From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Thu, 16 Nov 1995 15:27:11 -0500
From: forsyth@plan9.cs.york.ac.uk forsyth@plan9.cs.york.ac.uk
Subject: alef bug
Topicbox-Message-UUID: 34e4d54a-eac8-11e9-9e20-41e7f4b1d025
Message-ID: <19951116202711.BjtbwWObIEIJNMNwmkvMg0b-WKi860Hz8MnTGND3Pw8@z>

a student found an unpleasant feature of !{} which turns out to be a bug
on closer examination.  for example:

#include <alef.h>

void
crit2 (void)
!{
	print ("world\n");
}

void
crit1 (void)
!{
	print ("hello\n");
	crit2 ();
}

void
main (void)
{
	crit1 ();
}

this locks up because internnode uses
sprint(buf, ".i%d", stmp++);
but stmp is reset by fundecl (possibly right for some calls of internnode,
but not in this case).  the result is that several !{} in different functions
end up using the same synchronisation variable (but not if they appear
in the same function, or different source files).