandFromToken(oPtr->fPtr->interp, oPtr->myCommand); } /* + * The class of objects needs some special care; if it is deleted (and + * we're not killing the whole interpreter) we force the delete of the + * class of classes now as well. Due to the incestuous nature of those two + * classes, if one goes the other must too and yet the tangle can + * sometimes not go away automatically; we force it here. [Bug 2962664] + */ + if (!Tcl_InterpDeleted(interp) && IsRootObject(oPtr) + && !Deleted(fPtr->classCls->thisPtr)) { + Tcl_DeleteCommandFromToken(interp, fPtr->classCls->thisPtr->command); + } + + if (oPtr->classPtr != NULL) { + ReleaseClassContents(interp, oPtr); + } + + /* * Splice the object out of its context. After this, we must *not* call * methods on the object. */ @@ -1259,77 +1257,27 @@ ObjectNamespaceDeleted( } /* - * If this was a class, there's additional deletion work to do. - */ - - if (clsPtr != NULL) { - Tcl_ObjectMetadataType *metadataTypePtr; - ClientData value; - - if (clsPtr->metadataPtr != NULL) { - FOREACH_HASH(metadataTypePtr, value, clsPtr->metadataPtr) { - metadataTypePtr->deleteProc(value); - } - Tcl_DeleteHashTable(clsPtr->metadataPtr); - ckfree(clsPtr->metadataPtr); - clsPtr->metadataPtr = NULL; - } - - FOREACH(filterObj, clsPtr->filters) { - TclDecrRefCount(filterObj); - } - if (i) { - ckfree(clsPtr->filters.list); - clsPtr->filters.num = 0; - } - - ClearMixins(clsPtr); - - ClearSuperclasses(clsPtr); - - if (clsPtr->subclasses.list) { - ckfree(clsPtr->subclasses.list); - clsPtr->subclasses.list = NULL; - clsPtr->subclasses.num = 0; - } - if (clsPtr->instances.list) { - ckfree(clsPtr->instances.list); - clsPtr->instances.list = NULL; - clsPtr->instances.num = 0; - } - if (clsPtr->mixinSubs.list) { - ckfree(clsPtr->mixinSubs.list); - clsPtr->mixinSubs.list = NULL; - clsPtr->mixinSubs.num = 0; - } - - FOREACH_HASH_VALUE(mPtr, &clsPtr->classMethods) { - TclOODelMethodRef(mPtr); - } - Tcl_DeleteHashTable(&clsPtr->classMethods); - TclOODelMethodRef(clsPtr->constructorPtr); - TclOODelMethodRef(clsPtr->destructorPtr); - - FOREACH(variableObj, clsPtr->variables) { - TclDecrRefCount(variableObj); - } - if (i) { - ckfree(clsPtr->variables.list); - } - - DelRef(clsPtr); - } - - /* * Delete the object structure itself. */ - if (deleteAlreadyInProgress) { - oPtr->classPtr = NULL; - oPtr->namespacePtr = NULL; - } else { + oPtr->classPtr = NULL; + oPtr->namespacePtr = NULL; + + DelRef(fPtr->classCls->thisPtr); + DelRef(fPtr->objectCls->thisPtr); + DelRef(fPtr->classCls); + DelRef(fPtr->objectCls); + if (finished) { + /* + * ObjectRenamedTrace called us, and not the other way around. + */ DelRef(oPtr); + } else { + /* + * ObjectRenamedTrace will call DelRef(oPtr). + */ } + return; } @@ -1423,7 +1371,7 @@ TclOOAddToInstances( void TclOORemoveFromSubclasses( Class *subPtr, /* The subclass to remove. */ - Class *superPtr) /* The superclass to (possibly) remove the + Class *superPtr) /* The superclass to possibly remove the * subclass reference from. */ { int i; @@ -1494,7 +1442,7 @@ TclOOAddToSubclasses( void TclOORemoveFromMixinSubs( Class *subPtr, /* The subclass to remove. */ - Class *superPtr) /* The superclass to (possibly) remove the + Class *superPtr) /* The superclass to possibly remove the * subclass reference from. */ { int i; @@ -1568,7 +1516,7 @@ AllocClass( * class. */ Object *useThisObj) /* Object that is to act as the class * representation, or NULL if a new object - * (with automatic name) is to be used. */ + * with automatic name is to be used. */ { Foundation *fPtr = GetFoundation(interp); Class *clsPtr = ckalloc(sizeof(Class)); @@ -1640,7 +1588,6 @@ AllocClass( * * ---------------------------------------------------------------------- */ - Tcl_Object Tcl_NewObjectInstance( Tcl_Interp *interp, /* Interpreter context. */ @@ -1657,54 +1604,14 @@ Tcl_NewObjectInstance( * constructor. */ { register Class *classPtr = (Class *) cls; - Foundation *fPtr = GetFoundation(interp); Object *oPtr; - /* - * Check if we're going to create an object over an existing command; - * that's not allowed. - */ - - if (nameStr && Tcl_FindCommand(interp, nameStr, NULL, - TCL_NAMESPACE_ONLY)) { - Tcl_SetObjResult(interp, Tcl_ObjPrintf( - "can't create object \"%s\": command already exists with" - " that name", nameStr)); - Tcl_SetErrorCode(interp, "TCL", "OO", "OVERWRITE_OBJECT", NULL); - return NULL; - } - - /* - * Create the object. - */ - - oPtr = AllocObject(interp, nameStr, nsNameStr); - oPtr->selfCls = classPtr; - TclOOAddToInstances(oPtr, classPtr); - - /* - * Check to see if we're really creating a class. If so, allocate the - * class structure as well. - */ - - if (TclOOIsReachable(fPtr->classCls, classPtr)) { - /* - * Is a class, so attach a class structure. Note that the AllocClass - * function