/*
* 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 1.28.2.11 2010/08/04 16:47:15 andreas_kupries 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. NULL here
* signals the channel is dead because the
* interpreter/thread containing its Tcl
* command is gone.
*/
#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_Interp* dsti; /* Interpreter in the thread the op was forwarded to. */
/*
* Note regarding 'dsti' above: Its information is also available via the
* chain evPtr->rcPtr->interp, however, as can be seen, two more
* indirections are needed to retrieve it. And the evPtr may be gone,
* breaking the chain.
*/
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 channels owned by this thread. This is the
* per-thread version of the per-interpreter map.
*/
ReflectedChannelMap* rcmPtr;
} 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(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 ExitProc ensures that things do not deadlock when the sending thread
* involved in the forwarding exits. It 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);
#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);
static ReflectedChannelMap * GetThreadReflectedChannelMap(void);
static void DeleteThreadReflectedChannelMap(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 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);
static int ErrnoReturn(ReflectedChannel *rcPtr, Tcl_Obj* resObj);
/*
* 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_write_nothing = "{write wrote nothing}";
static const char *msg_seek_beforestart = "{Tried to seek before origin}";
#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}";
/*
* 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);
/* assert modeObj.refCount == 1 */
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);
#ifdef TCL_THREADS
rcmPtr = GetThreadReflectedChannelMap();
hPtr = Tcl_CreateHashEntry(&rcmPtr->map,
chanPtr->state->channelName, &isNew);
Tcl_SetHashValue(hPtr, chan);
#endif
/*
* 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' */
ReflectedChannelMap* rcmPtr; /* Map of reflected channels 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: DeleteThreadReflectedChannelMap() is the thread exit handler for the origin
* thread. Use this to clean up the structure? Except if lost?
*/
#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
Tcl_EventuallyFree (rcPtr, (Tcl_FreeProc *) FreeReflectedChannel);
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) {
Tcl_EventuallyFree (rcPtr, (Tcl_FreeProc *) FreeReflectedChannel);
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 */
/*
* Remove the channel from the map before releasing the memory, to
* prevent future accesses (like by 'postevent') from finding and
* dereferencing a dangling pointer.
*
* NOTE: The channel may not be in the map. This is ok, that happens
* when the channel 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 DeleteReflectedChannelMap exit-handler.
*/
if (rcPtr->interp) {
rcmPtr = GetReflectedChannelMap (rcPtr->interp);
hPtr = Tcl_FindHashEntry (&rcmPtr->map,
Tcl_GetChannelName (rcPtr->chan));
if (hPtr) {
Tcl_DeleteHashEntry (hPtr);
}
}
#ifdef TCL_THREADS
rcmPtr = GetThreadReflectedChannelMap();
hPtr = Tcl_FindHashEntry (&rcmPtr->map,
Tcl_GetChannelName (rcPtr->chan));
if (hPtr) {
Tcl_DeleteHashEntry (hPtr);
}
#endif
Tcl_EventuallyFree (rcPtr, (Tcl_FreeProc *) FreeReflectedChannel);
#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) {
if (p.base.code < 0) {
/* No error message, this is an errno signal. */
*errorCodePtr = -p.base.code;
} else {
PassReceivedError(rcPtr->chan, &p);
*errorCodePtr = EINVAL;
}
p.input.toRead = -1;
} else {
*errorCodePtr = EOK;
}
return p.input.toRead;
}
#endif
/* ASSERT: rcPtr->method & FLAG(METH_READ) */
/* ASSERT: rcPtr->mode & TCL_READABLE */
Tcl_Preserve(rcPtr);
toReadObj = Tcl_NewIntObj(toRead);
Tcl_IncrRefCount(toReadObj);
if (InvokeTclMethod(rcPtr, "read", toReadObj, NULL, &resObj)!=TCL_OK) {
int code = ErrnoReturn (rcPtr, resObj);
if (code < 0) {
*errorCodePtr = -code;
goto error;
}
Tcl_SetChannelError(rcPtr->chan, resObj);
goto invalid;
}
bytev = Tcl_GetByteArrayFromObj(resObj, &bytec);
if (toRead < bytec) {
SetChannelErrorStr(rcPtr->chan, msg_read_toomuch);
goto invalid;
}
*errorCodePtr = EOK;
if (bytec > 0) {
memcpy(buf, bytev, (size_t)bytec);
}
stop:
Tcl_DecrRefCount(toReadObj);
Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */
Tcl_Release(rcPtr);
return bytec;
invalid:
*errorCodePtr = EINVAL;
error:
bytec = -1;
goto stop;
}
/*
*----------------------------------------------------------------------
*
