Programming

My company recently switched from Visual SourceSafe (which I accessed using SourceOffsite) to Visual Studio Team System for version control, which has caused me endless grief.

The first annoyance was there’s no way to see which files were changed locally in the file list. The bigger problem is it can’t handle Unix/Mac line endings. If you use the compare feature, it will show the ENTIRE file changed because of the line endings.

I came up with a fix for the APE-related crash I found a few days ago. It seems that signals can be delivered to any active thread. If you have APE installed, it injects its own thread into the application. If the signal happens to be sent to APE’s thread, there’s a chance bad things might happen.

The fix was for my signal handler to make sure it’s running in the thread we want, and if it isn’t, I send the signal to the proper thread and don’t do anything else.

void MySignalHandler(int SigNum)
{
	if (!pthread_equal(_my_signal_thread,pthread_self()))
	{
		pthread_kill(_my_signal_thread,SigNum);
		return;
	}
 ... etc ...

Elsewhere, I save a reference to the desired thread when I install the signal handlers:

main(int argc, char **argv)
{
	_my_signal_thread = pthread_self();
	signal(SIGIO, MySignalHandler);
 ... etc ...

I know Unsanity’s Application Enhancer is often unjustly blamed for crashes, but in this case it definitely caused one of my applications to crash, as shown in this stack frame from the crash report.

Thread 1 Crashed:
0   com.absolute.ctmweb      	0x0002b9a9 CheckForListen() + 253
1   com.absolute.ctmweb      	0x0002bba0 MyNot(int) + 28
2   libSystem.B.dylib        	0x9011108c _sigtramp + 49
3   libSystem.B.dylib        	0x9000a5c7 mach_msg_trap + 7
4   com.unsanity.ape         	0xc0001d12 __ape_agent + 307
5   libSystem.B.dylib        	0x90024b07 _pthread_body + 84

UPDATE: I realized that it’s my signal handler code being executed in APE’s thread.

My company switched their source control from Visual SourceSafe (which I accessed using SourceOffsite) to Team Foundation Server (VSTS). Since XCode has no built-in support or plugins for either system, I always worked locally, did a checkout of any files changed locally, and then checked in my changes (after merging, if necessary). It was easy since SOS would show me which files were changed locally.

Unfortunately I don’t see any way for VSTS to show which files were changed locally if they aren’t checked out. If I had to check out every file before I worked on it, I would have to constantly bounce between VSTS in Windows XP running under Parallels and XCode.

Blogged with Flock

My copy of Mac OS X Internals: A Systems Approach arrived today. I’ve been buried in it most of the day. This is the first book I’ve seen that really goes deeply into how OS X works.