internal static bool SignalAndWait (StWaitable tos, StWaitable tow, StCancelArgs cargs)
{
if (tos == tow) {
return true;
}
var pk = new StParker ();
StWaitBlock hint = null;
int sc = 0;
StWaitBlock wb = tow._WaitAnyPrologue (pk, StParkStatus.Success, ref hint, ref sc);
if (!tos._Release ()) {
if (wb != null && pk.TryCancel ()) {
tow._CancelAcquire (wb, hint);
} else {
if (wb != null) {
pk.Park ();
}
tow._UndoAcquire ();
}
throw tos._SignalException;
}
int ws;
if (hint == INFLATED || (ws = pk.Park (sc, cargs)) == StParkStatus.Inflated) {
return tow.InflatedWait (cargs);
}
if (ws == StParkStatus.Success) {
tow._WaitEpilogue ();
return true;
}
tow._CancelAcquire (wb, hint);
cargs.ThrowIfException (ws);
return false;
}
internal abstract StWaitBlock _WaitAnyPrologue (StParker pk, int key, ref StWaitBlock hint, ref int sc);
internal static int WaitAny (StWaitable[] ws, StCancelArgs cargs)
{
if (ws == null) {
throw new ArgumentNullException ("ws");
}
int len = ws.Length;
for (int i = 0; i < len; i++) {
if (ws [i]._TryAcquire ()) {
return StParkStatus.Success + i;
}
}
if (cargs.Timeout == 0) {
return StParkStatus.Timeout;
}
retry:
/*
* Create a parker and execute the WaitAny prologue on all
* waitables. We stop executing prologues as soon as we detect
* that the acquire operation was accomplished.
*/
var pk = new StParker (1);
int inflated = 0;
int inflatedCount = 0;
var wbs = new StWaitBlock [len];
var hints = new StWaitBlock [len];
int lv = -1;
int gsc = 0;
for (int i = 0; !pk.IsLocked && i < len; i++) {
StWaitable w = ws [i];
int sc = 0;
if ((wbs [i] = w._WaitAnyPrologue (pk, i, ref hints [i], ref sc)) == null) {
if (hints [i] == INFLATED) {
inflated |= 1 << i;
inflatedCount += 1;
} else {
if (pk.TryLock ()) {
pk.UnparkSelf (i);
} else {
w._UndoAcquire ();
}
break;
}
} else if (gsc < sc) {
gsc = sc;
}
lv = i;
}
int wst = inflatedCount == len ? InflatedWaitMultiple (ws, false, inflated, inflatedCount, cargs)
: inflatedCount > 0 ? pk.Park (gsc, ws, inflated, inflatedCount, cargs)
: pk.Park (gsc, cargs);
StWaitable acq = wst >= StParkStatus.Success ? ws [wst] : null;
/*
* Cancel the acquire attempt on all waitables where we executed the WaitAny
* prologue, except the one we acquired and the ones that are inflated.
*/
for (int i = 0; i <= lv; i++) {
StWaitable w = ws [i];
StWaitBlock wb = wbs [i];
if (w != acq && wb != null) {
w._CancelAcquire (wb, hints [i]);
}
}
if (acq != null) {
try {
acq._WaitEpilogue ();
} catch (AbandonedMutexException e) {
e.MutexIndex = wst;
throw;
}
return wst;
}
if (wst == StParkStatus.Inflated) {
goto retry;
}
cargs.ThrowIfException (wst);
return StParkStatus.Timeout;
}
internal static bool WaitAll (StWaitable[] ws, StCancelArgs cargs)
{
if (ws == null) {
throw new ArgumentNullException ("ws");
}
int nevts;
int len = ws.Length;
var sws = new StWaitable [len];
int waitHint = SortAndCheckAllowAcquire (ws, sws, out nevts);
if (waitHint < 0) {
throw new DuplicateWaitObjectException ();
}
/*
* Return success if all synchronizers are notification events and are set.
*/
if (waitHint != 0) {
if (nevts == 0) {
return true;
}
} else if (cargs.Timeout == 0) {
return false;
}
/*
* If a timeout was specified, get the current time in order
* to adjust the timeout value later, if we re-wait.
*/
int lastTime = (cargs.Timeout != Timeout.Infinite) ? Environment.TickCount : 0;
StWaitBlock[] wbs = null;
StWaitBlock[] hints = null;
do {
int inflated = 0;
AbandonedMutexException ame = null;
if (waitHint == 0) {
if (wbs == null) {
wbs = new StWaitBlock [len];
hints = new StWaitBlock [len];
}
/*
* Create a parker for cooperative release, specifying as many
* releasers as the number of waitables. The parker is not reused
* because other threads may have references to it.
*/
var pk = new StParker (len);
int inflatedCount = 0;
int gsc = 1;
int sc = 0;
for (int i = 0; i < len; i++) {
if ((wbs [i] = sws [i]._WaitAllPrologue (pk, ref hints [i], ref sc)) == null) {
if (hints [i] == INFLATED) {
inflated |= 1 << i;
inflatedCount += 1;
} else if (pk.TryLock ()) {
pk.UnparkSelf (StParkStatus.StateChange);
}
} else if (gsc != 0) {
if (sc == 0) {
gsc = 0;
} else if (sc > gsc) {
gsc = sc;
}
}
}
if (inflatedCount > 0 && pk.TryLock (inflatedCount)) {
pk.UnparkSelf (StParkStatus.StateChange);
}
int wst = pk.Park (gsc, cargs);
/*
* We opt for a less efficient but simpler implementation instead
* of using the same approach as the WaitAny operation, because:
* - When parking, the thread would have to call into the park spot
* even if it was already unparked, since we have to wait for the
* other handles as well;
* - We would have to deal with cancellation in a different way,
* relying on interrupts instead of the TryCancel/Unpark pair;
* - The Unpark operation might not wake the target thread, which
* could lead to bugs.
