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[GR-33075] Remove --fiber-leave-context and implement forwarding a safepoint to all Fibers
PullRequest: truffleruby/2870
2 parents c49cf17 + 55964e1 commit 47a444e

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7 files changed

+75
-66
lines changed

7 files changed

+75
-66
lines changed

‎src/main/java/org/truffleruby/core/fiber/FiberManager.java

Lines changed: 55 additions & 20 deletions
Original file line numberDiff line numberDiff line change
@@ -24,6 +24,7 @@
2424
import org.truffleruby.core.proc.RubyProc;
2525
import org.truffleruby.core.thread.ThreadManager;
2626
import org.truffleruby.core.thread.ThreadManager.BlockingAction;
27+
import org.truffleruby.language.SafepointAction;
2728
import org.truffleruby.language.control.BreakException;
2829
import org.truffleruby.language.control.DynamicReturnException;
2930
import org.truffleruby.language.control.ExitException;
@@ -42,6 +43,7 @@
4243
public class FiberManager {
4344

4445
public static final String NAME_PREFIX = "Ruby Fiber";
46+
public static final Object[] SAFEPOINT_ARGS = new Object[]{ FiberSafepointMessage.class };
4547

4648
private final RubyLanguage language;
4749
private final RubyContext context;
@@ -89,9 +91,7 @@ public static void waitForInitialization(RubyContext context, RubyFiber fiber, N
8991

9092
private void fiberMain(RubyContext context, RubyFiber fiber, RubyProc block, Node currentNode) {
9193
assert !fiber.isRootFiber() : "Root Fibers execute threadMain() and not fiberMain()";
92-
93-
final boolean entered = !context.getOptions().FIBER_LEAVE_CONTEXT;
94-
assert entered == context.getEnv().getContext().isEntered();
94+
assertNotEntered("Fibers should start unentered to avoid triggering multithreading");
9595

9696
final Thread thread = Thread.currentThread();
9797
final SourceSection sourceSection = block.sharedMethodInfo.getSourceSection();
@@ -104,15 +104,11 @@ private void fiberMain(RubyContext context, RubyFiber fiber, RubyProc block, Nod
104104
fiber.initializedLatch.countDown();
105105

106106
final FiberMessage message = waitMessage(fiber, currentNode);
107-
final TruffleContext truffleContext = entered ? null : context.getEnv().getContext();
107+
final TruffleContext truffleContext = context.getEnv().getContext();
108108

109-
final Object prev;
110-
if (!entered) {
111-
prev = truffleContext.enter(currentNode);
112-
} else {
113-
prev = null;
114-
}
109+
final Object prev = truffleContext.enter(currentNode);
115110
language.setupCurrentThread(thread, fiber.rubyThread);
111+
fiber.rubyThread.setCurrentFiber(fiber);
116112

117113
FiberMessage lastMessage = null;
118114
try {
@@ -146,9 +142,7 @@ private void fiberMain(RubyContext context, RubyFiber fiber, RubyProc block, Nod
146142
fiber.alive = false;
147143
// Leave context before addToMessageQueue() -> parent Fiber starts executing
148144
language.setupCurrentThread(thread, null);
149-
if (!entered) {
150-
truffleContext.leave(currentNode, prev);
151-
}
145+
truffleContext.leave(currentNode, prev);
152146
cleanup(fiber, thread);
153147
thread.setName(oldName);
154148

@@ -205,12 +199,18 @@ class State {
205199
}
206200

207201
private void assertNotEntered(String reason) {
208-
assert !context.getOptions().FIBER_LEAVE_CONTEXT || !context.getEnv().getContext().isEntered() : reason;
202+
assert !context.getEnv().getContext().isEntered() : reason;
209203
}
210204

211205
@TruffleBoundary
212206
private Object[] handleMessage(RubyFiber fiber, FiberMessage message, Node currentNode) {
213-
fiber.rubyThread.setCurrentFiber(fiber);
207+
// Written as a loop to not grow the stack when processing guest safepoints
208+
while (message instanceof FiberSafepointMessage) {
209+
final FiberSafepointMessage safepointMessage = (FiberSafepointMessage) message;
210+
safepointMessage.action.run(fiber.rubyThread, currentNode);
211+
final RubyFiber sendingFiber = safepointMessage.sendingFiber;
212+
message = resumeAndWait(fiber, sendingFiber, FiberOperation.TRANSFER, SAFEPOINT_ARGS, currentNode);
213+
}
214214

