/* * tclIORTrans.c -- * * This file contains the implementation of Tcl's generic transformation * reflection code, which allows the implementation of Tcl channel * transformations in Tcl code. * * Parts of this file are based on code contributed by Jean-Claude * Wippler. * * See TIP #230 for the specification of this functionality. * * Copyright (c) 2007-2008 ActiveState. * * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. */ #include "tclInt.h" #include "tclIO.h" #include #ifndef EINVAL #define EINVAL 9 #endif #ifndef EOK #define EOK 0 #endif /* DUPLICATE of HaveVersion() in tclIO.c // TODO - MODULE_SCOPE */ static int HaveVersion(const Tcl_ChannelType *typePtr, Tcl_ChannelTypeVersion minimumVersion); /* * Signatures of all functions used in the C layer of the reflection. */ static int ReflectClose(ClientData clientData, Tcl_Interp *interp); static int ReflectInput(ClientData clientData, char *buf, int toRead, int *errorCodePtr); static int ReflectOutput(ClientData clientData, const char *buf, int toWrite, int *errorCodePtr); static void ReflectWatch(ClientData clientData, int mask); static int ReflectBlock(ClientData clientData, int mode); static Tcl_WideInt ReflectSeekWide(ClientData clientData, Tcl_WideInt offset, int mode, int *errorCodePtr); static int ReflectSeek(ClientData clientData, long offset, int mode, int *errorCodePtr); static int ReflectGetOption(ClientData clientData, Tcl_Interp *interp, const char *optionName, Tcl_DString *dsPtr); static int ReflectSetOption(ClientData clientData, Tcl_Interp *interp, const char *optionName, const char *newValue); static int ReflectHandle(ClientData clientData, int direction, ClientData *handle); static int ReflectNotify(ClientData clientData, int mask); /* * The C layer channel type/driver definition used by the reflection. */ static const Tcl_ChannelType tclRTransformType = { "tclrtransform", /* Type name. */ TCL_CHANNEL_VERSION_5, /* v5 channel. */ ReflectClose, /* Close channel, clean instance data. */ ReflectInput, /* Handle read request. */ ReflectOutput, /* Handle write request. */ ReflectSeek, /* Move location of access point. */ ReflectSetOption, /* Set options. */ ReflectGetOption, /* Get options. */ ReflectWatch, /* Initialize notifier. */ ReflectHandle, /* Get OS handle from the channel. */ NULL, /* No close2 support. NULL'able. */ ReflectBlock, /* Set blocking/nonblocking. */ NULL, /* Flush channel. Not used by core. * NULL'able. */ ReflectNotify, /* Handle events. */ ReflectSeekWide, /* Move access point (64 bit). */ NULL, /* thread action */ NULL /* truncate */ }; /* * Structure of the buffer to hold transform results to be consumed by higher * layers upon reading from the channel, plus the functions to manage such. */ typedef struct _ResultBuffer_ { unsigned char *buf; /* Reference to the buffer area. */ int allocated; /* Allocated size of the buffer area. */ int used; /* Number of bytes in the buffer, * <= allocated. */ } ResultBuffer; #define ResultLength(r) ((r)->used) /* static int ResultLength(ResultBuffer *r); */ static void ResultClear(ResultBuffer *r); static void ResultInit(ResultBuffer *r); static void ResultAdd(ResultBuffer *r, unsigned char *buf, int toWrite); static int ResultCopy(ResultBuffer *r, unsigned char *buf, int toRead); #define RB_INCREMENT (512) /* * Convenience macro to make some casts easier to use. */ #define UCHARP(x) ((unsigned char *) (x)) /* * Instance data for a reflected transformation. =========================== */ typedef struct { Tcl_Channel chan; /* Back reference to the channel of the * transformation itself. */ Tcl_Channel parent; /* Reference to the channel the transformation * was pushed on. */ Tcl_Interp *interp; /* Reference to the interpreter containing the * Tcl level part of the channel. */ Tcl_Obj *handle; /* Reference to transform handle. Also stored * in the argv, see below. The separate field * gives us direct access, needed when working * with the reflection maps. */ #ifdef TCL_THREADS Tcl_ThreadId thread; /* Thread the 'interp' belongs to. */ #endif Tcl_TimerToken timer; /* See [==] as well. * Storage for the command prefix and the additional words required for * the invocation of methods in the command handler. * * argv [0] ... [.] | [argc-2] [argc-1] | [argc] [argc+2] * cmd ... pfx | method chan | detail1 detail2 * ~~~~ CT ~~~ ~~ CT ~~ * * CT = Belongs to the 'Command handler Thread'. */ int argc; /* Number of preallocated words - 2. */ Tcl_Obj **argv; /* Preallocated array for calling the handler. * args[0] is placeholder for cmd word. * Followed by the arguments in the prefix, * plus 4 placeholders for method, channel, * and at most two varying (method specific) * words. */ int methods; /* Bitmask of supported methods. */ /* * NOTE (9): Should we have predefined shared literals for the method * names? */ int mode; /* Mask of R/W mode */ int nonblocking; /* Flag: Channel is blocking or not. */ int readIsDrained; /* Flag: Read buffers are flushed. */ int eofPending; /* Flag: EOF seen down, but not raised up */ int dead; /* Boolean signal that some operations * should no longer be attempted. */ ResultBuffer result; } ReflectedTransform; /* * Structure of the table mapping from transform handles to reflected * transform (channels). Each interpreter which has the handler command for * one or more reflected transforms records them in such a table, so that we * are able to find them during interpreter/thread cleanup even if the actual * channel they belong to was moved to a different interpreter and/or thread. * * The table is reachable via the standard interpreter AssocData, the key is * defined below. */ typedef struct { Tcl_HashTable map; } ReflectedTransformMap; #define RTMKEY "ReflectedTransformMap" /* * Method literals. ================================================== */ static const char *const methodNames[] = { "clear", /* OPT */ "drain", /* OPT, drain => read */ "finalize", /* */ "flush", /* OPT, flush => write */ "initialize", /* */ "limit?", /* OPT */ "read", /* OPT */ "write", /* OPT */ NULL }; typedef enum { METH_CLEAR, METH_DRAIN, METH_FINAL, METH_FLUSH, METH_INIT, METH_LIMIT, METH_READ, METH_WRITE } MethodName; #define FLAG(m) (1 << (m)) #define REQUIRED_METHODS \ (FLAG(METH_INIT) | FLAG(METH_FINAL)) #define RANDW \ (TCL_READABLE | TCL_WRITABLE) #define IMPLIES(a,b) ((!(a)) || (b)) #define NEGIMPL(a,b) #define HAS(x,f) (x & FLAG(f)) #ifdef TCL_THREADS /* * Thread specific types and structures. * * We are here essentially creating a very specific implementation of 'thread * send'. */ /* * Enumeration of all operations which can be forwarded. */ typedef enum { ForwardedClear, ForwardedClose, ForwardedDrain, ForwardedFlush, ForwardedInput, ForwardedLimit, ForwardedOutput } ForwardedOperation; /* * Event used to forward driver invocations to the thread actually managing * the channel. We cannot construct the command to execute and forward that. * Because then it will contain a mixture of Tcl_Obj's belonging to both the * command handler thread (CT), and the thread managing the channel (MT), * executed in CT. Tcl_Obj's are not allowed to cross thread boundaries. So we * forward an operation code, the argument details, and reference to results. * The command is assembled in the CT and belongs fully to that thread. No * sharing problems. */ typedef struct ForwardParamBase { int code; /* O: Ok/Fail of the cmd handler */ char *msgStr; /* O: Error message for handler failure */ int mustFree; /* O: True if msgStr is allocated, false if * otherwise (static). */ } ForwardParamBase; /* * Operation specific parameter/result structures. (These are "subtypes" of * ForwardParamBase. Where an operation does not need any special types, it * has no "subtype" and just uses ForwardParamBase, as listed above.) */ struct ForwardParamTransform { ForwardParamBase base; /* "Supertype". MUST COME FIRST. */ char *buf; /* I: Bytes to transform, * O: Bytes in transform result */ int size; /* I: #bytes to transform, * O: #bytes in the transform result */ }; struct ForwardParamLimit { ForwardParamBase base; /* "Supertype". MUST COME FIRST. */ int max; /* O: Character read limit */ }; /* * Now join all these together in a single union for convenience. */ typedef union ForwardParam { ForwardParamBase base; struct ForwardParamTransform transform; struct ForwardParamLimit limit; } ForwardParam; /* * Forward declaration. */ typedef struct ForwardingResult ForwardingResult; /* * General event structure, with reference to operation specific data. */ typedef struct ForwardingEvent { Tcl_Event event; /* Basic event data, has to be first item */ ForwardingResult *resultPtr; ForwardedOperation op; /* Forwarded driver operation */ ReflectedTransform *rtPtr; /* Channel instance */ ForwardParam *param; /* Packaged arguments and return values, a * ForwardParam pointer. */ } ForwardingEvent; /* * Structure to manage the result of the forwarding. This is not the result of * the operation itself, but about the success of the forward event itself. * The event can be successful, even if the operation which was forwarded * failed. It is also there to manage the synchronization between the involved * threads. */ struct ForwardingResult { Tcl_ThreadId src; /* Originating thread. */ Tcl_ThreadId dst; /* Thread the op was forwarded to. */ Tcl_Interp *dsti; /* Interpreter in the thread the op was * forwarded to. */ Tcl_Condition done; /* Condition variable the forwarder blocks * on. */ int result; /* TCL_OK or TCL_ERROR */ ForwardingEvent *evPtr; /* Event the result belongs to. */ ForwardingResult *prevPtr, *nextPtr; /* Links into the list of pending forwarded * results. */ }; typedef struct ThreadSpecificData { /* * Table of all reflected transformations owned by this thread. */ ReflectedTransformMap *rtmPtr; } ThreadSpecificData; static Tcl_ThreadDataKey dataKey; /* * List of forwarded operations which have not completed yet, plus the mutex * to protect the access to this process global list. */ static ForwardingResult *forwardList = NULL; TCL_DECLARE_MUTEX(rtForwardMutex) /* * Function containing the generic code executing a forward, and wrapper * macros for the actual operations we wish to forward. Uses ForwardProc