diff -r 000000000000 -r bde4ae8d615e os/persistentdata/persistentstorage/sqlite3api/TEST/TCL/tcldistribution/generic/tclPreserve.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/os/persistentdata/persistentstorage/sqlite3api/TEST/TCL/tcldistribution/generic/tclPreserve.c Fri Jun 15 03:10:57 2012 +0200 @@ -0,0 +1,486 @@ +/* + * tclPreserve.c -- + * + * This file contains a collection of procedures that are used + * to make sure that widget records and other data structures + * aren't reallocated when there are nested procedures that + * depend on their existence. + * + * Copyright (c) 1991-1994 The Regents of the University of California. + * Copyright (c) 1994-1998 Sun Microsystems, Inc. + * Portions Copyright (c) 2007-2008 Nokia Corporation and/or its subsidiaries. All rights reserved. + * + * See the file "license.terms" for information on usage and redistribution + * of this file, and for a DISCLAIMER OF ALL WARRANTIES. + * + * RCS: @(#) $Id: tclPreserve.c,v 1.3.34.2 2005/06/24 18:21:41 kennykb Exp $ + */ + +#include "tclInt.h" + +/* + * The following data structure is used to keep track of all the + * Tcl_Preserve calls that are still in effect. It grows as needed + * to accommodate any number of calls in effect. + */ + +typedef struct { + ClientData clientData; /* Address of preserved block. */ + int refCount; /* Number of Tcl_Preserve calls in effect + * for block. */ + int mustFree; /* Non-zero means Tcl_EventuallyFree was + * called while a Tcl_Preserve call was in + * effect, so the structure must be freed + * when refCount becomes zero. */ + Tcl_FreeProc *freeProc; /* Procedure to call to free. */ +} Reference; + +#if !defined(__SYMBIAN32__) || !defined(__WINSCW__) +static Reference *refArray; /* First in array of references. */ +static int spaceAvl = 0; /* Total number of structures available + * at *firstRefPtr. */ +static int inUse = 0; /* Count of structures currently in use + * in refArray. */ +#else +#define refArray (*(Reference**)get_refArray()) +#define spaceAvl (*(int *)get_spaceAvl()) +#define inUse (*(int *)get_inUse()) +#endif +#define INITIAL_SIZE 2 +TCL_DECLARE_MUTEX(preserveMutex)/* To protect the above statics */ + +/* + * The following data structure is used to keep track of whether an + * arbitrary block of memory has been deleted. This is used by the + * TclHandle code to avoid the more time-expensive algorithm of + * Tcl_Preserve(). This mechanism is mainly used when we have lots of + * references to a few big, expensive objects that we don't want to live + * any longer than necessary. + */ + +typedef struct HandleStruct { + VOID *ptr; /* Pointer to the memory block being + * tracked. This field will become NULL when + * the memory block is deleted. This field + * must be the first in the structure. */ +#ifdef TCL_MEM_DEBUG + VOID *ptr2; /* Backup copy of the abpve pointer used to + * ensure that the contents of the handle are + * not changed by anyone else. */ +#endif + int refCount; /* Number of TclHandlePreserve() calls in + * effect on this handle. */ +} HandleStruct; + + + +/* + *---------------------------------------------------------------------- + * + * TclFinalizePreserve -- + * + * Called during exit processing to clean up the reference array. + * + * Results: + * None. + * + * Side effects: + * Frees the storage of the reference array. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +void +TclFinalizePreserve() +{ + Tcl_MutexLock(&preserveMutex); + if (spaceAvl != 0) { + ckfree((char *) refArray); + refArray = (Reference *) NULL; + inUse = 0; + spaceAvl = 0; + } + Tcl_MutexUnlock(&preserveMutex); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_Preserve -- + * + * This procedure is used by a procedure to declare its interest + * in a particular block of memory, so that the block will not be + * reallocated until a matching call to Tcl_Release has been made. + * + * Results: + * None. + * + * Side effects: + * Information is retained so that the block of memory will + * not be freed until at least the matching call to Tcl_Release. + * + *---------------------------------------------------------------------- + */ + +EXPORT_C void +Tcl_Preserve(clientData) + ClientData clientData; /* Pointer to malloc'ed block of memory. */ +{ + Reference *refPtr; + int i; + + /* + * See if there is already a reference for this pointer. If so, + * just increment its reference count. + */ + + Tcl_MutexLock(&preserveMutex); + for (i = 0, refPtr = refArray; i < inUse; i++, refPtr++) { + if (refPtr->clientData == clientData) { + refPtr->refCount++; + Tcl_MutexUnlock(&preserveMutex); + return; + } + } + + /* + * Make a reference array if it doesn't already exist, or make it + * bigger if it is full. + */ + + if (inUse == spaceAvl) { + if (spaceAvl == 0) { + refArray = (Reference *) ckalloc((unsigned) + (INITIAL_SIZE*sizeof(Reference))); + spaceAvl = INITIAL_SIZE; + } else { + Reference *new; + + new = (Reference *) ckalloc((unsigned) + (2*spaceAvl*sizeof(Reference))); + memcpy((VOID *) new, (VOID *) refArray, + spaceAvl*sizeof(Reference)); + ckfree((char *) refArray); + refArray = new; + spaceAvl *= 2; + } + } + + /* + * Make a new entry for the new reference. + */ + + refPtr = &refArray[inUse]; + refPtr->clientData = clientData; + refPtr->refCount = 1; + refPtr->mustFree = 0; + refPtr->freeProc = TCL_STATIC; + inUse += 1; + Tcl_MutexUnlock(&preserveMutex); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_Release -- + * + * This procedure is called to cancel a previous call to + * Tcl_Preserve, thereby allowing a block of memory to be + * freed (if no one else cares about it). + * + * Results: + * None. + * + * Side effects: + * If Tcl_EventuallyFree has been called for clientData, and if + * no other call to Tcl_Preserve is still in effect, the block of + * memory is freed. + * + *---------------------------------------------------------------------- + */ + +EXPORT_C void +Tcl_Release(clientData) + ClientData clientData; /* Pointer to malloc'ed block of memory. */ +{ + Reference *refPtr; + int mustFree; + Tcl_FreeProc *freeProc; + int i; + + Tcl_MutexLock(&preserveMutex); + for (i = 0, refPtr = refArray; i < inUse; i++, refPtr++) { + if (refPtr->clientData != clientData) { + continue; + } + refPtr->refCount--; + if (refPtr->refCount == 0) { + + /* + * Must remove information from the slot before calling freeProc + * to avoid reentrancy problems if the freeProc calls Tcl_Preserve + * on the same clientData. Copy down the last reference in the + * array to overwrite the current slot. + */ + + freeProc = refPtr->freeProc; + mustFree = refPtr->mustFree; + inUse--; + if (i < inUse) { + refArray[i] = refArray[inUse]; + } + if (mustFree) { + if (freeProc == TCL_DYNAMIC) { + ckfree((char *) clientData); + } else { + Tcl_MutexUnlock(&preserveMutex); + (*freeProc)((char *) clientData); + return; + } + } + } + Tcl_MutexUnlock(&preserveMutex); + return; + } + Tcl_MutexUnlock(&preserveMutex); + + /* + * Reference not found. This is a bug in the caller. + */ + + panic("Tcl_Release couldn't find reference for 0x%x", clientData); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_EventuallyFree -- + * + * Free up a block of memory, unless a call to Tcl_Preserve is in + * effect for that block. In this case, defer the free until all + * calls to Tcl_Preserve have been undone by matching calls to + * Tcl_Release. + * + * Results: + * None. + * + * Side effects: + * Ptr may be released by calling free(). + * + *---------------------------------------------------------------------- + */ + +EXPORT_C void +Tcl_EventuallyFree(clientData, freeProc) + ClientData clientData; /* Pointer to malloc'ed block of memory. */ + Tcl_FreeProc *freeProc; /* Procedure to actually do free. */ +{ + Reference *refPtr; + int i; + + /* + * See if there is a reference for this pointer. If so, set its + * "mustFree" flag (the flag had better not be set already!). + */ + + Tcl_MutexLock(&preserveMutex); + for (i = 0, refPtr = refArray; i < inUse; i++, refPtr++) { + if (refPtr->clientData != clientData) { + continue; + } + if (refPtr->mustFree) { + panic("Tcl_EventuallyFree called twice for 0x%x\n", clientData); + } + refPtr->mustFree = 1; + refPtr->freeProc = freeProc; + Tcl_MutexUnlock(&preserveMutex); + return; + } + Tcl_MutexUnlock(&preserveMutex); + + /* + * No reference for this block. Free it now. + */ + + if (freeProc == TCL_DYNAMIC) { + ckfree((char *) clientData); + } else { + (*freeProc)((char *)clientData); + } +} + +/* + *--------------------------------------------------------------------------- + * + * TclHandleCreate -- + * + * Allocate a handle that contains enough information to determine + * if an arbitrary malloc'd block has been deleted. This is + * used to avoid the more time-expensive algorithm of Tcl_Preserve(). + * + * Results: + * The return value is a TclHandle that refers to the given malloc'd + * block. Doubly dereferencing the returned handle will give + * back the pointer to the block, or will give NULL if the block has + * been deleted. + * + * Side effects: + * The caller must keep track of