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// RUN: %boogie -noinfer -typeEncoding:m -useArrayTheory "%s" > "%t"
// RUN: %diff "%s.expect" "%t"
type X;
function {:builtin "MapConst"} mapconstbool(bool): [X]bool;
const nil: X;
var {:layer 0,1} ghostLock: X;
var {:layer 0,1} lock: X;
var {:layer 0,1} currsize: int;
var {:layer 0,1} newsize: int;
function {:builtin "MapConst"} MapConstBool(bool) : [X]bool;
function {:inline} {:linear "tid"} TidCollector(x: X) : [X]bool
{
MapConstBool(false)[x := true]
}
function {:inline} {:linear "tid"} TidSetCollector(x: [X]bool) : [X]bool
{
x
}
function {:inline} Inv(ghostLock: X, currsize: int, newsize: int) : (bool)
{
0 <= currsize && currsize <= newsize &&
(ghostLock == nil <==> currsize == newsize)
}
procedure {:yields} {:layer 1} Yield()
requires {:layer 1} Inv(ghostLock, currsize, newsize);
ensures {:layer 1} Inv(ghostLock, currsize, newsize);
{
yield;
assert {:layer 1} Inv(ghostLock, currsize, newsize);
}
procedure {:yields} {:layer 1} YieldToReadCache({:linear "tid"} tid: X)
requires {:layer 1} Inv(ghostLock, currsize, newsize) && tid != nil;
ensures {:layer 1} Inv(ghostLock, currsize, newsize) && old(currsize) <= currsize;
{
yield;
assert {:layer 1} Inv(ghostLock, currsize, newsize) && old(currsize) <= currsize;
}
procedure {:yields} {:layer 1} YieldToWriteCache({:linear "tid"} tid: X)
requires {:layer 1} Inv(ghostLock, currsize, newsize) && ghostLock == tid && tid != nil;
ensures {:layer 1} Inv(ghostLock, currsize, newsize) && ghostLock == tid && old(currsize) == currsize && old(newsize) == newsize;
{
yield;
assert {:layer 1} Inv(ghostLock, currsize, newsize) && tid != nil && ghostLock == tid && old(currsize) == currsize && old(newsize) == newsize;
}
procedure {:yields} {:layer 1} Allocate() returns ({:linear "tid"} xl: X)
ensures {:layer 1} xl != nil;
{
yield;
call xl := AllocateLow();
yield;
}
procedure {:yields} {:layer 1} main({:linear_in "tid"} xls: [X]bool)
requires {:layer 1} xls == mapconstbool(true);
{
var {:linear "tid"} tid: X;
yield;
call Init(xls);
yield;
assert {:layer 1} Inv(ghostLock, currsize, newsize);
while (*)
invariant {:layer 1} Inv(ghostLock, currsize, newsize);
{
par tid := Allocate() | Yield();
yield;
assert {:layer 1} Inv(ghostLock, currsize, newsize);
async call Thread(tid);
yield;
assert {:layer 1} Inv(ghostLock, currsize, newsize);
}
yield;
}
procedure {:yields} {:layer 1} Thread({:linear "tid"} tid: X)
requires {:layer 1} tid != nil;
requires {:layer 1} Inv(ghostLock, currsize, newsize);
{
var start, size, bytesRead: int;
havoc start, size;
assume (0 <= start && 0 <= size);
call bytesRead := Read(tid, start, size);
}
procedure {:yields} {:layer 1} Read({:linear "tid"} tid: X, start : int, size : int) returns (bytesRead : int)
requires {:layer 1} tid != nil;
requires {:layer 1} 0 <= start && 0 <= size;
requires {:layer 1} Inv(ghostLock, currsize, newsize);
ensures {:layer 1} 0 <= bytesRead && bytesRead <= size;
{
var i, tmp: int;
par YieldToReadCache(tid);
bytesRead := size;
call acquire(tid);
call i := ReadCurrsize(tid);
call tmp := ReadNewsize(tid);
if (start + size <= i) {
call release(tid);
goto COPY_TO_BUFFER;
} else if (tmp > i) {
bytesRead := if (start <= i) then (i - start) else 0;
call release(tid);
goto COPY_TO_BUFFER;
} else {
call WriteNewsize(tid, start + size);
call release(tid);
goto READ_DEVICE;
}
READ_DEVICE:
par YieldToWriteCache(tid);
call WriteCache(tid, start + size);
par YieldToWriteCache(tid);
call acquire(tid);
