tclIORChan.c Go to the documentation of this file. /* * tclIORChan.c -- * * This file contains the implementation of Tcl's generic channel * reflection code, which allows the implementation of Tcl channels in * Tcl code. * * Parts of this file are based on code contributed by Jean-Claude * Wippler. * * See TIP #219 for the specification of this functionality. * * Copyright (c) 2004-2005 ActiveState, a divison of Sophos * * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. * * RCS: @(#) $Id: tclIORChan.c,v 1.27 2007/12/13 15:23:18 dgp Exp $ */ #include <tclInt.h> #include <tclIO.h> #include <assert.h> #ifndef EINVAL #define EINVAL 9 #endif #ifndef EOK #define EOK 0 #endif /* * 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); /* * The C layer channel type/driver definition used by the reflection. This is * a version 3 structure. */ static Tcl_ChannelType tclRChannelType = { "tclrchannel", /* 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. NULL'able */ ReflectSetOption, /* Set options. NULL'able */ ReflectGetOption, /* Get options. NULL'able */ ReflectWatch, /* Initialize notifier */ NULL, /* Get OS handle from the channel. NULL'able */ NULL, /* No close2 support. NULL'able */ ReflectBlock, /* Set blocking/nonblocking. NULL'able */ NULL, /* Flush channel. Not used by core. NULL'able */ NULL, /* Handle events. NULL'able */ ReflectSeekWide, /* Move access point (64 bit). NULL'able */ NULL, /* thread action */ NULL, /* truncate */ }; /* * Instance data for a reflected channel. =========================== */ typedef struct { Tcl_Channel chan; /* Back reference to generic channel * structure. */ Tcl_Interp *interp; /* Reference to the interpreter containing the * Tcl level part of the channel. */ #ifdef TCL_THREADS Tcl_ThreadId thread; /* Thread the 'interp' belongs to. */ #endif /* 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 interest; /* Mask of events the channel is interested * in. */ /* * Note regarding the usage of timers. * * Most channel implementations need a timer in the C level to ensure that * data in buffers is flushed out through the generation of fake file * events. * * See 'rechan', 'memchan', etc. * * Here this is _not_ required. Interest in events is posted to the Tcl * level via 'watch'. And posting of events is possible from the Tcl level * as well, via 'chan postevent'. This means that the generation of all * events, fake or not, timer based or not, is completely in the hands of * the Tcl level. Therefore no timer here. */ } ReflectedChannel; /* * Structure of the table maping from channel handles to reflected * channels. Each interpreter which has the handler command for one or more * reflected channels records them in such a table, so that 'chan postevent' * is able to find them even if the actual channel 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; } ReflectedChannelMap; #define RCMKEY "ReflectedChannelMap" /* * Event literals. ================================================== */ static const char *eventOptions[] = { "read", "write", NULL }; typedef enum { EVENT_READ, EVENT_WRITE } EventOption; /* * Method literals. ================================================== */ static const char *methodNames[] = { "blocking", /* OPT */ "cget", /* OPT \/ Together or none */ "cgetall", /* OPT /\ of these two */ "configure", /* OPT */ "finalize", /* */ "initialize", /* */ "read", /* OPT */ "seek", /* OPT */ "watch", /* */ "write", /* OPT */ NULL }; typedef enum { METH_BLOCKING, METH_CGET, METH_CGETALL, METH_CONFIGURE, METH_FINAL, METH_INIT, METH_READ, METH_SEEK, METH_WATCH, METH_WRITE, } MethodName; #define FLAG(m) (1 << (m)) #define REQUIRED_METHODS \ (FLAG(METH_INIT) | FLAG(METH_FINAL) | FLAG(METH_WATCH)) #define NULLABLE_METHODS \ (FLAG(METH_BLOCKING) | FLAG(METH_SEEK) | \ FLAG(METH_CONFIGURE) | FLAG(METH_CGET) | FLAG(METH_CGETALL)) #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 { ForwardedClose, ForwardedInput, ForwardedOutput, ForwardedSeek, ForwardedWatch, ForwardedBlock, ForwardedSetOpt, ForwardedGetOpt, ForwardedGetOptAll } 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 ForwardParamInput { ForwardParamBase base; /* "Supertype". MUST COME FIRST. */ char *buf; /* O: Where to store the read bytes */ int toRead; /* I: #bytes to read, * O: #bytes actually read */ }; struct ForwardParamOutput { ForwardParamBase base; /* "Supertype". MUST COME FIRST. */ const char *buf; /* I: Where the bytes to write come from */ int toWrite; /* I: #bytes to write, * O: #bytes actually written */ }; struct ForwardParamSeek { ForwardParamBase base; /* "Supertype". MUST COME FIRST. */ int seekMode; /* I: How to seek */ Tcl_WideInt offset; /* I: Where to seek, * O: New location */ }; struct ForwardParamWatch { ForwardParamBase base; /* "Supertype". MUST COME FIRST. */ int mask; /* I: What events to watch for */ }; struct ForwardParamBlock { ForwardParamBase base; /* "Supertype". MUST COME FIRST. */ int nonblocking; /* I: What mode to activate */ }; struct ForwardParamSetOpt { ForwardParamBase base; /* "Supertype". MUST COME FIRST. */ const char *name; /* Name of option to set */ const char *value; /* Value to set */ }; struct ForwardParamGetOpt { ForwardParamBase base; /* "Supertype". MUST COME FIRST. */ const char *name; /* Name of option to get, maybe NULL */ Tcl_DString *value; /* Result */ }; /* * Now join all these together in a single union for convenience. */ typedef union ForwardParam { ForwardParamBase base; struct ForwardParamInput input; struct ForwardParamOutput output; struct ForwardParamSeek seek; struct ForwardParamWatch watch; struct ForwardParamBlock block; struct ForwardParamSetOpt setOpt; struct ForwardParamGetOpt getOpt; } 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 */ ReflectedChannel *rcPtr; /* 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_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. */ }; /* * 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(rcForwardMutex) /* * 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(ReflectedChannel *rcPtr, ForwardedOperation op, const VOID *param); static int ForwardProc(Tcl_Event *evPtr, int mask); static void SrcExitProc(ClientData clientData); static void DstExitProc(ClientData clientData); #define FreeReceivedError(p) \ if ((p)->base.mustFree) { \ ckfree((p)->base.msgStr); \ } #define PassReceivedErrorInterp(i,p) \ if ((i) != NULL) { \ Tcl_SetChannelErrorInterp((i), \ Tcl_NewStringObj((p)->base.msgStr, -1)); \ } \ FreeReceivedError(p) #define PassReceivedError(c,p) \ Tcl_SetChannelError((c), Tcl_NewStringObj((p)->base.msgStr, -1)); \ FreeReceivedError(p) #define ForwardSetStaticError(p,emsg) \ (p)->base.code = TCL_ERROR; \ (p)->base.mustFree = 0; \ (p)->base.msgStr = (char *) (emsg) #define ForwardSetDynamicError(p,emsg) \ (p)->base.code = TCL_ERROR; \ (p)->base.mustFree = 1; \ (p)->base.msgStr = (char *) (emsg) static void ForwardSetObjError(ForwardParam *p, Tcl_Obj *objPtr); #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 int EncodeEventMask(Tcl_Interp *interp, const char *objName, Tcl_Obj *obj, int *mask); static Tcl_Obj * DecodeEventMask(int mask); static ReflectedChannel * NewReflectedChannel(Tcl_Interp *interp, Tcl_Obj *cmdpfxObj, int mode, Tcl_Obj *handleObj); static Tcl_Obj * NextHandle(void); static void FreeReflectedChannel(ReflectedChannel *rcPtr); static int InvokeTclMethod(ReflectedChannel *rcPtr, const char *method, Tcl_Obj *argOneObj, Tcl_Obj *argTwoObj, Tcl_Obj **resultObjPtr); static ReflectedChannelMap * GetReflectedChannelMap(Tcl_Interp *interp); static void DeleteReflectedChannelMap(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_read_toomuch = "{read delivered more than requested}"; static const char *msg_write_unsup = "{write not supported by Tcl driver}"; static const char *msg_write_toomuch = "{write wrote more than requested}"; static const char *msg_seek_beforestart = "{Tried to seek before origin}"; #ifdef TCL_THREADS static const char *msg_send_originlost = "{Origin thread lost}"; static const char *msg_send_dstlost = "{Destination thread lost}"; #endif /* TCL_THREADS */  /* * Main methods to plug into the 'chan' ensemble'. ================== */ /* *---------------------------------------------------------------------- * * TclChanCreateObjCmd -- * * This function is invoked to process the "chan create" 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 TclChanCreateObjCmd( ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const *objv) { ReflectedChannel *rcPtr; /* Instance data of the new channel */ Tcl_Obj *rcId; /* Handle of the new channel */ int mode; /* R/W mode of new channel. Has to match * abilities of handler commands */ Tcl_Obj *cmdObj; /* Command prefix, list of words */ Tcl_Obj *cmdNameObj; /* Command name */ Tcl_Channel chan; /* Token for the new 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. */ Channel *chanPtr; /* 'chan' resolved to internal struct. */ Tcl_Obj *err; /* Error message */ ReflectedChannelMap* rcmPtr; /* Map of reflected channels with handlers in this interp */ Tcl_HashEntry* hPtr; /* Entry in the above map */ int isNew; /* Placeholder. */ /* * Syntax: chan create MODE CMDPREFIX * [0] [1] [2] [3] * * Actually: rCreate MODE CMDPREFIX * [0] [1] [2] */ #define MODE (1) #define CMD (2) /* * Number of arguments... */ if (objc != 3) { Tcl_WrongNumArgs(interp, 1, objv, "mode cmdprefix"); return TCL_ERROR; } /* * First argument is a list of modes. Allowed entries are "read", "write". * Expect at least one list element. Abbreviations are ok. */ modeObj = objv[MODE]; if (EncodeEventMask(interp, "mode", objv[MODE], &mode) != TCL_OK) { return TCL_ERROR; } /* * 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 channel. */ rcId = NextHandle(); rcPtr = NewReflectedChannel(interp, cmdObj, mode, rcId); chan = Tcl_CreateChannel(&tclRChannelType, TclGetString(rcId), rcPtr, mode); rcPtr->chan = chan; chanPtr = (Channel *) chan; /* * Invoke 'initialize' and validate that the handler is present and ok. * Squash the channel if not. * * Note: The conversion of 'mode' back into a Tcl_Obj ensures that * 'initialize' is invoked with canonical mode names, and no * abbreviations. Using modeObj directly could feed abbreviations into the * handler, and the handler is not specified to handle such. */ modeObj = DecodeEventMask(mode); result = InvokeTclMethod(rcPtr, "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) { TclNewLiteralStringObj(err, "chan handler \""); Tcl_AppendObjToObj(err, cmdObj); Tcl_AppendToObj(err, " initialize\" returned non-list: ", -1); Tcl_AppendObjToObj(err, resObj); Tcl_SetObjResult(interp, err); Tcl_DecrRefCount(resObj); goto error; } methods = 0; while (listc > 0) { if (Tcl_GetIndexFromObj(interp, listv[listc-1], methodNames, "method", TCL_EXACT, &methIndex) != TCL_OK) { TclNewLiteralStringObj(err, "chan handler \""); Tcl_AppendObjToObj(err, cmdObj); Tcl_AppendToObj(err, " initialize\" returned ", -1); Tcl_AppendObjToObj(err, Tcl_GetObjResult(interp)); Tcl_SetObjResult(interp, err); Tcl_DecrRefCount(resObj); goto error; } methods |= FLAG(methIndex); listc--; } Tcl_DecrRefCount(resObj); if ((REQUIRED_METHODS & methods) != REQUIRED_METHODS) { TclNewLiteralStringObj(err, "chan handler \""); Tcl_AppendObjToObj(err, cmdObj); Tcl_AppendToObj(err, "\" does not support all required methods", -1); Tcl_SetObjResult(interp, err); goto error; } if ((mode & TCL_READABLE) && !HAS(methods, METH_READ)) { TclNewLiteralStringObj(err, "chan handler \""); Tcl_AppendObjToObj(err, cmdObj); Tcl_AppendToObj(err, "\" lacks a \"read\" method", -1); Tcl_SetObjResult(interp, err); goto error; } if ((mode & TCL_WRITABLE) && !HAS(methods, METH_WRITE)) { TclNewLiteralStringObj(err, "chan handler \""); Tcl_AppendObjToObj(err, cmdObj); Tcl_AppendToObj(err, "\" lacks a \"write\" method", -1); Tcl_SetObjResult(interp, err); goto error; } if (!IMPLIES(HAS(methods, METH_CGET), HAS(methods, METH_CGETALL))) { TclNewLiteralStringObj(err, "chan handler \""); Tcl_AppendObjToObj(err, cmdObj); Tcl_AppendToObj(err, "\" supports \"cget\" but not \"cgetall\"", -1); Tcl_SetObjResult(interp, err); goto error; } if (!IMPLIES(HAS(methods, METH_CGETALL), HAS(methods, METH_CGET))) { TclNewLiteralStringObj(err, "chan handler \""); Tcl_AppendObjToObj(err, cmdObj); Tcl_AppendToObj(err, "\" supports \"cgetall\" but not \"cget\"", -1); Tcl_SetObjResult(interp, err); goto error; } Tcl_ResetResult(interp); /* * Everything is fine now. */ rcPtr->methods = methods; if ((methods & NULLABLE_METHODS) != NULLABLE_METHODS) { /* * Some of the nullable methods are not supported. We clone the * channel type, null the associated C functions, and use the result * as the actual channel type. */ Tcl_ChannelType *clonePtr = (Tcl_ChannelType *) ckalloc(sizeof(Tcl_ChannelType)); memcpy(clonePtr, &tclRChannelType, sizeof(Tcl_ChannelType)); if (!(methods & FLAG(METH_CONFIGURE))) { clonePtr->setOptionProc = NULL; } if (!(methods & FLAG(METH_CGET)) && !(methods & FLAG(METH_CGETALL))) { clonePtr->getOptionProc = NULL; } if (!(methods & FLAG(METH_BLOCKING))) { clonePtr->blockModeProc = NULL; } if (!(methods & FLAG(METH_SEEK))) { clonePtr->seekProc = NULL; clonePtr->wideSeekProc = NULL; } chanPtr->typePtr = clonePtr; } /* * Register the channel in the I/O system, and in our our map for 'chan * postevent'. */ Tcl_RegisterChannel(interp, chan); rcmPtr = GetReflectedChannelMap (interp); hPtr = Tcl_CreateHashEntry(&rcmPtr->map, chanPtr->state->channelName, &isNew); if (!isNew) { if (chanPtr != Tcl_GetHashValue(hPtr)) { Tcl_Panic("TclChanCreateObjCmd: duplicate channel names"); } } Tcl_SetHashValue(hPtr, chan); /* * Return handle as result of command. */ Tcl_SetObjResult(interp, rcId); return TCL_OK; error: /* * Signal to ReflectClose to not call 'finalize'. */ rcPtr->methods = 0; Tcl_Close(interp, chan); return TCL_ERROR; #undef MODE #undef CMD }  /* *---------------------------------------------------------------------- * * TclChanPostEventObjCmd -- * * This function is invoked to process the "chan postevent" 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 TclChanPostEventObjCmd( ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const *objv) { /* * Syntax: chan postevent CHANNEL EVENTSPEC * [0] [1] [2] [3] * * Actually: rPostevent CHANNEL EVENTSPEC * [0] [1] [2] * * where EVENTSPEC = {read write ...} (Abbreviations allowed as well). */ #define CHAN (1) #define EVENT (2) const char *chanId; /* Tcl level channel handle */ Tcl_Channel chan; /* Channel associated to the handle */ const Tcl_ChannelType *chanTypePtr; /* Its associated driver structure */ ReflectedChannel *rcPtr; /* Associated instance data */ int events; /* Mask of events to post */ ReflectedChannelMap* rcmPtr; /* Map of reflected channels with handlers in this interp */ Tcl_HashEntry* hPtr; /* Entry in the above map */ /* * Number of arguments... */ if (objc != 3) { Tcl_WrongNumArgs(interp, 1, objv, "channel eventspec"); return TCL_ERROR; } /* * First argument is a channel, a reflected channel, and the call of this * command is done from the interp defining the channel handler cmd. */ chanId = TclGetString(objv[CHAN]); rcmPtr = GetReflectedChannelMap (interp); hPtr = Tcl_FindHashEntry (&rcmPtr->map, chanId); if (hPtr == NULL) { Tcl_AppendResult(interp, "can not find reflected channel named \"", chanId, "\"", NULL); Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "CHANNEL", chanId, NULL); return TCL_ERROR; } /* * Note that the search above subsumes several of the older checks, namely: * * (1) Does the channel handle refer to a reflected channel ? * (2) Is the post event issued from the interpreter holding the handler * of the reflected channel ? * * A successful search answers yes to both. Because the map holds only * handles of reflected channels, and only of such whose handler is * defined in this interpreter. * * We keep the old checks for both, for paranioa, but abort now instead of * throwing errors, as failure now means that our internal datastructures * have gone seriously haywire. */ chan = Tcl_GetHashValue(hPtr); chanTypePtr = Tcl_GetChannelType(chan); /* * We use a function referenced by the channel type as our cookie to * detect calls to non-reflecting channels. The channel type itself is not * suitable, as it might not be the static definition in this file, but a * clone thereof. And while we have reserved the name of the type nothing * in the core checks against violation, so someone else might have * created a channel type using our name, clashing with ourselves. */ if (chanTypePtr->watchProc != &ReflectWatch) { Tcl_Panic ("TclChanPostEventObjCmd: channel is not a reflected channel"); } rcPtr = (ReflectedChannel *) Tcl_GetChannelInstanceData(chan); if (rcPtr->interp != interp) { Tcl_Panic ("TclChanPostEventObjCmd: postevent accepted for call from outside interpreter"); } /* * Second argument is a list of events. Allowed entries are "read", * "write". Expect at least one list element. Abbreviations are ok. */ if (EncodeEventMask(interp, "event", objv[EVENT], &events) != TCL_OK) { return TCL_ERROR; } /* * Check that the channel is actually interested in the provided events. */ if (events & ~rcPtr->interest) { Tcl_AppendResult(interp, "tried to post events channel \"", chanId, "\" is not interested in", NULL); return TCL_ERROR; } /* * We have the channel and the events to post. */ Tcl_NotifyChannel(chan, events); /* * Squash interp results left by the event script. */ Tcl_ResetResult(interp); return TCL_OK; #undef CHAN #undef EVENT }  /* * 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]); } (void) Tcl_SetReturnOptions(interp, Tcl_NewListObj(numOptions, lv)); ((Interp *)interp)->flags &= ~ERR_ALREADY_LOGGED; } int TclChanCaughtErrorBypass( Tcl_Interp *interp, Tcl_Channel chan) { Tcl_Obj *chanMsgObj = NULL; Tcl_Obj *interpMsgObj = NULL; Tcl_Obj *msgObj = NULL; /* * Get a bypassed error message from channel and/or interpreter, save the * reference, then kill the returned objects, if there were any. If there * are messages in both the channel has preference. */ if ((chan == NULL) && (interp == NULL)) { return 0; } if (chan != NULL) { Tcl_GetChannelError(chan, &chanMsgObj); } if (interp != NULL) { Tcl_GetChannelErrorInterp(interp, &interpMsgObj); } if (chanMsgObj != NULL) { msgObj = chanMsgObj; } else if (interpMsgObj != NULL) { msgObj = interpMsgObj; } if (msgObj != NULL) { Tcl_IncrRefCount(msgObj); } if (chanMsgObj != NULL) { Tcl_DecrRefCount(chanMsgObj); } if (interpMsgObj != NULL) { Tcl_DecrRefCount(interpMsgObj); } /* * No message returned, nothing caught. */ if (msgObj == NULL) { return 0; } UnmarshallErrorResult(interp, msgObj); Tcl_DecrRefCount(msgObj); return 1; }  /* * 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) { ReflectedChannel *rcPtr = (ReflectedChannel *) clientData; int result; /* Result code for 'close' */ Tcl_Obj *resObj; /* Result data for 'close' */ if (interp == NULL) { /* * 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: Have a thread delete handler for the origin thread. Use this * to clean up the structure! */ #ifdef TCL_THREADS if (rcPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; ForwardOpToOwnerThread(rcPtr, ForwardedClose, &p); result = p.base.code; /* * FreeReflectedChannel is done in the forwarded operation!, in * the other thread. rcPtr here is gone! */ if (result != TCL_OK) { FreeReceivedError(&p); } return EOK; } #endif FreeReflectedChannel(rcPtr); return EOK; } /* * -- No -- ASSERT rcPtr->methods & FLAG(METH_FINAL) * * A cleaned method mask here implies that the channel creation was * aborted, and "finalize" must not be called. */ if (rcPtr->methods == 0) { FreeReflectedChannel(rcPtr); return EOK; } /* * Are we in the correct thread? */ #ifdef TCL_THREADS if (rcPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; ForwardOpToOwnerThread(rcPtr, ForwardedClose, &p); result = p.base.code; /* * FreeReflectedChannel is done in the forwarded operation!, in the * other thread. rcPtr here is gone! */ if (result != TCL_OK) { PassReceivedErrorInterp(interp, &p); } } else { #endif result = InvokeTclMethod(rcPtr, "finalize", NULL, NULL, &resObj); if ((result != TCL_OK) && (interp != NULL)) { Tcl_SetChannelErrorInterp(interp, resObj); } Tcl_DecrRefCount(resObj); /* Remove reference we held from the * invoke */ FreeReflectedChannel(rcPtr); #ifdef TCL_THREADS } #endif return (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) { ReflectedChannel *rcPtr = (ReflectedChannel *) clientData; Tcl_Obj *toReadObj; int bytec; /* Number of returned bytes */ unsigned char *bytev; /* Array of returned bytes */ Tcl_Obj *resObj; /* Result data for 'read' */ /* * 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 (!(rcPtr->methods & FLAG(METH_READ))) { SetChannelErrorStr(rcPtr->chan, msg_read_unsup); *errorCodePtr = EINVAL; return -1; } /* * Are we in the correct thread? */ #ifdef TCL_THREADS if (rcPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; p.input.buf = buf; p.input.toRead = toRead; ForwardOpToOwnerThread(rcPtr, ForwardedInput, &p); if (p.base.code != TCL_OK) { PassReceivedError(rcPtr->chan, &p); *errorCodePtr = EINVAL; } else { *errorCodePtr = EOK; } return p.input.toRead; } #endif /* ASSERT: rcPtr->method & FLAG(METH_READ) */ /* ASSERT: rcPtr->mode & TCL_READABLE */ toReadObj = Tcl_NewIntObj(toRead); if (InvokeTclMethod(rcPtr, "read", toReadObj, NULL, &resObj)!=TCL_OK) { Tcl_SetChannelError(rcPtr->chan, resObj); Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ *errorCodePtr = EINVAL; return -1; } bytev = Tcl_GetByteArrayFromObj(resObj, &bytec); if (toRead < bytec) { Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ SetChannelErrorStr(rcPtr->chan, msg_read_toomuch); *errorCodePtr = EINVAL; return -1; } *errorCodePtr = EOK; if (bytec > 0) { memcpy(buf, bytev, (size_t)bytec); } Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ return bytec; }  /* *---------------------------------------------------------------------- * * ReflectOutput -- * * This function is invoked when data is writen 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) { ReflectedChannel *rcPtr = (ReflectedChannel *) clientData; Tcl_Obj *bufObj; Tcl_Obj *resObj; /* Result data for 'write' */ int written; /* * 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 (!(rcPtr->methods & FLAG(METH_WRITE))) { SetChannelErrorStr(rcPtr->chan, msg_write_unsup); *errorCodePtr = EINVAL; return -1; } /* * Are we in the correct thread? */ #ifdef TCL_THREADS if (rcPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; p.output.buf = buf; p.output.toWrite = toWrite; ForwardOpToOwnerThread(rcPtr, ForwardedOutput, &p); if (p.base.code != TCL_OK) { PassReceivedError(rcPtr->chan, &p); *errorCodePtr = EINVAL; } else { *errorCodePtr = EOK; } return p.output.toWrite; } #endif /* ASSERT: rcPtr->method & FLAG(METH_WRITE) */ /* ASSERT: rcPtr->mode & TCL_WRITABLE */ bufObj = Tcl_NewByteArrayObj((unsigned char *) buf, toWrite); if (InvokeTclMethod(rcPtr, "write", bufObj, NULL, &resObj) != TCL_OK) { Tcl_SetChannelError(rcPtr->chan, resObj); Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ *errorCodePtr = EINVAL; return -1; } if (Tcl_GetIntFromObj(rcPtr->interp, resObj, &written) != TCL_OK) { Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ Tcl_SetChannelError(rcPtr->chan, MarshallError(rcPtr->interp)); *errorCodePtr = EINVAL; return -1; } Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ if ((written == 0) || (toWrite < written)) { /* * The