static void ts_set_preStateOnError(ShadowThread ts, FastTrackGuardState v) {
Assert.panic("Bad");
}
private void error(
final AccessEvent ae,
final int errorCase,
final String prevOp,
final int prevTid,
final String curOp,
final int curTid) {
try {
if (ae instanceof FieldAccessEvent) {
FieldAccessEvent fae = (FieldAccessEvent) ae;
final FieldInfo fd = fae.getInfo().getField();
final ShadowThread currentThread = fae.getThread();
final Object target = fae.getTarget();
fieldErrors.error(
currentThread,
fd,
"Guard State",
fae.getOriginalShadow(),
"Current Thread",
toString(currentThread),
"Class",
target == null ? fd.getOwner() : target.getClass(),
"Field",
Util.objectToIdentityString(target) + "." + fd,
"Prev Op",
prevOp + prevTid,
"Cur Op",
curOp + curTid,
"Case",
"#" + errorCase,
"Stack",
ShadowThread.stackDumpForErrorMessage(currentThread));
if (!fieldErrors.stillLooking(fd)) {
advance(ae);
return;
}
} else {
ArrayAccessEvent aae = (ArrayAccessEvent) ae;
final ShadowThread currentThread = aae.getThread();
final Object target = aae.getTarget();
arrayErrors.error(
currentThread,
aae.getInfo(),
"Alloc Site",
ArrayAllocSiteTracker.allocSites.get(aae.getTarget()),
"Guard State",
aae.getOriginalShadow(),
"Current Thread",
toString(currentThread),
"Array",
Util.objectToIdentityString(target) + "[" + aae.getIndex() + "]",
"Prev Op",
prevOp + prevTid + ("name = " + ShadowThread.get(prevTid).getThread().getName()),
"Cur Op",
curOp + curTid + ("name = " + ShadowThread.get(curTid).getThread().getName()),
"Case",
"#" + errorCase,
"Stack",
ShadowThread.stackDumpForErrorMessage(currentThread));
aae.getArrayState().specialize();
if (!arrayErrors.stillLooking(aae.getInfo())) {
advance(aae);
return;
}
}
} catch (Throwable e) {
Assert.panic(e);
}
}
/** *** */
static FastTrackGuardState ts_get_preStateOnError(ShadowThread ts) {
Assert.panic("Bad");
return null;
}
@Override
public void access(final AccessEvent fae) {
final ShadowVar var = fae.getOriginalShadow();
final ShadowThread td = fae.getThread();
if (var instanceof FastTrackGuardState) {
// load the error guard state set by the fast path if it exists.
final FastTrackGuardState isItAnError = ts_get_preStateOnError(td);
final FastTrackGuardState x = (isItAnError != null) ? isItAnError : (FastTrackGuardState) var;
ts_set_preStateOnError(td, null);
final int tdEpoch = ts_get_epoch(td);
final CV tdCV = ts_get_cv(td);
Object target = fae.getTarget();
if (target == null) {
CV initTime = classInitTime.get(((FieldAccessEvent) fae).getInfo().getField().getOwner());
tdCV.max(initTime);
}
if (!fae.isWrite()) {
// READ
retry:
do {
final long orig = x.getWREpochs();
final int lastReadEpoch = EpochPair.read(orig);
if (lastReadEpoch == tdEpoch) {
break; // commit : same epoch
}
final int tid = td.getTid();
final int lastWriteEpoch = EpochPair.write(orig);
if (lastReadEpoch == Epoch.READ_SHARED) {
if (x.get(tid) != tdEpoch) { // (*) racy access -> should be fine.
synchronized (x) {
if (orig != x.getWREpochs()) {
Yikes.yikes("concurrent mod");
continue retry;
}
x.set(tid, tdEpoch);
}
}
} else {
final int lastReader = Epoch.tid(lastReadEpoch);
if (lastReader == tid) {
if (!x.cas(orig, lastWriteEpoch, tdEpoch)) {
Yikes.yikes("concurrent mod");
continue retry;
}
// commit: read-exclusive fast case
} else if (lastReadEpoch <= tdCV.get(lastReader)) {
if (!x.cas(orig, lastWriteEpoch, tdEpoch)) {
Yikes.yikes("concurrent mod");
continue retry;
}
// commit: read-exclusive slow case
} else {
synchronized (x) {
x.makeCV(INIT_CV_SIZE); // do first, in case we need it at (*)
if (!x.cas(orig, lastWriteEpoch, Epoch.READ_SHARED)) {
Yikes.yikes("concurrent mod");
continue retry;
}
// commit: read share
x.set(lastReader, lastReadEpoch);
x.set(td.getTid(), tdEpoch);
}
}
}
final int lastWriter = Epoch.tid(lastWriteEpoch);
if (lastWriter != tid && lastWriteEpoch > tdCV.get(lastWriter)) {
error(fae, 4, "write-by-thread-", lastWriter, "read-by-thread-", tid);
}
} while (false); // awesome...
} else {
// WRITE
retry:
do {
final long orig = x.getWREpochs();
final int lastWriteEpoch = EpochPair.write(orig);
if (lastWriteEpoch == tdEpoch) {
break; // commit: same epoch
}
final int tid = td.getTid();
final int lastReadEpoch = EpochPair.read(orig);
if (lastReadEpoch == tdEpoch) {
if (!x.cas(orig, tdEpoch, tdEpoch)) {
Yikes.yikes("concurrent mod");
continue retry;
}
// commit: write exclusive fast case
} else if (lastReadEpoch != Epoch.READ_SHARED) {
if (!x.cas(orig, tdEpoch, tdEpoch)) {
Yikes.yikes("concurrent mod");
continue retry;
}
// commit: write exclusive slow case
final int lastReader = Epoch.tid(lastReadEpoch);
if (lastReader != tid && lastReadEpoch > tdCV.get(lastReader)) {
error(fae, 2, "read-by-thread-", lastReader, "write-by-thread-", tid);
}
} else {
synchronized (x) {
if (!x.cas(orig, tdEpoch, tdEpoch)) {
Yikes.yikes("concurrent mod");
continue retry;
}
// commit write shared
if (x.anyGt(tdCV)) {
int errorCount = 0;
for (int prevReader = x.nextGt(tdCV, 0);
prevReader > -1;
prevReader = x.nextGt(tdCV, prevReader + 1)) {
if (prevReader != tid) {
errorCount++;
error(fae, 3, "read-by-thread-", prevReader, "write-by-thread-", tid);
}
}
if (errorCount == 0) {
Assert.fail("Bad error count");
}
}
}
}
final int lastWriter = Epoch.tid(lastWriteEpoch);
if (lastWriter != tid && lastWriteEpoch > tdCV.get(lastWriter)) {
error(fae, 1, "write-by-thread-", lastWriter, "write-by-thread-", tid);
}
} while (false);
}
} else {
super.access(fae);
}
}
static void ts_set_cv(ShadowThread ts, CV cv) {
Assert.panic("Bad");
}
static CV ts_get_cv(ShadowThread ts) {
Assert.panic("Bad");
return null;
}
static void ts_set_epoch(ShadowThread ts, int v) {
Assert.panic("Bad");
}
static int ts_get_epoch(ShadowThread ts) {
Assert.panic("Bad");
return -1;
}