D daemon & GC?

[JD via Digitalmars-d-learn]

> I can already say that it nevertheless works with DMD git. Will 
> test soon with Digger, unfortunately Bitbucket is currently 
> down, and Digger depends on it.

In the meantime I installed DMD 2.066 and I changed the exit() 
function after the fork as Dicebot suggested. Unfortunately I got 
the same result:

$ ./testdaemon
Starting daemon mode, process id = 30510

core.exception.InvalidMemoryOperationError@(0)
core.exception.InvalidMemoryOperationError@(0)

I think the issue is the way the parent is stopped after the 
fork(). Being quite new to D I have to familiarise myself some 
more with D's runtime and GC to see it...

---

The changed example code:

module testdaemon;

import std.stdio;
import std.c.stdlib : exit, EXIT_FAILURE, EXIT_SUCCESS;
import core.thread : Thread, dur;
import core.sys.posix.sys.stat : umask;
import core.sys.posix.unistd : fork, setsid, chdir, close, 
STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO;

extern (C)
{
	void _Exit(int);
}

void daemonize()
{
	// fork this process
	auto pid = fork();
	if (pid == -1) exit(EXIT_FAILURE);

	// this is the parent; terminate it
	if (pid > 0)
	{
		writefln("Starting daemon mode, process id = %d\n", pid);
		_Exit(EXIT_SUCCESS);
	}
	//unmask the file mode
	umask(0);
	
	// become process group leader
	auto sid = setsid();
	if(sid < 0) exit(EXIT_FAILURE);
	
	// do not lock any directories
	chdir("/");

	// Close stdin, stdout and stderr
	close(STDIN_FILENO);
//	close(STDOUT_FILENO);
//	close(STDERR_FILENO);
}

void main()
{	
	auto log = File("testdaemon.log", "w");
	daemonize();
	while(true)
	{	
		try
		{	
			// this statement causes 
core.exception.InvalidMemoryOperationError
			auto t = new char[4096];

			log.write(".");
		}
		catch(Exception e)
		{
			log.write(e.msg);
		}
		finally
		{
			log.flush();
		}
		Thread.sleep(dur!("seconds")(5));
	}
}