215215
if (message instanceof FiberShutdownMessage) {
216216
throw new FiberShutdownException(currentNode);
@@ -219,13 +219,16 @@ private Object[] handleMessage(RubyFiber fiber, FiberMessage message, Node curre
219219
} else if (message instanceof FiberResumeMessage) {
220220
final FiberResumeMessage resumeMessage = (FiberResumeMessage) message;
221221
assert language.getCurrentThread() == resumeMessage.getSendingFiber().rubyThread;
222-
if (resumeMessage.getOperation() == FiberOperation.RESUME ||
223-
resumeMessage.getOperation() == FiberOperation.RAISE) {
222+
final FiberOperation operation = resumeMessage.getOperation();
223+
224+
if (operation == FiberOperation.RESUME || operation == FiberOperation.RAISE) {
224225
fiber.lastResumedByFiber = resumeMessage.getSendingFiber();
225226
}
226-
if (resumeMessage.getOperation() == FiberOperation.RAISE) {
227+
228+
if (operation == FiberOperation.RAISE) {
227229
throw new RaiseException(context, (RubyException) resumeMessage.getArgs()[0]);
228230
}
231+
229232
return resumeMessage.getArgs();
230233
} else {
231234
throw CompilerDirectives.shouldNotReachHere();
@@ -241,16 +244,38 @@ private void resume(RubyFiber fromFiber, RubyFiber fiber, FiberOperation operati
241244
@TruffleBoundary
242245
public Object[] transferControlTo(RubyFiber fromFiber, RubyFiber fiber, FiberOperation operation, Object[] args,
243246
Node currentNode) {
244-
final TruffleContext truffleContext = context.getEnv().getContext();
247+
final FiberMessage message = resumeAndWait(fromFiber, fiber, operation, args, currentNode);
248+
return handleMessage(fromFiber, message, currentNode);
249+
}
245250

251+
@TruffleBoundary
252+
private FiberMessage resumeAndWait(RubyFiber fromFiber, RubyFiber fiber, FiberOperation operation, Object[] args,
253+
Node currentNode) {
254+
final TruffleContext truffleContext = context.getEnv().getContext();
246255
final FiberMessage message = context
247256
.getThreadManager()
248257
.leaveAndEnter(truffleContext, currentNode, () -> {
249258
resume(fromFiber, fiber, operation, args);
250259
return waitMessage(fromFiber, currentNode);
251260
});
261+
fromFiber.rubyThread.setCurrentFiber(fromFiber);
262+
return message;
263+
}
252264

253-
return handleMessage(fromFiber, message, currentNode);
265+
@TruffleBoundary
266+
public void safepoint(RubyFiber fromFiber, RubyFiber fiber, SafepointAction action, Node currentNode) {
267+
final TruffleContext truffleContext = context.getEnv().getContext();
268+
final FiberResumeMessage returnMessage = (FiberResumeMessage) context
269+
.getThreadManager()
270+
.leaveAndEnter(truffleContext, currentNode, () -> {
271+
addToMessageQueue(fiber, new FiberSafepointMessage(fromFiber, action));
272+
return waitMessage(fromFiber, currentNode);
273+
});
274+
fromFiber.rubyThread.setCurrentFiber(fromFiber);
275+
276+
if (returnMessage.getArgs() != SAFEPOINT_ARGS) {
277+
throw CompilerDirectives.shouldNotReachHere();
278+
}
254279
}
255280

256281
public void start(RubyFiber fiber, Thread javaThread) {
@@ -394,6 +419,16 @@ public Object[] getArgs() {
394419

