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Diffstat (limited to 'doc/CrtChannel.3')
| -rw-r--r-- | doc/CrtChannel.3 | 679 |
1 files changed, 518 insertions, 161 deletions
diff --git a/doc/CrtChannel.3 b/doc/CrtChannel.3 index 354665a..1c5c665 100644 --- a/doc/CrtChannel.3 +++ b/doc/CrtChannel.3 @@ -1,16 +1,15 @@ '\" '\" Copyright (c) 1996-1997 Sun Microsystems, Inc. +'\" Copyright (c) 1997-2000 Ajuba Solutions. '\" '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. -'\" -'\" SCCS: @(#) CrtChannel.3 1.29 97/06/20 13:37:45 +.TH Tcl_CreateChannel 3 8.4 Tcl "Tcl Library Procedures" .so man.macros -.TH Tcl_CreateChannel 3 8.0 Tcl "Tcl Library Procedures" .BS '\" Note: do not modify the .SH NAME line immediately below! .SH NAME -Tcl_CreateChannel, Tcl_GetChannelInstanceData, Tcl_GetChannelType, Tcl_GetChannelName, Tcl_GetChannelHandle, Tcl_GetChannelMode, Tcl_GetChannelBufferSize, Tcl_SetDefaultTranslation, Tcl_SetChannelBufferSize, Tcl_NotifyChannel, Tcl_BadChannelOption \- procedures for creating and manipulating channels +Tcl_CreateChannel, Tcl_GetChannelInstanceData, Tcl_GetChannelType, Tcl_GetChannelName, Tcl_GetChannelHandle, Tcl_GetChannelMode, Tcl_GetChannelBufferSize, Tcl_SetChannelBufferSize, Tcl_NotifyChannel, Tcl_BadChannelOption, Tcl_ChannelName, Tcl_ChannelVersion, Tcl_ChannelBlockModeProc, Tcl_ChannelCloseProc, Tcl_ChannelClose2Proc, Tcl_ChannelInputProc, Tcl_ChannelOutputProc, Tcl_ChannelSeekProc, Tcl_ChannelWideSeekProc, Tcl_ChannelTruncateProc, Tcl_ChannelSetOptionProc, Tcl_ChannelGetOptionProc, Tcl_ChannelWatchProc, Tcl_ChannelGetHandleProc, Tcl_ChannelFlushProc, Tcl_ChannelHandlerProc, Tcl_ChannelThreadActionProc, Tcl_IsChannelShared, Tcl_IsChannelRegistered, Tcl_CutChannel, Tcl_SpliceChannel, Tcl_IsChannelExisting, Tcl_ClearChannelHandlers, Tcl_GetChannelThread, Tcl_ChannelBuffered \- procedures for creating and manipulating channels .SH SYNOPSIS .nf \fB#include <tcl.h>\fR @@ -21,43 +20,114 @@ Tcl_Channel ClientData \fBTcl_GetChannelInstanceData\fR(\fIchannel\fR) .sp -Tcl_ChannelType * +const Tcl_ChannelType * \fBTcl_GetChannelType\fR(\fIchannel\fR) .sp -char * +const char * \fBTcl_GetChannelName\fR(\fIchannel\fR) -.VS .sp int \fBTcl_GetChannelHandle\fR(\fIchannel, direction, handlePtr\fR) -.VE .sp -int -\fBTcl_GetChannelFlags\fR(\fIchannel\fR) +Tcl_ThreadId +\fBTcl_GetChannelThread\fR(\fIchannel\fR) .sp -\fBTcl_SetDefaultTranslation\fR(\fIchannel, transMode\fR) +int +\fBTcl_GetChannelMode\fR(\fIchannel\fR) .sp int \fBTcl_GetChannelBufferSize\fR(\fIchannel\fR) .sp \fBTcl_SetChannelBufferSize\fR(\fIchannel, size\fR) .sp -.VS \fBTcl_NotifyChannel\fR(\fIchannel, mask\fR) .sp int \fBTcl_BadChannelOption\fR(\fIinterp, optionName, optionList\fR) -.VE +.sp +int +\fBTcl_IsChannelShared\fR(\fIchannel\fR) +.sp +int +\fBTcl_IsChannelRegistered\fR(\fIinterp, channel\fR) +.sp +int +\fBTcl_IsChannelExisting\fR(\fIchannelName\fR) +.sp +void +\fBTcl_CutChannel\fR(\fIchannel\fR) +.sp +void +\fBTcl_SpliceChannel\fR(\fIchannel\fR) +.sp +void +\fBTcl_ClearChannelHandlers\fR(\fIchannel\fR) +.sp +int +\fBTcl_ChannelBuffered\fR(\fIchannel\fR) +.sp +const char * +\fBTcl_ChannelName\fR(\fItypePtr\fR) +.sp +Tcl_ChannelTypeVersion +\fBTcl_ChannelVersion\fR(\fItypePtr\fR) +.sp +Tcl_DriverBlockModeProc * +\fBTcl_ChannelBlockModeProc\fR(\fItypePtr\fR) +.sp +Tcl_DriverCloseProc * +\fBTcl_ChannelCloseProc\fR(\fItypePtr\fR) +.sp +Tcl_DriverClose2Proc * +\fBTcl_ChannelClose2Proc\fR(\fItypePtr\fR) +.sp +Tcl_DriverInputProc * +\fBTcl_ChannelInputProc\fR(\fItypePtr\fR) +.sp +Tcl_DriverOutputProc * +\fBTcl_ChannelOutputProc\fR(\fItypePtr\fR) +.sp +Tcl_DriverSeekProc * +\fBTcl_ChannelSeekProc\fR(\fItypePtr\fR) +.sp +Tcl_DriverWideSeekProc * +\fBTcl_ChannelWideSeekProc\fR(\fItypePtr\fR) +.sp +Tcl_DriverThreadActionProc * +\fBTcl_ChannelThreadActionProc\fR(\fItypePtr\fR) +.sp +Tcl_DriverTruncateProc * +\fBTcl_ChannelTruncateProc\fR(\fItypePtr\fR) +.sp +Tcl_DriverSetOptionProc * +\fBTcl_ChannelSetOptionProc\fR(\fItypePtr\fR) +.sp +Tcl_DriverGetOptionProc * +\fBTcl_ChannelGetOptionProc\fR(\fItypePtr\fR) +.sp +Tcl_DriverWatchProc * +\fBTcl_ChannelWatchProc\fR(\fItypePtr\fR) +.sp +Tcl_DriverGetHandleProc * +\fBTcl_ChannelGetHandleProc\fR(\fItypePtr\fR) +.sp +Tcl_DriverFlushProc * +\fBTcl_ChannelFlushProc\fR(\fItypePtr\fR) +.sp +Tcl_DriverHandlerProc * +\fBTcl_ChannelHandlerProc\fR(\fItypePtr\fR) .sp .SH ARGUMENTS -.AS Tcl_EolTranslation *channelName in -.AP Tcl_ChannelType *typePtr in +.AS "const Tcl_ChannelType" *channelName +.AP "const Tcl_ChannelType" *typePtr in Points to a structure containing the addresses of procedures that can be called to perform I/O and other functions on the channel. -.AP char *channelName in +.AP "const char" *channelName in The name of this channel, such as \fBfile3\fR; must not be in use by any other channel. Can be NULL, in which case the channel is -created without a name. +created without a name. If the created channel is assigned to one +of the standard channels (\fBstdin\fR, \fBstdout\fR or \fBstderr\fR), +the assigned channel name will be the name of the standard channel. .AP ClientData instanceData in Arbitrary one-word value to be associated with this channel. This value is passed to procedures in \fItypePtr\fR when they are invoked. @@ -66,36 +136,28 @@ OR-ed combination of \fBTCL_READABLE\fR and \fBTCL_WRITABLE\fR to indicate whether a channel is readable and writable. .AP Tcl_Channel channel in The channel to operate on. -.VS .AP int direction in \fBTCL_READABLE\fR means the input handle is wanted; \fBTCL_WRITABLE\fR means the output handle is wanted. .AP ClientData *handlePtr out Points to the location where the desired OS-specific handle should be stored. -.VE -.AP Tcl_EolTranslation transMode in -The translation mode; one of the constants \fBTCL_TRANSLATE_AUTO\fR, -\fBTCL_TRANSLATE_CR\fR, \fBTCL_TRANSLATE_LF\fR and \fBTCL_TRANSLATE_CRLF\fR. .AP int size in The size, in bytes, of buffers to allocate in this channel. -.VS .AP int mask in An OR-ed combination of \fBTCL_READABLE\fR, \fBTCL_WRITABLE\fR and \fBTCL_EXCEPTION\fR that indicates events that have occurred on this channel. .AP Tcl_Interp *interp in Current interpreter. (can be NULL) -.AP char *optionName in +.AP "const char" *optionName in Name of the invalid option. -.AP char *optionList in -Specific options list (space separated words, without "-") +.AP "const char" *optionList in +Specific options list (space separated words, without +.QW \- ) to append to the standard generic options list. Can be NULL for generic options error message only. -.VE - .BE - .SH DESCRIPTION .PP Tcl uses a two-layered channel architecture. It provides a generic upper @@ -114,7 +176,7 @@ driver provides a \fBTcl_ChannelType\fR structure containing pointers to functions implementing the various operations used by the generic layer to communicate with the channel driver. The \fBTcl_ChannelType\fR structure and the functions referenced by it are described in the section -TCL_CHANNELTYPE, below. +\fBTCL_CHANNELTYPE\fR, below. .PP Second, channel drivers usually provide a Tcl command to create instances of that type of channel. For example, the Tcl \fBopen\fR @@ -141,7 +203,16 @@ structure to perform operations on the channel. \fItypePtr\fR and \fIinstanceData\fR with it. The channel is opened in the mode indicated by \fImask\fR. For a discussion of channel drivers, their operations and the -\fBTcl_ChannelType\fR structure, see the section TCL_CHANNELTYPE, below. +\fBTcl_ChannelType\fR structure, see the section \fBTCL_CHANNELTYPE\fR, below. +.PP +\fBTcl_CreateChannel\fR interacts with the code managing the standard +channels. Once a standard channel was initialized either through a +call to \fBTcl_GetStdChannel\fR or a call to \fBTcl_SetStdChannel\fR +closing this standard channel will cause the next call to +\fBTcl_CreateChannel\fR to make the new channel the new standard +channel too. See \fBTcl_StandardChannels\fR for a general treatise +about standard channels and the behavior of the Tcl library with +regard to them. .PP \fBTcl_GetChannelInstanceData\fR returns the instance data associated with the channel in \fIchannel\fR. This is the same as the \fIinstanceData\fR @@ -156,7 +227,6 @@ the same as the \fItypePtr\fR argument in the call to with the channel, or NULL if the \fIchannelName\fR argument to \fBTcl_CreateChannel\fR was NULL. .PP -.VS \fBTcl_GetChannelHandle\fR places the OS-specific device handle associated with \fIchannel\fR for the given \fIdirection\fR in the location specified by \fIhandlePtr\fR and returns \fBTCL_OK\fR. If @@ -164,90 +234,173 @@ the channel does not have a device handle for the specified direction, then \fBTCL_ERROR\fR is returned instead. Different channel drivers will return different types of handle. Refer to the manual entries for each driver to determine what type of handle is returned. -.VE +.PP +\fBTcl_GetChannelThread\fR returns the id of the thread currently managing +the specified \fIchannel\fR. This allows channel drivers to send their file +events to the correct event queue even for a multi-threaded core. .PP \fBTcl_GetChannelMode\fR returns an OR-ed combination of \fBTCL_READABLE\fR and \fBTCL_WRITABLE\fR, indicating whether the channel is open for input and output. .PP -\fBTcl_SetDefaultTranslation\fR sets the default end of line translation -mode. This mode will be installed as the translation mode for the channel -if an attempt is made to output on the channel while it is still in -\fBTCL_TRANSLATE_AUTO\fR mode. For a description of end of line translation -modes, see the manual entry for \fBfconfigure\fR. -.PP \fBTcl_GetChannelBufferSize\fR returns the size, in bytes, of buffers -allocated to store input or output in \fIchan\fR. If the value was not set +allocated to store input or output in \fIchannel\fR. If the value was not set by a previous call to \fBTcl_SetChannelBufferSize\fR, described below, then the default value of 4096 is returned. .PP \fBTcl_SetChannelBufferSize\fR sets the size, in bytes, of buffers that will be allocated in subsequent operations on the channel to store input or -output. The \fIsize\fR argument should be between ten and one million, -allowing buffers of ten bytes to one million bytes. If \fIsize\fR is +output. The \fIsize\fR argument should be between one and one million, +allowing buffers of one byte to one million bytes. If \fIsize\fR is outside this range, \fBTcl_SetChannelBufferSize\fR sets the buffer size to 4096. .PP -.VS \fBTcl_NotifyChannel\fR is called by a channel driver to indicate to the generic layer that the events specified by \fImask\fR have occurred on the channel. Channel drivers are responsible for invoking this function whenever the channel handlers need to be called for the channel. See \fBWATCHPROC\fR below for more details. -.VE .PP -.VS -\fBTcl_BadChannelOption\fR is called from driver specific set or get option -procs to generate a complete error message. -.VE - +\fBTcl_BadChannelOption\fR is called from driver specific +\fIsetOptionProc\fR or \fIgetOptionProc\fR to generate a complete +error message. +.PP +\fBTcl_ChannelBuffered\fR returns the number of bytes of input +currently buffered in the internal buffer (push back area) of the +channel itself. It does not report about the data in the overall +buffers for the stack of channels the supplied channel is part of. +.PP +\fBTcl_IsChannelShared\fR checks the refcount of the specified +\fIchannel\fR and returns whether the \fIchannel\fR was shared among +multiple interpreters (result == 1) or not (result == 0). +.PP +\fBTcl_IsChannelRegistered\fR checks whether the specified \fIchannel\fR is +registered in the given \fIinterp\fRreter (result == 1) or not +(result == 0). +.PP +\fBTcl_IsChannelExisting\fR checks whether a channel with the specified +name is registered in the (thread)-global list of all channels (result +== 1) or not (result == 0). +.PP +\fBTcl_CutChannel\fR removes the specified \fIchannel\fR from the +(thread)global list of all channels (of the current thread). +Application to a channel still registered in some interpreter +is not allowed. +Also notifies the driver if the \fBTcl_ChannelType\fR version is +\fBTCL_CHANNEL_VERSION_4\fR (or higher), and +\fBTcl_DriverThreadActionProc\fR is defined for it. +.PP +\fBTcl_SpliceChannel\fR adds the specified \fIchannel\fR to the +(thread)global list of all channels (of the current thread). +Application to a channel registered in some interpreter is not allowed. +Also notifies the driver if the \fBTcl_ChannelType\fR version is +\fBTCL_CHANNEL_VERSION_4\fR (or higher), and +\fBTcl_DriverThreadActionProc\fR is defined for it. +.PP +\fBTcl_ClearChannelHandlers\fR removes all channel handlers and event +scripts associated with the specified \fIchannel\fR, thus shutting +down all event processing for this channel. .SH TCL_CHANNELTYPE .PP A channel driver provides a \fBTcl_ChannelType\fR structure that contains pointers to functions that implement the various operations on a channel; -these operations are invoked as needed by the generic layer. The -\fBTcl_ChannelType\fR structure contains the following fields: +these operations are invoked as needed by the generic layer. The structure +was versioned starting in Tcl 8.3.2/8.4 to correct a problem with stacked +channel drivers. See the \fBOLD CHANNEL TYPES\fR section below for +details about the old structure. +.PP +The \fBTcl_ChannelType\fR structure contains the following fields: .PP -.VS .CS typedef struct Tcl_ChannelType { - char *\fItypeName\fR; - Tcl_DriverBlockModeProc *\fIblockModeProc\fR; - Tcl_DriverCloseProc *\fIcloseProc\fR; - Tcl_DriverInputProc *\fIinputProc\fR; - Tcl_DriverOutputProc *\fIoutputProc\fR; - Tcl_DriverSeekProc *\fIseekProc\fR; - Tcl_DriverSetOptionProc *\fIsetOptionProc\fR; - Tcl_DriverGetOptionProc *\fIgetOptionProc\fR; - Tcl_DriverWatchProc *\fIwatchProc\fR; - Tcl_DriverGetHandleProc *\fIgetHandleProc\fR; -} Tcl_ChannelType; + const char *\fItypeName\fR; + Tcl_ChannelTypeVersion \fIversion\fR; + Tcl_DriverCloseProc *\fIcloseProc\fR; + Tcl_DriverInputProc *\fIinputProc\fR; + Tcl_DriverOutputProc *\fIoutputProc\fR; + Tcl_DriverSeekProc *\fIseekProc\fR; + Tcl_DriverSetOptionProc *\fIsetOptionProc\fR; + Tcl_DriverGetOptionProc *\fIgetOptionProc\fR; + Tcl_DriverWatchProc *\fIwatchProc\fR; + Tcl_DriverGetHandleProc *\fIgetHandleProc\fR; + Tcl_DriverClose2Proc *\fIclose2Proc\fR; + Tcl_DriverBlockModeProc *\fIblockModeProc\fR; + Tcl_DriverFlushProc *\fIflushProc\fR; + Tcl_DriverHandlerProc *\fIhandlerProc\fR; + Tcl_DriverWideSeekProc *\fIwideSeekProc\fR; + Tcl_DriverThreadActionProc *\fIthreadActionProc\fR; + Tcl_DriverTruncateProc *\fItruncateProc\fR; +} \fBTcl_ChannelType\fR; .CE -.VE -.PP -The driver must provide implementations for all functions except -\fIblockModeProc\fR, \fIseekProc\fR, \fIsetOptionProc\fR, and -\fIgetOptionProc\fR, which may be specified as NULL to indicate that the -channel does not support