代码拉取完成，页面将自动刷新
From 2286646981811c818e7da61a806426d38481218b Mon Sep 17 00:00:00 2001
Date: Wed, 4 Jan 2023 20:45:23 +0800
Subject: Fast Serializer
---
src/hotspot/share/prims/unsafe.cpp | 5 +
src/hotspot/share/runtime/globals.hpp | 4 +
.../classes/java/io/ObjectInputStream.java | 222 +++++++++++++++---
.../classes/java/io/ObjectOutputStream.java | 83 ++++++-
.../classes/java/io/ObjectStreamClass.java | 81 +++++++
.../classes/jdk/internal/misc/Unsafe.java | 2 +-
6 files changed, 355 insertions(+), 42 deletions(-)
diff --git a/src/hotspot/share/prims/unsafe.cpp b/src/hotspot/share/prims/unsafe.cpp
index ee6c218f5..97f36a2db 100644
--- a/src/hotspot/share/prims/unsafe.cpp
+++ b/src/hotspot/share/prims/unsafe.cpp
@@ -870,6 +870,10 @@ UNSAFE_ENTRY(jint, Unsafe_GetLoadAverage0(JNIEnv *env, jobject unsafe, jdoubleAr
return ret;
} UNSAFE_END
+UNSAFE_ENTRY(jboolean, Unsafe_GetUseFastSerializer(JNIEnv *env, jobject unsafe)) {
+ return UseFastSerializer;
+}
+UNSAFE_END
/// JVM_RegisterUnsafeMethods
@@ -951,6 +955,7 @@ static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
{CC "loadFence", CC "()V", FN_PTR(Unsafe_LoadFence)},
{CC "storeFence", CC "()V", FN_PTR(Unsafe_StoreFence)},
{CC "fullFence", CC "()V", FN_PTR(Unsafe_FullFence)},
+ {CC "getUseFastSerializer", CC "()Z", FN_PTR(Unsafe_GetUseFastSerializer)},
};
#undef CC
diff --git a/src/hotspot/share/runtime/globals.hpp b/src/hotspot/share/runtime/globals.hpp
index 8c61e6a05..6852f1ac3 100644
--- a/src/hotspot/share/runtime/globals.hpp
+++ b/src/hotspot/share/runtime/globals.hpp
@@ -2071,6 +2071,10 @@ const intx ObjectAlignmentInBytes = 8;
JFR_ONLY(product(ccstr, StartFlightRecording, NULL, \
"Start flight recording with options")) \
\
+ product(bool, UseFastSerializer, false, EXPERIMENTAL, \
+ "Cache-based serialization.It is extremely fast, but it" \
+ "can only be effective in certain scenarios.") \
+ \
product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
"Use platform unstable time where supported for timestamps only") \
\
diff --git a/src/java.base/share/classes/java/io/ObjectInputStream.java b/src/java.base/share/classes/java/io/ObjectInputStream.java
index b3e063b3d..1cf3a38c8 100644
--- a/src/java.base/share/classes/java/io/ObjectInputStream.java
+++ b/src/java.base/share/classes/java/io/ObjectInputStream.java
@@ -41,6 +41,7 @@ import java.security.PrivilegedExceptionAction;
import java.util.Arrays;
import java.util.Map;
import java.util.Objects;
+import java.util.concurrent.ConcurrentHashMap;
import jdk.internal.access.SharedSecrets;
import jdk.internal.event.DeserializationEvent;
@@ -312,6 +313,23 @@ public class ObjectInputStream
filterLogger = (filterLog.isLoggable(Logger.Level.DEBUG)
|| filterLog.isLoggable(Logger.Level.TRACE)) ? filterLog : null;
}
+
+ /*
+ * Logger for FastSerializer.
+ * Setup the FastSerializer logger if it is set to DEBUG.
+ * (Assuming it will not change).
+ */
+ static final System.Logger fastSerLogger;
+
+ static {
+ if (printFastSerializer) {
+ Logger fastSerLog = System.getLogger("fastSerializer");
+ fastSerLogger = (fastSerLog.isLoggable(Logger.Level.DEBUG))
+ ? fastSerLog : null;
+ } else {
+ fastSerLogger = null;
+ }
+ }
}
/** filter stream for handling block data conversion */
@@ -337,6 +355,9 @@ public class ObjectInputStream
/** if true, invoke resolveObject() */
private boolean enableResolve;
+ /** Used to get the commandline option: useFastSerializer */
+ private static final Unsafe UNSAFE = Unsafe.getUnsafe();
+
/**
* Context during upcalls to class-defined readObject methods; holds
* object currently being deserialized and descriptor for current class.