as * the event function executed by the thread receiving a forwarding event * (which executes the appropriate function and collects the result, if any). * * The two ExitProcs are handlers so that things do not deadlock when either * thread involved in the forwarding exits. They also clean things up so that * we don't leak resources when threads go away. */ static void ForwardOpToOwnerThread(ReflectedTransform *rtPtr, ForwardedOperation op, const void *param); static int ForwardProc(Tcl_Event *evPtr, int mask); static void SrcExitProc(ClientData clientData); #define FreeReceivedError(p) \ do { \ if ((p)->base.mustFree) { \ ckfree((p)->base.msgStr); \ } \ } while (0) #define PassReceivedErrorInterp(i,p) \ do { \ if ((i) != NULL) { \ Tcl_SetChannelErrorInterp((i), \ Tcl_NewStringObj((p)->base.msgStr, -1)); \ } \ FreeReceivedError(p); \ } while (0) #define PassReceivedError(c,p) \ do { \ Tcl_SetChannelError((c), \ Tcl_NewStringObj((p)->base.msgStr, -1)); \ FreeReceivedError(p); \ } while (0) #define ForwardSetStaticError(p,emsg) \ do { \ (p)->base.code = TCL_ERROR; \ (p)->base.mustFree = 0; \ (p)->base.msgStr = (char *) (emsg); \ } while (0) #define ForwardSetDynamicError(p,emsg) \ do { \ (p)->base.code = TCL_ERROR; \ (p)->base.mustFree = 1; \ (p)->base.msgStr = (char *) (emsg); \ } while (0) static void ForwardSetObjError(ForwardParam *p, Tcl_Obj *objPtr); static ReflectedTransformMap * GetThreadReflectedTransformMap(void); static void DeleteThreadReflectedTransformMap( ClientData clientData); #endif /* TCL_THREADS */ #define SetChannelErrorStr(c,msgStr) \ Tcl_SetChannelError((c), Tcl_NewStringObj((msgStr), -1)) static Tcl_Obj * MarshallError(Tcl_Interp *interp); static void UnmarshallErrorResult(Tcl_Interp *interp, Tcl_Obj *msgObj); /* * Static functions for this file: */ static Tcl_Obj * DecodeEventMask(int mask); static ReflectedTransform * NewReflectedTransform(Tcl_Interp *interp, Tcl_Obj *cmdpfxObj, int mode, Tcl_Obj *handleObj, Tcl_Channel parentChan); static Tcl_Obj * NextHandle(void); static void FreeReflectedTransform(ReflectedTransform *rtPtr); static void FreeReflectedTransformArgs(ReflectedTransform *rtPtr); static int InvokeTclMethod(ReflectedTransform *rtPtr, const char *method, Tcl_Obj *argOneObj, Tcl_Obj *argTwoObj, Tcl_Obj **resultObjPtr); static ReflectedTransformMap * GetReflectedTransformMap(Tcl_Interp *interp); static void DeleteReflectedTransformMap(ClientData clientData, Tcl_Interp *interp); /* * Global constant strings (messages). ================== * These string are used directly as bypass errors, thus they have to be valid * Tcl lists where the last element is the message itself. Hence the * list-quoting to keep the words of the message together. See also [x]. */ static const char *msg_read_unsup = "{read not supported by Tcl driver}"; static const char *msg_write_unsup = "{write not supported by Tcl driver}"; #ifdef TCL_THREADS static const char *msg_send_originlost = "{Channel thread lost}"; static const char *msg_send_dstlost = "{Owner lost}"; #endif /* TCL_THREADS */ static const char *msg_dstlost = "-code 1 -level 0 -errorcode NONE -errorinfo {} -errorline 1 {Owner lost}"; /* * Timer management (flushing out buffered data via artificial events). */ /* * Helper functions encapsulating some of the thread forwarding to make the * control flow in callers easier. */ static void TimerKill(ReflectedTransform *rtPtr); static void TimerSetup(ReflectedTransform *rtPtr); static void TimerRun(ClientData clientData); static int TransformRead(ReflectedTransform *rtPtr, int *errorCodePtr, Tcl_Obj *bufObj); static int TransformWrite(ReflectedTransform *rtPtr, int *errorCodePtr, unsigned char *buf, int toWrite); static int TransformDrain(ReflectedTransform *rtPtr, int *errorCodePtr); static int TransformFlush(ReflectedTransform *rtPtr, int *errorCodePtr, int op); static void TransformClear(ReflectedTransform *rtPtr); static int TransformLimit(ReflectedTransform *rtPtr, int *errorCodePtr, int *maxPtr); /* * Operation codes for TransformFlush(). */ #define FLUSH_WRITE 1 #define FLUSH_DISCARD 0 /* * Main methods to plug into the 'chan' ensemble'. ================== */ /* *---------------------------------------------------------------------- * * TclChanPushObjCmd -- * * This function is invoked to process the "chan push" Tcl command. See * the user documentation for details on what it does. * * Results: * A standard Tcl result. The handle of the new channel is placed in the * interp result. * * Side effects: * Creates a new channel. * *---------------------------------------------------------------------- */ int TclChanPushObjCmd( ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const *objv) { ReflectedTransform *rtPtr; /* Instance data of the new (transform) * channel. */ Tcl_Obj *chanObj; /* Handle of parent channel */ Tcl_Channel parentChan; /* Token of parent channel */ int mode; /* R/W mode of parent, later the new channel. * Has to match the abilities of the handler * commands */ Tcl_Obj *cmdObj; /* Command prefix, list of words */ Tcl_Obj *cmdNameObj; /* Command name */ Tcl_Obj *rtId; /* Handle of the new transform (channel) */ Tcl_Obj *modeObj; /* mode in obj form for method call */ int listc; /* Result of 'initialize', and of */ Tcl_Obj **listv; /* its sublist in the 2nd element */ int methIndex; /* Encoded method name */ int result; /* Result code for 'initialize' */ Tcl_Obj *resObj; /* Result data for 'initialize' */ int methods; /* Bitmask for supported methods. */ ReflectedTransformMap *rtmPtr; /* Map of reflected transforms with handlers * in this interp. */ Tcl_HashEntry *hPtr; /* Entry in the above map */ int isNew; /* Placeholder. */ /* * Syntax: chan push CHANNEL CMDPREFIX * [0] [1] [2] [3] * * Actually: rPush CHANNEL CMDPREFIX * [0] [1] [2] */ #define CHAN (1) #define CMD (2) /* * Number of arguments... */ if (objc != 3) { Tcl_WrongNumArgs(interp, 1, objv, "channel cmdprefix"); return TCL_ERROR; } /* * First argument is a channel handle. */ chanObj = objv[CHAN]; parentChan = Tcl_GetChannel(interp, Tcl_GetString(chanObj), &mode); if (parentChan == NULL) { return TCL_ERROR; } parentChan = Tcl_GetTopChannel(parentChan); /* * Second argument is command prefix, i.e. list of words, first word is * name of handler command, other words are fixed arguments. Run the * 'initialize' method to get the list of supported methods. Validate * this. */ cmdObj = objv[CMD]; /* * Basic check that the command prefix truly is a list. */ if (Tcl_ListObjIndex(interp, cmdObj, 0, &cmdNameObj) != TCL_OK) { return TCL_ERROR; } /* * Now create the transformation (channel). */ rtId = NextHandle(); rtPtr = NewReflectedTransform(interp, cmdObj, mode, rtId, parentChan); /* * Invoke 'initialize' and validate that the handler is present and ok. * Squash the transformation if not. */ modeObj = DecodeEventMask(mode); /* assert modeObj.refCount == 1 */ result = InvokeTclMethod(rtPtr, "initialize", modeObj, NULL, &resObj); Tcl_DecrRefCount(modeObj); if (result != TCL_OK) { UnmarshallErrorResult(interp, resObj); Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ goto error; } /* * Verify the result. * - List, of method names. Convert to mask. Check for non-optionals * through the mask. Compare open mode against optional r/w. */ if (Tcl_ListObjGetElements(NULL, resObj, &listc, &listv) != TCL_OK) { Tcl_SetObjResult(interp, Tcl_ObjPrintf( "chan handler \"%s initialize\" returned non-list: %s", Tcl_GetString(cmdObj), Tcl_GetString(resObj))); Tcl_DecrRefCount(resObj); goto error; } methods = 0; while (listc > 0) { if (Tcl_GetIndexFromObj(interp, listv[listc-1], methodNames, "method", TCL_EXACT, &methIndex) != TCL_OK) { Tcl_SetObjResult(interp, Tcl_ObjPrintf( "chan handler \"%s initialize\" returned %s", Tcl_GetString(cmdObj), Tcl_GetString(Tcl_GetObjResult(interp)))); Tcl_DecrRefCount(resObj); goto error; } methods |= FLAG(methIndex); listc--; } Tcl_DecrRefCount(resObj); if ((REQUIRED_METHODS & methods) != REQUIRED_METHODS) { Tcl_SetObjResult(interp, Tcl_ObjPrintf( "chan handler \"%s\" does not support all required methods", Tcl_GetString(cmdObj))); goto error; } /* * Mode tell us what the parent channel supports. The methods tell us what * the handler supports. We remove the non-supported bits from the mode * and check that the channel is not completely inacessible. Afterward the * mode tells us which methods are still required, and these methods will * also be supported by the handler, by design of the check. */ if (!HAS(methods, METH_READ)) { mode &= ~TCL_READABLE; } if (!HAS(methods, METH_WRITE)) { mode &= ~TCL_WRITABLE; } if (!mode) { Tcl_SetObjResult(interp, Tcl_ObjPrintf( "chan handler \"%s\" makes the channel inaccessible", Tcl_GetString(cmdObj))); goto error; } /* * The mode and support for it is ok, now check the internal constraints. */ if (!IMPLIES(HAS(methods, METH_DRAIN), HAS(methods, METH_READ))) { Tcl_SetObjResult(interp, Tcl_ObjPrintf( "chan handler \"%s\" supports \"drain\" but not \"read\"", Tcl_GetString(cmdObj))); goto error; } if (!IMPLIES(HAS(methods, METH_FLUSH), HAS(methods, METH_WRITE))) { Tcl_SetObjResult(interp, Tcl_ObjPrintf( "chan handler \"%s\" supports \"flush\" but not \"write\"", Tcl_GetString(cmdObj))); goto error; } Tcl_ResetResult(interp); /* * Everything is fine now. */ rtPtr->methods = methods; rtPtr->mode = mode; rtPtr->chan = Tcl_StackChannel(interp, &tclRTransformType, rtPtr, mode, rtPtr->parent); /* * Register the transform in our our map for proper handling of deleted * interpreters and/or threads. */ rtmPtr = GetReflectedTransformMap(interp); hPtr = Tcl_CreateHashEntry(&rtmPtr->map, Tcl_GetString(rtId), &isNew); if (!isNew && rtPtr != Tcl_GetHashValue(hPtr)) { Tcl_Panic("TclChanPushObjCmd: duplicate transformation handle"); } Tcl_SetHashValue(hPtr, rtPtr); #ifdef TCL_THREADS rtmPtr = GetThreadReflectedTransformMap(); hPtr = Tcl_CreateHashEntry(&rtmPtr->map, Tcl_GetString(rtId), &isNew); Tcl_SetHashValue(hPtr, rtPtr); #endif /* TCL_THREADS */ /* * Return the channel as the result of the command. */ Tcl_SetObjResult(interp, Tcl_NewStringObj( Tcl_GetChannelName(rtPtr->chan), -1)); return TCL_OK; error: /* * We are not going through ReflectClose as we never had a