Tcl Source Code

2012-06-25  Don Porter  <[email protected]>

	* generic/tclFileSystem.h:	[Bug 3024359] Make sure that the
	* generic/tclIOUtil.c:	per-thread cache of the list of file systems
	* generic/tclPathObj.c:	currently registered is only updated at times
	when no active loops are traversing it.  Also reduce the amount of
	epoch storing and checking to where it can make a difference.

2012-06-25  Donal K. Fellows  <[email protected]>

	* generic/tclCmdAH.c (EncodingDirsObjCmd): [Bug 3537605]: Do the right
	thing when reporting errors with the number of arguments.

2012-06-25  Jan Nijtmans  <[email protected]>

typedef struct ThreadSpecificData {
    int initialized;
    int cwdPathEpoch;
    int filesystemEpoch;
    Tcl_Obj *cwdPathPtr;
    ClientData cwdClientData;
    FilesystemRecord *filesystemList;
    int claims;
} ThreadSpecificData;

/*
 * The internal TclFS API provides routines for handling and manipulating
 * paths efficiently, taking direct advantage of the "path" Tcl_Obj type.
 *
 * These functions are not exported at all at present.

static FilesystemRecord*FsGetFirstFilesystem(void);
static void		FsThrExitProc(ClientData cd);
static Tcl_Obj *	FsListMounts(Tcl_Obj *pathPtr, const char *pattern);
static void		FsAddMountsToGlobResult(Tcl_Obj *resultPtr,
			    Tcl_Obj *pathPtr, const char *pattern,
			    Tcl_GlobTypeData *types);
static void		FsUpdateCwd(Tcl_Obj *cwdObj, ClientData clientData);

static void		FsRecacheFilesystemList(void);
static void		Claim(void);
static void		Disclaim(void);

static void *		DivertFindSymbol(Tcl_Interp *interp,
			    Tcl_LoadHandle loadHandle, const char *symbol);
static void		DivertUnloadFile(Tcl_LoadHandle loadHandle);

/*
 * These form part of the native filesystem support. They are needed here
 * because we have a few native filesystem functions (which are the same for

/*
 * This is incremented each time we modify the linked list of filesystems. Any
 * time it changes, all cached filesystem representations are suspect and must
 * be freed. For multithreading builds, change of the filesystem epoch will
 * trigger cache cleanup in all threads.
 */

static int theFilesystemEpoch = 1;

/*
 * Stores the linked list of filesystems. A 1:1 copy of this list is also
 * maintained in the TSD for each thread. This is to avoid synchronization
 * issues.
 */

	    return 1;
	} else {
	    return 0;
	}
    }
}


static void
FsRecacheFilesystemList(void)
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&tclFsDataKey);
    FilesystemRecord *fsRecPtr, *tmpFsRecPtr = NULL, *toFree = NULL, *list;

    /*
     * Trash the current cache.
     */

    fsRecPtr = tsdPtr->filesystemList;
    while (fsRecPtr != NULL) {
	tmpFsRecPtr = fsRecPtr->nextPtr;

	fsRecPtr->nextPtr = toFree;
	toFree = fsRecPtr;
	fsRecPtr = tmpFsRecPtr;
    }


    /*



     * Locate tail of the global filesystem list.
     */

    Tcl_MutexLock(&filesystemMutex);
    fsRecPtr = filesystemList;
    while (fsRecPtr != NULL) {
	tmpFsRecPtr = fsRecPtr;
	fsRecPtr = fsRecPtr->nextPtr;
    }

    /*
     * Refill the cache honouring the order.
     */

    list = NULL;
    fsRecPtr = tmpFsRecPtr;
    while (fsRecPtr != NULL) {
	tmpFsRecPtr = ckalloc(sizeof(FilesystemRecord));
	*tmpFsRecPtr = *fsRecPtr;
	tmpFsRecPtr->nextPtr = list;
	tmpFsRecPtr->prevPtr = NULL;



	list = tmpFsRecPtr;
	fsRecPtr = fsRecPtr->prevPtr;
    }
    tsdPtr->filesystemList = list;
    tsdPtr->filesystemEpoch = theFilesystemEpoch;
    Tcl_MutexUnlock(&filesystemMutex);

    while (toFree) {
	FilesystemRecord *next = toFree->nextPtr;
	toFree->fsPtr = NULL;
	ckfree(toFree);
	toFree = next;
    }