* 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) {
if (p.base.code < 0) {
/* No error message, this is an errno signal. */
*errorCodePtr = -p.base.code;
} else {
PassReceivedError(rcPtr->chan, &p);
*errorCodePtr = EINVAL;
}
p.output.toWrite = -1;
} else {
*errorCodePtr = EOK;
}
return p.output.toWrite;
}
#endif
/* ASSERT: rcPtr->method & FLAG(METH_WRITE) */
/* ASSERT: rcPtr->mode & TCL_WRITABLE */
Tcl_Preserve(rcPtr);
bufObj = Tcl_NewByteArrayObj((unsigned char *) buf, toWrite);
Tcl_IncrRefCount(bufObj);
if (InvokeTclMethod(rcPtr, "write", bufObj, NULL, &resObj) != TCL_OK) {
int code = ErrnoReturn(rcPtr, resObj);
if (code < 0) {
*errorCodePtr = -code;
goto error;
}
Tcl_SetChannelError(rcPtr->chan, resObj);
goto invalid;
}
if (Tcl_GetIntFromObj(rcPtr->interp, resObj, &written) != TCL_OK) {
Tcl_SetChannelError(rcPtr->chan, MarshallError(rcPtr->interp));
goto invalid;
}
if ((written == 0) && (toWrite > 0)) {
/*
* The handler claims to have written nothing of what it was
* given. That is bad.
*/
SetChannelErrorStr(rcPtr->chan, msg_write_nothing);
goto invalid;
}
if (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);
goto invalid;
}
*errorCodePtr = EOK;
stop:
Tcl_DecrRefCount(bufObj);
Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */
Tcl_Release(rcPtr);
return written;
invalid:
*errorCodePtr = EINVAL;
error:
written = -1;
goto stop;
}
/*
*----------------------------------------------------------------------
*
* 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;
p.seek.offset = -1;
} else {
*errorCodePtr = EOK;
}
return p.seek.offset;
}
#endif
/* ASSERT: rcPtr->method & FLAG(METH_SEEK) */
Tcl_Preserve(rcPtr);
offObj = Tcl_NewWideIntObj(offset);
baseObj = Tcl_NewStringObj((seekMode == SEEK_SET) ? "start" :
((seekMode == SEEK_CUR) ? "current" : "end"), -1);
Tcl_IncrRefCount(offObj);
Tcl_IncrRefCount(baseObj);
if (InvokeTclMethod(rcPtr, "seek", offObj, baseObj, &resObj)!=TCL_OK) {
Tcl_SetChannelError(rcPtr->chan, resObj);
goto invalid;
}
if (Tcl_GetWideIntFromObj(rcPtr->interp, resObj, &newLoc) != TCL_OK) {
Tcl_SetChannelError(rcPtr->chan, MarshallError(rcPtr->interp));
goto invalid;
}
if (newLoc < Tcl_LongAsWide(0)) {
SetChannelErrorStr(rcPtr->chan, msg_seek_beforestart);
goto invalid;
}
*errorCodePtr = EOK;
stop:
Tcl_DecrRefCount(offObj);
Tcl_DecrRefCount(baseObj);
Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */
Tcl_Release(rcPtr);
return newLoc;
invalid:
*errorCodePtr = EINVAL;
newLoc = -1;
goto stop;
}
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
Tcl_Preserve(rcPtr);
maskObj = DecodeEventMask(mask);
/* assert maskObj.refCount == 1 */
(void) InvokeTclMethod(rcPtr, "watch", maskObj, NULL, NULL);
Tcl_DecrRefCount(maskObj);
Tcl_Release(rcPtr);
}
/*
*----------------------------------------------------------------------
*
* 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);
Tcl_IncrRefCount(blockObj);
Tcl_Preserve(rcPtr);
if (InvokeTclMethod(rcPtr, "blocking", blockObj, NULL, &resObj) != TCL_OK) {
Tcl_SetChannelError(rcPtr->chan, resObj);
errorNum = EINVAL;
} else {
errorNum = EOK;
}
Tcl_DecrRefCount(blockObj);
Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */
Tcl_Release(rcPtr);
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
Tcl_Preserve(rcPtr);
optionObj = Tcl_NewStringObj(optionName, -1);
valueObj = Tcl_NewStringObj(newValue, -1);
Tcl_IncrRefCount(optionObj);
Tcl_IncrRefCount(valueObj);
result = InvokeTclMethod(rcPtr, "configure",optionObj,valueObj, &resObj);
if (result != TCL_OK) {
UnmarshallErrorResult(interp, resObj);
}
Tcl_DecrRefCount(optionObj);
Tcl_DecrRefCount(valueObj);
Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */
Tcl_Release(rcPtr);
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, result = TCL_OK;
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);
Tcl_IncrRefCount(optionObj);
}
Tcl_Preserve(rcPtr);
if (InvokeTclMethod(rcPtr, method, optionObj, NULL, &resObj)!=TCL_OK) {
UnmarshallErrorResult(interp, resObj);
goto 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);
goto 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) {
goto 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")));
goto error;
} else {
int len;
char *str = Tcl_GetStringFromObj(resObj, &len);
if (len) {
Tcl_DStringAppend(dsPtr, " ", 1);
Tcl_DStringAppend(dsPtr, str, len);
}
goto ok;
}
ok:
result = TCL_OK;
stop:
if (optionObj) {
Tcl_DecrRefCount(optionObj);
}
Tcl_DecrRefCount(resObj); /* Remove reference held from invoke */
Tcl_Release(rcPtr);
return result;
error:
result = TCL_ERROR;
goto stop;
}
/*
* 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.
