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digitalmars.D - std.concurrency: layout-dependent problem with sending structs

reply "thedeemon" <dlang thedeemon.com> writes:
Found a strange bug where when trying to send a message of some 
struct the sender thread silently dies. However with different 
struct layout everything works fine. I'm using DMD 2.062 under 
Windows. Here's a code sample:

import std.concurrency, std.stdio, core.time;

struct Msg {
	string name;
	int sz;
	double progress;
}

void myfun(Tid tid)
{
	writeln("10");
	tid.send(Msg("a", 123, 0.2));
	writeln("20");
}

void main(string[] argv)
{
	int[] arr = [1,2,3];
	spawn(&myfun, thisTid);

	void RcvMsgAnalyzing(Msg m)
	{
		writeln(m.sz);
	}

	while(true) {
		while(receiveTimeout(dur!"msecs"(100), &RcvMsgAnalyzing)) {}
	}
}

When run like this it prints "10" and then nothing happens, and 
the Task Manager shows there is only 1 thread working after that. 
But if you comment out any field of Msg struct leaving the other 
two (and correct Msg instance creation) then it works just fine, 
the message gets delivered and worker thread function runs to its 
end.

Debugger shows something goes wrong at concurrency.d line 572:
tid.mbox.put( msg );
Something inside variant.d goes mad but I haven't figured out yet 
what exactly.
Mar 09 2013
parent "thedeemon" <dlang thedeemon.com> writes:
On Saturday, 9 March 2013 at 11:56:14 UTC, thedeemon wrote:
 struct Msg {
 	string name;
 	int sz;
 	double progress;
 }

BTW if I change double to float everything works fine.
Mar 09 2013