io.github.vipcxj.jasync.ng.runtime.promise.PromiseTrigger Maven / Gradle / Ivy
package io.github.vipcxj.jasync.ng.runtime.promise;
import io.github.vipcxj.jasync.ng.spec.JPromise;
import io.github.vipcxj.jasync.ng.spec.JPromiseTrigger;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
public class PromiseTrigger implements JPromiseTrigger {
private T value;
private Throwable error;
private volatile int state = 0;
@SuppressWarnings("rawtypes")
private static final AtomicIntegerFieldUpdater STATE = AtomicIntegerFieldUpdater.newUpdater(PromiseTrigger.class, "state");
private static final int ST_UNRESOLVED = 0;
private static final int ST_RESOLVING = 1;
private static final int ST_RESOLVED = 2;
private static final int ST_REJECTING = 3;
private static final int ST_REJECTED = 4;
private volatile int tmState = 0;
@SuppressWarnings("rawtypes")
private static final AtomicIntegerFieldUpdater TM_STATE = AtomicIntegerFieldUpdater.newUpdater(PromiseTrigger.class, "tmState");
private static final int ST_TM_VALID = 0;
private static final int ST_TM_BUSY = 1;
private static final int ST_TM_BUSY_INVALID = 2;
private static final int ST_TM_INVALID = 3;
private volatile int cbState = 0;
@SuppressWarnings("rawtypes")
private static final AtomicIntegerFieldUpdater CB_STATE = AtomicIntegerFieldUpdater.newUpdater(PromiseTrigger.class, "cbState");
private static final int ST_CB_SAFE = 0;
private static final int ST_CB_READING = 1;
private static final int ST_CB_PUTTING = 2;
private List> callbacks;
public PromiseTrigger() { }
@Override
public void resolve(T result) {
if (TM_STATE.get(this) == ST_TM_INVALID) {
return;
}
while (true) {
if (TM_STATE.weakCompareAndSet(this, ST_TM_VALID, ST_TM_BUSY)) {
try {
if (STATE.compareAndSet(this, ST_UNRESOLVED, ST_RESOLVING)) {
value = result;
state = ST_RESOLVED;
while (true) {
if (CB_STATE.weakCompareAndSet(this, ST_CB_SAFE, ST_CB_READING)) {
try {
if (callbacks != null) {
for (ThunkAndContext callback : callbacks) {
if (tmState == ST_TM_BUSY_INVALID) {
return;
}
callback.getThunk().resolve(value, callback.getContext());
}
callbacks = null;
}
} finally {
CB_STATE.set(this, ST_CB_SAFE);
}
return;
} else if (tmState == ST_TM_BUSY_INVALID) {
return;
}
}
} else {
throw new IllegalStateException("The promise has been resolved or rejected.");
}
} finally {
TM_STATE.set(this, ST_TM_VALID);
}
} else if (TM_STATE.get(this) == ST_TM_INVALID) {
return;
}
}
}
@Override
public void reject(Throwable error) {
if (TM_STATE.get(this) == ST_TM_INVALID) {
return;
}
while (true) {
if (TM_STATE.weakCompareAndSet(this, ST_TM_VALID, ST_TM_BUSY)) {
try {
if (STATE.compareAndSet(this, ST_UNRESOLVED, ST_REJECTING)) {
this.error = error;
state = ST_REJECTED;
while (true) {
if (CB_STATE.weakCompareAndSet(this, ST_CB_SAFE, ST_CB_READING)) {
try {
if (callbacks != null) {
for (ThunkAndContext callback : callbacks) {
if (tmState == ST_TM_BUSY_INVALID) {
return;
}
callback.getThunk().reject(error, callback.getContext());
}
callbacks = null;
}
} finally {
CB_STATE.set(this, ST_CB_SAFE);
}
return;
} else if (tmState == ST_TM_BUSY_INVALID) {
return;
}
}
} else {
throw new IllegalStateException("The promise has been resolved or rejected.");
}
} finally {
TM_STATE.set(this, ST_TM_VALID);
}
} else if (TM_STATE.get(this) == ST_TM_INVALID) {
return;
}
}
}
@Override
public void cancel() {
if (TM_STATE.get(this) == ST_TM_INVALID) {
return;
}
while (true) {
if (TM_STATE.weakCompareAndSet(this, ST_TM_VALID, ST_TM_INVALID)) {
while (true) {
if (CB_STATE.weakCompareAndSet(this, ST_CB_SAFE, ST_CB_READING)) {
try {
if (callbacks != null) {
for (ThunkAndContext callback : callbacks) {
callback.getThunk().interrupt(callback.getContext());
}
callbacks = null;
}
} finally {
CB_STATE.set(this, ST_CB_SAFE);
}
return;
}
}
} else if (TM_STATE.get(this) == ST_TM_INVALID) {
return;
} else {
TM_STATE.weakCompareAndSet(this, ST_TM_BUSY, ST_TM_BUSY_INVALID);
}
}
}
@Override
public JPromise getPromise() {
return JPromise.generate((thunk, context) -> {
if (STATE.get(this) == ST_RESOLVED) {
thunk.resolve(value, context);
} else if (STATE.get(this) == ST_REJECTED) {
thunk.reject(error, context);
} else if (TM_STATE.get(this) == ST_TM_INVALID) {
thunk.interrupt(context);
} else {
while (true) {
if (TM_STATE.weakCompareAndSet(this, ST_TM_VALID, ST_TM_BUSY)) {
try {
while (true) {
if (CB_STATE.weakCompareAndSet(this, ST_CB_SAFE, ST_CB_PUTTING)) {
try {
if (callbacks == null) {
callbacks = new ArrayList<>(1);
}
callbacks.add(new ThunkAndContext<>(thunk, context));
} finally {
CB_STATE.set(this, ST_CB_SAFE);
}
return;
} else if (STATE.get(this) == ST_RESOLVED) {
thunk.resolve(value, context);
return;
} else if (STATE.get(this) == ST_REJECTED) {
thunk.reject(error, context);
return;
} else if (TM_STATE.get(this) == ST_TM_INVALID) {
thunk.interrupt(context);
return;
}
}
} finally {
TM_STATE.set(this, ST_TM_VALID);
}
} else if (TM_STATE.get(this) == ST_TM_INVALID) {
thunk.interrupt(context);
return;
}
}
}
});
}
}
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