*
* 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, ...}
*
*----------------------------------------------------------------------
*/
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. */
if (!rcPtr->interp) {
/*
* The channel 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);
}
/*
* Not touching argOneObj, argTwoObj, they have not been used.
* See the contract as well.
*/
return TCL_ERROR;
}
/*
* NOTE (5): Decide impl. issue: Cache objects with method names? Needs
* 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);
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) {
rcPtr->argv[cmdc] = argOneObj;
cmdc++;
if (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.
*
* 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;
}
/*
*----------------------------------------------------------------------
*
* ErrnoReturn --
*
* Checks a method error result if it returned an 'errno'.
*
* Results:
* The negative errno found in the error result, or 0.
*
* Side effects:
* None.
*
* Users:
* ReflectInput/Output(), to enable the signaling of EAGAIN
* on 0-sized short reads/writes.
*
*----------------------------------------------------------------------
*/
static int
ErrnoReturn(ReflectedChannel *rcPtr, Tcl_Obj* resObj)
{
int code;
Tcl_InterpState sr; /* State of handler interp */
if (!rcPtr->interp) {
return 0;
}
sr = Tcl_SaveInterpState(rcPtr->interp, 0 /* Dummy */);
UnmarshallErrorResult(rcPtr->interp, resObj);
resObj = Tcl_GetObjResult(rcPtr->interp);
if (((Tcl_GetIntFromObj(rcPtr->interp, resObj, &code) != TCL_OK) || (code >= 0))) {
if (strcmp ("EAGAIN",Tcl_GetString(resObj)) == 0) {
code = - EAGAIN;
} else {
code = 0;
}
}
Tcl_RestoreInterpState(rcPtr->interp, sr);
return code;
}
/*
*----------------------------------------------------------------------
*
* 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. */
ReflectedChannel* rcPtr;
Tcl_Channel chan;
#ifdef TCL_THREADS
ForwardingResult *resultPtr;
ForwardingEvent *evPtr;
ForwardParam *paramPtr;
#endif
/*
* 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
* DeleteThreadReflectedChannelMap(), just restricted to the channels of
* this interp.
*/
rcmPtr = clientData;
for (hPtr = Tcl_FirstHashEntry(&rcmPtr->map, &hSearch);
hPtr != NULL;
hPtr = Tcl_FirstHashEntry(&rcmPtr->map, &hSearch)) {
chan = (Tcl_Channel) Tcl_GetHashValue (hPtr);
rcPtr = (ReflectedChannel *) Tcl_GetChannelInstanceData(chan);
rcPtr->interp = NULL;
Tcl_DeleteHashEntry(hPtr);
}
Tcl_DeleteHashTable(&rcmPtr->map);
ckfree((char *) &rcmPtr->map);
#ifdef TCL_THREADS
/*
* The origin interpreter for one or more reflected channels is gone.
*/
/*
* 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(&rcForwardMutex);
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;
paramPtr = evPtr->param;
evPtr->resultPtr = NULL;
resultPtr->evPtr = NULL;
resultPtr->result = TCL_ERROR;
ForwardSetStaticError(paramPtr, msg_send_dstlost);
Tcl_ConditionNotify(&resultPtr->done);
}
/*
* Get the map of all channels handled by the current thread. This is a
* ReflectedChannelMap, 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.
