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Diffstat (limited to 'doc/LinkVar.3')
-rw-r--r-- | doc/LinkVar.3 | 120 |
1 files changed, 100 insertions, 20 deletions
diff --git a/doc/LinkVar.3 b/doc/LinkVar.3 index 7f5dfa0..c64720b 100644 --- a/doc/LinkVar.3 +++ b/doc/LinkVar.3 @@ -5,10 +5,8 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: LinkVar.3,v 1.9 2004/10/07 15:15:38 dkf Exp $ -'\" -.so man.macros .TH Tcl_LinkVar 3 7.5 Tcl "Tcl Library Procedures" +.so man.macros .BS .SH NAME Tcl_LinkVar, Tcl_UnlinkVar, Tcl_UpdateLinkedVar \- link Tcl variable to C variable @@ -28,18 +26,19 @@ int Interpreter that contains \fIvarName\fR. Also used by \fBTcl_LinkVar\fR to return error messages. .AP "const char" *varName in -Name of global variable. +Name of global variable. .AP char *addr in Address of C variable that is to be linked to \fIvarName\fR. .AP int type in -Type of C variable. Must be one of \fBTCL_LINK_INT\fR, \fBTCL_LINK_DOUBLE\fR, -.VS 8.4 -\fBTCL_LINK_WIDE_INT\fR, -.VE 8.4 -\fBTCL_LINK_BOOLEAN\fR, or \fBTCL_LINK_STRING\fR, optionally OR'ed with -\fBTCL_LINK_READ_ONLY\fR to make Tcl variable read-only. +Type of C variable. Must be one of \fBTCL_LINK_INT\fR, +\fBTCL_LINK_UINT\fR, \fBTCL_LINK_CHAR\fR, \fBTCL_LINK_UCHAR\fR, +\fBTCL_LINK_SHORT\fR, \fBTCL_LINK_USHORT\fR, \fBTCL_LINK_LONG\fR, +\fBTCL_LINK_ULONG\fR, \fBTCL_LINK_WIDE_INT\fR, +\fBTCL_LINK_WIDE_UINT\fR, \fBTCL_LINK_FLOAT\fR, +\fBTCL_LINK_DOUBLE\fR, \fBTCL_LINK_BOOLEAN\fR, or +\fBTCL_LINK_STRING\fR, optionally OR'ed with \fBTCL_LINK_READ_ONLY\fR +to make Tcl variable read-only. .BE - .SH DESCRIPTION .PP \fBTcl_LinkVar\fR uses variable traces to keep the Tcl variable @@ -64,6 +63,59 @@ form acceptable to \fBTcl_GetIntFromObj\fR; attempts to write non-integer values into \fIvarName\fR will be rejected with Tcl errors. .TP +\fBTCL_LINK_UINT\fR +The C variable is of type \fBunsigned int\fR. +Any value written into the Tcl variable must have a proper unsigned +integer form acceptable to \fBTcl_GetWideIntFromObj\fR and in the +platform's defined range for the \fBunsigned int\fR type; attempts to +write non-integer values (or values outside the range) into +\fIvarName\fR will be rejected with Tcl errors. +.TP +\fBTCL_LINK_CHAR\fR +The C variable is of type \fBchar\fR. +Any value written into the Tcl variable must have a proper integer +form acceptable to \fBTcl_GetIntFromObj\fR and be in the range of the +\fBchar\fR datatype; attempts to write non-integer or out-of-range +values into \fIvarName\fR will be rejected with Tcl errors. +.TP +\fBTCL_LINK_UCHAR\fR +The C variable is of type \fBunsigned char\fR. +Any value written into the Tcl variable must have a proper unsigned +integer form acceptable to \fBTcl_GetIntFromObj\fR and in the +platform's defined range for the \fBunsigned char\fR type; attempts to +write non-integer values (or values outside the range) into +\fIvarName\fR will be rejected with Tcl errors. +.TP +\fBTCL_LINK_SHORT\fR +The C variable is of type \fBshort\fR. +Any value written into the Tcl variable must have a proper integer +form acceptable to \fBTcl_GetIntFromObj\fR and be in the range of the +\fBshort\fR datatype; attempts to write non-integer or out-of-range +values into \fIvarName\fR will be rejected with Tcl errors. +.TP +\fBTCL_LINK_USHORT\fR +The C variable is of type \fBunsigned short\fR. +Any value written into the Tcl variable must have a proper unsigned +integer form acceptable to \fBTcl_GetIntFromObj\fR and in the +platform's defined range for the \fBunsigned short\fR type; attempts to +write non-integer values (or values outside the range) into +\fIvarName\fR will be rejected with Tcl errors. +.TP +\fBTCL_LINK_LONG\fR +The C variable is of type \fBlong\fR. +Any value written into the Tcl variable must have a proper integer +form acceptable to \fBTcl_GetLongFromObj\fR; attempts to write +non-integer or out-of-range +values into \fIvarName\fR will be rejected