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Refactored GC wait loops
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@pmconrad
pmconrad committed Dec 31, 2023
1 parent 8512a00 commit c525bcd
Showing 1 changed file with 50 additions and 43 deletions.
93 changes: 50 additions & 43 deletions test/com/sun/jna/CallbacksTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -34,7 +34,6 @@
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.WeakHashMap;

import com.sun.jna.Callback.UncaughtExceptionHandler;
import com.sun.jna.CallbacksTest.TestLibrary.CbCallback;
Expand Down Expand Up @@ -80,6 +79,24 @@ protected void waitFor(Thread thread) {
}
}

public static abstract class Condition<T> {
protected final T obj;

public Condition(T t) { obj = t; }

public boolean evaluate() { return evaluate(obj); }

abstract boolean evaluate(T t);
}
protected static void waitForGc(Condition<?> condition) throws Exception {
for (int i = 0; i < 2 * Cleaner.MASTER_CLEANUP_INTERVAL_MS / 10 + 5 && condition.evaluate(); ++i) {
synchronized (CallbacksTest.class) { // cleanups happen in a different thread, make sure we see it here
System.gc();
}
Thread.sleep(10); // Give the GC a chance to run
}
}

public static class SmallTestStructure extends Structure {
public static final List<String> FIELDS = createFieldsOrder("value");
public double value;
Expand Down Expand Up @@ -355,31 +372,26 @@ public void callback() {
lib.callVoidCallback(cb);
assertTrue("Callback not called", called[0]);

Map<Callback, CallbackReference> refs = new WeakHashMap<>(callbackCache());
assertTrue("Callback not cached", refs.containsKey(cb));
assertTrue("Callback not cached", callbackCache().containsKey(cb));
final Map<Callback, CallbackReference> refs = callbackCache();
CallbackReference ref = refs.get(cb);
refs = callbackCache();
Pointer cbstruct = ref.cbstruct;
final Pointer cbstruct = ref.cbstruct;

cb = null;
System.gc();
for (int i = 0; i < Cleaner.MASTER_CLEANUP_INTERVAL_MS / 10 + 5 && (ref.get() != null || refs.containsValue(ref)); ++i) {
Thread.sleep(10); // Give the GC a chance to run
System.gc();
}
waitForGc(new Condition<CallbackReference>(ref) {
public boolean evaluate(CallbackReference _ref) {
return _ref.get() != null || refs.containsValue(_ref);
}
});
assertNull("Callback not GC'd", ref.get());
assertFalse("Callback still in map", refs.containsValue(ref));

ref = null;
System.gc();
for (int i = 0; i < Cleaner.MASTER_CLEANUP_INTERVAL_MS / 10 + 5 && (cbstruct.peer != 0 || refs.size() > 0); ++i) {
// Flush weak hash map
refs.size();
Thread.sleep(10); // Give the GC a chance to run
synchronized (CallbacksTest.class) { // the cbstruct.peer cleanup happens in a different thread, make sure we see it here
System.gc();
waitForGc(new Condition<Object>(null) {
public boolean evaluate(Object o) {
return refs.size() > 0 || cbstruct.peer != 0;
}
}
});
assertEquals("Callback trampoline not freed", 0, cbstruct.peer);
}

Expand Down Expand Up @@ -679,7 +691,7 @@ public String callback(String arg, String arg2) {
assertEquals("Wrong String return", VALUE + VALUE2, value);
}

public void testStringCallbackMemoryReclamation() throws InterruptedException {
public void testStringCallbackMemoryReclamation() throws Exception {
TestLibrary.StringCallback cb = new TestLibrary.StringCallback() {
@Override
public String callback(String arg, String arg2) {
Expand All @@ -688,24 +700,22 @@ public String callback(String arg, String arg2) {
};

// A little internal groping
Map<?, ?> m = CallbackReference.allocations;
final Map<?, ?> m = CallbackReference.allocations;
m.clear();

Charset charset = Charset.forName(Native.getDefaultStringEncoding());
String arg = getName() + "1" + charset.decode(charset.encode(UNICODE));
String arg2 = getName() + "2" + charset.decode(charset.encode(UNICODE));
String value = lib.callStringCallback(cb, arg, arg2);
WeakReference<Object> ref = new WeakReference<>(value);
final WeakReference<Object> ref = new WeakReference<>(value);

arg = null;
value = null;
System.gc();
for (int i = 0; i < 100 && (ref.get() != null || m.size() > 0); ++i) {
try {
Thread.sleep(10); // Give the GC a chance to run
System.gc();
} finally {}
}
waitForGc(new Condition<Object>(null) {
public boolean evaluate(Object o) {
return m.size() > 0 || ref.get() != null;
}
});
assertNull("NativeString reference not GC'd", ref.get());
assertEquals("NativeString reference still held: " + m.values(), 0, m.size());
}
Expand Down Expand Up @@ -1478,30 +1488,27 @@ public void callback() {
assertEquals("Wrong module HANDLE for DLL function pointer", handle, pref.getValue());

// Check slot re-use
Map<Callback, CallbackReference> refs = new WeakHashMap<>(callbackCache());
assertTrue("Callback not cached", refs.containsKey(cb));
assertTrue("Callback not cached", callbackCache().containsKey(cb));
final Map<Callback, CallbackReference> refs = callbackCache();
CallbackReference ref = refs.get(cb);
refs = callbackCache();
Pointer cbstruct = ref.cbstruct;
Pointer first_fptr = cbstruct.getPointer(0);

cb = null;
System.gc();
for (int i = 0; i < 100 && (ref.get() != null || refs.containsValue(ref)); ++i) {
Thread.sleep(10); // Give the GC a chance to run
System.gc();
}
waitForGc(new Condition<CallbackReference>(ref) {
public boolean evaluate(CallbackReference _ref) {
return _ref.get() != null || refs.containsValue(_ref);
}
});
assertNull("Callback not GC'd", ref.get());
assertFalse("Callback still in map", refs.containsValue(ref));

ref = null;
System.gc();
for (int i = 0; i < 100 && (cbstruct.peer != 0 || refs.size() > 0); ++i) {
// Flush weak hash map
refs.size();
Thread.sleep(10); // Give the GC a chance to run
System.gc();
}
waitForGc(new Condition<Pointer>(cbstruct) {
public boolean evaluate(Pointer p) {
return refs.size() > 0 || p.peer != 0;
}
});
assertEquals("Callback trampoline not freed", 0, cbstruct.peer);

// Next allocation should be at same place
Expand Down

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