395420
}
396421

422+
private static class FiberSafepointMessage implements FiberMessage {
423+
private final RubyFiber sendingFiber;
424+
private final SafepointAction action;
425+
426+
private FiberSafepointMessage(RubyFiber sendingFiber, SafepointAction action) {
427+
this.sendingFiber = sendingFiber;
428+
this.action = action;
429+
}
430+
}
431+
397432
/** Used to cleanup and terminate Fibers when the parent Thread dies. */
398433
private static class FiberShutdownException extends TerminationException {
399434
private static final long serialVersionUID = 1522270454305076317L;

‎src/main/java/org/truffleruby/core/thread/ThreadManager.java

Lines changed: 7 additions & 23 deletions
Original file line numberDiff line numberDiff line change
@@ -78,11 +78,11 @@ public class ThreadManager {
7878
private final Set<RubyThread> runningRubyThreads = ConcurrentHashMap.newKeySet();
7979

8080
/** The set of Java threads TruffleRuby created, and is responsible to exit in {@link #killAndWaitOtherThreads()}.
81-
* Needs to be weak because {@link RubyLanguage#disposeThread} is called late for Fibers with --fiber-leave-context
82-
* as that uses a "host thread" (disposeThread is only called on Context#close for those), and there might be
83-
* multiple Fibers per such thread with the pool. If a Thread is unreachable we do not need to wait for it in
84-
* {@link #killAndWaitOtherThreads()}, but otherwise we need to and we can never remove from this Set as otherwise
85-
* we cannot guarantee we wait until the Thread truly finishes execution. */
81+
* Needs to be weak because {@link RubyLanguage#disposeThread} is called late as Fibers use a "host thread"
82+
* (disposeThread is only called on Context#close for those), and there might be multiple Fibers per such thread
83+
* with the pool. If a Thread is unreachable we do not need to wait for it in {@link #killAndWaitOtherThreads()},
84+
* but otherwise we need to and we can never remove from this Set as otherwise we cannot guarantee we wait until the
85+
* Thread truly finishes execution. */
8686
private final Set<Thread> rubyManagedThreads = Collections
8787
.newSetFromMap(Collections.synchronizedMap(new WeakHashMap<>()));
8888

@@ -155,12 +155,7 @@ private Thread createFiberJavaThread(Runnable runnable) {
155155
throw new UnsupportedOperationException("fibers should not be created while pre-initializing the context");
156156
}
157157

158-
final Thread thread;
159-
if (context.getOptions().FIBER_LEAVE_CONTEXT) {
160-
thread = new Thread(runnable); // context.getEnv().createUnenteredThread(runnable);
161-
} else {
162-
thread = context.getEnv().createThread(runnable);
163-
}
158+
final Thread thread = new Thread(runnable); // context.getEnv().createUnenteredThread(runnable);
164159
rubyManagedThreads.add(thread); // need to be set before initializeThread()
165160
thread.setUncaughtExceptionHandler((javaThread, throwable) -> {
166161
System.err.println("Throwable escaped Fiber pool thread:");
@@ -472,25 +467,14 @@ public interface BlockingAction<T> {
472467
T block() throws InterruptedException;
473468
}
474469

475-
/** Only leaves the context if FIBER_LEAVE_CONTEXT is true */
476470
public <T> T leaveAndEnter(TruffleContext truffleContext, Node currentNode, Supplier<T> runWhileOutsideContext) {
477471
assert truffleContext.isEntered();
478-
479-
if (context.getOptions().FIBER_LEAVE_CONTEXT) {
480-
return truffleContext.leaveAndEnter(currentNode, runWhileOutsideContext);
481-
} else {
482-
return runWhileOutsideContext.get();
483-
}
472+
return truffleContext.leaveAndEnter(currentNode, runWhileOutsideContext);
484473
}
485474

486475
/** Only use when the context is not entered. */
487476
@TruffleBoundary
488477
public <T> void retryWhileInterrupted(Node currentNode, TruffleSafepoint.Interruptible<T> interruptible, T object) {
489-
if (!context.getOptions().FIBER_LEAVE_CONTEXT) {
490-
runUntilResultKeepStatus(currentNode, interruptible, object);
491-
return;
492-
}
493-
494478
assert !context.getEnv().getContext().isEntered() : "Use runUntilResult*() when entered";
495479
boolean interrupted = false;
496480
try {