    /*
     * Make sure the above gets released on thread exit.
     */

    if (tsdPtr->initialized == 0) {
	Tcl_CreateThreadExitHandler(FsThrExitProc, tsdPtr);
	tsdPtr->initialized = 1;
    }
}


static FilesystemRecord *
FsGetFirstFilesystem(void)
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&tclFsDataKey);







    if (tsdPtr->filesystemList == NULL || ((tsdPtr->claims == 0)
	    && (tsdPtr->filesystemEpoch != theFilesystemEpoch))) {
	FsRecacheFilesystemList();

    }

    return tsdPtr->filesystemList;


}

/*
 * The epoch can be changed both by filesystems being added or removed and by
 * env(HOME) changing.
 */

int
TclFSEpochOk(
    int filesystemEpoch)
{
    return (filesystemEpoch == 0 || filesystemEpoch == theFilesystemEpoch);
}

static void
Claim()
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&tclFsDataKey);
    tsdPtr->claims++;
}

static void
Disclaim()
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&tclFsDataKey);
    tsdPtr->claims--;
}

/*
 * If non-NULL, clientData is owned by us and must be freed later.
 */

static void

	/* The native filesystem is static, so we don't free it. */

	if (fsRecPtr != &nativeFilesystemRecord) {
	    ckfree(fsRecPtr);
	}
	fsRecPtr = tmpFsRecPtr;
    }
    theFilesystemEpoch++;
    filesystemList = NULL;

    /*
     * Now filesystemList is NULL. This means that any attempt to use the
     * filesystem is likely to fail.
     */

 *----------------------------------------------------------------------
 */

void
TclResetFilesystem(void)
{
    filesystemList = &nativeFilesystemRecord;
    theFilesystemEpoch++;

#ifdef __WIN32__
    /*
     * Cleans up the win32 API filesystem proc lookup table. This must happen
     * very late in finalization so that deleting of copied dlls can occur.
     */

     * special case, in which if we have a native filesystem handler, we call
     * it first. This is because the root of Tcl's filesystem is always a
     * native filesystem (i.e. '/' on unix is native).
     */

    firstFsRecPtr = FsGetFirstFilesystem();

    Claim();
    for (fsRecPtr=firstFsRecPtr; fsRecPtr!=NULL; fsRecPtr=fsRecPtr->nextPtr) {
	if (fsRecPtr->fsPtr != &tclNativeFilesystem) {
	    continue;
	}

	/*
	 * TODO: Assume that we always find the native file system; it should

	/*
	 * We could add an efficiency check like this:
	 *		if (retVal == length-of(pathPtr)) {break;}
	 * but there's not much benefit.
	 */
    }
    Disclaim();

    return startAt;
}

/*
 *---------------------------------------------------------------------------
 *

	/*
	 * We've never been called before, try to find a cwd. Call each of the
	 * "Tcl_GetCwd" function in succession. A non-NULL return value
	 * indicates the particular function has succeeded.
	 */

	fsRecPtr = FsGetFirstFilesystem();
	Claim();
	for (; (retVal == NULL) && (fsRecPtr != NULL);
		fsRecPtr = fsRecPtr->nextPtr) {
	    ClientData retCd;
	    TclFSGetCwdProc2 *proc2;
	    if (fsRecPtr->fsPtr->getCwdProc == NULL) {
		continue;
	    }

		    FsUpdateCwd(norm, retCd);
		    Tcl_DecrRefCount(norm);
		} else {
		    fsRecPtr->fsPtr->freeInternalRepProc(retCd);
		}
		Tcl_DecrRefCount(retVal);
		retVal = NULL;
		Disclaim();
		goto cdDidNotChange;
	    } else if (interp != NULL) {
		Tcl_AppendResult(interp,
			"error getting working directory name: ",
			Tcl_PosixError(interp), NULL);
	    }
	}
	Disclaim();

