prio/Paper/Paper.thy
changeset 353 32186d6a1951
parent 352 ee58e3d99f8a
child 354 677364c67cc8
equal deleted inserted replaced
352:ee58e3d99f8a 353:32186d6a1951
  1280   lemma. We were also able to establish the property that the choice of
  1280   lemma. We were also able to establish the property that the choice of
  1281   the next thread which takes over a lock is irrelevant for the correctness
  1281   the next thread which takes over a lock is irrelevant for the correctness
  1282   of PIP. 
  1282   of PIP. 
  1283 
  1283 
  1284   PIP is a scheduling algorithm for single-processor systems. We are
  1284   PIP is a scheduling algorithm for single-processor systems. We are
  1285   now living in a multi-processor world. So the question naturally
  1285   now living in a multi-processor world. Priority Inversion certainly
  1286   arises whether PIP has any relevance in such a world beyond
  1286   occurs also there.  However, there is very little ``foundational''
  1287   teaching. Priority Inversion certainly occurs also in
  1287   work about PIP-algorithms on multi-processor systems.  We are not
  1288   multi-processor systems.  However, the answer is that
  1288   aware of any correctness proofs, not even informal ones. There is an
  1289   there is very little work about PIP and multi-processors in the literature. 
  1289   implementation of a PIP-algorithm for multi-processors as part of the
  1290   We are not aware of any proofs in this area, not even informal ones. There
  1290   ``real-time'' effort in Linux, including an informal description of the implemented scheduling
  1291   is an implementation of PIP on multi-processors in Linux as part of the ``real-time'' effort,
  1291   algorithm given in \cite{LINUX}.  We estimate that the formal
  1292   with an informal description given in \cite{LINUX}.
  1292   verification of this algorithm, involving more fine-grained events,
  1293   We estimate that the formal verification of this algorithm, involving more
  1293   is a magnitude harder than the one we presented here, but still
  1294   fine-grained events, is a magnitude harder than the one we presented here, but 
  1294   within reach of current theorem proving technology. We leave this
  1295   still within reach of current theorem proving technology. We leave this for future 
  1295   for future work.
  1296   work. 
       
  1297 
  1296 
  1298   The most closely related work to ours is the formal verification in
  1297   The most closely related work to ours is the formal verification in
  1299   PVS of the Priority Ceiling Protocol done by Dutertre
  1298   PVS of the Priority Ceiling Protocol done by Dutertre
  1300   \cite{dutertre99b}---another solution to the Priority Inversion
  1299   \cite{dutertre99b}---another solution to the Priority Inversion
  1301   problem, which however needs static analysis of programs in order to
  1300   problem, which however needs static analysis of programs in order to