com.oracle.graal.python.runtime.GilNode Maven / Gradle / Ivy
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package com.oracle.graal.python.runtime;
import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
import com.oracle.truffle.api.TruffleSafepoint;
import com.oracle.truffle.api.dsl.NeverDefault;
import com.oracle.truffle.api.nodes.Node;
import com.oracle.truffle.api.profiles.ConditionProfile;
public abstract class GilNode extends Node {
private static final class Cached extends GilNode {
// The same profile is used for all methods. The profile condition should always be so that
// we profile if a boundary call needs to be made at all.
private final ConditionProfile binaryProfile = ConditionProfile.create();
@Override
public boolean isAdoptable() {
return true;
}
@Override
public void release(boolean wasAcquired) {
release(PythonContext.get(this), wasAcquired);
}
@Override
public boolean acquire(Node location) {
return acquire(PythonContext.get(this), location);
}
@Override
public void release(PythonContext context, boolean wasAcquired) {
// n.b.: we cannot make any optimizations here based on the singleThreadedAssumption of
// the language. You would think that you could use that assumption to get rid even of
// the ownsGil check, but we need to actually release the GIL around blocking operations
// like sleeping. Consider an embedded use where one Python thread goes to sleep, while
// another thread enters the same Python context, invalidating the assumption. The
// regular "release GIL" logic will start to tick, but the second thread won't be able
// to acquire the GIL at all until the first one has finished sleeping and actually runs
// into the next (e.g. regular) GIL release. So we need to always have this ownsGil
// check.
if (binaryProfile.profile(wasAcquired)) {
context.releaseGil();
}
}
@Override
public boolean acquire(PythonContext context, Node location) {
if (binaryProfile.profile(!context.ownsGil())) {
TruffleSafepoint.setBlockedThreadInterruptible(location, PythonContext::acquireGil, context);
return true;
}
return false;
}
@Override
public final boolean tryRelease() {
PythonContext context = PythonContext.get(this);
if (binaryProfile.profile(context.ownsGil())) {
context.releaseGil();
return true;
}
return false;
}
}
private abstract static class Uncached extends GilNode implements AutoCloseable {
@Override
public boolean isAdoptable() {
return false;
}
@Override
@TruffleBoundary
public final boolean acquire(Node location) {
return acquire(PythonContext.get(this), location);
}
@Override
@TruffleBoundary
public final void release(boolean wasAcquired) {
release(PythonContext.get(this), wasAcquired);
}
@Override
@TruffleBoundary
public final boolean acquire(PythonContext context, Node location) {
if (!context.ownsGil()) {
if (!context.tryAcquireGil()) {
TruffleSafepoint.setBlockedThreadInterruptible(location, PythonContext::acquireGil, context);
}
return true;
}
return false;
}
@Override
@TruffleBoundary
public final void release(PythonContext context, boolean wasAcquired) {
if (wasAcquired) {
context.releaseGil();
}
}
@Override
@TruffleBoundary
public final boolean tryRelease() {
PythonContext context = PythonContext.get(this);
if (context.ownsGil()) {
context.releaseGil();
return true;
}
return false;
}
public abstract void close();
}
public static final class UncachedRelease extends Uncached {
private UncachedRelease() {
}
private static final UncachedRelease INSTANCE = new UncachedRelease();
@Override
public final void close() {
acquire();
}
}
public static final class UncachedAcquire extends Uncached {
private UncachedAcquire() {
}
private static final UncachedAcquire INSTANCE_WITH_RELEASE = new UncachedAcquire();
private static final UncachedAcquire INSTANCE_WITHOUT_RELEASE = new UncachedAcquire();
@Override
public final void close() {
if (PythonContext.get(this).ownsGil()) {
// we are forgiving in this usage for cases where the gil is released and we're
// exiting with an exception
release(this == INSTANCE_WITH_RELEASE);
}
}
}
@TruffleBoundary
private final void yieldGil() {
release(true);
Thread.yield();
acquire();
}
/**
* @see #acquire(Node)
*/
public final boolean acquire() {
return acquire(this);
}
/**
* @see #acquire(Node)
*/
public final boolean acquire(PythonContext context) {
return acquire(context, this);
}
/**
* Acquires the GIL if it isn't already held. Returns {@code true} if the GIL had to be
* acquired. Pass the return value into the {@link #release(boolean wasAcquired)} method in
* order to ensure releasing the GIL only if it has been acquired.
*
* The {@code location} parameter is used to support the safepoint mechanism.
*/
public abstract boolean acquire(Node location);
/**
* @see #acquire(Node)
*/
public abstract boolean acquire(PythonContext context, Node location);
/**
* Release the GIL if {@code wasAcquired} is {@code true}.
*
* @param wasAcquired - the return value of the preceding {@link #acquire} call.
*/
public abstract void release(boolean wasAcquired);
/**
* @see #release(boolean)
*/
public abstract void release(PythonContext context, boolean wasAcquired);
/**
* Release the GIL if it is currently owned by this Thread and preemption is allowed. Preemption
* may be disabled while running C extension code that does not expect to be preempted or for
* certain built-in operations of the implementation.
*
* @return {@code true} if GIL was released, {@code false} if it wasn't locked by this Thread
*/
public abstract boolean tryRelease();
@NeverDefault
public static GilNode create() {
return new Cached();
}
public static UncachedRelease uncachedRelease() {
assert PythonContext.get(UncachedRelease.INSTANCE).ownsGil();
UncachedRelease.INSTANCE.release(true);
return UncachedRelease.INSTANCE;
}
public static UncachedAcquire uncachedAcquire() {
// if we already had the GIL, we don't acquire it again
boolean wasAcquired = UncachedAcquire.INSTANCE_WITH_RELEASE.acquire();
if (wasAcquired) {
// the close method of this instance will release it again
return UncachedAcquire.INSTANCE_WITH_RELEASE;
} else {
return UncachedAcquire.INSTANCE_WITHOUT_RELEASE;
}
}
public static GilNode getUncached() {
// it doesn't matter which is used for the default uncached case
return UncachedRelease.INSTANCE;
}
}
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