channel * structure. */ Tcl_EventuallyFree(rtPtr, (Tcl_FreeProc *) FreeReflectedTransform); return TCL_ERROR; #undef CHAN #undef CMD } /* *---------------------------------------------------------------------- * * TclChanPopObjCmd -- * * This function is invoked to process the "chan pop" Tcl command. See * the user documentation for details on what it does. * * Results: * A standard Tcl result. * * Side effects: * Posts events to a reflected channel, invokes event handlers. The * latter implies that arbitrary side effects are possible. * *---------------------------------------------------------------------- */ int TclChanPopObjCmd( ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const *objv) { /* * Syntax: chan pop CHANNEL * [0] [1] [2] * * Actually: rPop CHANNEL * [0] [1] */ #define CHAN (1) const char *chanId; /* Tcl level channel handle */ Tcl_Channel chan; /* Channel associated to the handle */ int mode; /* Channel r/w mode */ /* * Number of arguments... */ if (objc != 2) { Tcl_WrongNumArgs(interp, 1, objv, "channel"); return TCL_ERROR; } /* * First argument is a channel, which may have a (reflected) * transformation. */ chanId = TclGetString(objv[CHAN]); chan = Tcl_GetChannel(interp, chanId, &mode); if (chan == NULL) { return TCL_ERROR; } /* * Removing transformations is generic, and not restricted to reflected * transformations. */ Tcl_UnstackChannel(interp, chan); return TCL_OK; #undef CHAN } /* * Channel error message marshalling utilities. */ static Tcl_Obj * MarshallError( Tcl_Interp *interp) { /* * Capture the result status of the interpreter into a string. => List of * options and values, followed by the error message. The result has * refCount 0. */ Tcl_Obj *returnOpt = Tcl_GetReturnOptions(interp, TCL_ERROR); /* * => returnOpt.refCount == 0. We can append directly. */ Tcl_ListObjAppendElement(NULL, returnOpt, Tcl_GetObjResult(interp)); return returnOpt; } static void UnmarshallErrorResult( Tcl_Interp *interp, Tcl_Obj *msgObj) { int lc; Tcl_Obj **lv; int explicitResult; int numOptions; /* * Process the caught message. * * Syntax = (option value)... ?message? * * Bad syntax causes a panic. This is OK because the other side uses * Tcl_GetReturnOptions and list construction functions to marshall the * information; if we panic here, something has gone badly wrong already. */ if (Tcl_ListObjGetElements(interp, msgObj, &lc, &lv) != TCL_OK) { Tcl_Panic("TclChanCaughtErrorBypass: Bad syntax of caught result"); } if (interp == NULL) { return; } explicitResult = lc & 1; /* Odd number of values? */ numOptions = lc - explicitResult; if (explicitResult) { Tcl_SetObjResult(interp, lv[lc-1]); } Tcl_SetReturnOptions(interp, Tcl_NewListObj(numOptions, lv)); ((Interp *) interp)->flags &= ~ERR_ALREADY_LOGGED; } /* * Driver functions. ================================================ */ /* *---------------------------------------------------------------------- * * ReflectClose -- * * This function is invoked when the channel is closed, to delete the * driver specific instance data. * * Results: * A posix error. * * Side effects: * Releases memory. Arbitrary, as it calls upon a script. * *---------------------------------------------------------------------- */ static int ReflectClose( ClientData clientData, Tcl_Interp *interp) { ReflectedTransform *rtPtr = clientData; int errorCode, errorCodeSet = 0; int result = TCL_OK; /* Result code for 'close' */ Tcl_Obj *resObj; /* Result data for 'close' */ ReflectedTransformMap *rtmPtr; /* Map of reflected transforms with handlers * in this interp. */ Tcl_HashEntry *hPtr; /* Entry in the above map */ if (TclInThreadExit()) { /* * This call comes from TclFinalizeIOSystem. There are no * interpreters, and therefore we cannot call upon the handler command * anymore. Threading is irrelevant as well. We simply clean up all * our C level data structures and leave the Tcl level to the other * finalization functions. */ /* * THREADED => Forward this to the origin thread * * Note: DeleteThreadReflectedTransformMap() is the thread exit handler * for the origin thread. Use this to clean up the structure? Except * if lost? */ #ifdef TCL_THREADS if (rtPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; ForwardOpToOwnerThread(rtPtr, ForwardedClose, &p); result = p.base.code; if (result != TCL_OK) { FreeReceivedError(&p); } } #endif /* TCL_THREADS */ Tcl_EventuallyFree(rtPtr, (Tcl_FreeProc *) FreeReflectedTransform); return EOK; } /* * In the reflected channel implementation a cleaned method mask here * implies that the channel creation was aborted, and "finalize" must not * be called. for transformations however we are not going through here on * such an abort, but directly through FreeReflectedTransform. So for us * that check is not necessary. We always go through 'finalize'. */ if (HAS(rtPtr->methods, METH_DRAIN) && !rtPtr->readIsDrained) { if (!TransformDrain(rtPtr, &errorCode)) { #ifdef TCL_THREADS if (rtPtr->thread != Tcl_GetCurrentThread()) { Tcl_EventuallyFree(rtPtr, (Tcl_FreeProc *) FreeReflectedTransform); return errorCode; } #endif /* TCL_THREADS */ errorCodeSet = 1; goto cleanup; } } if (HAS(rtPtr->methods, METH_FLUSH)) { if (!TransformFlush(rtPtr, &errorCode, FLUSH_WRITE)) { #ifdef TCL_THREADS if (rtPtr->thread != Tcl_GetCurrentThread()) { Tcl_EventuallyFree(rtPtr, (Tcl_FreeProc *) FreeReflectedTransform); return errorCode; } #endif /* TCL_THREADS */ errorCodeSet = 1; goto cleanup; } } /* * Are we in the correct thread? */ #ifdef TCL_THREADS if (rtPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; ForwardOpToOwnerThread(rtPtr, ForwardedClose, &p); result = p.base.code; Tcl_EventuallyFree(rtPtr, (Tcl_FreeProc *) FreeReflectedTransform); if (result != TCL_OK) { PassReceivedErrorInterp(interp, &p); return EINVAL; } return EOK; } #endif /* TCL_THREADS */ /* * Do the actual invokation of "finalize" now; we're in the right thread. */ result = InvokeTclMethod(rtPtr, "finalize", NULL, NULL, &resObj); if ((result != TCL_OK) && (interp != NULL)) { Tcl_SetChannelErrorInterp(interp, resObj); } Tcl_DecrRefCount(resObj); /* Remove reference we held from the * invoke. */ cleanup: /* * Remove the transform from the map before releasing the memory, to * prevent future accesses from finding and dereferencing a dangling * pointer. * * NOTE: The transform may not be in the map. This is ok, that happens * when the transform was created in a different interpreter and/or thread * and then was moved here. * * NOTE: The channel may have been removed from the map already via * the per-interp DeleteReflectedTransformMap exit-handler. */ if (!rtPtr->dead) { rtmPtr = GetReflectedTransformMap(rtPtr->interp); hPtr = Tcl_FindHashEntry(&rtmPtr->map, Tcl_GetString(rtPtr->handle)); if (hPtr) { Tcl_DeleteHashEntry(hPtr); } /* * In a threaded interpreter we manage a per-thread map as well, * to allow us to survive if the script level pulls the rug out * under a channel by deleting the owning thread. */ #ifdef TCL_THREADS rtmPtr = GetThreadReflectedTransformMap(); hPtr = Tcl_FindHashEntry(&rtmPtr->map, Tcl_GetString(rtPtr->handle)); if (hPtr) { Tcl_DeleteHashEntry(hPtr); } #endif /* TCL_THREADS */ } Tcl_EventuallyFree (rtPtr, (Tcl_FreeProc *) FreeReflectedTransform); return errorCodeSet ? errorCode : ((result == TCL_OK) ? EOK : EINVAL); } /* *---------------------------------------------------------------------- * * ReflectInput -- * * This function is invoked when more data is requested from the channel. * * Results: * The number of bytes read. * * Side effects: * Allocates memory. Arbitrary, as it calls upon a script. * *---------------------------------------------------------------------- */ static int ReflectInput( ClientData clientData, char *buf, int toRead, int *errorCodePtr) { ReflectedTransform *rtPtr = clientData; int gotBytes, copied, readBytes; Tcl_Obj *bufObj; /* * The following check can be done before thread redirection, because we * are reading from an item which is readonly, i.e. will never change * during the lifetime of the channel. */ if (!(rtPtr->methods & FLAG(METH_READ))) { SetChannelErrorStr(rtPtr->chan, msg_read_unsup); *errorCodePtr = EINVAL; return -1; } Tcl_Preserve(rtPtr); /* TODO: Consider a more appropriate buffer size. */ bufObj = Tcl_NewByteArrayObj(NULL, toRead); Tcl_IncrRefCount(bufObj); gotBytes = 0; if (rtPtr->eofPending) { goto stop; } rtPtr->readIsDrained = 0; while (toRead > 0) { /* * Loop until the request is satisfied (or no data available from * below, possibly EOF). */ copied = ResultCopy(&rtPtr->result, UCHARP(buf), toRead); toRead -= copied; buf += copied; gotBytes += copied; if (toRead == 0) { goto stop; } if (rtPtr->eofPending) { goto stop; } /* * The buffer is exhausted, but the caller wants even more. We now * have to go to the underlying channel, get more bytes and then * transform them for delivery. We may not get what we want (full EOF * or temporarily out of data). * * Length (rtPtr->result) == 0, toRead > 0 here. Use 'buf'! as target * to store the intermediary information read from the parent channel. * * Ask the transform how much data it allows us to read from the * underlying channel. This feature allows the transform to signal EOF * upstream although there is none downstream. Useful to control an * unbounded 'fcopy' for example, either through counting bytes, or by * pattern matching. */ if ((rtPtr->methods & FLAG(METH_LIMIT))) { int maxRead = -1; if (!TransformLimit(rtPtr, errorCodePtr, &maxRead)) { goto error; } if (maxRead == 0) { goto stop; } else if (maxRead > 0) { if (maxRead < toRead) { toRead = maxRead; } } /* else: 'maxRead < 0' == Accept the current value of toRead */ } if (toRead <= 0) { goto stop; } readBytes = Tcl_ReadRaw(rtPtr->parent, (char *) Tcl_SetByteArrayLength(bufObj, toRead), toRead); if (readBytes < 0) { if (Tcl_InputBlocked(rtPtr->parent) && (gotBytes > 0)) { /* * Down channel is blocked and offers zero additional bytes. * The nonzero gotBytes already returned makes the total * operation a valid short read. Return to caller. */ goto stop; } /* * Either the down channel is not blocked (a real error) * or it is and there are gotBytes==0 byte copied so far. * In either case, pass up the error, so we either