‎src/main/java/org/truffleruby/language/SafepointAction.java

Lines changed: 11 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -14,6 +14,7 @@
1414
import com.oracle.truffle.api.nodes.Node;
1515
import org.truffleruby.RubyContext;
1616
import org.truffleruby.RubyLanguage;
17+
import org.truffleruby.core.fiber.RubyFiber;
1718
import org.truffleruby.core.thread.RubyThread;
1819

1920
import java.util.Objects;
@@ -62,7 +63,17 @@ protected final void perform(Access access) {
6263
final RubyThread rubyThread = context.getThreadManager().getRubyThreadForJavaThread(access.getThread());
6364
if (filter.test(context, rubyThread, this)) {
6465
run(rubyThread, access.getLocation());
66+
67+
if (filter == SafepointPredicate.ALL_THREADS_AND_FIBERS) {
68+
final RubyFiber currentFiber = rubyThread.getCurrentFiber();
69+
for (RubyFiber fiber : rubyThread.runningFibers) {
70+
if (fiber != currentFiber) {
71+
context.fiberManager.safepoint(currentFiber, fiber, this, access.getLocation());
72+
}
73+
}
74+
}
6575
}
76+
6677
}
6778

6879
public boolean isSynchronous() {

‎src/main/java/org/truffleruby/options/Options.java

Lines changed: 0 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -69,8 +69,6 @@ public class Options {
6969
public final boolean PATCHING;
7070
/** --hashing-deterministic=false */
7171
public final boolean HASHING_DETERMINISTIC;
72-
/** --fiber-leave-context=true */
73-
public final boolean FIBER_LEAVE_CONTEXT;
7472
/** --fiber-pool=true */
7573
public final boolean FIBER_POOL;
7674
/** --log-subprocess=false */
@@ -228,7 +226,6 @@ public Options(Env env, OptionValues options, LanguageOptions languageOptions) {
228226
PATTERN_MATCHING = options.get(OptionsCatalog.PATTERN_MATCHING_KEY);
229227
PATCHING = options.get(OptionsCatalog.PATCHING_KEY);
230228
HASHING_DETERMINISTIC = options.get(OptionsCatalog.HASHING_DETERMINISTIC_KEY);
231-
FIBER_LEAVE_CONTEXT = options.get(OptionsCatalog.FIBER_LEAVE_CONTEXT_KEY);
232229
FIBER_POOL = options.get(OptionsCatalog.FIBER_POOL_KEY);
233230
LOG_SUBPROCESS = options.get(OptionsCatalog.LOG_SUBPROCESS_KEY);
234231
WARN_LOCALE = options.get(OptionsCatalog.WARN_LOCALE_KEY);
@@ -345,8 +342,6 @@ public Object fromDescriptor(OptionDescriptor descriptor) {
345342
return PATCHING;
346343
case "ruby.hashing-deterministic":
347344
return HASHING_DETERMINISTIC;
348-
case "ruby.fiber-leave-context":
349-
return FIBER_LEAVE_CONTEXT;
350345
case "ruby.fiber-pool":
351346
return FIBER_POOL;
352347
case "ruby.log-subprocess":

‎src/main/ruby/truffleruby/core/main.rb

Lines changed: 2 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -56,11 +56,7 @@ def to_s
5656
end
5757

5858
show_backtraces = -> {
59-
if Truffle::Boot.get_option('fiber-leave-context')
60-
$stderr.puts 'All Thread backtraces (use --fiber-leave-context=false to see all Fiber backtraces):'
61-
else
62-
$stderr.puts 'All Fiber backtraces:'
63-
end
59+
$stderr.puts 'All Thread and Fiber backtraces:'
6460
Primitive.all_fibers_backtraces.each do |fiber, backtrace|
6561
$stderr.puts "#{fiber} of #{Primitive.fiber_thread(fiber)}", backtrace, nil
6662
end
@@ -72,7 +68,7 @@ def to_s
7268
if Truffle::Boot.get_option('platform-handle-interrupt')
7369
Primitive.vm_watch_signal 'INT', true, -> _signo do
7470
if Truffle::Boot.get_option('backtraces-on-interrupt')
75-
puts 'Interrupting...'
71+
$stderr.puts 'Interrupting...'
7672
show_backtraces.call
7773
end
7874