@@ -350,6 +371,40 @@ public class ObjectInputStream
*/
private ObjectInputFilter serialFilter;
+ /**
+ * value of "useFastSerializer" property
+ */
+ private static final boolean defaultFastSerializer = UNSAFE.getUseFastSerializer();
+
+ /**
+ * true or false for open FastSerilizer
+ * May be changed in readStreamHeader
+ */
+ private boolean useFastSerializer = defaultFastSerializer;
+
+ /**
+ * Value of "fastSerializerEscapeMode" property. It can be turned on
+ * when useFastSerializer is true.
+ */
+ @SuppressWarnings("removal")
+ private static final boolean fastSerializerEscapeMode = java.security.AccessController.doPrivileged(
+ new sun.security.action.GetBooleanAction(
+ "fastSerializerEscapeMode")).booleanValue();
+
+ /**
+ * Magic number that is written to the stream header when using fastserilizer.
+ */
+ private static final short STREAM_MAGIC_FAST = (short)0xdeca;
+
+ /**
+ * value of "printFastSerializer" property,
+ * as true or false for printing FastSerializer logs.
+ */
+ @SuppressWarnings("removal")
+ private static final boolean printFastSerializer = java.security.AccessController.doPrivileged(
+ new sun.security.action.GetBooleanAction(
+ "printFastSerializer")).booleanValue();
+
/**
* True if the stream-specific filter has been set; initially false.
*/
@@ -437,6 +492,9 @@ public class ObjectInputStream
* transitively so that a complete equivalent graph of objects is
* reconstructed by readObject.
*
+ * The difference between fastSerialzation and default serialization is the
+ * descriptor serialization. The data serialization is same with each other.
+ *
* <p>The root object is completely restored when all of its fields and the
* objects it references are completely restored. At this point the object
* validation callbacks are executed in order based on their registered
@@ -726,11 +784,20 @@ public class ObjectInputStream
vlist.register(obj, prio);
}
+ /**
+ * Cache the class meta during serialization.
+ * Only used in FastSerilizer.
+ */
+ private static ConcurrentHashMap<String,Class<?>> nameToClass = new ConcurrentHashMap<>();
+
/**
* Load the local class equivalent of the specified stream class
* description. Subclasses may implement this method to allow classes to
* be fetched from an alternate source.
*
+ * When fastSerializer is turned on, fields of desc will be null except
+ * name. When resolveClass is override, this may cause null pointer exception.
+ *
* <p>The corresponding method in {@code ObjectOutputStream} is
* {@code annotateClass}. This method will be invoked only once for
* each unique class in the stream. This method can be implemented by
@@ -769,16 +836,29 @@ public class ObjectInputStream
throws IOException, ClassNotFoundException
{
String name = desc.getName();
- try {
- return Class.forName(name, false, latestUserDefinedLoader());
- } catch (ClassNotFoundException ex) {
- Class<?> cl = primClasses.get(name);
+ Class<?> cl = null;
+
+ if (useFastSerializer) {
+ cl = nameToClass.get(name);
if (cl != null) {
return cl;
- } else {
+ }
+ }
+
+ try {
+ cl = Class.forName(name, false, latestUserDefinedLoader());
+ } catch (ClassNotFoundException ex) {
+ cl = primClasses.get(name);
+ if (cl == null) {
throw ex;
}
}
+
+ if (useFastSerializer) {
+ nameToClass.put(name, cl);
+ }
+
+ return cl;
}
/**
@@ -953,9 +1033,33 @@ public class ObjectInputStream
{
short s0 = bin.readShort();
short s1 = bin.readShort();
- if (s0 != STREAM_MAGIC || s1 != STREAM_VERSION) {
- throw new StreamCorruptedException(
- String.format("invalid stream header: %04X%04X", s0, s1));
+ if (useFastSerializer) {
+ if (s0 != STREAM_MAGIC_FAST || s1 != STREAM_VERSION) {
+ if (s0 != STREAM_MAGIC) {
+ throw new StreamCorruptedException(
+ String.format("invalid stream header: %04X%04X, and FastSerializer is activated", s0, s1));
+ }
+
+ if (!fastSerializerEscapeMode) {
+ throw new StreamCorruptedException(
+ String.format("invalid stream header: %04X%04X.Fast serialization does not support " +
+ "original serialized files", s0, s1));
+ }
+
+ // Escape to default serialization
+ useFastSerializer = false;
+ if (Logging.fastSerLogger != null) {
+ Logging.fastSerLogger.log(Logger.Level.DEBUG, "[Deserialize]: Escape and disable FastSerializer");
+ }
+ }
+ } else if (s0 != STREAM_MAGIC || s1 != STREAM_VERSION) {
+ if (s0 == STREAM_MAGIC_FAST && s1 == STREAM_VERSION) {
+ throw new StreamCorruptedException(
+ String.format("invalid stream header: %04X%04X, and it is a FastSerializer stream", s0, s1));
+ } else {
+ throw new StreamCorruptedException(
+ String.format("invalid stream header: %04X%04X", s0, s1));
+ }
}
}
@@ -969,6 +1073,11 @@ public class ObjectInputStream
* this method reads class descriptors according to the format defined in
* the Object Serialization specification.