report * any real error, or do not mistakenly signal EOF by * returning 0 to the caller. */ *errorCodePtr = Tcl_GetErrno(); goto error; } if (readBytes == 0) { /* * Zero returned from Tcl_ReadRaw() always indicates EOF * on the down channel. */ rtPtr->eofPending = 1; /* * Now this is a bit different. The partial data waiting is * converted and returned. */ if (HAS(rtPtr->methods, METH_DRAIN)) { if (!TransformDrain(rtPtr, errorCodePtr)) { goto error; } } if (ResultLength(&rtPtr->result) == 0) { /* * The drain delivered nothing. */ goto stop; } continue; /* at: while (toRead > 0) */ } /* readBytes == 0 */ /* * Transform the read chunk, which was not empty. Anything we got back * is a transformation result is put into our buffers, and the next * iteration will put it into the result. */ Tcl_SetByteArrayLength(bufObj, readBytes); if (!TransformRead(rtPtr, errorCodePtr, bufObj)) { goto error; } if (Tcl_IsShared(bufObj)) { Tcl_DecrRefCount(bufObj); bufObj = Tcl_NewObj(); Tcl_IncrRefCount(bufObj); } Tcl_SetByteArrayLength(bufObj, 0); } /* while toRead > 0 */ stop: if (gotBytes == 0) { rtPtr->eofPending = 0; } Tcl_DecrRefCount(bufObj); Tcl_Release(rtPtr); return gotBytes; error: gotBytes = -1; goto stop; } /* *---------------------------------------------------------------------- * * ReflectOutput -- * * This function is invoked when data is written to the channel. * * Results: * The number of bytes actually written. * * Side effects: * Allocates memory. Arbitrary, as it calls upon a script. * *---------------------------------------------------------------------- */ static int ReflectOutput( ClientData clientData, const char *buf, int toWrite, int *errorCodePtr) { ReflectedTransform *rtPtr = clientData; /* * The following check can be done before thread redirection, because we * are reading from an item which is readonly, i.e. will never change * during the lifetime of the channel. */ if (!(rtPtr->methods & FLAG(METH_WRITE))) { SetChannelErrorStr(rtPtr->chan, msg_write_unsup); *errorCodePtr = EINVAL; return -1; } if (toWrite == 0) { /* * Nothing came in to write, ignore the call */ return 0; } /* * Discard partial data in the input buffers, i.e. on the read side. Like * we do when explicitly seeking as well. */ Tcl_Preserve(rtPtr); if ((rtPtr->methods & FLAG(METH_CLEAR))) { TransformClear(rtPtr); } /* * Hand the data to the transformation itself. Anything it deigned to * return to us is a (partial) transformation result and written to the * parent channel for further processing. */ if (!TransformWrite(rtPtr, errorCodePtr, UCHARP(buf), toWrite)) { Tcl_Release(rtPtr); return -1; } *errorCodePtr = EOK; Tcl_Release(rtPtr); return toWrite; } /* *---------------------------------------------------------------------- * * ReflectSeekWide / ReflectSeek -- * * This function is invoked when the user wishes to seek on the channel. * * Results: * The new location of the access point. * * Side effects: * Allocates memory. Arbitrary, per the parent channel, and the called * scripts. * *---------------------------------------------------------------------- */ static Tcl_WideInt ReflectSeekWide( ClientData clientData, Tcl_WideInt offset, int seekMode, int *errorCodePtr) { ReflectedTransform *rtPtr = clientData; Channel *parent = (Channel *) rtPtr->parent; Tcl_WideInt curPos; /* Position on the device. */ Tcl_DriverSeekProc *seekProc = Tcl_ChannelSeekProc(Tcl_GetChannelType(rtPtr->parent)); /* * Fail if the parent channel is not seekable. */ if (seekProc == NULL) { Tcl_SetErrno(EINVAL); return Tcl_LongAsWide(-1); } /* * Check if we can leave out involving the Tcl level, i.e. transformation * handler. This is true for tell requests, and transformations which * support neither flush, nor drain. For these cases we can pass the * request down and the result back up unchanged. */ Tcl_Preserve(rtPtr); if (((seekMode != SEEK_CUR) || (offset != 0)) && (HAS(rtPtr->methods, METH_CLEAR) || HAS(rtPtr->methods, METH_FLUSH))) { /* * Neither a tell request, nor clear/flush both not supported. We have * to go through the Tcl level to clear and/or flush the * transformation. */ if (rtPtr->methods & FLAG(METH_CLEAR)) { TransformClear(rtPtr); } /* * When flushing the transform for seeking the generated results are * irrelevant. We cannot put them into the channel, this would move * the location, throwing it off with regard to where we are and are * seeking to. */ if (HAS(rtPtr->methods, METH_FLUSH)) { if (!TransformFlush(rtPtr, errorCodePtr, FLUSH_DISCARD)) { Tcl_Release(rtPtr); return -1; } } } /* * Now seek to the new position in the channel as requested by the * caller. Note that we prefer the wideSeekProc if that is available and * non-NULL... */ if (HaveVersion(parent->typePtr, TCL_CHANNEL_VERSION_3) && parent->typePtr->wideSeekProc != NULL) { curPos = parent->typePtr->wideSeekProc(parent->instanceData, offset, seekMode, errorCodePtr); } else if (offset < Tcl_LongAsWide(LONG_MIN) || offset > Tcl_LongAsWide(LONG_MAX)) { *errorCodePtr = EOVERFLOW; curPos = Tcl_LongAsWide(-1); } else { curPos = Tcl_LongAsWide(parent->typePtr->seekProc( parent->instanceData, Tcl_WideAsLong(offset), seekMode, errorCodePtr)); } if (curPos == Tcl_LongAsWide(-1)) { Tcl_SetErrno(*errorCodePtr); } *errorCodePtr = EOK; Tcl_Release(rtPtr); return curPos; } static int ReflectSeek( ClientData clientData, long offset, int seekMode, int *errorCodePtr) { /* * This function can be invoked from a transformation which is based on * standard seeking, i.e. non-wide. Because of this we have to implement * it, a dummy is not enough. We simply delegate the call to the wide * routine. */ return (int) ReflectSeekWide(clientData, Tcl_LongAsWide(offset), seekMode, errorCodePtr); } /* *---------------------------------------------------------------------- * * ReflectWatch -- * * This function is invoked to tell the channel what events the I/O * system is interested in. * * Results: * None. * * Side effects: * Allocates memory. Arbitrary, as it calls upon a script. * *---------------------------------------------------------------------- */ static void ReflectWatch( ClientData clientData, int mask) { ReflectedTransform *rtPtr = clientData; Tcl_DriverWatchProc *watchProc; watchProc = Tcl_ChannelWatchProc(Tcl_GetChannelType(rtPtr->parent)); watchProc(Tcl_GetChannelInstanceData(rtPtr->parent), mask); /* * Management of the internal timer. */ if (!(mask & TCL_READABLE) || (ResultLength(&rtPtr->result) == 0)) { /* * A pending timer may exist, but either is there no (more) interest * in the events it generates or nothing is available for reading. * Remove it, if existing. */ TimerKill(rtPtr); } else { /* * There might be no pending timer, but there is interest in readable * events and we actually have data waiting, so generate a timer to * flush that if it does not exist. */ TimerSetup(rtPtr); } } /* *---------------------------------------------------------------------- * * ReflectBlock -- * * This function is invoked to tell the channel which blocking behaviour * is required of it. * * Results: * A posix error number. * * Side effects: * Allocates memory. Arbitrary, as it calls upon a script. * *---------------------------------------------------------------------- */ static int ReflectBlock( ClientData clientData, int nonblocking) { ReflectedTransform *rtPtr = clientData; /* * Transformations simply record the blocking mode in their C level * structure for use by --> ReflectInput. The Tcl level doesn't see this * information or change. As such thread forwarding is not required. */ rtPtr->nonblocking = nonblocking; return EOK; } /* *---------------------------------------------------------------------- * * ReflectSetOption -- * * This function is invoked to configure a channel option. * * Results: * A standard Tcl result code. * * Side effects: * Arbitrary, per the parent channel. * *---------------------------------------------------------------------- */ static int ReflectSetOption( ClientData clientData, /* Channel to query */ Tcl_Interp *interp, /* Interpreter to leave error messages in */ const char *optionName, /* Name of requested option */ const char *newValue) /* The new value */ { ReflectedTransform *rtPtr = clientData; /* * Transformations have no options. Thus the call is passed down unchanged * to the parent channel for processing. Its results are passed back * unchanged as well. This all happens in the thread we are in. As the Tcl * level is not involved there is no need for thread forwarding. */ Tcl_DriverSetOptionProc *setOptionProc = Tcl_ChannelSetOptionProc(Tcl_GetChannelType(rtPtr->parent)); if (setOptionProc == NULL) { return TCL_ERROR; } return setOptionProc(Tcl_GetChannelInstanceData(rtPtr->parent), interp, optionName, newValue); } /* *---------------------------------------------------------------------- * * ReflectGetOption -- * * This function is invoked to retrieve all or a channel options. * * Results: * A standard Tcl result code. * * Side effects: * Arbitrary, per the parent channel. * *---------------------------------------------------------------------- */ static int ReflectGetOption( ClientData clientData, /* Channel to query */ Tcl_Interp *interp, /* Interpreter to leave error messages in */ const char *optionName, /* Name of reuqested option */ Tcl_DString *dsPtr) /* String to place the result into */ { ReflectedTransform *rtPtr = clientData; /* * Transformations have no options. Thus the call is passed down unchanged * to the parent channel for processing. Its results are passed back * unchanged as well. This all happens in the thread we are in. As the Tcl * level is not involved there is no need for thread forwarding. * * Note that the parent not having a driver for option retrieval is not an * immediate error. A query for all options is ok. Only a request for a * specific option has to fail. */ Tcl_DriverGetOptionProc *getOptionProc = Tcl_ChannelGetOptionProc(Tcl_GetChannelType(rtPtr->parent)); if (getOptionProc != NULL) { return getOptionProc(Tcl_GetChannelInstanceData(rtPtr->parent), interp, optionName, dsPtr); } else if (optionName == NULL) { return TCL_OK; } else { return TCL_ERROR; } } /* *---------------------------------------------------------------------- * * ReflectHandle -- * * This function is invoked to retrieve the associated file handle. * * Results: * A standard Tcl result code. * * Side effects: * Arbitrary, per the parent channel. * *---------------------------------------------------------------------- */ static int ReflectHandle( ClientData clientData, int direction, ClientData *handlePtr) { ReflectedTransform *rtPtr = clientData; /* * Transformations have no handle of their own. As such we simply query * the parent channel for it. This way the qery will ripple down through * all transformations until reaches the base channel. Which then returns * its handle, or fails. The former will then ripple up the stack. * * This all happens in the thread we are in. As the Tcl level is not * involved no forwarding is required. */ return Tcl_GetChannelHandle(rtPtr->parent, direction, handlePtr); } /* *---------------------------------------------------------------------- * * ReflectNotify -- * * This function is invoked to reported incoming events. * * Results: * A standard Tcl result code. * * Side effects: * Arbitrary, per the parent channel. * *---------------------------------------------------------------------- */ static int ReflectNotify( ClientData clientData, int mask) { ReflectedTransform *rtPtr = clientData; /* * An event occured in the underlying channel. * * We delete our timer. It was not fired, yet we are here, so the channel * below generated such an event and we don't have to. The renewal of the * interest after the execution of channel handlers will eventually cause * us to recreate the timer (in ReflectWatch). */ TimerKill(rtPtr); /* * Pass to higher layers. */ return mask; } /* * Helpers. ========================================================= */ /* *---------------------------------------------------------------------- * * DecodeEventMask -- * * This function takes an internal bitmask of events and constructs the * equivalent list of event items. * * Results: * A Tcl_Obj reference. The object will have a refCount of one. The user * has to decrement it to release the object. * * Side effects: * None. * *---------------------------------------------------------------------- * DUPLICATE of 'DecodeEventMask' in tclIORChan.c */ static Tcl_Obj * DecodeEventMask( int mask) { register const char *eventStr; Tcl_Obj *evObj; switch (mask & RANDW) { case RANDW: eventStr = "read write"; break; case TCL_READABLE: eventStr = "read"; break; case TCL_WRITABLE: eventStr = "write"; break; default: eventStr = ""; break; } evObj = Tcl_NewStringObj(eventStr, -1); Tcl_IncrRefCount(evObj); return evObj; } /* *---------------------------------------------------------------------- * * NewReflectedTransform -- * * This function is invoked to allocate and initialize the instance data * of a new reflected channel. * * Results: * A heap-allocated channel instance. * * Side effects: * Allocates memory. * *---------------------------------------------------------------------- */ static ReflectedTransform * NewReflectedTransform( Tcl_Interp *interp, Tcl_Obj *cmdpfxObj, int mode, Tcl_Obj *handleObj, Tcl_Channel parentChan) { ReflectedTransform *rtPtr; int listc; Tcl_Obj **listv; int i; rtPtr = ckalloc(sizeof(ReflectedTransform)); /* rtPtr->chan: Assigned by caller. Dummy data here. */ /* rtPtr->methods: Assigned by caller. Dummy data here. */ rtPtr->chan = NULL; rtPtr->methods = 0; #ifdef TCL_THREADS rtPtr->thread = Tcl_GetCurrentThread(); #endif rtPtr->parent = parentChan; rtPtr->interp = interp; rtPtr->handle = handleObj; Tcl_IncrRefCount(handleObj); rtPtr->timer = NULL; rtPtr->mode = 0; rtPtr->readIsDrained = 0; rtPtr->eofPending = 0; rtPtr->nonblocking = (((Channel *) parentChan)->state->flags & CHANNEL_NONBLOCKING); rtPtr->dead = 0; /* * Query parent for current blocking mode. */ ResultInit(&rtPtr->result); /* * Method placeholder. */ /* ASSERT: cmdpfxObj is a Tcl List */ Tcl_ListObjGetElements(interp, cmdpfxObj, &listc, &listv); /* * See [==] as well. * Storage for the command prefix and the additional words required for * the invocation of methods in the command handler. * * listv [0] [listc-1] | [listc] [listc+1] | * argv [0] ... [.] | [argc-2] [argc-1] | [argc] [argc+2] * cmd ... pfx | method chan | detail1 detail2 */ rtPtr->argc = listc + 2; rtPtr->argv = ckalloc(sizeof(Tcl_Obj *) * (listc+4)); /* * Duplicate object references. */ for (i=0; iargv[i] = listv[i]; Tcl_IncrRefCount(word); } i++; /* Skip placeholder for method */ /* * See [x] in FreeReflectedTransform for release */ rtPtr->argv[i] = handleObj; Tcl_IncrRefCount(handleObj); /* * The next two objects are kept empty, varying arguments. */ /* * Initialization complete. */ return rtPtr; } /* *---------------------------------------------------------------------- * * NextHandle -- * * This function is invoked to generate a channel handle for a new * reflected channel. * * Results: * A Tcl_Obj containing the string of the new channel handle. The * refcount of the returned object is -- zero --. * * Side effects: * May allocate memory. Mutex protected critical section locks out other * threads for a short time. * *---------------------------------------------------------------------- */ static Tcl_Obj * NextHandle(void) { /* * Count number of generated reflected channels. Used for id generation. * Ids are never reclaimed and there is no dealing with wrap around. On * the other hand, "unsigned long" should be big enough except for * absolute longrunners (generate a 100 ids per second => overflow will * occur in 1 1/3 years). */ TCL_DECLARE_MUTEX(rtCounterMutex) static unsigned long rtCounter = 0; Tcl_Obj *resObj; Tcl_MutexLock(&rtCounterMutex); resObj = Tcl_ObjPrintf("rt%lu", rtCounter); rtCounter++; Tcl_MutexUnlock(&rtCounterMutex); return resObj; } static void FreeReflectedTransformArgs( ReflectedTransform *rtPtr) { int i, n = rtPtr->argc - 2; if (n < 0) { return; } Tcl_DecrRefCount(rtPtr->handle); rtPtr->handle = NULL; for (i=0; iargv[i]); } /* * See [x] in NewReflectedTransform for lock * n+1 = argc-1. */ Tcl_DecrRefCount(rtPtr->argv[n+1]); rtPtr->argc = 1; } static void FreeReflectedTransform( ReflectedTransform *rtPtr) { TimerKill(rtPtr); ResultClear(&rtPtr->result); FreeReflectedTransformArgs(rtPtr); ckfree(rtPtr->argv); ckfree(rtPtr); } /* *---------------------------------------------------------------------- * * InvokeTclMethod -- * * This function is used to invoke the Tcl level of a reflected channel. * It handles all the command assembly, invokation, and generic state and * result mgmt. It does *not* handle thread redirection; that is the * responsibility of clients of this function. * * Results: * Result code and data as returned by the method. * * Side effects: * Arbitrary, as it calls upon a Tcl script. * * Contract: * argOneObj.refCount >= 1 on entry and exit, if argOneObj != NULL * argTwoObj.refCount >= 1 on entry and exit, if argTwoObj != NULL * resObj.refCount in {0, 1, ...} * *---------------------------------------------------------------------- * Semi-DUPLICATE of 'InvokeTclMethod' in tclIORChan.c * - Semi because different structures are used. * - Still possible to factor out the commonalities into a separate structure. */ static int InvokeTclMethod( ReflectedTransform *rtPtr, const char *method, Tcl_Obj *argOneObj, /* NULL'able */ Tcl_Obj *argTwoObj, /* NULL'able */ Tcl_Obj **resultObjPtr) /* NULL'able */ { int cmdc; /* #words in constructed command */ Tcl_Obj *methObj = NULL; /* Method name in object form */ Tcl_InterpState sr; /* State of handler interp */ int result; /* Result code of method invokation */ Tcl_Obj *resObj = NULL; /* Result of method invokation. */ if (rtPtr->dead) { /* * The transform is marked as dead. Bail out immediately, with an * appropriate error. */ if (resultObjPtr != NULL) { resObj = Tcl_NewStringObj(msg_dstlost,-1); *resultObjPtr = resObj; Tcl_IncrRefCount(resObj); } return TCL_ERROR; } /* * NOTE (5): Decide impl. issue: Cache objects with method names? * Requires TSD data as reflections can be created in many different * threads. * NO: Caching of command resolutions means storage per channel. */ /* * Insert method into the pre-allocated area, after the command prefix, * before the channel id. */ methObj = Tcl_NewStringObj(method, -1); Tcl_IncrRefCount(methObj); rtPtr->argv[rtPtr->argc - 2] = methObj; /* * Append the additional argument containing method specific details * behind the channel id. If specified. * * Because of the contract there is no need to increment the refcounts. * The objects will survive the Tcl_EvalObjv without change. */ cmdc = rtPtr->argc; if (argOneObj) { rtPtr->argv[cmdc] = argOneObj; cmdc++; if (argTwoObj) { rtPtr->argv[cmdc] = argTwoObj; cmdc++; } } /* * And run the handler... This is done in auch a manner which leaves any * existing state intact. */ sr = Tcl_SaveInterpState(rtPtr->interp, 0 /* Dummy */); Tcl_Preserve(rtPtr); Tcl_Preserve(rtPtr->interp); result = Tcl_EvalObjv(rtPtr->interp, cmdc, rtPtr->argv, TCL_EVAL_GLOBAL); /* * We do not try to extract the result information if the caller has no * interest in it. I.e. there is no need to put effort into creating * something which is discarded immediately after. */ if (resultObjPtr) { if (result == TCL_OK) { /* * Ok result taken as is, also if the caller requests that there * is no capture. */ resObj = Tcl_GetObjResult(rtPtr->interp); } else { /* * Non-ok result is always treated as an error. We have to capture * the full state of the result, including additional options. * * This is complex and ugly, and would be completely unnecessary * if we only added support for a TCL_FORBID_EXCEPTIONS flag. */ if (result != TCL_ERROR) { Tcl_Obj *cmd = Tcl_NewListObj(cmdc, rtPtr->argv); int cmdLen; const char *cmdString = Tcl_GetStringFromObj(cmd, &cmdLen); Tcl_IncrRefCount(cmd); Tcl_ResetResult(rtPtr->interp); Tcl_SetObjResult(rtPtr->interp, Tcl_ObjPrintf( "chan handler returned bad code: %d", result)); Tcl_LogCommandInfo(rtPtr->interp, cmdString, cmdString, cmdLen); Tcl_DecrRefCount(cmd); result = TCL_ERROR; } Tcl_AppendObjToErrorInfo(rtPtr->interp, Tcl_ObjPrintf( "\n (chan handler subcommand \"%s\")", method)); resObj = MarshallError(rtPtr->interp); } Tcl_IncrRefCount(resObj); } Tcl_RestoreInterpState(rtPtr->interp, sr); Tcl_Release(rtPtr->interp); Tcl_Release(rtPtr); /* * Cleanup of the dynamic parts of the command. * * The detail objects survived the Tcl_EvalObjv without change because of * the contract. Therefore there is no need to decrement the refcounts. Only * the internal method object has to be disposed of. */ Tcl_DecrRefCount(methObj); /* * The resObj has a ref count of 1 at this location. This means that the * caller of InvokeTclMethod has to dispose of it (but only if it was * returned to it). */ if (resultObjPtr != NULL) { *resultObjPtr = resObj; } /* * There no need to handle the case where nothing is returned, because for * that case resObj was not set anyway. */ return result; } /* *---------------------------------------------------------------------- * * GetReflectedTransformMap -- * * Gets and potentially initializes the reflected channel map for an * interpreter. * * Results: * A pointer to the map created, for use by the caller. * * Side effects: * Initializes the reflected channel map for an interpreter. * *---------------------------------------------------------------------- */ static ReflectedTransformMap * GetReflectedTransformMap( Tcl_Interp *interp) { ReflectedTransformMap *rtmPtr = Tcl_GetAssocData(interp, RTMKEY, NULL); if (rtmPtr == NULL) { rtmPtr = ckalloc(sizeof(ReflectedTransformMap)); Tcl_InitHashTable(&rtmPtr->map, TCL_STRING_KEYS); Tcl_SetAssocData(interp, RTMKEY, (Tcl_InterpDeleteProc *) DeleteReflectedTransformMap, rtmPtr); } return rtmPtr; } /* *---------------------------------------------------------------------- * * DeleteReflectedTransformMap -- * * Deletes the channel table for an interpreter, closing any open * channels whose refcount reaches zero. This procedure is invoked when * an interpreter is deleted, via the AssocData cleanup mechanism. * * Results: * None. * * Side effects: * Deletes the hash table of channels. May close channels. May flush * output on closed channels. Removes any channeEvent handlers that were * registered in this interpreter. * *---------------------------------------------------------------------- */ static void DeleteReflectedTransformMap( ClientData clientData, /* The per-interpreter data structure. */ Tcl_Interp *interp) /* The interpreter being deleted. */ { ReflectedTransformMap *rtmPtr; /* The map */ Tcl_HashSearch hSearch; /* Search variable. */ Tcl_HashEntry *hPtr; /* Search variable. */ ReflectedTransform *rtPtr; #ifdef TCL_THREADS ForwardingResult *resultPtr; ForwardingEvent *evPtr; ForwardParam *paramPtr; #endif /* TCL_THREADS */ /* * Delete all entries. The channels may have been closed already, or will * be closed later, by the standard IO finalization of an interpreter * under destruction. Except for the channels which were moved to a * different interpreter and/or thread. They do not exist from the IO * systems point of view and will not get closed. Therefore mark all as * dead so that any future access will cause a proper error. For channels * in a different thread we actually do the same as * DeleteThreadReflectedTransformMap(), just restricted to the channels of * this interp. */ rtmPtr = clientData; for (hPtr = Tcl_FirstHashEntry(&rtmPtr->map, &hSearch); hPtr != NULL; hPtr = Tcl_FirstHashEntry(&rtmPtr->map, &hSearch)) { rtPtr = Tcl_GetHashValue(hPtr); rtPtr->dead = 1; Tcl_DeleteHashEntry(hPtr); } Tcl_DeleteHashTable(&rtmPtr->map); ckfree(&rtmPtr->map); #ifdef TCL_THREADS /* * The origin interpreter for one or more reflected channels is gone. */ /* * Get the map of all channels handled by the current thread. This is a * ReflectedTransformMap, but on a per-thread basis, not per-interp. Go * through the channels and remove all which were handled by this * interpreter. They have already been marked as dead. */ rtmPtr = GetThreadReflectedTransformMap(); for (hPtr = Tcl_FirstHashEntry(&rtmPtr->map, &hSearch); hPtr != NULL; hPtr = Tcl_NextHashEntry(&hSearch)) { rtPtr = Tcl_GetHashValue(hPtr); if (rtPtr->interp != interp) { /* * Ignore entries for other interpreters. */ continue; } rtPtr->dead = 1; FreeReflectedTransformArgs(rtPtr); Tcl_DeleteHashEntry(hPtr); } /* * Go through the list of pending results and cancel all whose events were * destined for this interpreter. While this is in progress we block any * other access to the list of pending results. */ Tcl_MutexLock(&rtForwardMutex); for (resultPtr = forwardList; resultPtr != NULL; resultPtr = resultPtr->nextPtr) { if (resultPtr->dsti != interp) { /* * Ignore results/events for other interpreters. */ continue; } /* * The receiver for the event exited, before processing the event. We * detach the result now, wake the originator up and signal failure. */ evPtr = resultPtr->evPtr; if (evPtr == NULL) { continue; } paramPtr = evPtr->param; evPtr->resultPtr = NULL; resultPtr->evPtr = NULL; resultPtr->result = TCL_ERROR; ForwardSetStaticError(paramPtr, msg_send_dstlost); Tcl_ConditionNotify(&resultPtr->done); } Tcl_MutexUnlock(&rtForwardMutex); #endif /* TCL_THREADS */ } #ifdef TCL_THREADS /* *---------------------------------------------------------------------- * * GetThreadReflectedTransformMap -- * * Gets and potentially initializes the reflected channel map for a * thread. * * Results: * A pointer to the map created, for use by the caller. * * Side effects: * Initializes the reflected channel map for a thread. * *---------------------------------------------------------------------- */ static ReflectedTransformMap * GetThreadReflectedTransformMap(void) { ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); if (!tsdPtr->rtmPtr) { tsdPtr->rtmPtr = ckalloc(sizeof(ReflectedTransformMap)); Tcl_InitHashTable(&tsdPtr->rtmPtr->map, TCL_STRING_KEYS); Tcl_CreateThreadExitHandler(DeleteThreadReflectedTransformMap, NULL); } return tsdPtr->rtmPtr; } /* *---------------------------------------------------------------------- * * DeleteThreadReflectedTransformMap -- * * Deletes the channel table for a thread. This procedure is invoked when * a thread is deleted. The channels have already been marked as dead, in * DeleteReflectedTransformMap(). * * Results: * None. * * Side effects: * Deletes the hash table of channels. * *---------------------------------------------------------------------- */ static void DeleteThreadReflectedTransformMap( ClientData clientData) /* The per-thread data structure. */ { Tcl_HashSearch hSearch; /* Search variable. */ Tcl_HashEntry *hPtr; /* Search variable. */ Tcl_ThreadId self = Tcl_GetCurrentThread(); ReflectedTransformMap *rtmPtr; /* The map */ ForwardingResult *resultPtr; /* * The origin thread for one or more reflected channels is gone. * NOTE: If this function is called due to a thread getting killed the * per-interp DeleteReflectedTransformMap is apparently not called. */ /* * Get the map of all channels handled by the current thread. This is a * ReflectedTransformMap, but on a per-thread basis, not per-interp. Go * through the channels, remove all, mark them as dead. */ rtmPtr = GetThreadReflectedTransformMap(); for (hPtr = Tcl_FirstHashEntry(&rtmPtr->map, &hSearch); hPtr != NULL; hPtr = Tcl_FirstHashEntry(&rtmPtr->map, &hSearch)) { ReflectedTransform *rtPtr = Tcl_GetHashValue(hPtr); rtPtr->dead = 1; FreeReflectedTransformArgs(rtPtr); Tcl_DeleteHashEntry(hPtr); } ckfree(rtmPtr); /* * Go through the list of pending results and cancel all whose events were * destined for this thread. While this is in progress we block any * other access to the list of pending results. */ Tcl_MutexLock(&rtForwardMutex); for (resultPtr = forwardList; resultPtr != NULL; resultPtr = resultPtr->nextPtr) { ForwardingEvent *evPtr; ForwardParam *paramPtr; if (resultPtr->dst != self) { /* * Ignore results/events for other threads. */ continue; } /* * The receiver for the event exited, before processing the event. We * detach the result now, wake the originator up and signal failure. */ evPtr = resultPtr->evPtr; if (evPtr == NULL) { continue; } paramPtr = evPtr->param; evPtr->resultPtr = NULL; resultPtr->evPtr = NULL; resultPtr->result = TCL_ERROR; ForwardSetStaticError(paramPtr, msg_send_dstlost); Tcl_ConditionNotify(&resultPtr->done); } Tcl_MutexUnlock(&rtForwardMutex); } static void ForwardOpToOwnerThread( ReflectedTransform *rtPtr, /* Channel instance */ ForwardedOperation op, /* Forwarded driver operation */ const void *param) /* Arguments */ { Tcl_ThreadId dst = rtPtr->thread; ForwardingEvent *evPtr; ForwardingResult *resultPtr; /* * We gather the lock early. This allows us to check the liveness of the * channel without interference from DeleteThreadReflectedTransformMap(). */ Tcl_MutexLock(&rtForwardMutex); if (rtPtr->dead) { /* * The channel is marked as dead. Bail out immediately, with an * appropriate error. Do not forget to unlock the mutex on this path. */ ForwardSetStaticError((ForwardParam *) param, msg_send_dstlost); Tcl_MutexUnlock(&rtForwardMutex); return; } /* * Create and initialize the event and data structures. */ evPtr = ckalloc(sizeof(ForwardingEvent)); resultPtr = ckalloc(sizeof(ForwardingResult)); evPtr->event.proc = ForwardProc; evPtr->resultPtr = resultPtr; evPtr->op = op; evPtr->rtPtr = rtPtr; evPtr->param = (ForwardParam *) param; resultPtr->src = Tcl_GetCurrentThread(); resultPtr->dst = dst; resultPtr->dsti = rtPtr->interp; resultPtr->done = NULL; resultPtr->result = -1; resultPtr->evPtr = evPtr; /* * Now execute the forward. */ TclSpliceIn(resultPtr, forwardList); /* Do not unlock here. That is done by the ConditionWait */ /* * Ensure cleanup of the event if the origin thread exits while this event * is pending or in progress. Exit of the destination thread is handled by * DeleteThreadReflectionChannelMap(), this is set up by * GetThreadReflectedTransformMap(). This is what we use the 'forwardList' * (see above) for. */ Tcl_CreateThreadExitHandler(SrcExitProc, evPtr); /* * Queue the event and poke the other thread's notifier. */ Tcl_ThreadQueueEvent(dst, (Tcl_Event *) evPtr, TCL_QUEUE_TAIL); Tcl_ThreadAlert(dst); /* * (*) Block until the other thread has either processed the transfer or * rejected it. */ while (resultPtr->result < 0) { /* * NOTE (1): Is it possible that the current