seeking. Other functions that can not be -implemented for this type of device should return \fBEINVAL\fR when invoked -to indicate that they are not implemented. - -.SH TYPENAME +.PP +It is not necessary to provide implementations for all channel +operations. Those which are not necessary may be set to NULL in the +struct: \fIblockModeProc\fR, \fIseekProc\fR, \fIsetOptionProc\fR, +\fIgetOptionProc\fR, and \fIclose2Proc\fR, in addition to +\fIflushProc\fR, \fIhandlerProc\fR, \fIthreadActionProc\fR, and +\fItruncateProc\fR. Other functions that cannot be implemented in a +meaningful way should return \fBEINVAL\fR when called, to indicate +that the operations they represent are not available. Also note that +\fIwideSeekProc\fR can be NULL if \fIseekProc\fR is. +.PP +The user should only use the above structure for \fBTcl_ChannelType\fR +instantiation. When referencing fields in a \fBTcl_ChannelType\fR +structure, the following functions should be used to obtain the values: +\fBTcl_ChannelName\fR, \fBTcl_ChannelVersion\fR, +\fBTcl_ChannelBlockModeProc\fR, \fBTcl_ChannelCloseProc\fR, +\fBTcl_ChannelClose2Proc\fR, \fBTcl_ChannelInputProc\fR, +\fBTcl_ChannelOutputProc\fR, \fBTcl_ChannelSeekProc\fR, +\fBTcl_ChannelWideSeekProc\fR, \fBTcl_ChannelThreadActionProc\fR, +\fBTcl_ChannelTruncateProc\fR, +\fBTcl_ChannelSetOptionProc\fR, \fBTcl_ChannelGetOptionProc\fR, +\fBTcl_ChannelWatchProc\fR, \fBTcl_ChannelGetHandleProc\fR, +\fBTcl_ChannelFlushProc\fR, or \fBTcl_ChannelHandlerProc\fR. +.PP +The change to the structures was made in such a way that standard channel +types are binary compatible. However, channel types that use stacked +channels (i.e. TLS, Trf) have new versions to correspond to the above change +since the previous code for stacked channels had problems. +.SS TYPENAME .PP The \fItypeName\fR field contains a null-terminated string that identifies the type of the device implemented by this driver, e.g. \fBfile\fR or \fBsocket\fR. +.PP +This value can be retrieved with \fBTcl_ChannelName\fR, which returns +a pointer to the string. +.SS VERSION +.PP -.SH BLOCKMODEPROC +The \fIversion\fR field should be set to the version of the structure +that you require. \fBTCL_CHANNEL_VERSION_2\fR is the minimum recommended. +\fBTCL_CHANNEL_VERSION_3\fR must be set to specify the \fIwideSeekProc\fR member. +\fBTCL_CHANNEL_VERSION_4\fR must be set to specify the \fIthreadActionProc\fR member +(includes \fIwideSeekProc\fR). +\fBTCL_CHANNEL_VERSION_5\fR must be set to specify the +\fItruncateProc\fR members (includes +\fIwideSeekProc\fR and \fIthreadActionProc\fR). +If it is not set to any of these, then this +\fBTcl_ChannelType\fR is assumed to have the original structure. See +\fBOLD CHANNEL TYPES\fR for more details. While Tcl will recognize +and function with either structures, stacked channels must be of at +least \fBTCL_CHANNEL_VERSION_2\fR to function correctly. +.PP +This value can be retrieved with \fBTcl_ChannelVersion\fR, which returns +one of +\fBTCL_CHANNEL_VERSION_5\fR, +\fBTCL_CHANNEL_VERSION_4\fR, +\fBTCL_CHANNEL_VERSION_3\fR, +\fBTCL_CHANNEL_VERSION_2\fR or \fBTCL_CHANNEL_VERSION_1\fR. +.SS BLOCKMODEPROC .PP The \fIblockModeProc\fR field contains the address of a function called by the generic layer to set blocking and nonblocking mode on the device. \fIBlockModeProc\fR should match the following prototype: .PP .CS -typedef int Tcl_DriverBlockModeProc( - ClientData \fIinstanceData\fR, - int \fImode\fR); +typedef int \fBTcl_DriverBlockModeProc\fR( + ClientData \fIinstanceData\fR, + int \fImode\fR); .CE .PP The \fIinstanceData\fR is the same as the value passed to @@ -263,17 +416,26 @@ nonblocking mode and to implement the blocking or nonblocking behavior. For some device types, the blocking and nonblocking behavior can be implemented by the underlying operating system; for other device types, the behavior must be emulated in the channel driver. - -.SH CLOSEPROC +.PP +This value can be retrieved with \fBTcl_ChannelBlockModeProc\fR, which returns +a pointer to the function. +.PP +A channel driver \fBnot\fR supplying a \fIblockModeProc\fR has to be +very, very careful. It has to tell the generic layer exactly which +blocking mode is acceptable to it, and should this also document for +the user so that the blocking mode of the channel is not changed to an +unacceptable value. Any confusion here may lead the interpreter into a +(spurious and difficult to find) deadlock. +.SS "CLOSEPROC AND CLOSE2PROC" .PP The \fIcloseProc\fR field contains the address of a function called by the generic layer to clean up driver-related information when the channel is closed. \fICloseProc\fR must match the following prototype: .PP .CS -typedef int Tcl_DriverCloseProc( - ClientData \fIinstanceData\fR, - Tcl_Interp *\fIinterp\fR); +typedef int \fBTcl_DriverCloseProc\fR( + ClientData \fIinstanceData\fR, + Tcl_Interp *\fIinterp\fR); .CE .PP The \fIinstanceData\fR argument is the same as the value provided to @@ -285,20 +447,50 @@ and no further driver operations will be invoked on this instance after calling the \fIcloseProc\fR. If the close operation is successful, the procedure should return zero; otherwise it should return a nonzero POSIX error code. In addition, if an error occurs and \fIinterp\fR is not NULL, -the procedure should store an error message in \fIinterp->result\fR. - -.SH INPUTPROC +the procedure should store an error message in the interpreter's result. +.PP +Alternatively, channels that support closing the read and write sides +independently may set \fIcloseProc\fR to \fBTCL_CLOSE2PROC\fR and set +\fIclose2Proc\fR to the address of a function that matches the +following prototype: +.PP +.CS +typedef int \fBTcl_DriverClose2Proc\fR( + ClientData \fIinstanceData\fR, + Tcl_Interp *\fIinterp\fR, + int \fIflags\fR); +.CE +.PP +The \fIclose2Proc\fR will be called with \fIflags\fR set to an OR'ed +combination of \fBTCL_CLOSE_READ\fR or \fBTCL_CLOSE_WRITE\fR to +indicate that the driver should close the read and/or write side of +the channel. The channel driver may be invoked to perform +additional operations on the channel after \fIclose2Proc\fR is +called to close one or both sides of the channel. If \fIflags\fR is +\fB0\fR (zero), the driver should close the channel in the manner +described above for \fIcloseProc\fR. No further operations will be +invoked on this instance after \fIclose2Proc\fR is called with all +flags cleared. In all cases, the \fIclose2Proc\fR function should +return zero if the close operation was successful; otherwise it should +return a nonzero POSIX error code. In addition, if an error occurs and +\fIinterp\fR is not NULL, the procedure should store an error message +in the interpreter's result. +.PP +The \fIcloseProc\fR and \fIclose2Proc\fR values can be retrieved with +\fBTcl_ChannelCloseProc\fR or \fBTcl_ChannelClose2Proc\fR, which +return a pointer to the respective function. +.SS INPUTPROC .PP The \fIinputProc\fR field contains the address of a function called by the generic layer to read data from the file or device and store it in an internal buffer. \fIInputProc\fR must match the following prototype: .PP .CS -typedef int Tcl_DriverInputProc( - ClientData \fIinstanceData\fR, - char *\fIbuf\fR, - int \fIbufSize\fR, - int *\fIerrorCodePtr\fR); +typedef int \fBTcl_DriverInputProc\fR( + ClientData \fIinstanceData\fR, + char *\fIbuf\fR, + int \fIbufSize\fR, + int *\fIerrorCodePtr\fR); .CE .PP \fIInstanceData\fR is the same as the value passed to @@ -328,19 +520,21 @@ whatsoever and the channel is in blocking mode, the function should block for the shortest possible time until at least one byte of data can be read from the device; then, it should return as much data as it can read without blocking. - -.SH OUTPUTPROC +.PP +This value can be retrieved with \fBTcl_ChannelInputProc\fR, which returns +a pointer to the function. +.SS OUTPUTPROC .PP The \fIoutputProc\fR field contains the address of a function called by the generic layer to transfer data from an internal buffer to the output device. \fIOutputProc\fR must match the following prototype: .PP .CS -typedef int Tcl_DriverOutputProc( - ClientData \fIinstanceData\fR, - char *\fIbuf\fR, - int \fItoWrite\fR, - int *\fIerrorCodePtr\fR); +typedef int \fBTcl_DriverOutputProc\fR( + ClientData \fIinstanceData\fR, + const char *\fIbuf\fR, + int \fItoWrite\fR, + int *\fIerrorCodePtr\fR); .CE .PP \fIInstanceData\fR is the same as the value passed to @@ -364,8 +558,10 @@ error, some data may have been written to the device. If the channel is nonblocking and the output device is unable to absorb any data whatsoever, the function should return -1 with an \fBEAGAIN\fR error without writing any data. - -.SH SEEKPROC +.PP +This value can be retrieved with \fBTcl_ChannelOutputProc\fR, which returns +a pointer to the function. +.SS "SEEKPROC AND WIDESEEKPROC" .PP The \fIseekProc\fR field contains the address of a function called by the generic layer to move the access point at which subsequent input or output @@ -373,16 +569,16 @@ operations will be applied. \fISeekProc\fR must match the following prototype: .PP .CS -typedef int Tcl_DriverSeekProc( - ClientData \fIinstanceData\fR, - long \fIoffset\fR, - int \fIseekMode\fR, - int *\fIerrorCodePtr\fR); +typedef int \fBTcl_DriverSeekProc\fR( + ClientData \fIinstanceData\fR, + long \fIoffset\fR, + int \fIseekMode\fR, + int *\fIerrorCodePtr\fR); .CE .PP The \fIinstanceData\fR argument is the same as the value given to \fBTcl_CreateChannel\fR when this channel was created. \fIOffset\fR and -\fIseekMode\fR have the same meaning as for the \fBTcl_SeekChannel\fR +\fIseekMode\fR have the same meaning as for the \fBTcl_Seek\fR procedure (described in the manual entry for \fBTcl_OpenFileChannel\fR). .PP The \fIerrorCodePtr\fR argument points to an integer variable provided by @@ -393,29 +589,53 @@ does not implement seeking. .PP The return value is the new access point or -1 in case of error. If