diff options
Diffstat (limited to 'doc/LinkVar.3')
| -rw-r--r-- | doc/LinkVar.3 | 93 |
1 files changed, 58 insertions, 35 deletions
diff --git a/doc/LinkVar.3 b/doc/LinkVar.3 index 042d242..c80d30d 100644 --- a/doc/LinkVar.3 +++ b/doc/LinkVar.3 @@ -4,11 +4,9 @@ '\" '\" 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 1.12 2005/09/08 10:49:19 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 @@ -33,20 +31,14 @@ Name of global variable. 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, -.VS 8.5 \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, -.VE 8.5 -\fBTCL_LINK_WIDE_INT\fR, -.VS 8.5 +\fBTCL_LINK_ULONG\fR, \fBTCL_LINK_WIDE_INT\fR, \fBTCL_LINK_WIDE_UINT\fR, \fBTCL_LINK_FLOAT\fR, -.VE 8.5 \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 @@ -69,8 +61,9 @@ The C variable is of type \fBint\fR. Any value written into the Tcl variable must have a proper integer form acceptable to \fBTcl_GetIntFromObj\fR; attempts to write non-integer values into \fIvarName\fR will be rejected with -Tcl errors. -.VS 8.5 +Tcl errors. Incomplete integer representations (like the empty +string, '+', '-' or the hex/octal/binary prefix) are accepted +as if they are valid too. .TP \fBTCL_LINK_UINT\fR The C variable is of type \fBunsigned int\fR. @@ -78,14 +71,18 @@ 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. +\fIvarName\fR will be rejected with Tcl errors. Incomplete integer +representations (like the empty string, '+', '-' or the hex/octal/binary +prefix) are accepted as if they are valid too. .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. +values into \fIvarName\fR will be rejected with Tcl errors. Incomplete +integer representations (like the empty string, '+', '-' or the +hex/octal/binary prefix) are accepted as if they are valid too. .TP \fBTCL_LINK_UCHAR\fR The C variable is of type \fBunsigned char\fR. @@ -93,14 +90,18 @@ 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. +\fIvarName\fR will be rejected with Tcl errors. Incomplete integer +representations (like the empty string, '+', '-' or the hex/octal/binary +prefix) are accepted as if they are valid too. .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. +values into \fIvarName\fR will be rejected with Tcl errors. Incomplete +integer representations (like the empty string, '+', '-' or the +hex/octal/binary prefix) are accepted as if they are valid too. .TP \fBTCL_LINK_USHORT\fR The C variable is of type \fBunsigned short\fR. @@ -108,14 +109,18 @@ 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. +\fIvarName\fR will be rejected with Tcl errors. Incomplete integer +representations (like the empty string, '+', '-' or the hex/octal/binary +prefix) are accepted as if they are valid too. .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. +values into \fIvarName\fR will be rejected with Tcl errors. Incomplete +integer representations (like the empty string, '+', '-' or the +hex/octal/binary prefix) are accepted as if they are valid too. .TP \fBTCL_LINK_ULONG\fR The C variable is of type \fBunsigned long\fR. @@ -123,16 +128,18 @@ 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. -.VE 8.5 +\fIvarName\fR will be rejected with Tcl errors. Incomplete integer +representations (like the empty string, '+', '-' or the hex/octal/binary +prefix) are accepted as if they are valid too. .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 form acceptable to \fBTcl_GetDoubleFromObj\fR; attempts to write non-real values into \fIvarName\fR will be rejected with -Tcl errors. -.VS 8.5 +Tcl errors. Incomplete integer or real representations (like the +empty string, '.', '+', '-' or the hex/octal/binary prefix) are +accepted as if they are valid too. .TP \fBTCL_LINK_FLOAT\fR The C variable is of type \fBfloat\fR. @@ -140,8 +147,9 @@ 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. -.VE 8.5 +\fIvarName\fR will be rejected with Tcl errors. Incomplete integer +or real representations (like the empty string, '.', '+', '-' or +the hex/octal/binary prefix) are accepted as if they are valid too. .TP \fBTCL_LINK_WIDE_INT\fR The C variable is of type \fBTcl_WideInt\fR (which is an integer type @@ -149,8 +157,9 @@ 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. -.VS 8.5 +Tcl errors. Incomplete integer representations (like the empty +string, '+', '-' or the hex/octal/binary prefix) are accepted +as if they are valid too. .TP \fBTCL_LINK_WIDE_UINT\fR The C variable is of type \fBTcl_WideUInt\fR (which is an unsigned @@ -159,15 +168,18 @@ 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. +.\" FIXME! Use bignums instead. attempts to write non-integer values into \fIvarName\fR will be -rejected with Tcl errors. -.VE 8.5 +rejected with Tcl errors. Incomplete integer representations (like +the empty string, '+', '-' or the hex/octal/binary prefix) are accepted +as if they are valid too. .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 @@ -183,7 +195,8 @@ 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 @@ -203,6 +216,16 @@ 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 |