*/
if (wst == StParkStatus.StateChange && inflatedCount > 0) {
if (!cargs.AdjustTimeout (ref lastTime)) {
return false;
}
wst = InflatedWaitMultiple (ws, true, inflated, inflatedCount, cargs);
}
if (wst != StParkStatus.StateChange) {
for (int i = 0; i < len; i++) {
StWaitBlock wb = wbs [i];
if (wb != null) {
sws [i]._CancelAcquire (wb, hints [i]);
}
}
if (wst == StParkStatus.Inflated) {
waitHint = 0;
continue;
}
cargs.ThrowIfException (wst);
return false;
}
}
/*
* All waitables where we inserted wait blocks seem to allow an
* immediate acquire operation; so, try to acquire all non-inflated
* waitables that are not notification events.
*/
int idx;
for (idx = 0; idx < nevts; idx++) {
try {
if ((inflated & (1 << idx)) == 0 && !sws[idx]._TryAcquire()) {
break;
}
} catch (AbandonedMutexException e) {
ame = e;
ame.MutexIndex = idx;
}
}
if (idx == nevts) {
if (ame != null) {
throw ame;
}
return true;
}
/*
* We failed to acquire all waitables, so undo the acquires
* that we did above.
*/
for (int i = idx + 1; i < nevts; ++i) {
if ((inflated & (1 << idx)) != 0) {
sws[i]._UndoAcquire ();
}
}
while (--idx >= 0) {
sws[idx]._UndoAcquire ();
}
if (!cargs.AdjustTimeout (ref lastTime)) {
return false;
}
waitHint = 0;
} while (true);
}
private CancellationTokenSource (bool cancelled)
{
state = cancelled ? CANCELLED : CANNOT_BE_CANCELLED;
}
internal bool TryWaitOne (StCancelArgs cargs)
{
if (_TryAcquire ()) {
return true;
}
if (cargs.Timeout == 0) {
return false;
}
var pk = new StParker ();
StWaitBlock hint = null;
int sc = 0;
StWaitBlock wb;
if ((wb = _WaitAnyPrologue (pk, StParkStatus.Success, ref hint, ref sc)) == null) {
return hint != INFLATED || InflatedWait (cargs);
}
int ws = pk.Park (sc, cargs);
if (ws == StParkStatus.Success) {
_WaitEpilogue ();
return true;
}
if (ws == StParkStatus.Inflated) {
return InflatedWait (cargs);
}
_CancelAcquire (wb, hint);
cargs.ThrowIfException (ws);
return false;
}
private void SlowDeregisterParker (StParker pk)
{
StParker next;
if ((next = pk.pnext) != null && next.IsLocked) {
next = next.pnext;
}
StParker p = state;
while (p != null && p != next && state != null && !(state is SentinelParker)) {
StParker n = p.pnext;
if (n != null && n.IsLocked) {
p.CasNext (n, n.pnext);
} else {
p = n;
}
}
}
internal void Reset (int releasers)
{
pnext = null;
state = releasers | WAIT_IN_PROGRESS;
}
internal bool RegisterParker (StParker pk)
{
ThrowIfDisposed ();
if (state == CANNOT_BE_CANCELLED) {
throw new InvalidOperationException ("CancellationTokenSource can't be cancelled");
}
do {
StParker s;
if ((s = state) == CANCELLED) {
return false;
}
pk.pnext = s;
if (Interlocked.CompareExchange (ref state, pk, s) == s) {
return true;
}
} while (true);
}
internal void DeregisterParker (StParker pk)
{
if (pk.pnext == null && Interlocked.CompareExchange (ref state, null, pk) == pk) {
return;
}
SlowDeregisterParker (pk);
}
private StWaitBlock WaitWithParker (StParker pk, WaitType type, int key,
ref StWaitBlock hint, ref int sc)
{
StWaitBlock wb = null;
do {
StWaitBlock s;
if ((s = state) == SET) {
return null;
}
if (s == INFLATED) {
hint = INFLATED;
return null;
}
if (wb == null) {
wb = new StWaitBlock (pk, type, 0, key);
}
wb.next = s;
if (Interlocked.CompareExchange (ref state, wb, s) == s) {
sc = s == null ? spinCount : 0;
return wb;
}
} while (true);
}
internal override StWaitBlock _WaitAllPrologue (StParker pk, ref StWaitBlock hint,
ref int sc)
{
return WaitWithParker (pk, WaitType.WaitAll, StParkStatus.StateChange, ref hint, ref sc);
}
internal override StWaitBlock _WaitAnyPrologue (StParker pk, int key,
ref StWaitBlock hint, ref int sc)
{
return WaitWithParker (pk, WaitType.WaitAny, key, ref hint, ref sc);
}
internal abstract StWaitBlock _WaitAllPrologue (StParker pk, ref StWaitBlock hint, ref int sc);
public CancellationTokenSource ()
{
state = NOT_CANCELLED;
}
internal override StWaitBlock _WaitAllPrologue (StParker pk, ref StWaitBlock hint, ref int sc)
{
hint = INFLATED;
return null;
}
internal bool CasNext (StParker n, StParker nn)
{
return pnext == n &&
Interlocked.CompareExchange (ref pnext, nn, n) == n;
}