*
+ * In fastSerialize mode, the descriptor is obtained by lookup method. And
+ * the resolveClass method is called here to get the classmeta. Since the
+ * descriptor is obtained by lookup, the descriptor is same as localdesc.
+ * So we cann't distinguish the receiver desc and local desc.
+ *
* @return the class descriptor read
* @throws IOException If an I/O error has occurred.
* @throws ClassNotFoundException If the Class of a serialized object used
@@ -979,6 +1088,29 @@ public class ObjectInputStream
protected ObjectStreamClass readClassDescriptor()
throws IOException, ClassNotFoundException
{
+ // fastSerializer
+ if (useFastSerializer) {
+ String name = readUTF();
+ Class<?> cl = null;
+ ObjectStreamClass desc = new ObjectStreamClass(name);
+ try {
+ // In order to match this method, we add an annotateClass method in
+ // writeClassDescriptor.
+ cl = resolveClass(desc);
+ } catch (ClassNotFoundException ex) {
+ // resolveClass is just used to obtain Class which required by lookup method
+ // and it will be called again later, so we don't throw ClassNotFoundException here.
+ return desc;
+ }
+ if (cl != null) {
+ // This desc is localDesc. It may be different from the descriptor
+ // obtained from the stream.
+ desc = ObjectStreamClass.lookup(cl, true);
+ }
+ return desc;
+ }
+
+ // Default deserialization. If the Class cannot be found, throw ClassNotFoundException.
ObjectStreamClass desc = new ObjectStreamClass();
desc.readNonProxy(this);
return desc;
@@ -2045,41 +2177,63 @@ public class ObjectInputStream
skipCustomData();
- try {
- totalObjectRefs++;
- depth++;
- desc.initNonProxy(readDesc, cl, resolveEx, readClassDesc(false));
+ totalObjectRefs++;
+ depth++;
- if (cl != null) {
- // Check that serial filtering has been done on the local class descriptor's superclass,
- // in case it does not appear in the stream.
-
- // Find the next super descriptor that has a local class descriptor.
- // Descriptors for which there is no local class are ignored.
- ObjectStreamClass superLocal = null;
- for (ObjectStreamClass sDesc = desc.getSuperDesc(); sDesc != null; sDesc = sDesc.getSuperDesc()) {
- if ((superLocal = sDesc.getLocalDesc()) != null) {
- break;
+ if (useFastSerializer) {
+ desc.initNonProxyFast(readDesc, resolveEx);
+ ObjectStreamClass superDesc = desc.getSuperDesc();
+ long originDepth = depth - 1;
+ // Since desc is obtained from the lookup method, we will lose the depth and
+ // totalObjectRefs of superDesc. So we add a loop here to compute the depth
+ // and objectRef of superDesc.
+ while (superDesc != null && superDesc.forClass() != null) {
+ filterCheck(superDesc.forClass(), -1);
+ superDesc = superDesc.getSuperDesc();
+ totalObjectRefs++;
+ depth++;
+ }
+ depth = originDepth;
+ } else {
+ try {
+ desc.initNonProxy(readDesc, cl, resolveEx, readClassDesc(false));
+
+ if (cl != null) {
+ // Check that serial filtering has been done on the local class descriptor's superclass,
+ // in case it does not appear in the stream.
+ // Find the next super descriptor that has a local class descriptor.
+ // Descriptors for which there is no local class are ignored.