handler claims to have written more than it was given. That is * bad. Note that the I/O core would crash if we were to return this * information, trying to write -nnn bytes in the next iteration. */ SetChannelErrorStr(rcPtr->chan, msg_write_toomuch); *errorCodePtr = EINVAL; return -1; } *errorCodePtr = EOK; return written; }  /* *---------------------------------------------------------------------- * * 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, as it calls upon a script. * *---------------------------------------------------------------------- */ static Tcl_WideInt ReflectSeekWide( ClientData clientData, Tcl_WideInt offset, int seekMode, int *errorCodePtr) { ReflectedChannel *rcPtr = (ReflectedChannel *) clientData; Tcl_Obj *offObj, *baseObj; Tcl_Obj *resObj; /* Result for 'seek' */ Tcl_WideInt newLoc; /* * Are we in the correct thread? */ #ifdef TCL_THREADS if (rcPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; p.seek.seekMode = seekMode; p.seek.offset = offset; ForwardOpToOwnerThread(rcPtr, ForwardedSeek, &p); if (p.base.code != TCL_OK) { PassReceivedError(rcPtr->chan, &p); *errorCodePtr = EINVAL; } else { *errorCodePtr = EOK; } return p.seek.offset; } #endif /* ASSERT: rcPtr->method & FLAG(METH_SEEK) */ offObj = Tcl_NewWideIntObj(offset); baseObj = Tcl_NewStringObj((seekMode == SEEK_SET) ? "start" : ((seekMode == SEEK_CUR) ? "current" : "end"), -1); if (InvokeTclMethod(rcPtr, "seek", offObj, baseObj, &resObj)!=TCL_OK) { Tcl_SetChannelError(rcPtr->chan, resObj); Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ *errorCodePtr = EINVAL; return -1; } if (Tcl_GetWideIntFromObj(rcPtr->interp, resObj, &newLoc) != TCL_OK) { Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ Tcl_SetChannelError(rcPtr->chan, MarshallError(rcPtr->interp)); *errorCodePtr = EINVAL; return -1; } Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ if (newLoc < Tcl_LongAsWide(0)) { SetChannelErrorStr(rcPtr->chan, msg_seek_beforestart); *errorCodePtr = EINVAL; return -1; } *errorCodePtr = EOK; return newLoc; } 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) { ReflectedChannel *rcPtr = (ReflectedChannel *) clientData; Tcl_Obj *maskObj; /* ASSERT rcPtr->methods & FLAG(METH_WATCH) */ /* * We restrict the interest to what the channel can support. IOW there * will never be write events for a channel which is not writable. * Analoguously for read events and non-readable channels. */ mask &= rcPtr->mode; if (mask == rcPtr->interest) { /* * Same old, same old, why should we do something? */ return; } rcPtr->interest = mask; /* * Are we in the correct thread? */ #ifdef TCL_THREADS if (rcPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; p.watch.mask = mask; ForwardOpToOwnerThread(rcPtr, ForwardedWatch, &p); /* * Any failure from the forward is ignored. We have no place to put * this. */ return; } #endif maskObj = DecodeEventMask(mask); (void) InvokeTclMethod(rcPtr, "watch", maskObj, NULL, NULL); Tcl_DecrRefCount(maskObj); }  /* *---------------------------------------------------------------------- * * 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) { ReflectedChannel *rcPtr = (ReflectedChannel *) clientData; Tcl_Obj *blockObj; int errorNum; /* EINVAL or EOK (success). */ Tcl_Obj *resObj; /* Result data for 'blocking' */ /* * Are we in the correct thread? */ #ifdef TCL_THREADS if (rcPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; p.block.nonblocking = nonblocking; ForwardOpToOwnerThread(rcPtr, ForwardedBlock, &p); if (p.base.code != TCL_OK) { PassReceivedError(rcPtr->chan, &p); return EINVAL; } return EOK; } #endif blockObj = Tcl_NewBooleanObj(!nonblocking); if (InvokeTclMethod(rcPtr, "blocking", blockObj, NULL, &resObj) != TCL_OK) { Tcl_SetChannelError(rcPtr->chan, resObj); errorNum = EINVAL; } else { errorNum = EOK; } Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ return errorNum; }  /* *---------------------------------------------------------------------- * * ReflectSetOption -- * * This function is invoked to configure a channel option. * * Results: * A standard Tcl result code. * * Side effects: * Arbitrary, as it calls upon a Tcl script. * *---------------------------------------------------------------------- */ 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 */ { ReflectedChannel *rcPtr = (ReflectedChannel *) clientData; Tcl_Obj *optionObj, *valueObj; int result; /* Result code for 'configure' */ Tcl_Obj *resObj; /* Result data for 'configure' */ /* * Are we in the correct thread? */ #ifdef TCL_THREADS if (rcPtr->thread != Tcl_GetCurrentThread()) { ForwardParam p; p.setOpt.name = optionName; p.setOpt.value = newValue; ForwardOpToOwnerThread(rcPtr, ForwardedSetOpt, &p); if (p.base.code != TCL_OK) { Tcl_Obj *err = Tcl_NewStringObj(p.base.msgStr, -1); UnmarshallErrorResult(interp, err); Tcl_DecrRefCount(err); FreeReceivedError(&p); } return p.base.code; } #endif optionObj = Tcl_NewStringObj(optionName, -1); valueObj = Tcl_NewStringObj(newValue, -1); result = InvokeTclMethod(rcPtr, "configure",optionObj,valueObj, &resObj); if (result != TCL_OK) { UnmarshallErrorResult(interp, resObj); } Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ return result; }  /* *---------------------------------------------------------------------- * * ReflectGetOption -- * * This function is invoked to retrieve all or a channel option. * * Results: * A standard Tcl result code. * * Side effects: * Arbitrary, as it calls upon a Tcl script. * *---------------------------------------------------------------------- */ 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 */ { /* * This code is special. It has regular passing of Tcl result, and errors. * The bypass functions are not required. */ ReflectedChannel *rcPtr = (ReflectedChannel*) clientData; Tcl_Obj *optionObj; Tcl_Obj *resObj; /* Result data for 'configure' */ int listc; Tcl_Obj **listv; const char *method; /* * Are we in the correct thread? */ #ifdef TCL_THREADS if (rcPtr->thread != Tcl_GetCurrentThread()) { int opcode; ForwardParam p; p.getOpt.name = optionName; p.getOpt.value = dsPtr; if (optionName == NULL) { opcode = ForwardedGetOptAll; } else { opcode = ForwardedGetOpt; } ForwardOpToOwnerThread(rcPtr, opcode, &p); if (p.base.code != TCL_OK) { Tcl_Obj *err = Tcl_NewStringObj(p.base.msgStr, -1); UnmarshallErrorResult(interp, err); Tcl_DecrRefCount(err); FreeReceivedError(&p); } return p.base.code; } #endif if (optionName == NULL) { /* * Retrieve all options. */ method = "cgetall"; optionObj = NULL; } else { /* * Retrieve the value of one option. */ method = "cget"; optionObj = Tcl_NewStringObj(optionName, -1); } if (InvokeTclMethod(rcPtr, method, optionObj, NULL, &resObj)!