*/
rcmPtr = GetThreadReflectedChannelMap();
for (hPtr = Tcl_FirstHashEntry(&rcmPtr->map, &hSearch);
hPtr != NULL;
hPtr = Tcl_NextHashEntry(&hSearch)) {
chan = (Tcl_Channel) Tcl_GetHashValue (hPtr);
rcPtr = (ReflectedChannel *) Tcl_GetChannelInstanceData(chan);
if (rcPtr->interp != interp) {
/* Ignore entries for other interpreters */
continue;
}
Tcl_DeleteHashEntry(hPtr);
}
Tcl_MutexUnlock(&rcForwardMutex);
#endif
}
#ifdef TCL_THREADS
/*
*----------------------------------------------------------------------
*
* GetThreadReflectedChannelMap --
*
* 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 ReflectedChannelMap *
GetThreadReflectedChannelMap()
{
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
if (!tsdPtr->rcmPtr) {
tsdPtr->rcmPtr = (ReflectedChannelMap *) ckalloc(sizeof(ReflectedChannelMap));
Tcl_InitHashTable(&tsdPtr->rcmPtr->map, TCL_STRING_KEYS);
Tcl_CreateThreadExitHandler(DeleteThreadReflectedChannelMap, NULL);
}
return tsdPtr->rcmPtr;
}
/*
*----------------------------------------------------------------------
*
* DeleteThreadReflectedChannelMap --
*
* 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
* DeleteReflectedChannelMap().
*
* Results:
* None.
*
* Side effects:
* Deletes the hash table of channels.
*
*----------------------------------------------------------------------
*/
static void
DeleteThreadReflectedChannelMap(
ClientData clientData) /* The per-thread data structure. */
{
Tcl_HashSearch hSearch; /* Search variable. */
Tcl_HashEntry *hPtr; /* Search variable. */
Tcl_ThreadId self = Tcl_GetCurrentThread();
ReflectedChannelMap* rcmPtr; /* The map */
Tcl_Channel chan;
ReflectedChannel* rcPtr;
ForwardingResult *resultPtr;
ForwardingEvent *evPtr;
ForwardParam *paramPtr;
/*
* 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 DeleteReflectedChannelMap is apparently not called.
*/
/*
* 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(&rcForwardMutex);
for (resultPtr = forwardList;
resultPtr != NULL;
resultPtr = resultPtr->nextPtr) {
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;
paramPtr = evPtr->param;
evPtr->resultPtr = NULL;
resultPtr->evPtr = NULL;
resultPtr->result = TCL_ERROR;
ForwardSetStaticError(paramPtr, msg_send_dstlost);
Tcl_ConditionNotify(&resultPtr->done);
}
/*
* Get the map of all channels handled by the current thread. This is a
* ReflectedChannelMap, but on a per-thread basis, not per-interp. Go
* through the channels, remove all, mark them as dead.
*/
rcmPtr = GetThreadReflectedChannelMap();
for (hPtr = Tcl_FirstHashEntry(&rcmPtr->map, &hSearch);
hPtr != NULL;
hPtr = Tcl_FirstHashEntry(&rcmPtr->map, &hSearch)) {
chan = (Tcl_Channel) Tcl_GetHashValue (hPtr);
rcPtr = (ReflectedChannel *) Tcl_GetChannelInstanceData(chan);
rcPtr->interp = NULL;
Tcl_DeleteHashEntry(hPtr);
}
Tcl_MutexUnlock(&rcForwardMutex);
}
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;
/*
* We gather the lock early. This allows us to check the liveness of the
* channel without interference from DeleteThreadReflectedChannelMap().
*/
Tcl_MutexLock(&rcForwardMutex);
if (rcPtr->interp == NULL) {
/*
* 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(&rcForwardMutex);
return;
}
/*
* 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->dsti = rcPtr->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. Exitus of the destination thread is handled
* by DeleteThreadReflectionChannelMap(), this is set up by
* GetThreadReflectedChannelMap(). This is what we use the 'forwardList'
* (see above) for.
*/
Tcl_CreateThreadExitHandler(SrcExitProc, (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"
*
* The ConditionWait unlocks the mutex during the wait and relocks it
* immediately after.
*/
Tcl_ConditionWait(&resultPtr->done, &rcForwardMutex, 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(&rcForwardMutex);
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.
*/
Tcl_DeleteThreadExitHandler(SrcExitProc, (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 */
ReflectedChannelMap* rcmPtr; /* 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
* 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
*
* We remove the channel from both interpreter and thread maps before
* releasing the memory, to prevent future accesses (like by
* 'postevent') from finding and dereferencing a dangling pointer.
