Re: relinquishing timeslices in a transaction

   Date: Tue, 15 Sep 2009 19:51:39 +0000 (UTC)
   From: Richard Kelsey <[email protected]>

      Date: Tue, 15 Sep 2009 15:15:54 -0400
      From: Taylor R Campbell <[email protected]>

      When the Scheme48 virtual machine delivers an interrupt, it saves the
      current proposal, to be restored when control returns from the
      interrupt handler.  This is how per-thread proposals are preserved
      when switching threads in the timer interrupt handler,

   Not quite.  Each thread has its own proposal, so switching
   threads automatically switches proposals as well, whether
   or not an interrupt is involved.  The virtual machine
   keeps the current proposal in a fixed slot of the current
   thread, which is itself kept in a VM register.  There is
   no separate proposal register.

Right, thanks.  That's what I was missing.