=TCL_OK) { UnmarshallErrorResult(interp, resObj); Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ return TCL_ERROR; } /* * The result has to go into the 'dsPtr' for propagation to the caller of * the driver. */ if (optionObj != NULL) { Tcl_DStringAppend(dsPtr, TclGetString(resObj), -1); Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ return TCL_OK; } /* * Extract the list and append each item as element. */ /* * NOTE (4): If we extract the string rep we can assume a properly quoted * string. Together with a separating space this way of simply appending * the whole string rep might be faster. It also doesn't check if the * result is a valid list. Nor that the list has an even number elements. */ if (Tcl_ListObjGetElements(interp, resObj, &listc, &listv) != TCL_OK) { Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ return TCL_ERROR; } if ((listc % 2) == 1) { /* * Odd number of elements is wrong. */ Tcl_ResetResult(interp); Tcl_SetObjResult(interp, Tcl_ObjPrintf( "Expected list with even number of " "elements, got %d element%s instead", listc, (listc == 1 ? "" : "s"))); Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ return TCL_ERROR; } else { int len; char *str = Tcl_GetStringFromObj(resObj, &len); if (len) { Tcl_DStringAppend(dsPtr, " ", 1); Tcl_DStringAppend(dsPtr, str, len); } Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */ return TCL_OK; } }  /* * Helpers. ========================================================= */ /* *---------------------------------------------------------------------- * * EncodeEventMask -- * * This function takes a list of event items and constructs the * equivalent internal bitmask. The list must contain at least one * element. Elements are "read", "write", or any unique abbreviation of * them. Note that the bitmask is not changed if problems are * encountered. * * Results: * A standard Tcl error code. A bitmask where TCL_READABLE and/or * TCL_WRITABLE can be set. * * Side effects: * May shimmer 'obj' to a list representation. May place an error message * into the interp result. * *---------------------------------------------------------------------- */ static int EncodeEventMask( Tcl_Interp *interp, const char *objName, Tcl_Obj *obj, int *mask) { int events; /* Mask of events to post */ int listc; /* #elements in eventspec list */ Tcl_Obj **listv; /* Elements of eventspec list */ int evIndex; /* Id of event for an element of the eventspec * list. */ if (Tcl_ListObjGetElements(interp, obj, &listc, &listv) != TCL_OK) { return TCL_ERROR; } if (listc < 1) { Tcl_AppendResult(interp, "bad ", objName, " list: is empty", NULL); return TCL_ERROR; } events = 0; while (listc > 0) { if (Tcl_GetIndexFromObj(interp, listv[listc-1], eventOptions, objName, 0, &evIndex) != TCL_OK) { return TCL_ERROR; } switch (evIndex) { case EVENT_READ: events |= TCL_READABLE; break; case EVENT_WRITE: events |= TCL_WRITABLE; break; } listc --; } *mask = events; return TCL_OK; }  /* *---------------------------------------------------------------------- * * 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. * *---------------------------------------------------------------------- */ 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; }  /* *---------------------------------------------------------------------- * * NewReflectedChannel -- * * 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 ReflectedChannel * NewReflectedChannel( Tcl_Interp *interp, Tcl_Obj *cmdpfxObj, int mode, Tcl_Obj *handleObj) { ReflectedChannel *rcPtr; int i, listc; Tcl_Obj **listv; rcPtr = (ReflectedChannel *) ckalloc(sizeof(ReflectedChannel)); /* rcPtr->chan: Assigned by caller. Dummy data here. */ /* rcPtr->methods: Assigned by caller. Dummy data here. */ rcPtr->chan = NULL; rcPtr->methods = 0; rcPtr->interp = interp; #ifdef TCL_THREADS rcPtr->thread = Tcl_GetCurrentThread(); #endif rcPtr->mode = mode; rcPtr->interest = 0; /* Initially no interest registered */ /* * 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 */ rcPtr->argc = listc + 2; rcPtr->argv = (Tcl_Obj **) ckalloc(sizeof(Tcl_Obj *) * (listc+4)); /* * Duplicate object references. */ for (i=0; i<listc ; i++) { Tcl_Obj *word = rcPtr->argv[i] = listv[i]; Tcl_IncrRefCount(word); } i++; /* Skip placeholder for method */ /* * [Bug 1667990]: See [x] in FreeReflectedChannel for release */ rcPtr->argv[i] = handleObj; Tcl_IncrRefCount(handleObj); /* * The next two objects are kept empty, varying arguments. */ /* * Initialization complete. */ return rcPtr; }  /* *---------------------------------------------------------------------- * * 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(rcCounterMutex) static unsigned long rcCounter = 0; Tcl_Obj *resObj; Tcl_MutexLock(&rcCounterMutex); resObj = Tcl_ObjPrintf("rc%lu", rcCounter); rcCounter++; Tcl_MutexUnlock(&rcCounterMutex); return resObj; }  static void FreeReflectedChannel( ReflectedChannel *rcPtr) { Channel *chanPtr = (Channel *) rcPtr->chan; int i, n; if (chanPtr->typePtr != &tclRChannelType) { /* * Delete a cloned