thread goes away while * waiting here? IOW Is it possible that "SrcExitProc" is called * while we are here? See complementary note (2) in "SrcExitProc" * * The ConditionWait unlocks the mutex during the wait and relocks it * immediately after. */ Tcl_ConditionWait(&resultPtr->done, &rtForwardMutex, NULL); } /* * Unlink result from the forwarder list. No need to lock. Either still * locked, or locked by the ConditionWait */ TclSpliceOut(resultPtr, forwardList); resultPtr->nextPtr = NULL; resultPtr->prevPtr = NULL; Tcl_MutexUnlock(&rtForwardMutex); Tcl_ConditionFinalize(&resultPtr->done); /* * Kill the cleanup handler now, and the result structure as well, before * returning the success code. * * Note: The event structure has already been deleted by the destination * notifier, after it serviced the event. */ Tcl_DeleteThreadExitHandler(SrcExitProc, evPtr); ckfree(resultPtr); } static int ForwardProc( Tcl_Event *evGPtr, int mask) { /* * Notes regarding access to the referenced data. * * In principle the data belongs to the originating thread (see * evPtr->src), however this thread is currently blocked at (*), i.e. * quiescent. Because of this we can treat the data as belonging to us, * without fear of race conditions. I.e. we can read and write as we like. * * The only thing we cannot be sure of is the resultPtr. This can be be * NULLed if the originating thread went away while the event is handled * here now. */ ForwardingEvent *evPtr = (ForwardingEvent *) evGPtr; ForwardingResult *resultPtr = evPtr->resultPtr; ReflectedTransform *rtPtr = evPtr->rtPtr; Tcl_Interp *interp = rtPtr->interp; ForwardParam *paramPtr = evPtr->param; Tcl_Obj *resObj = NULL; /* Interp result of InvokeTclMethod */ ReflectedTransformMap *rtmPtr; /* Map of reflected channels with handlers in * this interp. */ Tcl_HashEntry *hPtr; /* Entry in the above map */ /* * Ignore the event if no one is waiting for its result anymore. */ if (!resultPtr) { return 1; } paramPtr->base.code = TCL_OK; paramPtr->base.msgStr = NULL; paramPtr->base.mustFree = 0; switch (evPtr->op) { /* * The destination thread for the following operations is * rtPtr->thread, which contains rtPtr->interp, the interp we have to * call upon for the driver. */ case ForwardedClose: /* * No parameters/results. */ if (InvokeTclMethod(rtPtr, "finalize", NULL, NULL, &resObj) != TCL_OK) { ForwardSetObjError(paramPtr, resObj); } /* * Freeing is done here, in the origin thread, because the argv[] * objects belong to this thread. Deallocating them in a different * thread is not allowed */ /* * Remove the channel from the map before releasing the memory, to * prevent future accesses (like by 'postevent') from finding and * dereferencing a dangling pointer. */ rtmPtr = GetReflectedTransformMap(interp); hPtr = Tcl_FindHashEntry(&rtmPtr->map, Tcl_GetString(rtPtr->handle)); Tcl_DeleteHashEntry(hPtr); /* * In a threaded interpreter we manage a per-thread map as well, to * allow us to survive if the script level pulls the rug out under a * channel by deleting the owning thread. */ rtmPtr = GetThreadReflectedTransformMap(); hPtr = Tcl_FindHashEntry(&rtmPtr->map, Tcl_GetString(rtPtr->handle)); Tcl_DeleteHashEntry(hPtr); FreeReflectedTransformArgs(rtPtr); break; case ForwardedInput: { Tcl_Obj *bufObj = Tcl_NewByteArrayObj((unsigned char *) paramPtr->transform.buf, paramPtr->transform.size); Tcl_IncrRefCount(bufObj); if (InvokeTclMethod(rtPtr, "read", bufObj, NULL, &resObj) != TCL_OK) { ForwardSetObjError(paramPtr, resObj); paramPtr->transform.size = -1; } else { /* * Process a regular return. Contains the transformation result. * Sent it back to the request originator. */ int bytec; /* Number of returned bytes */ unsigned char *bytev; /* Array of returned bytes */ bytev = Tcl_GetByteArrayFromObj(resObj, &bytec); paramPtr->transform.size = bytec; if (bytec > 0) { paramPtr->transform.buf = ckalloc(bytec); memcpy(paramPtr->transform.buf, bytev, (size_t)bytec); } else { paramPtr->transform.buf = NULL; } } Tcl_DecrRefCount(bufObj); break; } case ForwardedOutput: { Tcl_Obj *bufObj = Tcl_NewByteArrayObj((unsigned char *) paramPtr->transform.buf, paramPtr->transform.size); Tcl_IncrRefCount(bufObj); if (InvokeTclMethod(rtPtr, "write", bufObj, NULL, &resObj) != TCL_OK) { ForwardSetObjError(paramPtr, resObj); paramPtr->transform.size = -1; } else { /* * Process a regular return. Contains the transformation result. * Sent it back to the request originator. */ int bytec; /* Number of returned bytes */ unsigned char *bytev; /* Array of returned bytes */ bytev = Tcl_GetByteArrayFromObj(resObj, &bytec); paramPtr->transform.size = bytec; if (bytec > 0) { paramPtr->transform.buf = ckalloc(bytec); memcpy(paramPtr->transform.buf, bytev, (size_t)bytec); } else { paramPtr->transform.buf = NULL; } } Tcl_DecrRefCount(bufObj); break; } case ForwardedDrain: if (InvokeTclMethod(rtPtr, "drain", NULL, NULL, &resObj) != TCL_OK) { ForwardSetObjError(paramPtr, resObj); paramPtr->transform.size = -1; } else { /* * Process a regular return. Contains the transformation result. * Sent it back to the request originator. */ int bytec; /* Number of returned bytes */ unsigned char *bytev; /* Array of returned bytes */ bytev = Tcl_GetByteArrayFromObj(resObj, &bytec); paramPtr->transform.size = bytec; if (bytec > 0) { paramPtr->transform.buf = ckalloc(bytec); memcpy(paramPtr->transform.buf, bytev, (size_t)bytec); } else { paramPtr->transform.buf = NULL; } } break; case ForwardedFlush: if (InvokeTclMethod(rtPtr, "flush", NULL, NULL, &resObj) != TCL_OK) { ForwardSetObjError(paramPtr, resObj); paramPtr->transform.size = -1; } else { /* * Process a regular return. Contains the transformation result. * Sent it back to the request originator. */ int bytec; /* Number of returned bytes */ unsigned char *bytev; /* Array of returned bytes */ bytev = Tcl_GetByteArrayFromObj(resObj, &bytec); paramPtr->transform.size = bytec; if (bytec > 0) { paramPtr->transform.buf = ckalloc(bytec); memcpy(paramPtr->transform.buf, bytev, (size_t)bytec); } else { paramPtr->transform.buf = NULL; } } break; case ForwardedClear: (void) InvokeTclMethod(rtPtr, "clear", NULL, NULL, NULL); break; case ForwardedLimit: if (InvokeTclMethod(rtPtr, "limit?", NULL, NULL, &resObj) != TCL_OK) { ForwardSetObjError(paramPtr, resObj); paramPtr->limit.max = -1; } else if (Tcl_GetIntFromObj(interp, resObj, ¶mPtr->limit.max) != TCL_OK) { ForwardSetObjError(paramPtr, MarshallError(interp)); paramPtr->limit.max = -1; } break; default: /* * Bad operation code. */ Tcl_Panic("Bad operation code in ForwardProc"); break; } /* * Remove the reference we held on the result of the invoke, if we had * such. */ if (resObj != NULL) { Tcl_DecrRefCount(resObj); } if (resultPtr) { /* * Report the forwarding result synchronously to the waiting caller. * This unblocks (*) as well. This is wrapped into a conditional * because the caller may have exited in the mean time. */ Tcl_MutexLock(&rtForwardMutex); resultPtr->result = TCL_OK; Tcl_ConditionNotify(&resultPtr->done); Tcl_MutexUnlock(&rtForwardMutex); } return 1; } static void SrcExitProc( ClientData clientData) { ForwardingEvent *evPtr = clientData; ForwardingResult *resultPtr; ForwardParam *paramPtr; /* * NOTE (2): Can this handler be called with the originator blocked? */ /* * The originator for the event exited. It is not sure if this can happen, * as the originator should be blocked at (*) while the event is in * transit/pending. * * We make sure that the event cannot refer to the result anymore, remove * it from the list of pending results and free the structure. Locking the * access ensures that we cannot get in conflict with "ForwardProc", * should it already execute the event. */ Tcl_MutexLock(&rtForwardMutex); resultPtr = evPtr->resultPtr; paramPtr = evPtr->param; evPtr->resultPtr = NULL; resultPtr->evPtr = NULL; resultPtr->result = TCL_ERROR; ForwardSetStaticError(paramPtr, msg_send_originlost); /* * See below: TclSpliceOut(resultPtr, forwardList); */ Tcl_MutexUnlock(&rtForwardMutex); /* * This unlocks (*). The structure will be spliced out and freed by * "ForwardProc". Maybe. */ Tcl_ConditionNotify(&resultPtr->done); } static void ForwardSetObjError( ForwardParam *paramPtr, Tcl_Obj *obj) { int len; const char *msgStr = Tcl_GetStringFromObj(obj, &len); len++; ForwardSetDynamicError(paramPtr, ckalloc(len)); memcpy(paramPtr->base.msgStr, msgStr, (unsigned) len); } #endif /* TCL_THREADS */ /* *---------------------------------------------------------------------- * * TimerKill -- * * Timer management. Removes the internal timer if it exists. * * Side effects: * See above. * * Result: * None. * *---------------------------------------------------------------------- */ static void TimerKill( ReflectedTransform *rtPtr) { if (rtPtr->timer == NULL) { return; } /* * Delete an existing flush-out timer, prevent it from firing on a * removed/dead channel. */ Tcl_DeleteTimerHandler(rtPtr->timer); rtPtr->timer = NULL; } /* *---------------------------------------------------------------------- * * TimerSetup -- * * Timer management. Creates the internal timer if it does not exist. * * Side effects: * See above. * * Result: * None. * *---------------------------------------------------------------------- */ static void TimerSetup( ReflectedTransform *rtPtr) { if (rtPtr->timer != NULL) { return; } rtPtr->timer = Tcl_CreateTimerHandler(SYNTHETIC_EVENT_TIME, TimerRun, rtPtr); } /* *---------------------------------------------------------------------- * * TimerRun -- * * Called by the notifier (-> timer) to flush out information waiting in * channel buffers. * * Side effects: * As of 'Tcl_NotifyChannel'. * * Result: * None. * *---------------------------------------------------------------------- */ static void TimerRun( ClientData clientData) { ReflectedTransform *rtPtr = clientData; rtPtr->timer = NULL; Tcl_NotifyChannel(rtPtr->chan, TCL_READABLE); } /* *---------------------------------------------------------------------- * * ResultInit -- * * Initializes the specified buffer structure. The structure will contain * valid information for an emtpy buffer. * * Side effects: * See above. * * Result: * None. * *---------------------------------------------------------------------- */ static void ResultInit( ResultBuffer *rPtr) /* Reference to the structure to * initialize. */ { rPtr->used = 0; rPtr->allocated = 0; rPtr->buf = NULL; } /* *---------------------------------------------------------------------- * * ResultClear -- * * Deallocates any memory allocated by 'ResultAdd'. * * Side effects: * See above. * * Result: * None. * *---------------------------------------------------------------------- */ static void ResultClear( ResultBuffer *rPtr) /* Reference to the buffer to clear out */ { rPtr->used = 0; if (!rPtr->allocated) { return; } ckfree((char *) rPtr->buf); rPtr->buf = NULL; rPtr->allocated = 0; } /* *---------------------------------------------------------------------- * * ResultAdd -- * * Adds the bytes in the specified array to the buffer, by appending it. * * Side effects: * See above. * * Result: * None. * *---------------------------------------------------------------------- */ static void ResultAdd( ResultBuffer *rPtr, /* The buffer to extend */ unsigned char *buf, /* The buffer to read from */ int toWrite) /* The number of bytes in 'buf' */ { if ((rPtr->used + toWrite + 1) > rPtr->allocated) { /* * Extension of the internal buffer is required. * NOTE: Currently linear. Should be doubling to amortize. */ if (rPtr->allocated == 0) { rPtr->allocated = toWrite + RB_INCREMENT; rPtr->buf = UCHARP(ckalloc(rPtr->allocated)); } else { rPtr->allocated += toWrite + RB_INCREMENT; rPtr->buf = UCHARP(ckrealloc((char *) rPtr->buf, rPtr->allocated)); } } /* * Now copy data. */ memcpy(rPtr->buf + rPtr->used, buf, toWrite); rPtr->used += toWrite; } /* *---------------------------------------------------------------------- * * ResultCopy -- * * Copies the requested number of bytes from the buffer into the * specified array and removes them from the buffer afterward. Copies * less if there is not enough data in the buffer. * * Side effects: * See above. * * Result: * The number of actually copied bytes, possibly less than 'toRead'. * *---------------------------------------------------------------------- */ static int ResultCopy( ResultBuffer *rPtr, /* The buffer to read from */ unsigned char *buf, /* The buffer to copy into */ int toRead) /* Number of requested bytes */ { int copied; if (rPtr->used == 0) { /* * Nothing to copy in the case of an empty buffer. */ copied = 0; } else if (rPtr->used == toRead) { /* * We have just enough. Copy everything to the caller. */ memcpy(buf, rPtr->buf, toRead); rPtr->used = 0; copied = toRead; } else if (rPtr->used > toRead) { /* * The internal buffer contains more than requested. Copy the * requested subset to the caller, and shift the remaining bytes down. */ memcpy(buf, rPtr->buf, toRead); memmove(rPtr->buf, rPtr->buf + toRead, rPtr->used - toRead); rPtr->used -= toRead; copied = toRead; } else { /* * There is not enough in the buffer to satisfy the caller, so take * everything. */ memcpy(buf, rPtr->buf, rPtr->used); toRead = rPtr->used; rPtr->used = 0; copied = toRead; } /* -- common postwork code ------- */ return copied; } static int TransformRead( ReflectedTransform *rtPtr, int *errorCodePtr, Tcl_Obj *bufObj) { Tcl_Obj *resObj; int bytec; /* Number of returned bytes */ unsigned char *bytev; /* Array of returned bytes */ /* * Are we in the correct thread? */ #ifdef TCL_THREADS if (rtPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; p.transform.buf = (char *) Tcl_GetByteArrayFromObj(bufObj, &(p.transform.size)); ForwardOpToOwnerThread(rtPtr, ForwardedInput, &p); if (p.base.code != TCL_OK) { PassReceivedError(rtPtr->chan, &p); *errorCodePtr = EINVAL; return 0; } *errorCodePtr = EOK; ResultAdd(&rtPtr->result, UCHARP(p.transform.buf), p.transform.size); ckfree(p.transform.buf); return 1; } #endif /* TCL_THREADS */ /* ASSERT: rtPtr->method & FLAG(METH_READ) */ /* ASSERT: rtPtr->mode & TCL_READABLE */ if (InvokeTclMethod(rtPtr, "read", bufObj, NULL, &resObj) != TCL_OK) { Tcl_SetChannelError(rtPtr->chan, resObj); Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ *errorCodePtr = EINVAL; return 0; } bytev = Tcl_GetByteArrayFromObj(resObj, &bytec); ResultAdd(&rtPtr->result, bytev, bytec); Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ return 1; } static int TransformWrite( ReflectedTransform *rtPtr, int *errorCodePtr, unsigned char *buf, int toWrite) { Tcl_Obj *bufObj; Tcl_Obj *resObj; int bytec; /* Number of returned bytes */ unsigned char *bytev; /* Array of returned bytes */ int res; /* * Are we in the correct thread? */ #ifdef TCL_THREADS if (rtPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; p.transform.buf = (char *) buf; p.transform.size = toWrite; ForwardOpToOwnerThread(rtPtr, ForwardedOutput, &p); if (p.base.code != TCL_OK) { PassReceivedError(rtPtr->chan, &p); *errorCodePtr = EINVAL; return 0; } *errorCodePtr = EOK; res = Tcl_WriteRaw(rtPtr->parent, (char *) p.transform.buf, p.transform.size); ckfree(p.transform.buf); } else #endif /* TCL_THREADS */ { /* ASSERT: rtPtr->method & FLAG(METH_WRITE) */ /* ASSERT: rtPtr->mode & TCL_WRITABLE */ bufObj = Tcl_NewByteArrayObj((unsigned char *) buf, toWrite); Tcl_IncrRefCount(bufObj); if (InvokeTclMethod(rtPtr, "write", bufObj, NULL, &resObj) != TCL_OK) { *errorCodePtr = EINVAL; Tcl_SetChannelError(rtPtr->chan, resObj); Tcl_DecrRefCount(bufObj); Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ return 0; } *errorCodePtr = EOK; bytev = Tcl_GetByteArrayFromObj(resObj, &bytec); res = Tcl_WriteRaw(rtPtr->parent, (char *) bytev, bytec); Tcl_DecrRefCount(bufObj); Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ } if (res < 0) { *errorCodePtr = Tcl_GetErrno(); return 0; } return 1; } static int TransformDrain( ReflectedTransform *rtPtr, int *errorCodePtr) { Tcl_Obj *resObj; int bytec; /* Number of returned bytes */ unsigned char *bytev; /* Array of returned bytes */ /* * Are we in the correct thread? */ #ifdef TCL_THREADS if (rtPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; ForwardOpToOwnerThread(rtPtr, ForwardedDrain, &p); if (p.base.code != TCL_OK) { PassReceivedError(rtPtr->chan, &p); *errorCodePtr = EINVAL; return 0; } *errorCodePtr = EOK; ResultAdd(&rtPtr->result, UCHARP(p.transform.buf), p.transform.size); ckfree(p.transform.buf); } else #endif /* TCL_THREADS */ { if (InvokeTclMethod(rtPtr, "drain", NULL, NULL, &resObj)!=TCL_OK) { Tcl_SetChannelError(rtPtr->chan, resObj); Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ *errorCodePtr = EINVAL; return 0; } bytev = Tcl_GetByteArrayFromObj(resObj, &bytec); ResultAdd(&rtPtr->result, bytev, bytec); Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ } rtPtr->readIsDrained = 1; return 1; } static int TransformFlush( ReflectedTransform *rtPtr, int *errorCodePtr, int op) { Tcl_Obj *resObj; int bytec; /* Number of returned bytes */ unsigned char *bytev; /* Array of returned bytes */ int res; /* * Are we in the correct thread? */ #ifdef TCL_THREADS if (rtPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; ForwardOpToOwnerThread(rtPtr, ForwardedFlush, &p); if (p.base.code != TCL_OK) { PassReceivedError(rtPtr->chan, &p); *errorCodePtr = EINVAL; return 0; } *errorCodePtr = EOK; if (op == FLUSH_WRITE) { res = Tcl_WriteRaw(rtPtr->parent, (char *) p.transform.buf, p.transform.size); } else { res = 0; } ckfree(p.transform.buf); } else #endif /* TCL_THREADS */ { if (InvokeTclMethod(rtPtr, "flush", NULL, NULL, &resObj)!=TCL_OK) { Tcl_SetChannelError(rtPtr->chan, resObj); Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ *errorCodePtr = EINVAL; return 0; } if (op == FLUSH_WRITE) { bytev = Tcl_GetByteArrayFromObj(resObj, &bytec); res = Tcl_WriteRaw(rtPtr->parent, (char *) bytev, bytec); } else { res = 0; } Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ } if (res < 0) { *errorCodePtr = Tcl_GetErrno(); return 0; } return 1; } static void TransformClear( ReflectedTransform *rtPtr) { /* * Are we in the correct thread? */ #ifdef TCL_THREADS if (rtPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; ForwardOpToOwnerThread(rtPtr, ForwardedClear, &p); return; } #endif /* TCL_THREADS */ /* ASSERT: rtPtr->method & FLAG(METH_READ) */ /* ASSERT: rtPtr->mode & TCL_READABLE */ (void) InvokeTclMethod(rtPtr, "clear", NULL, NULL, NULL); rtPtr->readIsDrained = 0; rtPtr->eofPending = 0; ResultClear(&rtPtr->result); } static int TransformLimit( ReflectedTransform *rtPtr, int *errorCodePtr, int *maxPtr) { Tcl_Obj *resObj; Tcl_InterpState sr; /* State of handler interp */ /* * Are we in the correct thread? */ #ifdef TCL_THREADS if (rtPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; ForwardOpToOwnerThread(rtPtr, ForwardedLimit, &p); if (p.base.code != TCL_OK) { PassReceivedError(rtPtr->chan, &p); *errorCodePtr = EINVAL; return 0; } *errorCodePtr = EOK; *maxPtr = p.limit.max; return 1; } #endif /* ASSERT: rtPtr->method & FLAG(METH_WRITE) */ /* ASSERT: rtPtr->mode & TCL_WRITABLE */ if (InvokeTclMethod(rtPtr, "limit?", NULL, NULL, &resObj) != TCL_OK) { Tcl_SetChannelError(rtPtr->chan, resObj); Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ *errorCodePtr = EINVAL; return 0; } sr = Tcl_SaveInterpState(rtPtr->interp, 0 /* Dummy */); if (Tcl_GetIntFromObj(rtPtr->interp, resObj, maxPtr) != TCL_OK) { Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ Tcl_SetChannelError(rtPtr->chan, MarshallError(rtPtr->interp)); *errorCodePtr = EINVAL; Tcl_RestoreInterpState(rtPtr->interp, sr); return 0; } Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ Tcl_RestoreInterpState(rtPtr->interp, sr); return 1; } /* DUPLICATE of HaveVersion() in tclIO.c *---------------------------------------------------------------------- * * HaveVersion -- * * Return whether a channel type is (at least) of a given version. * * Results: * True if the minimum version is exceeded by the version actually * present. * * Side effects: * None. * *---------------------------------------------------------------------- */ static int HaveVersion( const Tcl_ChannelType *chanTypePtr, Tcl_ChannelTypeVersion minimumVersion) { Tcl_ChannelTypeVersion actualVersion = Tcl_ChannelVersion(chanTypePtr); return PTR2INT(actualVersion) >= PTR2INT(minimumVersion); } /* * Local Variables: * mode: c * c-basic-offset: 4 * fill-column: 78 * End: */