this handle (generally by storing + * it in a field in the malloc'd block) and call TclHandleFree() + * on this handle when the block is deleted. Everything else that + * wishes to keep track of whether the malloc'd block has been deleted + * should use calls to TclHandlePreserve() and TclHandleRelease() + * on the associated handle. + * + *--------------------------------------------------------------------------- + */ + +TclHandle +TclHandleCreate(ptr) + VOID *ptr; /* Pointer to an arbitrary block of memory + * to be tracked for deletion. Must not be + * NULL. */ +{ + HandleStruct *handlePtr; + + handlePtr = (HandleStruct *) ckalloc(sizeof(HandleStruct)); + handlePtr->ptr = ptr; +#ifdef TCL_MEM_DEBUG + handlePtr->ptr2 = ptr; +#endif + handlePtr->refCount = 0; + return (TclHandle) handlePtr; +} + +/* + *--------------------------------------------------------------------------- + * + * TclHandleFree -- + * + * Called when the arbitrary malloc'd block associated with the + * handle is being deleted. Modifies the handle so that doubly + * dereferencing it will give NULL. This informs any user of the + * handle that the block of memory formerly referenced by the + * handle has been freed. + * + * Results: + * None. + * + * Side effects: + * If nothing is referring to the handle, the handle will be reclaimed. + * + *--------------------------------------------------------------------------- + */ + +void +TclHandleFree(handle) + TclHandle handle; /* Previously created handle associated + * with a malloc'd block that is being + * deleted. The handle is modified so that + * doubly dereferencing it will give NULL. */ +{ + HandleStruct *handlePtr; + + handlePtr = (HandleStruct *) handle; +#ifdef TCL_MEM_DEBUG + if (handlePtr->refCount == 0x61616161) { + panic("using previously disposed TclHandle %x", handlePtr); + } + if (handlePtr->ptr2 != handlePtr->ptr) { + panic("someone has changed the block referenced by the handle %x\nfrom %x to %x", + handlePtr, handlePtr->ptr2, handlePtr->ptr); + } +#endif + handlePtr->ptr = NULL; + if (handlePtr->refCount == 0) { + ckfree((char *) handlePtr); + } +} + +/* + *--------------------------------------------------------------------------- + * + * TclHandlePreserve -- + * + * Declare an interest in the arbitrary malloc'd block associated + * with the handle. + * + * Results: + * The return value is the handle argument, with its ref count + * incremented. + * + * Side effects: + * For each call to TclHandlePreserve(), there should be a matching + * call to TclHandleRelease() when the caller is no longer interested + * in the malloc'd block associated with the handle. + * + *--------------------------------------------------------------------------- + */ + +TclHandle +TclHandlePreserve(handle) + TclHandle handle; /* Declare an interest in the block of + * memory referenced by this handle. */ +{ + HandleStruct *handlePtr; + + handlePtr = (HandleStruct *) handle; +#ifdef TCL_MEM_DEBUG + if (handlePtr->refCount == 0x61616161) { + panic("using previously disposed TclHandle %x", handlePtr); + } + if ((handlePtr->ptr != NULL) + && (handlePtr->ptr != handlePtr->ptr2)) { + panic("someone has changed the block referenced by the handle %x\nfrom %x to %x", + handlePtr, handlePtr->ptr2, handlePtr->ptr); + } +#endif + handlePtr->refCount++; + + return handle; +} + +/* + *--------------------------------------------------------------------------- + * + * TclHandleRelease -- + * + * This procedure is called to release an interest in the malloc'd + * block associated with the handle. + * + * Results: + * None. + * + * Side effects: + * The ref count of the handle is decremented. If the malloc'd block + * has been freed and if no one is using the handle any more, the + * handle will be reclaimed. + * + *--------------------------------------------------------------------------- + */ + +void +TclHandleRelease(handle) + TclHandle handle; /* Unregister interest in the block of + * memory referenced by this handle. */ +{ + HandleStruct *handlePtr; + + handlePtr = (HandleStruct *) handle; +#ifdef TCL_MEM_DEBUG + if (handlePtr->refCount == 0x61616161) { + panic("using previously disposed TclHandle %x", handlePtr); + } + if ((handlePtr->ptr != NULL) + && (handlePtr->ptr != handlePtr->ptr2)) { + panic("someone has changed the block referenced by the handle %x\nfrom %x to %x", + handlePtr, handlePtr->ptr2, handlePtr->ptr); + } +#endif + handlePtr->refCount--; + if ((handlePtr->refCount == 0) && (handlePtr->ptr == NULL)) { + ckfree((char *) handlePtr); + } +} +