ChannelType structure. */ ckfree((char*) chanPtr->typePtr); } n = rcPtr->argc - 2; for (i=0; i<n; i++) { Tcl_DecrRefCount(rcPtr->argv[i]); } /* * [Bug 1667990]: See [x] in NewReflectedChannel for lock. n+1 = argc-1. */ Tcl_DecrRefCount(rcPtr->argv[n+1]); ckfree((char*) rcPtr->argv); ckfree((char*) rcPtr); }  /* *---------------------------------------------------------------------- * * 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. * *---------------------------------------------------------------------- */ static int InvokeTclMethod( ReflectedChannel *rcPtr, 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. */ /* * NOTE (5): Decide impl. issue: Cache objects with method names? Needs * TSD data as reflections can be created in many different threads. */ /* * Insert method into the pre-allocated area, after the command prefix, * before the channel id. */ methObj = Tcl_NewStringObj(method, -1); Tcl_IncrRefCount(methObj); rcPtr->argv[rcPtr->argc - 2] = methObj; /* * Append the additional argument containing method specific details * behind the channel id. If specified. */ cmdc = rcPtr->argc; if (argOneObj) { Tcl_IncrRefCount(argOneObj); rcPtr->argv[cmdc] = argOneObj; cmdc++; if (argTwoObj) { Tcl_IncrRefCount(argTwoObj); rcPtr->argv[cmdc] = argTwoObj; cmdc++; } } /* * And run the handler... This is done in auch a manner which leaves any * existing state intact. */ sr = Tcl_SaveInterpState(rcPtr->interp, 0 /* Dummy */); Tcl_Preserve(rcPtr->interp); result = Tcl_EvalObjv(rcPtr->interp, cmdc, rcPtr->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(rcPtr->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, rcPtr->argv); int cmdLen; const char *cmdString = Tcl_GetStringFromObj(cmd, &cmdLen); Tcl_IncrRefCount(cmd); Tcl_ResetResult(rcPtr->interp); Tcl_SetObjResult(rcPtr->interp, Tcl_ObjPrintf( "chan handler returned bad code: %d", result)); Tcl_LogCommandInfo(rcPtr->interp, cmdString, cmdString, cmdLen); Tcl_DecrRefCount(cmd); result = TCL_ERROR; } Tcl_AppendObjToErrorInfo(rcPtr->interp, Tcl_ObjPrintf( "\n (chan handler subcommand \"%s\")", method)); resObj = MarshallError(rcPtr->interp); } Tcl_IncrRefCount(resObj); } Tcl_RestoreInterpState(rcPtr->interp, sr); Tcl_Release(rcPtr->interp); /* * Cleanup of the dynamic parts of the command. */ Tcl_DecrRefCount(methObj); if (argOneObj) { Tcl_DecrRefCount(argOneObj); if (argTwoObj) { Tcl_DecrRefCount(argTwoObj); } } /* * 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; }  /* *---------------------------------------------------------------------- * * GetReflectedChannelMap -- * * 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 ReflectedChannelMap * GetReflectedChannelMap( Tcl_Interp *interp) { ReflectedChannelMap* rcmPtr = Tcl_GetAssocData(interp, RCMKEY, NULL); if (rcmPtr == NULL) { rcmPtr = (ReflectedChannelMap *) ckalloc(sizeof(ReflectedChannelMap)); Tcl_InitHashTable(&rcmPtr->map, TCL_STRING_KEYS); Tcl_SetAssocData(interp, RCMKEY, (Tcl_InterpDeleteProc *) DeleteReflectedChannelMap, rcmPtr); } return rcmPtr; }  /* *---------------------------------------------------------------------- * * DeleteReflectedChannelMap -- * * 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 DeleteReflectedChannelMap( ClientData clientData, /* The per-interpreter data structure. */ Tcl_Interp *interp) /* The interpreter being deleted. */ { ReflectedChannelMap* rcmPtr; /* The map */ Tcl_HashSearch hSearch; /* Search variable. */ Tcl_HashEntry *hPtr; /* Search variable. */ /* * Delete all entries. The channels may have been closed alreay, or will * be closed later, by the standard IO finalization of an interpreter * under destruction. */ rcmPtr = clientData; for (hPtr = Tcl_FirstHashEntry(&rcmPtr->map, &hSearch); hPtr != NULL; hPtr = Tcl_FirstHashEntry(&rcmPtr->map, &hSearch)) { Tcl_DeleteHashEntry(hPtr); } Tcl_DeleteHashTable(&rcmPtr->map); ckfree((char *) &rcmPtr->map); }  #ifdef TCL_THREADS static void ForwardOpToOwnerThread( ReflectedChannel *rcPtr, /* Channel instance */ ForwardedOperation op, /* Forwarded driver operation */ const VOID *param) /* Arguments */ { Tcl_ThreadId dst = rcPtr->thread; ForwardingEvent *evPtr; ForwardingResult *resultPtr; int result; /* * Create and initialize the event and data structures. */ evPtr = (ForwardingEvent *) ckalloc(sizeof(ForwardingEvent)); resultPtr = (ForwardingResult *) ckalloc(sizeof(ForwardingResult)); evPtr->event.proc = ForwardProc; evPtr->resultPtr = resultPtr; evPtr->op = op; evPtr->rcPtr = rcPtr; evPtr->param = (ForwardParam *) param; resultPtr->src = Tcl_GetCurrentThread(); resultPtr->dst = dst; resultPtr->done = NULL; resultPtr->result = -1; resultPtr->evPtr = evPtr; /* * Now execute the forward. */ Tcl_MutexLock(&rcForwardMutex); TclSpliceIn(resultPtr, forwardList); /* * Ensure cleanup of the event if any of the two involved threads exits * while this event is pending or in progress. */ Tcl_CreateThreadExitHandler(SrcExitProc, (ClientData) evPtr); Tcl_CreateThreadExitHandler(DstExitProc, (ClientData) 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" */ Tcl_ConditionWait(&resultPtr->done, &rcForwardMutex, NULL); } /* * Unlink result from the forwarder list. */ TclSpliceOut(resultPtr, forwardList); resultPtr->nextPtr = NULL; resultPtr->prevPtr = NULL; Tcl_MutexUnlock(&rcForwardMutex); Tcl_ConditionFinalize(&resultPtr->done); /* * Kill the cleanup handlers now, and the result structure as well, before * returning the success code. * * Note: The event structure has already been deleted. */ Tcl_DeleteThreadExitHandler(SrcExitProc, (ClientData) evPtr); Tcl_DeleteThreadExitHandler(DstExitProc, (ClientData) evPtr); result = resultPtr->result; ckfree((char*) 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; ReflectedChannel *rcPtr = evPtr->rcPtr; Tcl_Interp *interp = rcPtr->interp; ForwardParam *paramPtr = evPtr->param; Tcl_Obj *resObj = NULL; /* Interp result of InvokeTclMethod */ /* * 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 * rcPtr->thread, which contains rcPtr->interp, the interp we have to * call upon for the driver. */ case ForwardedClose: /* * No parameters/results. */ if (InvokeTclMethod(rcPtr, "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 */ FreeReflectedChannel(rcPtr); break; case ForwardedInput: { Tcl_Obj *toReadObj = Tcl_NewIntObj(paramPtr->input.toRead); if (InvokeTclMethod(rcPtr, "read", toReadObj, NULL, &resObj)!