‎src/options.yml

Lines changed: 0 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -102,7 +102,6 @@ EXPERT:
102102
LAZY_TRANSLATION_USER: [lazy-translation-user, boolean, LAZY_CALLTARGETS, 'Lazily translation of stdlib, gem and user source files']
103103
PATCHING: [patching, boolean, true, Use patching]
104104
HASHING_DETERMINISTIC: [hashing-deterministic, boolean, false, Produce deterministic hash values]
105-
FIBER_LEAVE_CONTEXT: [fiber-leave-context, boolean, true, 'Leave the TruffleContext when suspending a Fiber (avoids triggering multithreading)']
106105
FIBER_POOL: [fiber-pool, boolean, true, 'Use a thread pool to speed up creating Fibers']
107106
LOG_SUBPROCESS: [log-subprocess, boolean, false, 'Log whenever a subprocess is created']
108107
WARN_LOCALE: [warn-locale, boolean, true, 'Warn when the system locale is not set properly']

‎src/shared/java/org/truffleruby/shared/options/OptionsCatalog.java

Lines changed: 0 additions & 11 deletions
Original file line numberDiff line numberDiff line change
@@ -52,7 +52,6 @@ public class OptionsCatalog {
5252
public static final OptionKey<Boolean> LAZY_TRANSLATION_USER_KEY = new OptionKey<>(LAZY_CALLTARGETS_KEY.getDefaultValue());
5353
public static final OptionKey<Boolean> PATCHING_KEY = new OptionKey<>(true);
5454
public static final OptionKey<Boolean> HASHING_DETERMINISTIC_KEY = new OptionKey<>(false);
55-
public static final OptionKey<Boolean> FIBER_LEAVE_CONTEXT_KEY = new OptionKey<>(true);
5655
public static final OptionKey<Boolean> FIBER_POOL_KEY = new OptionKey<>(true);
5756
public static final OptionKey<Boolean> LOG_SUBPROCESS_KEY = new OptionKey<>(false);
5857
public static final OptionKey<Boolean> WARN_LOCALE_KEY = new OptionKey<>(true);
@@ -387,13 +386,6 @@ public class OptionsCatalog {
387386
.stability(OptionStability.EXPERIMENTAL)
388387
.build();
389388

390-
public static final OptionDescriptor FIBER_LEAVE_CONTEXT = OptionDescriptor
391-
.newBuilder(FIBER_LEAVE_CONTEXT_KEY, "ruby.fiber-leave-context")
392-
.help("Leave the TruffleContext when suspending a Fiber (avoids triggering multithreading)")
393-
.category(OptionCategory.EXPERT)
394-
.stability(OptionStability.EXPERIMENTAL)
395-
.build();
396-
397389
public static final OptionDescriptor FIBER_POOL = OptionDescriptor
398390
.newBuilder(FIBER_POOL_KEY, "ruby.fiber-pool")
399391
.help("Use a thread pool to speed up creating Fibers")
@@ -1223,8 +1215,6 @@ public static OptionDescriptor fromName(String name) {
12231215
return PATCHING;
12241216
case "ruby.hashing-deterministic":
12251217
return HASHING_DETERMINISTIC;
1226-
case "ruby.fiber-leave-context":
1227-
return FIBER_LEAVE_CONTEXT;
12281218
case "ruby.fiber-pool":
12291219
return FIBER_POOL;
12301220
case "ruby.log-subprocess":
@@ -1482,7 +1472,6 @@ public static OptionDescriptor[] allDescriptors() {
14821472
LAZY_TRANSLATION_USER,
14831473
PATCHING,
14841474
HASHING_DETERMINISTIC,
1485-
FIBER_LEAVE_CONTEXT,
14861475
FIBER_POOL,
14871476
LOG_SUBPROCESS,
14881477
WARN_LOCALE,

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