+ ObjectStreamClass superLocal = null;
+ for (ObjectStreamClass sDesc = desc.getSuperDesc(); sDesc != null; sDesc = sDesc.getSuperDesc()) {
+ if ((superLocal = sDesc.getLocalDesc()) != null) {
+ break;
+ }
}
- }
- // Scan local descriptor superclasses for a match with the local descriptor of the super found above.
- // For each super descriptor before the match, invoke the serial filter on the class.
- // The filter is invoked for each class that has not already been filtered
- // but would be filtered if the instance had been serialized by this Java runtime.
- for (ObjectStreamClass lDesc = desc.getLocalDesc().getSuperDesc();
- lDesc != null && lDesc != superLocal;
- lDesc = lDesc.getSuperDesc()) {
- filterCheck(lDesc.forClass(), -1);
+ // Scan local descriptor superclasses for a match with the local descriptor of the super found above.
+ // For each super descriptor before the match, invoke the serial filter on the class.
+ // The filter is invoked for each class that has not already been filtered
+ // but would be filtered if the instance had been serialized by this Java runtime.
+ for (ObjectStreamClass lDesc = desc.getLocalDesc().getSuperDesc();
+ lDesc != null && lDesc != superLocal;
+ lDesc = lDesc.getSuperDesc()) {
+ filterCheck(lDesc.forClass(), -1);
+ }
}
+ } finally {
+ depth--;
}
- } finally {
- depth--;
}
handles.finish(descHandle);
passHandle = descHandle;
+ if (Logging.fastSerLogger != null) {
+ Logging.fastSerLogger.log(Logger.Level.DEBUG,
+ "[Deserialize] useFastSerializer:{0}, Class name:{1}, SerialVersionUID:{2}, flags:{3}",
+ useFastSerializer, desc.getName(), desc.getSerialVersionUID(), desc.getFlags(this));
+ }
+
return desc;
}
@@ -2946,8 +3100,6 @@ public class ObjectInputStream
}
}
- private static final Unsafe UNSAFE = Unsafe.getUnsafe();
-
/**
* Performs a "freeze" action, required to adhere to final field semantics.
*
diff --git a/src/java.base/share/classes/java/io/ObjectOutputStream.java b/src/java.base/share/classes/java/io/ObjectOutputStream.java
index be52df020..f855d6ee4 100644
--- a/src/java.base/share/classes/java/io/ObjectOutputStream.java
+++ b/src/java.base/share/classes/java/io/ObjectOutputStream.java
@@ -31,6 +31,7 @@ import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.StringJoiner;
+import jdk.internal.misc.Unsafe;
import sun.reflect.misc.ReflectUtil;
/**
@@ -173,6 +174,25 @@ public class ObjectOutputStream
};
}
+ private static class Logging {
+ /*
+ * Logger for FastSerializer.
+ * Setup the FastSerializer logger if it is set to DEBUG.
+ * (Assuming it will not change).
+ */
+ static final System.Logger fastSerLogger;
+
+ static {
+ if (printFastSerializer) {
+ System.Logger fastSerLog = System.getLogger("fastSerializer");
+ fastSerLogger = (fastSerLog.isLoggable(System.Logger.Level.DEBUG))
+ ? fastSerLog : null;
+ } else {
+ fastSerLogger = null;
+ }
+ }
+ }
+
/** filter stream for handling block data conversion */
private final BlockDataOutputStream bout;
/** obj -> wire handle map */
@@ -191,7 +211,6 @@ public class ObjectOutputStream
private final boolean enableOverride;
/** if true, invoke replaceObject() */
private boolean enableReplace;
-
// values below valid only during upcalls to writeObject()/writeExternal()
/**
* Context during upcalls to class-defined writeObject methods; holds
@@ -215,6 +234,28 @@ public class ObjectOutputStream
new sun.security.action.GetBooleanAction(
"sun.io.serialization.extendedDebugInfo")).booleanValue();
+ private static final Unsafe UNSAFE = Unsafe.getUnsafe();
+
+ /**
+ * Value of "UseFastSerializer" property, The fastSerializer is turned
+ * on when it is true.
+ */
+ private static final boolean useFastSerializer = UNSAFE.getUseFastSerializer();
+
+ /**
+ * value of "printFastSerializer" property,
+ * as true or false for printing FastSerializer logs.
+ */
+ @SuppressWarnings("removal")
+ private static final boolean printFastSerializer = java.security.AccessController.doPrivileged(
+ new sun.security.action.GetBooleanAction(
+ "printFastSerializer")).booleanValue();
+
+ /**
+ * Magic number that is written to the stream header when using fastserilizer.