=TCL_OK){ ForwardSetObjError(paramPtr, resObj); paramPtr->input.toRead = -1; } else { /* * Process a regular result. */ int bytec; /* Number of returned bytes */ unsigned char *bytev; /* Array of returned bytes */ bytev = Tcl_GetByteArrayFromObj(resObj, &bytec); if (paramPtr->input.toRead < bytec) { ForwardSetStaticError(paramPtr, msg_read_toomuch); paramPtr->input.toRead = -1; } else { if (bytec > 0) { memcpy(paramPtr->input.buf, bytev, (size_t)bytec); } paramPtr->input.toRead = bytec; } } break; } case ForwardedOutput: { Tcl_Obj *bufObj = Tcl_NewByteArrayObj((unsigned char *) paramPtr->output.buf, paramPtr->output.toWrite); if (InvokeTclMethod(rcPtr, "write", bufObj, NULL, &resObj) != TCL_OK) { ForwardSetObjError(paramPtr, resObj); paramPtr->output.toWrite = -1; } else { /* * Process a regular result. */ int written; if (Tcl_GetIntFromObj(interp, resObj, &written) != TCL_OK) { ForwardSetObjError(paramPtr, MarshallError(interp)); paramPtr->output.toWrite = -1; } else if (written==0 || paramPtr->output.toWrite<written) { ForwardSetStaticError(paramPtr, msg_write_toomuch); paramPtr->output.toWrite = -1; } else { paramPtr->output.toWrite = written; } } break; } case ForwardedSeek: { Tcl_Obj *offObj = Tcl_NewWideIntObj(paramPtr->seek.offset); Tcl_Obj *baseObj = Tcl_NewStringObj( (paramPtr->seek.seekMode==SEEK_SET) ? "start" : (paramPtr->seek.seekMode==SEEK_CUR) ? "current" : "end", -1); if (InvokeTclMethod(rcPtr, "seek", offObj, baseObj, &resObj)!=TCL_OK){ ForwardSetObjError(paramPtr, resObj); paramPtr->seek.offset = -1; } else { /* * Process a regular result. If the type is wrong this may change * into an error. */ Tcl_WideInt newLoc; if (Tcl_GetWideIntFromObj(interp, resObj, &newLoc) == TCL_OK) { if (newLoc < Tcl_LongAsWide(0)) { ForwardSetStaticError(paramPtr, msg_seek_beforestart); paramPtr->seek.offset = -1; } else { paramPtr->seek.offset = newLoc; } } else { ForwardSetObjError(paramPtr, MarshallError(interp)); paramPtr->seek.offset = -1; } } break; } case ForwardedWatch: { Tcl_Obj *maskObj = DecodeEventMask(paramPtr->watch.mask); (void) InvokeTclMethod(rcPtr, "watch", maskObj, NULL, NULL); Tcl_DecrRefCount(maskObj); break; } case ForwardedBlock: { Tcl_Obj *blockObj = Tcl_NewBooleanObj(!paramPtr->block.nonblocking); if (InvokeTclMethod(rcPtr, "blocking", blockObj, NULL, &resObj) != TCL_OK) { ForwardSetObjError(paramPtr, resObj); } break; } case ForwardedSetOpt: { Tcl_Obj *optionObj = Tcl_NewStringObj(paramPtr->setOpt.name, -1); Tcl_Obj *valueObj = Tcl_NewStringObj(paramPtr->setOpt.value, -1); if (InvokeTclMethod(rcPtr, "configure", optionObj, valueObj, &resObj) != TCL_OK) { ForwardSetObjError(paramPtr, resObj); } break; } case ForwardedGetOpt: { /* * Retrieve the value of one option. */ Tcl_Obj *optionObj = Tcl_NewStringObj(paramPtr->getOpt.name, -1); if (InvokeTclMethod(rcPtr, "cget", optionObj, NULL, &resObj)!=TCL_OK){ ForwardSetObjError(paramPtr, resObj); } else { Tcl_DStringAppend(paramPtr->getOpt.value, TclGetString(resObj), -1); } break; } case ForwardedGetOptAll: /* * Retrieve all options. */ if (InvokeTclMethod(rcPtr, "cgetall", NULL, NULL, &resObj) != TCL_OK){ ForwardSetObjError(paramPtr, resObj); } else { /* * Extract list, validate that it is a list, and #elements. See * NOTE (4) as well. */ int listc; Tcl_Obj **listv; if (Tcl_ListObjGetElements(interp, resObj, &listc, &listv) != TCL_OK) { ForwardSetObjError(paramPtr, MarshallError(interp)); } else if ((listc % 2) == 1) { /* * Odd number of elements is wrong. [x]. */ char *buf = ckalloc(200); sprintf(buf, "{Expected list with even number of elements, got %d %s instead}", listc, (listc == 1 ? "element" : "elements")); ForwardSetDynamicError(paramPtr, buf); } else { int len; const char *str = Tcl_GetStringFromObj(resObj, &len); if (len) { Tcl_DStringAppend(paramPtr->getOpt.value, " ", 1); Tcl_DStringAppend(paramPtr->getOpt.value, str, len); } } } 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(&rcForwardMutex); resultPtr->result = TCL_OK; Tcl_ConditionNotify(&resultPtr->done); Tcl_MutexUnlock(&rcForwardMutex); } return 1; }  static void SrcExitProc( ClientData clientData) { ForwardingEvent *evPtr = (ForwardingEvent *) 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(&rcForwardMutex); 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(&rcForwardMutex); /* * This unlocks (*). The structure will be spliced out and freed by * "ForwardProc". Maybe. */ Tcl_ConditionNotify(&resultPtr->done); }  static void DstExitProc( ClientData clientData) { ForwardingEvent *evPtr = (ForwardingEvent *) clientData; ForwardingResult *resultPtr = evPtr->resultPtr; ForwardParam *paramPtr = evPtr->param; /* * NOTE (3): It is not clear if the event still exists when this handler * is called. We might have to use 'resultPtr' as our clientData instead. */ /* * The receiver for the event exited, before processing the event. We * detach the result now, wake the originator up and signal failure. */ evPtr->resultPtr = NULL; resultPtr->evPtr = NULL; resultPtr->result = TCL_ERROR; ForwardSetStaticError(paramPtr, msg_send_dstlost); 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((unsigned) len)); memcpy(paramPtr->base.msgStr, msgStr, (unsigned) len); } #endif  /* * Local Variables: * mode: c * c-basic-offset: 4 * fill-column: 78 * End: */

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