splices the structure into the object, so we don't have - * to. Once that's done, we need to repatch the object to have the - * right class since AllocClass interferes with that. - */ - - AllocClass(interp, oPtr); - oPtr->selfCls = classPtr; - TclOOAddToSubclasses(oPtr->classPtr, fPtr->objectCls); - } else { - oPtr->classPtr = NULL; - } + oPtr = TclNewObjectInstanceCommon(interp, classPtr, nameStr, nsNameStr); + if (oPtr == NULL) {return NULL;} /* - * Run constructors, except when objc < 0 (a special flag case used for - * object cloning only). + * Run constructors, except when objc < 0, which is a special flag case + * used for object cloning only. */ if (objc >= 0) { @@ -1732,9 +1639,8 @@ Tcl_NewObjectInstance( } /* - * It's an error if the object was whacked in the constructor. - * Force this if it isn't already an error (don't want to lose - * errors by accident...) [Bug 2903011] + * Ensure an error if the object was deleted in the constructor. + * Don't want to lose errors by accident. [Bug 2903011] */ if (result != TCL_ERROR && Deleted(oPtr)) { @@ -1785,7 +1691,6 @@ TclNRNewObjectInstance( * successful allocation. */ { register Class *classPtr = (Class *) cls; - Foundation *fPtr = GetFoundation(interp); CallContext *contextPtr; Tcl_InterpState state; Object *oPtr; @@ -1795,45 +1700,8 @@ TclNRNewObjectInstance( */ AddRef(classPtr); - /* - * Check if we're going to create an object over an existing command; - * that's not allowed. - */ - - if (nameStr && Tcl_FindCommand(interp, nameStr, NULL, - TCL_NAMESPACE_ONLY)) { - Tcl_SetObjResult(interp, Tcl_ObjPrintf( - "can't create object \"%s\": command already exists with" - " that name", nameStr)); - Tcl_SetErrorCode(interp, "TCL", "OO", "OVERWRITE_OBJECT", NULL); - return TCL_ERROR; - } - - /* - * Create the object. - */ - - oPtr = AllocObject(interp, nameStr, nsNameStr); - oPtr->selfCls = classPtr; - TclOOAddToInstances(oPtr, classPtr); - - /* - * Check to see if we're really creating a class. If so, allocate the - * class structure as well. - */ - - if (TclOOIsReachable(fPtr->classCls, classPtr)) { - /* - * Is a class, so attach a class structure. Note that the AllocClass - * function splices the structure into the object, so we don't have - * to. Once that's done, we need to repatch the object to have the - * right class since AllocClass interferes with that. - */ - - AllocClass(interp, oPtr); - oPtr->selfCls = classPtr; - TclOOAddToSubclasses(oPtr->classPtr, fPtr->objectCls); - } + oPtr = TclNewObjectInstanceCommon(interp, classPtr, nameStr, nsNameStr); + if (oPtr == NULL) {return TCL_ERROR;} /* * Run constructors, except when objc < 0 (a special flag case used for @@ -1876,6 +1744,62 @@ TclNRNewObjectInstance( return TclOOInvokeContext(contextPtr, interp, objc, objv); } + +Object * +TclNewObjectInstanceCommon( + Tcl_Interp *interp, + Class *classPtr, + const char *nameStr, + const char *nsNameStr) +{ + Foundation *fPtr = GetFoundation(interp); + Object *oPtr; + + /* + * Disallow creation of an object over an existing command. + */ + + if (nameStr && Tcl_FindCommand(interp, nameStr, NULL, + TCL_NAMESPACE_ONLY)) { + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "can't create object \"%s\": command already exists with" + " that name", nameStr)); + Tcl_SetErrorCode(interp, "TCL", "OO", "OVERWRITE_OBJECT", NULL); + return NULL; + } + + /* + * Create the object. + */ + + oPtr = AllocObject(interp, nameStr, nsNameStr); + oPtr->selfCls = classPtr; + TclOOAddToInstances(oPtr, classPtr); + + /* + * Check to see if we're really creating a class. If so, allocate the + * class structure as well. + */ + + if (TclOOIsReachable(fPtr->classCls, classPtr)) { + /* + * Is a class, so attach a class structure. Note that the AllocClass + * function splices the structure into the object, so we don't have + * to. Once that's done, we need to repatch the object to have the + * right class since AllocClass interferes with that. + */ + + AllocClass(interp, oPtr); + oPtr->selfCls = classPtr; + TclOOAddToSubclasses(oPtr->classPtr, fPtr->objectCls); + } else { + oPtr->classPtr = NULL; + } + return oPtr; +} + + + static int FinalizeAlloc( ClientData data[], diff --git a/generic/tclOOInt.h b/generic/tclOOInt.h index 1eb787f..292293c 100644 --- a/generic/tclOOInt.h +++ b/generic/tclOOInt.h @@ -492,6 +492,10 @@ MODULE_SCOPE int TclNRNewObjectInstance(Tcl_Interp *interp, const char *nsNameStr, int objc, Tcl_Obj *const *objv, int skip, Tcl_Object *objectPtr); +MODULE_SCOPE Object * TclNewObjectInstanceCommon(Tcl_Interp *interp, + Class *classPtr, + const char *nameStr, + const char *nsNameStr); MODULE_SCOPE int TclOODefineSlots(Foundation *fPtr); MODULE_SCOPE void TclOODeleteChain(CallChain *callPtr); MODULE_SCOPE void TclOODeleteChainCache(Tcl_HashTable *tablePtr); -- cgit v0.12