Extreme memory usage when `synchronized( this )` is used

[tcak via Digitalmars-d-learn]

[code]
import std.stdio;

class Connection{
	private void other() shared{}

	public void close() shared{
		synchronized( this ){
			other();
		}
	}

	public void hasData() shared{ writeln("Has Data"); }
}

void main() {
	for(long i=0; i < 250_000_000; ++i){
		auto conn = new shared Connection();

		conn.hasData();

		conn.close();
	}
}
[/code]

With this code, memory usage of program is increasing very fast. 
In about 10 seconds, it reached 100MB for me.

If I comment out `synchronized( this )` line with its 
parentheses, OR remove `(this)` from it, it suddenly turns 
normal. Very little memory usage.

What's happening? Is object instance being stored somewhere at 
each iteration?

--

I tried the same thing by creating synchronisation object instead 
of object itself as blow, still usage lots of memory.

[code]
import std.stdio;

class Connection{
	private Object syncObject;

	public this() shared{
		syncObject = new shared Object();
	}

	private void other() shared{}

	public void close() shared{
		synchronized( syncObject ){
			other();
		}
	}

	public void hasData() shared{ writeln("Has Data"); }
}

void main() {
	for(long i=0; i < 250_000_000; ++i){
		auto conn = new shared Connection();

		conn.hasData();

		conn.close();
	}
}
[/code]