with Tcl errors. +.TP +\fBTCL_LINK_ULONG\fR +The C variable is of type \fBunsigned long\fR. +Any value written into the Tcl variable must have a proper unsigned +integer form acceptable to \fBTcl_GetWideIntFromObj\fR and in the +platform's defined range for the \fBunsigned long\fR type; attempts to +write non-integer values (or values outside the range) into +\fIvarName\fR will be rejected with Tcl errors. +.TP \fBTCL_LINK_DOUBLE\fR The C variable is of type \fBdouble\fR. Any value written into the Tcl variable must have a proper real @@ -71,20 +123,39 @@ form acceptable to \fBTcl_GetDoubleFromObj\fR; attempts to write non-real values into \fIvarName\fR will be rejected with Tcl errors. .TP +\fBTCL_LINK_FLOAT\fR +The C variable is of type \fBfloat\fR. +Any value written into the Tcl variable must have a proper real +form acceptable to \fBTcl_GetDoubleFromObj\fR and must be within the +range acceptable for a \fBfloat\fR; attempts to +write non-real values (or values outside the range) into +\fIvarName\fR will be rejected with Tcl errors. +.TP \fBTCL_LINK_WIDE_INT\fR -.VS 8.4 The C variable is of type \fBTcl_WideInt\fR (which is an integer type at least 64-bits wide on all platforms that can support it.) Any value written into the Tcl variable must have a proper integer form acceptable to \fBTcl_GetWideIntFromObj\fR; attempts to write non-integer values into \fIvarName\fR will be rejected with Tcl errors. -.VE 8.4 +.TP +\fBTCL_LINK_WIDE_UINT\fR +The C variable is of type \fBTcl_WideUInt\fR (which is an unsigned +integer type at least 64-bits wide on all platforms that can support +it.) +Any value written into the Tcl variable must have a proper unsigned +integer form acceptable to \fBTcl_GetWideIntFromObj\fR (it will be +cast to unsigned); +.\" FIXME! Use bignums instead. +attempts to write non-integer values into \fIvarName\fR will be +rejected with Tcl errors. .TP \fBTCL_LINK_BOOLEAN\fR The C variable is of type \fBint\fR. -If its value is zero then it will read from Tcl as ``0''; -otherwise it will read from Tcl as ``1''. +If its value is zero then it will read from Tcl as +.QW 0 ; +otherwise it will read from Tcl as +.QW 1 . Whenever \fIvarName\fR is modified, the C variable will be set to a 0 or 1 value. Any value written into the Tcl variable must have a proper boolean @@ -94,15 +165,14 @@ Tcl errors. .TP \fBTCL_LINK_STRING\fR The C variable is of type \fBchar *\fR. -.VS If its value is not NULL then it must be a pointer to a string allocated with \fBTcl_Alloc\fR or \fBckalloc\fR. -.VE Whenever the Tcl variable is modified the current C string will be freed and new memory will be allocated to hold a copy of the variable's new value. If the C variable contains a NULL pointer then the Tcl variable -will read as ``NULL''. +will read as +.QW NULL . .PP If the \fBTCL_LINK_READ_ONLY\fR flag is present in \fItype\fR then the variable will be read-only from Tcl, so that its value can only be @@ -122,6 +192,16 @@ Tk widget that wishes to display the value of the variable), the trace will not trigger when the C variable has changed. \fBTcl_UpdateLinkedVar\fR ensures that any traces on the Tcl variable are invoked. - +.PP +Note that, as with any call to a Tcl interpreter, \fBTcl_UpdateLinkedVar\fR +must be called from the same thread that created the interpreter. The safest +mechanism is to ensure that the C variable is only ever updated from the same +thread that created the interpreter (possibly in response to an event posted +with \fBTcl_ThreadQueueEvent\fR), but when it is necessary to update the +variable in a separate thread, it is advised that \fBTcl_AsyncMark\fR be used +to indicate to the thread hosting the interpreter that it is ready to run +\fBTcl_UpdateLinkedVar\fR. +.SH "SEE ALSO" +Tcl_TraceVar(3) .SH KEYWORDS -boolean, integer, link, read-only, real, string, traces, variable +boolean, integer, link, read-only, real, string, trace, variable |