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class Program {
method main(){
var buffer := new Queue;
call buffer.init();
share buffer;
var producer := new Producer;
call producer.init(buffer);
fork tkP := producer.run();
var consumer := new Consumer;
call consumer.init(buffer);
fork tkC := consumer.run();
join tkP;
join tkC;
acquire buffer;
unshare buffer;
var tmp := buffer.size();
}
}
class Producer module Producer {
var buffer: Queue;
method init(buff: Queue)
requires acc(buffer) && buff!=null;
ensures valid && getBuffer()==buff;
{
buffer := buff;
fold valid;
}
method run()
requires valid && rd(getBuffer().mu) && waitlevel << getBuffer().mu;
ensures rd(old(getBuffer()).mu);
{
var tmp: int;
while(true)
invariant valid && rd(getBuffer().mu) && waitlevel << getBuffer().mu;
{
unfold valid;
acquire buffer;
call buffer.enqueue(5);
release buffer;
fold valid;
}
unfold valid;
}
function getBuffer(): Queue
requires valid;
ensures result!=null;
{
unfolding valid in buffer
}
predicate valid {
acc(buffer) && buffer!=null
}
}
class Consumer module Consumer {
var buffer: Queue;
method init(buff: Queue)
requires acc(buffer) && buff!=null;
ensures valid && getBuffer()==buff;
{
buffer := buff;
fold valid;
}
method run()
requires valid && rd(getBuffer().mu) && waitlevel << getBuffer().mu;
ensures rd(old(getBuffer()).mu);
{
while(true)
invariant valid && rd(getBuffer().mu) && waitlevel << getBuffer().mu;
{
unfold valid;
acquire buffer;
if(0<=buffer.size()){
call buffer.enqueue(5);
}
release buffer;
fold valid;
}
unfold valid;
}
function getBuffer(): Queue
requires valid;
ensures result!=null;
{
unfolding valid in buffer
}
predicate valid {
acc(buffer) && buffer!=null
}
}
class Queue module Queue {
var contents: List;
invariant valid;
method init()
requires acc(contents);
ensures valid;
ensures size()==0;
{
contents := new List;
call contents.init();
fold valid;
}
method enqueue(x: int)
requires valid;
ensures valid;
ensures size() == old(size())+1;
{
unfold valid;
call contents.add(x);
fold valid;
}
method dequeue() returns (rt: int)
requires valid && 0<size();
ensures valid;
ensures size() == old(size())-1;
{
unfold valid;
call rt := contents.removeFirst();
fold valid;
}
function size(): int
requires valid;
{
unfolding valid in contents.size()
}
predicate valid {
acc(contents) && contents!=null && contents.valid
}
}
class List module Collections {
var contents: seq<int>;
method init()
requires acc(contents);
ensures valid && size()==0;
{
contents := nil<int>;
fold valid;
}
method add(x: int)
requires valid;
ensures valid && size() == old(size()+1) && get(size()-1) == x;
ensures forall i in [0..size()-1] :: get(i) == old(get(i));
{
unfold valid;
contents := contents ++ [x];
fold valid;
}
method removeFirst() returns (rt: int)
requires valid && 0<size();
ensures valid && size() == old(size()-1);
ensures forall i in [0..size()] :: get(i) == old(get(i+1));
{
unfold valid;
rt := contents[0];
contents := contents[1..];
fold valid;
}
function get(index: int): int
requires rd(valid) && 0<=index && index<size();
{
unfolding rd(valid) in contents[index]
}
function size(): int
requires rd(valid);
ensures 0<=result;
{
unfolding rd(valid) in |contents|
}
predicate valid {
acc(contents)
}
}
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