an error occurred, the function should not move the access point. - -.SH SETOPTIONPROC +.PP +If there is a non-NULL \fIseekProc\fR field, the \fIwideSeekProc\fR +field may contain the address of an alternative function to use which +handles wide (i.e. larger than 32-bit) offsets, so allowing seeks +within files larger than 2GB. The \fIwideSeekProc\fR will be called +in preference to the \fIseekProc\fR, but both must be defined if the +\fIwideSeekProc\fR is defined. \fIWideSeekProc\fR must match the +following prototype: +.PP +.CS +typedef Tcl_WideInt \fBTcl_DriverWideSeekProc\fR( + ClientData \fIinstanceData\fR, + Tcl_WideInt \fIoffset\fR, + int \fIseekMode\fR, + int *\fIerrorCodePtr\fR); +.CE +.PP +The arguments and return values mean the same thing as with +\fIseekProc\fR above, except that the type of offsets and the return +type are different. +.PP +The \fIseekProc\fR value can be retrieved with +\fBTcl_ChannelSeekProc\fR, which returns a pointer to the function, +and similarly the \fIwideSeekProc\fR can be retrieved with +\fBTcl_ChannelWideSeekProc\fR. +.SS SETOPTIONPROC .PP The \fIsetOptionProc\fR field contains the address of a function called by the generic layer to set a channel type specific option on a channel. \fIsetOptionProc\fR must match the following prototype: .PP .CS -typedef int Tcl_DriverSetOptionProc( - ClientData \fIinstanceData\fR, - Tcl_Interp *\fIinterp\fR, - char *\fIoptionName\fR, - char *\fIoptionValue\fR); +typedef int \fBTcl_DriverSetOptionProc\fR( + ClientData \fIinstanceData\fR, + Tcl_Interp *\fIinterp\fR, + const char *\fIoptionName\fR, + const char *\fInewValue\fR); .CE .PP -\fIoptionName\fR is the name of an option to set, and \fIoptionValue\fR is +\fIoptionName\fR is the name of an option to set, and \fInewValue\fR is the new value for that option, as a string. The \fIinstanceData\fR is the same as the value given to \fBTcl_CreateChannel\fR when this channel was created. The function should do whatever channel type specific action is required to implement the new value of the option. .PP Some options are handled by the generic code and this function is never -called to set them, e.g. \fB-blockmode\fR. Other options are specific to +called to set them, e.g. \fB\-blockmode\fR. Other options are specific to each channel type and the \fIsetOptionProc\fR procedure of the channel driver will get called to implement them. The \fIsetOptionProc\fR field can be NULL, which indicates that this channel type supports no type specific @@ -423,59 +643,56 @@ options. .PP If the option value is successfully modified to the new value, the function returns \fBTCL_OK\fR. -.VS It should call \fBTcl_BadChannelOption\fR which itself returns \fBTCL_ERROR\fR if the \fIoptionName\fR is unrecognized. -.VE -If \fIoptionValue\fR specifies a value for the option that +If \fInewValue\fR specifies a value for the option that is not supported or if a system call error occurs, the function should leave an error message in the \fIresult\fR field of \fIinterp\fR if \fIinterp\fR is not NULL. The function should also call \fBTcl_SetErrno\fR to store an appropriate POSIX error code. - -.SH GETOPTIONPROC +.PP +This value can be retrieved with \fBTcl_ChannelSetOptionProc\fR, which returns +a pointer to the function. +.SS GETOPTIONPROC .PP The \fIgetOptionProc\fR field contains the address of a function called by the generic layer to get the value of a channel type specific option on a channel. \fIgetOptionProc\fR must match the following prototype: .PP .CS -typedef int Tcl_DriverGetOptionProc( - ClientData \fIinstanceData\fR, -.VS - Tcl_Interp *\fIinterp\fR, -.VE - char *\fIoptionName\fR, - Tcl_DString *\fIdsPtr\fR); +typedef int \fBTcl_DriverGetOptionProc\fR( + ClientData \fIinstanceData\fR, + Tcl_Interp *\fIinterp\fR, + const char *\fIoptionName\fR, + Tcl_DString *\fIoptionValue\fR); .CE .PP \fIOptionName\fR is the name of an option supported by this type of channel. If the option name is not NULL, the function stores its current -value, as a string, in the Tcl dynamic string \fIdsPtr\fR. -If \fIoptionName\fR is NULL, the function stores in \fIdsPtr\fR an +value, as a string, in the Tcl dynamic string \fIoptionValue\fR. +If \fIoptionName\fR is NULL, the function stores in \fIoptionValue\fR an alternating list of all supported options and their current values. On success, the function returns \fBTCL_OK\fR. -.VS It should call \fBTcl_BadChannelOption\fR which itself returns \fBTCL_ERROR\fR if the \fIoptionName\fR is unrecognized. If a system call error occurs, the function should leave an error message in the -\fIresult\fR field of \fIinterp\fR if \fIinterp\fR is not NULL. The +result of \fIinterp\fR if \fIinterp\fR is not NULL. The function should also call \fBTcl_SetErrno\fR to store an appropriate POSIX error code. -.VE .PP Some options are handled by the generic code and this function is never -called to retrieve their value, e.g. \fB-blockmode\fR. Other options are +called to retrieve