call tmp := ReadNewsize(tid);
call WriteCurrsize(tid, tmp);
call release(tid);
COPY_TO_BUFFER:
par YieldToReadCache(tid);
call ReadCache(tid, start, bytesRead);
}
procedure {:yields} {:layer 1} WriteCache({:linear "tid"} tid: X, index: int)
requires {:layer 1} Inv(ghostLock, currsize, newsize);
requires {:layer 1} ghostLock == tid && tid != nil;
ensures {:layer 1} ghostLock == tid;
ensures {:layer 1} Inv(ghostLock, currsize, newsize) && old(currsize) == currsize && old(newsize) == newsize;
{
var j: int;
par YieldToWriteCache(tid);
call j := ReadCurrsize(tid);
while (j < index)
invariant {:layer 1} ghostLock == tid && currsize <= j && tid == tid;
invariant {:layer 1} Inv(ghostLock, currsize, newsize) && old(currsize) == currsize && old(newsize) == newsize;
{
par YieldToWriteCache(tid);
call WriteCacheEntry(tid, j);
j := j + 1;
}
par YieldToWriteCache(tid);
}
procedure {:yields} {:layer 1} ReadCache({:linear "tid"} tid: X, start: int, bytesRead: int)
requires {:layer 1} Inv(ghostLock, currsize, newsize);
requires {:layer 1} tid != nil;
requires {:layer 1} 0 <= start && 0 <= bytesRead;
requires {:layer 1} (bytesRead == 0 || start + bytesRead <= currsize);
ensures {:layer 1} Inv(ghostLock, currsize, newsize);
{
var j: int;
par YieldToReadCache(tid);
j := 0;
while(j < bytesRead)
invariant {:layer 1} 0 <= j;
invariant {:layer 1} bytesRead == 0 || start + bytesRead <= currsize;
invariant {:layer 1} Inv(ghostLock, currsize, newsize);
{
assert {:layer 1} start + j < currsize;
call ReadCacheEntry(tid, start + j);
j := j + 1;
par YieldToReadCache(tid);
}
par YieldToReadCache(tid);
}
procedure {:yields} {:layer 0,1} Init({:linear_in "tid"} xls:[X]bool);
ensures {:atomic} |{ A: assert xls == mapconstbool(true); currsize := 0; newsize := 0; lock := nil; ghostLock := nil; return true; }|;
procedure {:yields} {:layer 0,1} ReadCurrsize({:linear "tid"} tid: X) returns (val: int);
ensures {:right} |{A: assert tid != nil; assert lock == tid || ghostLock == tid; val := currsize; return true; }|;
procedure {:yields} {:layer 0,1} ReadNewsize({:linear "tid"} tid: X) returns (val: int);
ensures {:right} |{A: assert tid != nil; assert lock == tid || ghostLock == tid; val := newsize; return true; }|;
procedure {:yields} {:layer 0,1} WriteNewsize({:linear "tid"} tid: X, val: int);
ensures {:atomic} |{A: assert tid != nil; assert lock == tid && ghostLock == nil; newsize := val; ghostLock := tid; return true; }|;
procedure {:yields} {:layer 0,1} WriteCurrsize({:linear "tid"} tid: X, val: int);
ensures {:atomic} |{A: assert tid != nil; assert lock == tid && ghostLock == tid; currsize := val; ghostLock := nil; return true; }|;
procedure {:yields} {:layer 0,1} ReadCacheEntry({:linear "tid"} tid: X, index: int);
ensures {:atomic} |{ A: assert 0 <= index && index < currsize; return true; }|;
procedure {:yields} {:layer 0,1} WriteCacheEntry({:linear "tid"} tid: X, index: int);
ensures {:right} |{ A: assert tid != nil; assert currsize <= index && ghostLock == tid; return true; }|;
procedure {:yields} {:layer 0,1} acquire({:linear "tid"} tid: X);
ensures {:right} |{ A: assert tid != nil; assume lock == nil; lock := tid; return true; }|;
procedure {:yields} {:layer 0,1} release({:linear "tid"} tid: X);
ensures {:left} |{ A: assert tid != nil; assert lock == tid; lock := nil; return true; }|;
procedure {:yields} {:layer 0,1} AllocateLow() returns ({:linear "tid"} tid: X);
ensures {:atomic} |{ A: assume tid != nil; return true; }|;
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