+ */
+ private static final short STREAM_MAGIC_FAST = (short)0xdeca;
+
/**
* Creates an ObjectOutputStream that writes to the specified OutputStream.
* This constructor writes the serialization stream header to the
@@ -329,6 +370,9 @@ public class ObjectOutputStream
* object are written transitively so that a complete equivalent graph of
* objects can be reconstructed by an ObjectInputStream.
*
+ * The difference between fastSerialzation and default serialization is the
+ * descriptor serialization. The data serialization is same with each other.
+ *
* <p>Exceptions are thrown for problems with the OutputStream and for
* classes that should not be serialized. All exceptions are fatal to the
* OutputStream, which is left in an indeterminate state, and it is up to
@@ -638,7 +682,11 @@ public class ObjectOutputStream
* stream
*/
protected void writeStreamHeader() throws IOException {
- bout.writeShort(STREAM_MAGIC);
+ if (useFastSerializer) {
+ bout.writeShort(STREAM_MAGIC_FAST);
+ } else {
+ bout.writeShort(STREAM_MAGIC);
+ }
bout.writeShort(STREAM_VERSION);
}
@@ -653,6 +701,9 @@ public class ObjectOutputStream
* By default, this method writes class descriptors according to the format
* defined in the Object Serialization specification.
*
+ * In fastSerializer mode, we will only write the classname to the stream.
+ * The annotateClass is used to match the resolveClass in readClassDescriptor.
+ *
* <p>Note that this method will only be called if the ObjectOutputStream
* is not using the old serialization stream format (set by calling
* ObjectOutputStream's {@code useProtocolVersion} method). If this
@@ -670,7 +721,14 @@ public class ObjectOutputStream
protected void writeClassDescriptor(ObjectStreamClass desc)
throws IOException
{
- desc.writeNonProxy(this);
+ if (useFastSerializer) {
+ writeUTF(desc.getName());
+ // The annotateClass is used to match the resolveClass called in
+ // readClassDescriptor.
+ annotateClass(desc.forClass());
+ } else {
+ desc.writeNonProxy(this);
+ }
}
/**
@@ -1278,9 +1336,21 @@ public class ObjectOutputStream
bout.writeByte(TC_CLASSDESC);
handles.assign(unshared ? null : desc);
+ if (Logging.fastSerLogger != null) {
+ Logging.fastSerLogger.log(System.Logger.Level.DEBUG,
+ "[Serialize] useFastSerializer:{0}, Class name:{1}, SerialVersionUID:{2}, flags:{3}, protocol:{4}",
+ useFastSerializer, desc.getName(), desc.getSerialVersionUID(), desc.getFlags(this), protocol);
+ }
+
if (protocol == PROTOCOL_VERSION_1) {
// do not invoke class descriptor write hook with old protocol
- desc.writeNonProxy(this);
+ if (useFastSerializer) {
+ // only write name and annotate class when using FastSerializer
+ writeUTF(desc.getName());
+ annotateClass(desc.forClass());
+ } else {
+ desc.writeNonProxy(this);
+ }
} else {
writeClassDescriptor(desc);
}
@@ -1293,8 +1363,9 @@ public class ObjectOutputStream
annotateClass(cl);
bout.setBlockDataMode(false);
bout.writeByte(TC_ENDBLOCKDATA);
-
- writeClassDesc(desc.getSuperDesc(), false);
+ if (!useFastSerializer) {
+ writeClassDesc(desc.getSuperDesc(), false);
+ }
}
/**
diff --git a/src/java.base/share/classes/java/io/ObjectStreamClass.java b/src/java.base/share/classes/java/io/ObjectStreamClass.java
index afb3d8447..08488d19c 100644
--- a/src/java.base/share/classes/java/io/ObjectStreamClass.java
+++ b/src/java.base/share/classes/java/io/ObjectStreamClass.java
@@ -295,6 +295,40 @@ public class ObjectStreamClass implements Serializable {
return suid.longValue();
}
+ /**
+ * Return the flags for this class described by this descriptor. The flags
+ * means a set of bit masks for ObjectStreamClass, which indicate the status
+ * of SC_WRITE_METHOD, SC_SERIALIZABLE, SC_EXTERNALIZABLE, SC_BLOCK_DATA and
+ * SC_ENUM.
