diff options
Diffstat (limited to 'doc/unload.n')
| -rw-r--r-- | doc/unload.n | 40 |
1 files changed, 26 insertions, 14 deletions
diff --git a/doc/unload.n b/doc/unload.n index 8a2e51c..febd694 100644 --- a/doc/unload.n +++ b/doc/unload.n @@ -1,13 +1,11 @@ '\" -'\" Copyright (c) 2003 George Petasis, petasis@iit.demokritos.gr. +'\" Copyright (c) 2003 George Petasis <petasis@iit.demokritos.gr>. '\" '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: unload.n,v 1.8 2005/05/10 18:34:03 kennykb Exp $ -'\" -.so man.macros .TH unload n 8.5 Tcl "Tcl Built-In Commands" +.so man.macros .BS '\" Note: do not modify the .SH NAME line immediately below! .SH NAME @@ -19,7 +17,6 @@ unload \- Unload machine code .br \fBunload \fR?\fIswitches\fR? \fIfileName packageName interp\fR .BE - .SH DESCRIPTION .PP This command tries to unload shared libraries previously loaded @@ -35,22 +32,26 @@ The \fIinterp\fR argument is the path name of the interpreter from which to unload the package (see the \fBinterp\fR manual entry for details); if \fIinterp\fR is omitted, it defaults to the interpreter in which the \fBunload\fR command was invoked. -.LP +.PP If the initial arguments to \fBunload\fR start with \fB\-\fR then they are treated as switches. The following switches are currently supported: .TP \fB\-nocomplain\fR -Supresses all error messages. If this switch is given \fBunload\fR will +. +Suppresses all error messages. If this switch is given, \fBunload\fR will never report an error. .TP \fB\-keeplibrary\fR +. This switch will prevent \fBunload\fR from issuing the operating system call that will unload the library from the process. .TP \fB\-\|\-\fR +. Marks the end of switches. The argument following this one will be treated as a \fIfileName\fR even if it starts with a \fB\-\fR. +.SS "UNLOAD OPERATION" .PP When a file containing a shared library is loaded through the \fBload\fR command, Tcl associates two reference counts to the library @@ -59,7 +60,7 @@ loaded into normal (trusted) interpreters while the second describes how many times the library has been loaded into safe interpreters. As a file containing a shared library can be loaded only once by Tcl (with the first \fBload\fR call on the file), these counters track how many interpreters use the library. -Each subsequent call to \fBload\fR after the first, simply increaments the +Each subsequent call to \fBload\fR after the first simply increments the proper reference count. .PP \fBunload\fR works in the opposite direction. As a first step, \fBunload\fR @@ -84,11 +85,16 @@ procedure. If the unload procedure returns \fBTCL_OK\fR, \fBunload\fR will proce and decrease the proper reference count (depending on the target interpreter type). When both reference counts have reached 0, the library will be detached from the process. +.SS "UNLOAD HOOK PROTOTYPE" .PP The unload procedure must match the following prototype: +.PP .CS -typedef int Tcl_PackageUnloadProc(Tcl_Interp *\fIinterp\fR, int \fIflags\fR); +typedef int \fBTcl_PackageUnloadProc\fR( + Tcl_Interp *\fIinterp\fR, + int \fIflags\fR); .CE +.PP The \fIinterp\fR argument identifies the interpreter from which the library is to be unloaded. The unload procedure must return \fBTCL_OK\fR or \fBTCL_ERROR\fR to indicate whether or not it completed @@ -104,10 +110,11 @@ the library is used by other interpreters), library is used only by the target interpreter and the library will be detached from the application as soon as the unload procedure returns, the \fIflags\fR argument will be set to \fBTCL_UNLOAD_DETACH_FROM_PROCESS\fR. +.SS NOTES .PP The \fBunload\fR command cannot unload libraries that are statically linked with the application. -If \fIfileName\fR is an empty string, then \fIpackageName\fR must +If \fIfileName\fR is an empty string, then the \fIpackageName\fR argument must be specified. .PP If \fIpackageName\fR is omitted or specified as an empty string, @@ -125,8 +132,8 @@ module name \fBlast\fR. \fBUnix\fR\0\0\0\0\0 . Not all unix operating systems support library unloading. Under such -an operating system \fBunload\fR returns an error (unless -nocomplain has -been specified). +an operating system \fBunload\fR returns an error (unless \fB\-nocomplain\fR +has been specified). .SH BUGS .PP If the same file is \fBload\fRed by different \fIfileName\fRs, it will @@ -138,12 +145,16 @@ library is still loaded), it may be dangerous to use \fBunload\fR on such a library (as the library will be completely detached from the application while some interpreters will continue to use it). .SH EXAMPLE +.PP If an unloadable module in the file \fBfoobar.dll\fR had been loaded using the \fBload\fR command like this (on Windows): +.PP .CS load c:/some/dir/foobar.dll .CE +.PP then it would be unloaded like this: +.PP .CS \fBunload\fR c:/some/dir/foobar.dll .CE @@ -152,9 +163,10 @@ This allows a C code module to be installed temporarily into a long-running Tcl program and then removed again (either because it is no longer needed or because it is being updated with a new version) without having to shut down the overall Tcl process. - .SH "SEE ALSO" info sharedlibextension, load(n), safe(n) - .SH KEYWORDS binary code, unloading, safe interpreter, shared library +.\" Local Variables: +.\" mode: nroff +.\" End: |