diff options
6 files changed, 106 insertions, 42 deletions
diff --git a/src/share/classes/java/lang/invoke/LambdaForm.java b/src/share/classes/java/lang/invoke/LambdaForm.java index e1791719c0..2129f8618b 100644 --- a/src/share/classes/java/lang/invoke/LambdaForm.java +++ b/src/share/classes/java/lang/invoke/LambdaForm.java @@ -125,7 +125,7 @@ class LambdaForm { MemberName vmentry; // low-level behavior, or null if not yet prepared private boolean isCompiled; - Object transformCache; // managed by LambdaFormEditor + volatile Object transformCache; // managed by LambdaFormEditor public static final int VOID_RESULT = -1, LAST_RESULT = -2; diff --git a/src/share/classes/java/lang/invoke/LambdaFormBuffer.java b/src/share/classes/java/lang/invoke/LambdaFormBuffer.java index 872a2a5992..cdc88be325 100644 --- a/src/share/classes/java/lang/invoke/LambdaFormBuffer.java +++ b/src/share/classes/java/lang/invoke/LambdaFormBuffer.java @@ -46,19 +46,16 @@ final class LambdaFormBuffer { private static final int F_TRANS = 0x10, F_OWNED = 0x03; LambdaFormBuffer(LambdaForm lf) { - this(lf.arity, lf.names, lf.result); + this.arity = lf.arity; + setNames(lf.names); + int result = lf.result; + if (result == LAST_RESULT) result = length - 1; + if (result >= 0 && lf.names[result].type != V_TYPE) + resultName = lf.names[result]; debugName = lf.debugName; assert(lf.nameRefsAreLegal()); } - private LambdaFormBuffer(int arity, Name[] names, int result) { - this.arity = arity; - setNames(names); - if (result == LAST_RESULT) result = length - 1; - if (result >= 0 && names[result].type != V_TYPE) - resultName = names[result]; - } - private LambdaForm lambdaForm() { assert(!inTrans()); // need endEdit call to tidy things up return new LambdaForm(debugName, arity, nameArray(), resultIndex()); diff --git a/src/share/classes/java/lang/invoke/LambdaFormEditor.java b/src/share/classes/java/lang/invoke/LambdaFormEditor.java index 1c29d73b4c..1c23e94995 100644 --- a/src/share/classes/java/lang/invoke/LambdaFormEditor.java +++ b/src/share/classes/java/lang/invoke/LambdaFormEditor.java @@ -25,6 +25,7 @@ package java.lang.invoke; +import java.lang.ref.SoftReference; import java.util.Arrays; import static java.lang.invoke.LambdaForm.*; import static java.lang.invoke.LambdaForm.BasicType.*; @@ -58,10 +59,9 @@ class LambdaFormEditor { * The sequence is unterminated, ending with an indefinite number of zero bytes. * Sequences that are simple (short enough and with small enough values) pack into a 64-bit long. */ - private static final class Transform { + private static final class Transform extends SoftReference<LambdaForm> { final long packedBytes; final byte[] fullBytes; - final LambdaForm result; // result of transform, or null, if there is none available private enum Kind { NO_KIND, // necessary because ordinal must be greater than zero @@ -140,9 +140,9 @@ class LambdaFormEditor { Kind kind() { return Kind.values()[byteAt(0)]; } private Transform(long packedBytes, byte[] fullBytes, LambdaForm result) { + super(result); this.packedBytes = packedBytes; this.fullBytes = fullBytes; - this.result = result; } private Transform(long packedBytes) { this(packedBytes, null, null); @@ -243,6 +243,7 @@ class LambdaFormEditor { buf.append("unpacked"); buf.append(Arrays.toString(fullBytes)); } + LambdaForm result = get(); if (result != null) { buf.append(" result="); buf.append(result); @@ -253,7 +254,7 @@ class LambdaFormEditor { /** Find a previously cached transform equivalent to the given one, and return its result. */ private LambdaForm getInCache(Transform key) { - assert(key.result == null); + assert(key.get() == null); // The transformCache is one of null, Transform, Transform[], or ConcurrentHashMap. Object c = lambdaForm.transformCache; Transform k = null; @@ -276,7 +277,7 @@ class LambdaFormEditor { } } assert(k == null || key.equals(k)); - return k == null ? null : k.result; + return (k != null) ? k.get() : null; } /** Arbitrary but reasonable limits on Transform[] size for cache. */ @@ -293,7 +294,17 @@ class LambdaFormEditor { @SuppressWarnings("unchecked") ConcurrentHashMap<Transform,Transform> m = (ConcurrentHashMap<Transform,Transform>) c; Transform k = m.putIfAbsent(key, key); - return k != null ? k.result : form; + if (k == null) return