their value, e.g. \fB\-blockmode\fR. Other options are specific to each channel type and the \fIgetOptionProc\fR procedure of the channel driver will get called to implement them. The \fIgetOptionProc\fR field can be NULL, which indicates that this channel type supports no type specific options. - -.SH WATCHPROC -.VS +.PP +This value can be retrieved with \fBTcl_ChannelGetOptionProc\fR, which returns +a pointer to the function. +.SS WATCHPROC .PP The \fIwatchProc\fR field contains the address of a function called by the generic layer to initialize the event notification mechanism to @@ -483,11 +700,10 @@ notice events of interest on this channel. \fIWatchProc\fR should match the following prototype: .PP .CS -typedef void Tcl_DriverWatchProc( - ClientData \fIinstanceData\fR, - int \fImask\fR); +typedef void \fBTcl_DriverWatchProc\fR( + ClientData \fIinstanceData\fR, + int \fImask\fR); .CE -.VE .PP The \fIinstanceData\fR is the same as the value passed to \fBTcl_CreateChannel\fR when this channel was created. The \fImask\fR @@ -495,7 +711,6 @@ argument is an OR-ed combination of \fBTCL_READABLE\fR, \fBTCL_WRITABLE\fR and \fBTCL_EXCEPTION\fR; it indicates events the caller is interested in noticing on this channel. .PP -.VS The function should initialize device type specific mechanisms to notice when an event of interest is present on the channel. When one or more of the designated events occurs on the channel, the channel @@ -506,21 +721,23 @@ Tcl_NotifyChannel too frequently. Fairness can be insured by using the Tcl event queue to allow the channel event to be scheduled in sequence with other events. See the description of \fBTcl_QueueEvent\fR for details on how to queue an event. - -.SH GETHANDLEPROC +.PP +This value can be retrieved with \fBTcl_ChannelWatchProc\fR, which returns +a pointer to the function. +.SS GETHANDLEPROC .PP The \fIgetHandleProc\fR field contains the address of a function called by the generic layer to retrieve a device-specific handle from the channel. \fIGetHandleProc\fR should match the following prototype: .PP .CS -typedef int Tcl_DriverGetHandleProc( - ClientData \fIinstanceData\fR, - int \fIdirection\fR, - ClientData *\fIhandlePtr\fR); +typedef int \fBTcl_DriverGetHandleProc\fR( + ClientData \fIinstanceData\fR, + int \fIdirection\fR, + ClientData *\fIhandlePtr\fR); .CE .PP -\fIInstanceData is the same as the value passed to +\fIInstanceData\fR is the same as the value passed to \fBTcl_CreateChannel\fR when this channel was created. The \fIdirection\fR argument is either \fBTCL_READABLE\fR to retrieve the handle used for input, or \fBTCL_WRITABLE\fR to retrieve the handle used for @@ -533,39 +750,179 @@ stored in the location referred to by \fIhandlePtr\fR, and \fBTCL_OK\fR should be returned. If the channel is not open for the specified direction, or if the channel implementation does not use device handles, the function should return \fBTCL_ERROR\fR. -.VE +.PP +This value can be retrieved with \fBTcl_ChannelGetHandleProc\fR, which returns +a pointer to the function. +.SS FLUSHPROC +.PP +The \fIflushProc\fR field is currently reserved for future use. +It should be set to NULL. +\fIFlushProc\fR should match the following prototype: +.PP +.CS +typedef int \fBTcl_DriverFlushProc\fR( + ClientData \fIinstanceData\fR); +.CE +.PP +This value can be retrieved with \fBTcl_ChannelFlushProc\fR, which returns +a pointer to the function. +.SS HANDLERPROC +.PP +The \fIhandlerProc\fR field contains the address of a function called by +the generic layer to notify the channel that an event occurred. It should +be defined for stacked channel drivers that wish to be notified of events +that occur on the underlying (stacked) channel. +\fIHandlerProc\fR should match the following prototype: +.PP +.CS +typedef int \fBTcl_DriverHandlerProc\fR( + ClientData \fIinstanceData\fR, + int \fIinterestMask\fR); +.CE +.PP +\fIInstanceData\fR is the same as the value passed to \fBTcl_CreateChannel\fR +when this channel was created. The \fIinterestMask\fR is an OR-ed +combination of \fBTCL_READABLE\fR or \fBTCL_WRITABLE\fR; it indicates what +type of event occurred on this channel. +.PP +This value can be retrieved with \fBTcl_ChannelHandlerProc\fR, which returns +a pointer to the function. -.VS +.SS "THREADACTIONPROC" +.PP +The \fIthreadActionProc\fR field contains the address of the function +called by the generic layer when a channel is created, closed, or +going to move to a different thread, i.e. whenever thread-specific +driver state might have to initialized or updated. It can be NULL. +The action \fITCL_CHANNEL_THREAD_REMOVE\fR is used to notify the +driver that it should update or remove any thread-specific data it +might be maintaining for the channel. +.PP +The action \fITCL_CHANNEL_THREAD_INSERT\fR is used to notify the +driver that it should update or initialize any thread-specific data it +might be maintaining using the calling thread as the associate. See +\fBTcl_CutChannel\fR and \fBTcl_SpliceChannel\fR for more detail. +.PP +.CS +typedef void \fBTcl_DriverThreadActionProc\fR( + ClientData \fIinstanceData\fR, + int \fIaction\fR); +.CE +.PP +\fIInstanceData\fR is the same as the value passed to +\fBTcl_CreateChannel\fR when this channel was created. +.PP +These values can be retrieved with \fBTcl_ChannelThreadActionProc\fR, +which returns a pointer to the function. +.SS "TRUNCATEPROC" +.PP +The \fItruncateProc\fR field contains the address of the function +called by the generic layer when a channel is truncated to some +length. It can be NULL. +.PP +.CS +typedef int \fBTcl_DriverTruncateProc\fR( + ClientData \fIinstanceData\fR, + Tcl_WideInt \fIlength\fR); +.CE +.PP +\fIInstanceData\fR is the same as the value passed to +\fBTcl_CreateChannel\fR when this channel was created, and +\fIlength\fR is the new length of the underlying file, which should +not be negative. The result should be 0 on success or an errno code +(suitable for use with \fBTcl_SetErrno\fR) on failure. +.PP +These values can be retrieved with \fBTcl_ChannelTruncateProc\fR, +which returns a pointer to the function. .SH TCL_BADCHANNELOPTION .PP -This procedure generates a "bad option" error message in an +This procedure generates a +.QW "bad option" +error message in an (optional) interpreter. It is used by channel drivers when -a invalid Set/Get option is requested. Its purpose is to concatenate +an invalid Set/Get option is requested. Its purpose is to concatenate the generic options list to the specific ones and factorize the generic options error message string. .PP -It always return \fBTCL_ERROR\fR +It always returns \fBTCL_ERROR\fR .PP -An error message is generated in interp's result object to -indicate that a command was invoked with the a bad option +An error message is generated in \fIinterp\fR's result value to +indicate that a command was invoked with a bad option. The message has the form .CS bad option "blah": should be one of <...generic options...>+<...specific options...> +.CE so you get for instance: +.CS bad option "-blah": should be one of -blocking, -buffering, -buffersize, -eofchar, -translation, -peername, or -sockname -when called with optionList="peername sockname" .CE -"blah" is the optionName argument and "<specific options>" +when called with \fIoptionList\fR equal to +.QW "peername sockname" +.PP +.QW blah +is the \fIoptionName\fR argument and +.QW "<specific options>" is a space separated list of specific option words. The function takes good care of inserting minus signs before -each option, commas after, and an "or" before the last option. -.VE - +each option, commas after, and an +.QW or +before the last option. +.SH "OLD CHANNEL TYPES" +The original (8.3.1 and below) \fBTcl_ChannelType\fR structure contains +the following fields: +.PP +.CS +typedef struct Tcl_ChannelType { + const char *\fItypeName\fR; + Tcl_DriverBlockModeProc *\fIblockModeProc\fR; + Tcl_DriverCloseProc *\fIcloseProc\fR; + Tcl_DriverInputProc *\fIinputProc\fR; + Tcl_DriverOutputProc *\fIoutputProc\fR; + Tcl_DriverSeekProc *\fIseekProc\fR; + Tcl_DriverSetOptionProc *\fIsetOptionProc\fR; + Tcl_DriverGetOptionProc *\fIgetOptionProc\fR; + Tcl_DriverWatchProc *\fIwatchProc\fR; + Tcl_DriverGetHandleProc *\fIgetHandleProc\fR; + Tcl_DriverClose2Proc *\fIclose2Proc\fR; +} \fBTcl_ChannelType\fR; +.CE +.PP +It is still possible to create channel with the above structure. The +internal channel code will determine the version. It is imperative to use +the new \fBTcl_ChannelType\fR structure if you are creating a stacked +channel driver, due to problems with the earlier stacked channel +implementation (in 8.2.0 to 8.3.1). +.PP +Prior to 8.4.0 (i.e. during the later releases of 8.3 and early part +of the 8.4 development cycle) the \fBTcl_ChannelType\fR structure +contained the following fields: +.PP +.CS +typedef struct Tcl_ChannelType { + const char *\fItypeName\fR; + Tcl_ChannelTypeVersion \fIversion\fR; + Tcl_DriverCloseProc *\fIcloseProc\fR; + Tcl_DriverInputProc *\fIinputProc\fR; + Tcl_DriverOutputProc *\fIoutputProc\fR; + Tcl_DriverSeekProc *\fIseekProc\fR; + Tcl_DriverSetOptionProc *\fIsetOptionProc\fR; + Tcl_DriverGetOptionProc *\fIgetOptionProc\fR; + Tcl_DriverWatchProc *\fIwatchProc\fR; + Tcl_DriverGetHandleProc *\fIgetHandleProc\fR; + Tcl_DriverClose2Proc *\fIclose2Proc\fR; + Tcl_DriverBlockModeProc *\fIblockModeProc\fR; + Tcl_DriverFlushProc *\fIflushProc\fR; + Tcl_DriverHandlerProc *\fIhandlerProc\fR; + Tcl_DriverTruncateProc *\fItruncateProc\fR; +} \fBTcl_ChannelType\fR; +.CE +.PP +When the above structure is registered as a channel type, the +\fIversion\fR field should always be \fBTCL_CHANNEL_VERSION_2\fR. .SH "SEE ALSO" -Tcl_Close(3), Tcl_OpenFileChannel(3), Tcl_SetErrno(3), Tcl_QueueEvent(3) - +Tcl_Close(3), Tcl_OpenFileChannel(3), Tcl_SetErrno(3), Tcl_QueueEvent(3), Tcl_StackChannel(3), Tcl_GetStdChannel(3) .SH KEYWORDS blocking, channel driver, channel registration, channel type, nonblocking |