resume a calling thread

[Daniel919 at web.de]

Hi, I found a piece of code in the digitalmars.D.learn group about threads.

I didn't like the way it was checking whether one of the threads was stilling
running. It was something like: while (!allDone) { another check ... and
immediately repeat this loop } So it wasted 100% CPU.
Sure, I could have put a msleep(100) into it, but I thought about something
else: a way to make it respond without any delay.
This is the code up to now:
-----------------------------------------------------------------
import std.thread, std.stdio, std.c.time;

class Mainthread : Thread
{
this ()
{
super(&thread_main);
}

int thread_main ()
{
writefln("main thread started");

Subthread sub[];
uint allDone = 0;

// Create some threads of different durations.
sub ~= new Subthread(5);
sub ~= new Subthread(1);
sub ~= new Subthread(2);
sub ~= new Subthread(4);

// Start all the threads running.
foreach(Subthread t; sub)
{
writefln("Starting #%d for %d seconds", t.id, t.init_value);
t.start();
}

while (!allDone) {
writefln("loop");
allDone = 1;
foreach(int i, Subthread t; sub)
{
if (t.getState != Thread.TS.TERMINATED) allDone = 0;
};
pause();
writefln("pause done");
};

writefln("allDone");

// Ensure that they clean up.
foreach(int i, Subthread t; sub)
{
writefln("final wait #%d", t.id);
t.wait();
delete t;
};

writefln("cleanup done");
}
} 



class Subthread : Thread
{
private{
static int g_id;
static const uint OneSecond = 1000;
int m_id;
int m_V;
}

this (int V)
{
m_id = ++g_id;
m_V = V;

// Register callback function with Thread Central.
super(&thread_main);

writefln("create thread #%d", m_id);
}

~this()
{
writefln("destroy thread #%d", m_id);
}

int id()
{
return m_id;
}

int init_value()
{
return m_V;
}

int thread_main ()
{
writefln("in thread_main #%d", m_id);
for(int i = 0; i < m_V; i++)
{
msleep(OneSecond); // Do something very important
yield(); // Let someone else have some play time.
}
writefln("out thread_main #%d", m_id);
mainthread.resume();
return 0;
}
}



Mainthread mainthread;

int main ()
{
Mainthread mainthread = new Mainthread();
mainthread.start();
msleep(1000000);
return 0;
}
-----------------------------------------------------------------

So you see, instead of doing msleep() in main, I create a mainthread which then
spawns the other threads (Subthread).
In the "while (!allDone) ..." loop I pause() the mainthread, and wait for each
subthread to finish and then call resume() for the mainthread to let this loop
run again.
But unfortunately it's not working, I get this:
Error: Access Violation
when the subthread calls: mainthread.resume();

Any ideas how I can get this working ?

I would really appreciate your help, thanks !
/Daniel