form; + LambdaForm result = k.get(); + if (result != null) { + return result; + } else { + if (m.replace(key, k, key)) { + return form; + } else { + continue; + } + } } assert(pass == 0); synchronized (lambdaForm) { @@ -308,17 +319,27 @@ class LambdaFormEditor { if (c instanceof Transform) { Transform k = (Transform)c; if (k.equals(key)) { - return k.result; + LambdaForm result = k.get(); + if (result == null) { + lambdaForm.transformCache = key; + return form; + } else { + return result; + } + } else if (k.get() == null) { // overwrite stale entry + lambdaForm.transformCache = key; + return form; } // expand one-element cache to small array ta = new Transform[MIN_CACHE_ARRAY_SIZE]; ta[0] = k; - lambdaForm.transformCache = c = ta; + lambdaForm.transformCache = ta; } else { // it is already expanded ta = (Transform[])c; } int len = ta.length; + int stale = -1; int i; for (i = 0; i < len; i++) { Transform k = ta[i]; @@ -326,10 +347,18 @@ class LambdaFormEditor { break; } if (k.equals(key)) { - return k.result; + LambdaForm result = k.get(); + if (result == null) { + ta[i] = key; + return form; + } else { + return result; + } + } else if (stale < 0 && k.get() == null) { + stale = i; // remember 1st stale entry index } } - if (i < len) { + if (i < len || stale >= 0) { // just fall through to cache update } else if (len < MAX_CACHE_ARRAY_SIZE) { len = Math.min(len * 2, MAX_CACHE_ARRAY_SIZE); @@ -344,7 +373,8 @@ class LambdaFormEditor { // The second iteration will update for this query, concurrently. continue; } - ta[i] = key; + int idx = (stale >= 0) ? stale : i; + ta[idx] = key; return form; } } diff --git a/src/share/classes/java/lang/invoke/MethodTypeForm.java b/src/share/classes/java/lang/invoke/MethodTypeForm.java index 6733e29ef9..bcf16dba9d 100644 --- a/src/share/classes/java/lang/invoke/MethodTypeForm.java +++ b/src/share/classes/java/lang/invoke/MethodTypeForm.java @@ -26,9 +26,8 @@ package java.lang.invoke; import sun.invoke.util.Wrapper; +import java.lang.ref.SoftReference; import static java.lang.invoke.MethodHandleStatics.*; -import static java.lang.invoke.MethodHandleNatives.Constants.*; - import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP; /** * Shared information for a group of method types, which differ @@ -51,7 +50,7 @@ final class MethodTypeForm { final MethodType basicType; // the canonical erasure, with primitives simplified // Cached adapter information: - @Stable final MethodHandle[] methodHandles; + @Stable final SoftReference<MethodHandle>[] methodHandles; // Indexes into methodHandles: static final int MH_BASIC_INV = 0, // cached instance of MH.invokeBasic @@ -60,7 +59,7 @@ final class MethodTypeForm { MH_LIMIT = 3; // Cached lambda form information, for basic types only: - final @Stable LambdaForm[] lambdaForms; + final @Stable SoftReference<LambdaForm>[] lambdaForms; // Indexes into lambdaForms: static final int LF_INVVIRTUAL = 0, // DMH invokeVirtual @@ -108,26 +107,40 @@ final class MethodTypeForm { public MethodHandle cachedMethodHandle(int which) { assert(assertIsBasicType()); - return methodHandles[which]; + SoftReference<MethodHandle> entry = methodHandles[which]; + return (entry != null) ? entry.get() : null; } synchronized public MethodHandle setCachedMethodHandle(int which, MethodHandle mh) { // Simulate a CAS, to avoid racy duplication of results. - MethodHandle prev = methodHandles[which]; - if (prev != null) return prev; - return methodHandles[which] = mh; + SoftReference<MethodHandle> entry = methodHandles[which]; + if (entry != null) { + MethodHandle prev = entry.get(); + if (prev != null) { + return prev; + } + } + methodHandles[which] = new SoftReference<>(mh); + return mh; } public LambdaForm cachedLambdaForm(int which) { assert(assertIsBasicType()); - return lambdaForms[which]; + SoftReference<LambdaForm> entry = lambdaForms[which]; + return (entry != null) ? entry.get() : null; } synchronized public LambdaForm setCachedLambdaForm(int which, LambdaForm form) { // Simulate a CAS, to avoid racy duplication of results. - LambdaForm prev = lambdaForms[which]; - if (prev != null) return prev; - return lambdaForms[which] = form; + SoftReference<LambdaForm> entry = lambdaForms[which]; + if (entry != null) { + LambdaForm prev = entry.get(); + if (prev != null) { + return