	/*
	 * Now the 'cwd' may NOT be normalized, at least on some platforms.
	 * For the sake of efficiency, we want a completely normalized cwd at
	 * all times.
	 *
	 * Finally, if retVal is NULL, we do not have a cwd, which could be

     * Call each of the "listVolumes" function in succession. A non-NULL
     * return value indicates the particular function has succeeded. We call
     * all the functions registered, since we want a list of all drives from
     * all filesystems.
     */

    fsRecPtr = FsGetFirstFilesystem();
    Claim();
    while (fsRecPtr != NULL) {
	if (fsRecPtr->fsPtr->listVolumesProc != NULL) {
	    Tcl_Obj *thisFsVolumes = fsRecPtr->fsPtr->listVolumesProc();

	    if (thisFsVolumes != NULL) {
		Tcl_ListObjAppendList(NULL, resultPtr, thisFsVolumes);
		Tcl_DecrRefCount(thisFsVolumes);
	    }
	}
	fsRecPtr = fsRecPtr->nextPtr;
    }
    Disclaim();

    return resultPtr;
}

/*
 *---------------------------------------------------------------------------
 *

     * Call each of the "matchInDirectory" functions in succession, with the
     * specific type information 'mountsOnly'. A non-NULL return value
     * indicates the particular function has succeeded. We call all the
     * functions registered, since we want a list from each filesystems.
     */

    fsRecPtr = FsGetFirstFilesystem();
    Claim();
    while (fsRecPtr != NULL) {
	if (fsRecPtr->fsPtr != &tclNativeFilesystem &&
		fsRecPtr->fsPtr->matchInDirectoryProc != NULL) {
	    if (resultPtr == NULL) {
		resultPtr = Tcl_NewObj();
	    }
	    fsRecPtr->fsPtr->matchInDirectoryProc(NULL, resultPtr, pathPtr,
		    pattern, &mountsOnly);
	}
	fsRecPtr = fsRecPtr->nextPtr;
    }
    Disclaim();

    return resultPtr;
}

/*
 *---------------------------------------------------------------------------
 *

    /*
     * Call each of the "listVolumes" function in succession, checking whether
     * the given path is an absolute path on any of the volumes returned (this
     * is done by checking whether the path's prefix matches).
     */

    fsRecPtr = FsGetFirstFilesystem();
    Claim();
    while (fsRecPtr != NULL) {
	/*
	 * We want to skip the native filesystem in this loop because
	 * otherwise we won't necessarily pass all the Tcl testsuite - this is
	 * because some of the tests artificially change the current platform
	 * (between win, unix) but the list of volumes we get by calling
	 * fsRecPtr->fsPtr->listVolumesProc will reflect the current (real)

		    break;
		}
	    }
	}
	fsRecPtr = fsRecPtr->nextPtr;
    }
    Disclaim();
    return type;
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSRenameFile --

     * Check if the filesystem has changed in some way since this object's
     * internal representation was calculated. Before doing that, assure we
     * have the most up-to-date copy of the master filesystem. This is
     * accomplished by the FsGetFirstFilesystem() call.
     */

    fsRecPtr = FsGetFirstFilesystem();
    Claim();

    if (TclFSEnsureEpochOk(pathPtr, &retVal) != TCL_OK) {
	Disclaim();
	return NULL;
    } else if (retVal != NULL) {
	/* TODO: Can this happen? */
	Disclaim();
	return retVal;
    }

    /*
     * Call each of the "pathInFilesystem" functions in succession. A
     * non-return value of -1 indicates the particular function has succeeded.
     */

	if (fsRecPtr->fsPtr->pathInFilesystemProc(pathPtr, &clientData)!=-1) {
	    /*
	     * We assume the type of pathPtr hasn't been changed by the above
	     * call to the pathInFilesystemProc.
	     */

