Tcl Source Code

I'm embedding Tcl interpreter library (8.6.5) in a C++ application.

I can't create two interpreters from two different threads. The following code ends up in an infinite loop:

#include "tcl.h" #include <boost/thread.hpp>

void runScript() { Tcl_Interp* pInterp = Tcl_CreateInterp(); Tcl_DeleteInterp( pInterp ); }

int main( int argc, char* argv[] ) { Tcl_FindExecutable(NULL);

boost::thread thrd1( runScript ); thrd1.join();

Inifinite loop occures here:

void TclInitNotifier(void) { ThreadSpecificData *tsdPtr; Tcl_ThreadId threadId = Tcl_GetCurrentThread();

Tcl_MutexLock(&listLock); for (tsdPtr = firstNotifierPtr; tsdPtr && tsdPtr->threadId != threadId; tsdPtr = tsdPtr->nextPtr) { /* Empty loop body. */ // this loop never ends! }

Adding: if ( tsdPtr != NULL && tsdPtr->nextPtr == tsdPtr ) { tsdPtr = NULL; break; }

within the loop apparently fixes the issue.

Note that I compiled Tcl with a CMake script, I noticed that TCL_THREADS is not set (not sure it's related or not)

@dgp:TCL_THREADS was disabled because I compiled on windows using a CMake Lists.txt file I found on the web: this one was actually written for Linux and disabled thread support because it was unable to find pthread on my machine. I finally compiled Tcl libraries using the scripts provided  threading is enabled by default and the infinite loop is gone!

Thanks for your help!

I don't understand what you are asking.

I build only with the unix subdirectory toolchain.
In that build system, the --enable-threads option
to configure causes Tcl to be built supporting
multi-threaded operations under the "apartment
model".  This is the default setting in releases
Tcl 8.6.0 and higher.

@dgp Can you point me to the doc explaining how to do that? Especially where to find compatible pthread version and have it be found by build system?

TCL_THREADS=1 is the means by which Tcl is compiled to
support multi-threaded use.  From what you've posted,
I strongly suspect that's the problem here.

If you continue to have trouble with a --enable-threads
build of Tcl, please post again.