prev; + } + } + lambdaForms[which] = new SoftReference<>(form); + return form; } /** @@ -135,6 +148,7 @@ final class MethodTypeForm { * This MTF will stand for that type and all un-erased variations. * Eagerly compute some basic properties of the type, common to all variations. */ + @SuppressWarnings({"rawtypes", "unchecked"}) protected MethodTypeForm(MethodType erasedType) { this.erasedType = erasedType; @@ -234,8 +248,8 @@ final class MethodTypeForm { // Initialize caches, but only for basic types assert(basicType == erasedType); - this.lambdaForms = new LambdaForm[LF_LIMIT]; - this.methodHandles = new MethodHandle[MH_LIMIT]; + this.lambdaForms = new SoftReference[LF_LIMIT]; + this.methodHandles = new SoftReference[MH_LIMIT]; } private static long pack(int a, int b, int c, int d) { @@ -409,5 +423,4 @@ final class MethodTypeForm { public String toString() { return "Form"+erasedType; } - } diff --git a/test/java/lang/invoke/LFCaching/LFCachingTestCase.java b/test/java/lang/invoke/LFCaching/LFCachingTestCase.java index 30ba39ac2e..50a57e40c6 100644 --- a/test/java/lang/invoke/LFCaching/LFCachingTestCase.java +++ b/test/java/lang/invoke/LFCaching/LFCachingTestCase.java @@ -63,12 +63,17 @@ public abstract class LFCachingTestCase extends LambdaFormTestCase { } if (lambdaForm0 != lambdaForm1) { - System.err.println("Lambda form 0 toString is:"); - System.err.println(lambdaForm0); - System.err.println("Lambda form 1 toString is:"); - System.err.println(lambdaForm1); - throw new AssertionError("Error: Lambda forms of the two method handles" - + " are not the same. LF cahing does not work"); + // Since LambdaForm caches are based on SoftReferences, GC can cause element eviction. + if (noGCHappened()) { + System.err.println("Lambda form 0 toString is:"); + System.err.println(lambdaForm0); + System.err.println("Lambda form 1 toString is:"); + System.err.println(lambdaForm1); + throw new AssertionError("Error: Lambda forms of the two method handles" + + " are not the same. LF cahing does not work"); + } else { + System.err.println("LambdaForms differ, but there was a GC in between. Ignore the failure."); + } } } catch (IllegalAccessException | IllegalArgumentException | SecurityException | InvocationTargetException ex) { diff --git a/test/java/lang/invoke/LFCaching/LambdaFormTestCase.java b/test/java/lang/invoke/LFCaching/LambdaFormTestCase.java index 34df1b2dd8..7b6ce2eeff 100644 --- a/test/java/lang/invoke/LFCaching/LambdaFormTestCase.java +++ b/test/java/lang/invoke/LFCaching/LambdaFormTestCase.java @@ -23,9 +23,12 @@ import com.oracle.testlibrary.jsr292.Helper; import com.sun.management.HotSpotDiagnosticMXBean; + +import java.lang.management.GarbageCollectorMXBean; import java.lang.management.ManagementFactory; import java.lang.reflect.Method; import java.util.Collection; +import java.util.List; import java.util.function.Function; import jdk.testlibrary.Utils; import jdk.testlibrary.TimeLimitedRunner; @@ -50,6 +53,11 @@ public abstract class LambdaFormTestCase { * used to get a lambda form from a method handle. */ protected final static Method INTERNAL_FORM; + private static final List<GarbageCollectorMXBean> gcInfo; + + private static long gcCount() { + return gcInfo.stream().mapToLong(GarbageCollectorMXBean::getCollectionCount).sum(); + } static { try { @@ -59,6 +67,11 @@ public abstract class LambdaFormTestCase { } catch (Exception ex) { throw new Error("Unexpected exception: ", ex); } + + gcInfo = ManagementFactory.getGarbageCollectorMXBeans(); + if (gcInfo.size() == 0) { + throw new Error("No GarbageCollectorMXBeans found."); + } } private final TestMethods testMethod; @@ -67,6 +80,7 @@ public abstract class LambdaFormTestCase { private static boolean passed = true; private static int testCounter = 0; private static int failCounter = 0; + private long gcCountAtStart; /** * Test case constructor. Generates test cases with random method types for @@ -77,12 +91,17 @@ public abstract class LambdaFormTestCase { */ protected LambdaFormTestCase(TestMethods testMethod) { this.testMethod = testMethod; + this.gcCountAtStart = gcCount(); } public TestMethods getTestMethod() { return testMethod; } + protected boolean noGCHappened() { + return gcCount() == gcCountAtStart; + } + /** * Routine that executes a test case. */ |