*/
rcmPtr = GetReflectedChannelMap (interp);
hPtr = Tcl_FindHashEntry (&rcmPtr->map,
Tcl_GetChannelName (rcPtr->chan));
Tcl_DeleteHashEntry (hPtr);
rcmPtr = GetThreadReflectedChannelMap();
hPtr = Tcl_FindHashEntry (&rcmPtr->map,
Tcl_GetChannelName (rcPtr->chan));
Tcl_DeleteHashEntry (hPtr);
Tcl_EventuallyFree (rcPtr, (Tcl_FreeProc *) FreeReflectedChannel);
break;
case ForwardedInput: {
Tcl_Obj *toReadObj = Tcl_NewIntObj(paramPtr->input.toRead);
Tcl_IncrRefCount(toReadObj);
Tcl_Preserve(rcPtr);
if (InvokeTclMethod(rcPtr, "read", toReadObj, NULL, &resObj)!=TCL_OK){
int code = ErrnoReturn (rcPtr, resObj);
if (code < 0) {
paramPtr->base.code = code;
} else {
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;
}
}
Tcl_Release(rcPtr);
Tcl_DecrRefCount(toReadObj);
break;
}
case ForwardedOutput: {
Tcl_Obj *bufObj = Tcl_NewByteArrayObj((unsigned char *)
paramPtr->output.buf, paramPtr->output.toWrite);
Tcl_IncrRefCount(bufObj);
Tcl_Preserve(rcPtr);
if (InvokeTclMethod(rcPtr, "write", bufObj, NULL, &resObj) != TCL_OK) {
int code = ErrnoReturn(rcPtr, resObj);
if (code < 0) {
paramPtr->base.code = code;
} else {
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;
}
}
Tcl_Release(rcPtr);
Tcl_DecrRefCount(bufObj);
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);
Tcl_IncrRefCount(offObj);
Tcl_IncrRefCount(baseObj);
Tcl_Preserve(rcPtr);
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;
}
}
Tcl_Release(rcPtr);
Tcl_DecrRefCount(offObj);
Tcl_DecrRefCount(baseObj);
break;
}
case ForwardedWatch: {
Tcl_Obj *maskObj = DecodeEventMask(paramPtr->watch.mask);
/* assert maskObj.refCount == 1 */
Tcl_Preserve(rcPtr);
(void) InvokeTclMethod(rcPtr, "watch", maskObj, NULL, NULL);
Tcl_DecrRefCount(maskObj);
Tcl_Release(rcPtr);
break;
}
case ForwardedBlock: {
Tcl_Obj *blockObj = Tcl_NewBooleanObj(!paramPtr->block.nonblocking);
Tcl_IncrRefCount(blockObj);
Tcl_Preserve(rcPtr);
if (InvokeTclMethod(rcPtr, "blocking", blockObj, NULL,
&resObj) != TCL_OK) {
ForwardSetObjError(paramPtr, resObj);
}
Tcl_Release(rcPtr);
Tcl_DecrRefCount(blockObj);
break;
}
case ForwardedSetOpt: {
Tcl_Obj *optionObj = Tcl_NewStringObj(paramPtr->setOpt.name, -1);
Tcl_Obj *valueObj = Tcl_NewStringObj(paramPtr->setOpt.value, -1);
Tcl_IncrRefCount(optionObj);
Tcl_IncrRefCount(valueObj);
Tcl_Preserve(rcPtr);
if (InvokeTclMethod(rcPtr, "configure", optionObj, valueObj,
&resObj) != TCL_OK) {
ForwardSetObjError(paramPtr, resObj);
}
Tcl_Release(rcPtr);
Tcl_DecrRefCount(optionObj);
Tcl_DecrRefCount(valueObj);
break;
}
case ForwardedGetOpt: {
/*
* Retrieve the value of one option.
*/
Tcl_Obj *optionObj = Tcl_NewStringObj(paramPtr->getOpt.name, -1);
Tcl_IncrRefCount(optionObj);
Tcl_Preserve(rcPtr);
if (InvokeTclMethod(rcPtr, "cget", optionObj, NULL, &resObj)!=TCL_OK){
ForwardSetObjError(paramPtr, resObj);
} else {
Tcl_DStringAppend(paramPtr->getOpt.value,
TclGetString(resObj), -1);
}
Tcl_Release(rcPtr);
Tcl_DecrRefCount(optionObj);
break;
}
case ForwardedGetOptAll:
/*
* Retrieve all options.
*/
Tcl_Preserve(rcPtr);
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);
}
}
}
Tcl_Release(rcPtr);
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
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
* tab-width: 8
* indent-tabs-mode: nil
* End:
*/
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