+ *
+ * @param serialStream ObjectOutputStream or ObjectInputStream
+ *
+ * @return the flags for this class described by this descriptor
+ */
+ byte getFlags(Object serialStream) {
+ byte flags = 0;
+ if (externalizable) {
+ flags |= ObjectStreamConstants.SC_EXTERNALIZABLE;
+ if (serialStream instanceof ObjectOutputStream) {
+ int protocol = ((ObjectOutputStream)serialStream).getProtocolVersion();
+ if (protocol != ObjectStreamConstants.PROTOCOL_VERSION_1) {
+ flags |= ObjectStreamConstants.SC_BLOCK_DATA;
+ }
+ } else if (serialStream instanceof ObjectInputStream) {
+ flags |= ObjectStreamConstants.SC_BLOCK_DATA;
+ }
+ } else if (serializable) {
+ flags |= ObjectStreamConstants.SC_SERIALIZABLE;
+ }
+ if (hasWriteObjectData) {
+ flags |= ObjectStreamConstants.SC_WRITE_METHOD;
+ }
+ if (isEnum) {
+ flags |= ObjectStreamConstants.SC_ENUM;
+ }
+ return flags;
+ }
+
/**
* Return the class in the local VM that this version is mapped to. Null
* is returned if there is no corresponding local class.
@@ -467,6 +501,15 @@ public class ObjectStreamClass implements Serializable {
ObjectStreamClass() {
}
+ /**
+ * Create a blank class descriptor with name. It is only used
+ * in fastSerialize path.
+ * @param name class name
+ */
+ ObjectStreamClass(String name) {
+ this.name = name;
+ }
+
/**
* Creates a PermissionDomain that grants no permission.
*/
@@ -661,6 +704,44 @@ public class ObjectStreamClass implements Serializable {
initialized = true;
}
+ /**
+ * Initializes class descriptor representing a non-proxy class.
+ * Used in fast serialization mode.
+ */
+ void initNonProxyFast(ObjectStreamClass model,
+ ClassNotFoundException resolveEx)
+ {
+ this.cl = model.cl;
+ this.resolveEx = resolveEx;
+ this.superDesc = model.superDesc;
+ name = model.name;
+ this.suid = model.suid;
+ isProxy = false;
+ isEnum = model.isEnum;
+ serializable = model.serializable;
+ externalizable = model.externalizable;
+ hasBlockExternalData = model.hasBlockExternalData;
+ hasWriteObjectData = model.hasWriteObjectData;
+ fields = model.fields;
+ primDataSize = model.primDataSize;
+ numObjFields = model.numObjFields;
+
+ writeObjectMethod = model.writeObjectMethod;
+ readObjectMethod = model.readObjectMethod;
+ readObjectNoDataMethod = model.readObjectNoDataMethod;
+ writeReplaceMethod = model.writeReplaceMethod;
+ readResolveMethod = model.readResolveMethod;
+ if (deserializeEx == null) {
+ deserializeEx = model.deserializeEx;
+ }
+ domains = model.domains;
+ cons = model.cons;
+ fieldRefl = model.fieldRefl;
+ localDesc = model;
+
+ initialized = true;
+ }
+
/**
* Reads non-proxy class descriptor information from given input stream.
* The resulting class descriptor is not fully functional; it can only be
diff --git a/src/java.base/share/classes/jdk/internal/misc/Unsafe.java b/src/java.base/share/classes/jdk/internal/misc/Unsafe.java
index 22aa09c9d..b6e7978a5 100644
--- a/src/java.base/share/classes/jdk/internal/misc/Unsafe.java
+++ b/src/java.base/share/classes/jdk/internal/misc/Unsafe.java
@@ -3811,7 +3811,7 @@ public final class Unsafe {
private static long convEndian(boolean big, long n) { return big == BIG_ENDIAN ? n : Long.reverseBytes(n) ; }
-
+ public native boolean getUseFastSerializer();
private native long allocateMemory0(long bytes);
private native long reallocateMemory0(long address, long bytes);
private native void freeMemory0(long address);
--
2.37.0
此处可能存在不合适展示的内容，页面不予展示。您可通过相关编辑功能自查并修改。
如您确认内容无涉及 不当用语 / 纯广告导流 / 暴力 / 低俗色情 / 侵权 / 盗版 / 虚假 / 无价值内容或违法国家有关法律法规的内容，可点击提交进行申诉，我们将尽快为您处理。
马建仓 AI 助手