	    TclFSSetPathDetails(pathPtr, fsRecPtr->fsPtr, clientData);
	    Disclaim();
	    return fsRecPtr->fsPtr;
	}
    }
    Disclaim();

    return NULL;
}

/*
 *---------------------------------------------------------------------------
 *

    Tcl_Interp *interp,		/* Used for error reporting */
    Tcl_Obj *pathPtr,		/* Path to take dirname of */
    Tcl_PathPart portion)	/* Requested portion of name */
{
    if (pathPtr->typePtr == &tclFsPathType) {
	FsPath *fsPathPtr = PATHOBJ(pathPtr);


	if (PATHFLAGS(pathPtr) != 0) {
	    switch (portion) {
	    case TCL_PATH_DIRNAME: {
		/*
		 * Check if the joined-on bit has any directory delimiters in
		 * it. If so, the 'dirname' would be a joining of the main
		 * part with the dirname of the joined-on bit. We could handle
		 * that special case here, but we don't, and instead just use

    fsPathPtr->translatedPathPtr = NULL;
    fsPathPtr->normPathPtr = Tcl_NewStringObj(addStrRep, len);
    Tcl_IncrRefCount(fsPathPtr->normPathPtr);
    fsPathPtr->cwdPtr = dirPtr;
    Tcl_IncrRefCount(dirPtr);
    fsPathPtr->nativePathPtr = NULL;
    fsPathPtr->fsPtr = NULL;
    fsPathPtr->filesystemEpoch = 0;

    SETPATHOBJ(pathPtr, fsPathPtr);
    PATHFLAGS(pathPtr) = TCLPATH_APPENDED;
    pathPtr->typePtr = &tclFsPathType;
    pathPtr->bytes = NULL;
    pathPtr->length = 0;

     * Circular reference by design.
     */

    fsPathPtr->normPathPtr = pathPtr;
    fsPathPtr->cwdPtr = NULL;
    fsPathPtr->nativePathPtr = NULL;
    fsPathPtr->fsPtr = NULL;
    /* Remember the epoch under which we decided pathPtr was normalized */
    fsPathPtr->filesystemEpoch = tsdPtr->filesystemEpoch;

    SETPATHOBJ(pathPtr, fsPathPtr);
    PATHFLAGS(pathPtr) = 0;
    pathPtr->typePtr = &tclFsPathType;

    return TCL_OK;

	    if (translatedCwdPtr == NULL) {
		return NULL;
	    }

	    retObj = Tcl_FSJoinToPath(translatedCwdPtr, 1,
		    &srcFsPathPtr->normPathPtr);
	    srcFsPathPtr->translatedPathPtr = retObj;
	    if (translatedCwdPtr->typePtr == &tclFsPathType) {
		srcFsPathPtr->filesystemEpoch
			= PATHOBJ(translatedCwdPtr)->filesystemEpoch;
	    } else {
		srcFsPathPtr->filesystemEpoch = 0;
	    }
	    Tcl_IncrRefCount(retObj);
	    Tcl_DecrRefCount(translatedCwdPtr);
	} else {
	    /*
	     * It is a pure absolute, normalized path object. This is
	     * something like being a 'pure list'. The object's string,
	     * translatedPath and normalizedPath are all identical.

     */

    fsPathPtr = ckalloc(sizeof(FsPath));

    fsPathPtr->translatedPathPtr = transPtr;
    if (transPtr != pathPtr) {
	Tcl_IncrRefCount(fsPathPtr->translatedPathPtr);
	/* Redo translation when $env(HOME) changes */
	fsPathPtr->filesystemEpoch = tsdPtr->filesystemEpoch;
    } else {
	fsPathPtr->filesystemEpoch = 0;
    }
    fsPathPtr->normPathPtr = NULL;
    fsPathPtr->cwdPtr = NULL;
    fsPathPtr->nativePathPtr = NULL;
    fsPathPtr->fsPtr = NULL;


    /*
     * Free old representation before installing our new one.
     */

    TclFreeIntRep(pathPtr);
    SETPATHOBJ(pathPtr, fsPathPtr);