答复: 答复: 答复: HotSpot and IBM's J9 behave quite differently when processing monitorenters and monitorexits
陈雨亭
chenyt at cs.sjtu.edu.cn
Fri May 19 21:25:31 UTC 2017
HotSpot's verifyerror is given here. I read the specification (https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.10.1.9.invokeinterface) and did not get the hints. Not quite sure whether isAssignable should be enforced for verifying the invokeinterface instruction.
Location:
org/dacapo/h2/TPCC.loadData()V @3: invokeinterface
Reason:
Type uninitialized 0 (current frame, stack[0]) is not assignable to 'org/apache/derbyTesting/system/oe/client/Load'
Current Frame:
bci: @3
flags: { }
locals: { 'org/dacapo/h2/TPCC' }
stack: { uninitialized 0 }
Bytecode:
0x0000000: bb00 13b9 0018 0100 b1
-----邮件原件-----
发件人: 陈雨亭 [mailto:chenyt at cs.sjtu.edu.cn]
发送时间: 2017年5月19日 14:11
收件人: 'David Holmes' <david.holmes at oracle.com>
抄送: 'hotspot-runtime-dev at openjdk.java.net' <hotspot-runtime-dev at openjdk.java.net>
主题: 答复: 答复: 答复: HotSpot and IBM's J9 behave quite differently when processing monitorenters and monitorexits
Hi, David,
Hi, I saw the discussions (about the verification) at https://bugs.openjdk.java.net/browse/JDK-8180581. If the specification needs to be clarified, please also include a similar example. Similarly, an object is not initialized before the " invokeinterface" instruction. At this time, HotSpot's verifier reports a verifyerror, while J9 normally runs the code.
A verifier takes a def-use analysis to verify the bytecode, while when an object is really ready to use is not very clear.
public void loadData() throws java.lang.Exception;
descriptor: ()V
flags: ACC_PUBLIC
Code:
stack=1, locals=1, args_size=1
0: new #19 // class org/apache/derbyTesting/system/oe/load/ThreadInsert
3: invokeinterface #24, 1 // InterfaceMethod org/apache/derbyTesting/system/oe/client/Load.populateAllTables:()V
8: return
Exceptions:
throws java.lang.Exception
Regards,
Yuting
-----------------------
public class org.dacapo.h2.TPCC
minor version: 0
major version: 52
flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
#1 = Utf8 org/dacapo/h2/TPCC
#2 = Class #1 // org/dacapo/h2/TPCC
#3 = Utf8 java/lang/Object
#4 = Class #3 // java/lang/Object
#5 = Utf8 <clinit>
#6 = Utf8 ()V
#7 = Utf8 <init>
#8 = Utf8 (Lorg/dacapo/parser/Config;Ljava/io/File;ZZ)V
#9 = Utf8 java/lang/Exception
#10 = Class #9 // java/lang/Exception
#11 = NameAndType #7:#6 // "<init>":()V
#12 = Methodref #4.#11 // java/lang/Object."<init>":()V
#13 = Utf8 loadData
#14 = NameAndType #13:#6 // loadData:()V
#15 = Methodref #2.#14 // org/dacapo/h2/TPCC.loadData:()V
#16 = Utf8 iteration
#17 = Utf8 (Ljava/lang/String;)V
#18 = Utf8 org/apache/derbyTesting/system/oe/load/ThreadInsert
#19 = Class #18 // org/apache/derbyTesting/system/oe/load/ThreadInsert
#20 = Utf8 org/apache/derbyTesting/system/oe/client/Load
#21 = Class #20 // org/apache/derbyTesting/system/oe/client/Load
#22 = Utf8 populateAllTables
#23 = NameAndType #22:#6 // populateAllTables:()V
#24 = InterfaceMethodref #21.#23 // org/apache/derbyTesting/system/oe/client/Load.populateAllTables:()V
#25 = Utf8 make
#26 = Utf8 (Lorg/dacapo/parser/Config;Ljava/io/File;Ljava/lang/Boolean;Ljava/lang/Boolean;)Lorg/dacapo/h2/TPCC;
#27 = NameAndType #7:#8 // "<init>":(Lorg/dacapo/parser/Config;Ljava/io/File;ZZ)V
#28 = Methodref #2.#27 // org/dacapo/h2/TPCC."<init>":(Lorg/dacapo/parser/Config;Ljava/io/File;ZZ)V
#29 = Utf8 postIteration
#30 = Utf8 preIteration
#31 = Utf8 Code
#32 = Utf8 Exceptions
{
static {};
descriptor: ()V
flags: ACC_STATIC
Code:
stack=0, locals=0, args_size=0
0: return
public org.dacapo.h2.TPCC(org.dacapo.parser.Config, java.io.File, boolean, boolean) throws java.lang.Exception;
descriptor: (Lorg/dacapo/parser/Config;Ljava/io/File;ZZ)V
flags: ACC_PUBLIC
Code:
stack=1, locals=5, args_size=5
0: aload_0
1: invokespecial #12 // Method java/lang/Object."<init>":()V
4: aload_0
5: invokespecial #15 // Method loadData:()V
8: return
Exceptions:
throws java.lang.Exception
public void iteration(java.lang.String) throws java.lang.Exception;
descriptor: (Ljava/lang/String;)V
flags: ACC_PUBLIC
Code:
stack=0, locals=2, args_size=2
0: return
Exceptions:
throws java.lang.Exception
public void loadData() throws java.lang.Exception;
descriptor: ()V
flags: ACC_PUBLIC
Code:
stack=1, locals=1, args_size=1
0: new #19 // class org/apache/derbyTesting/system/oe/load/ThreadInsert
3: invokeinterface #24, 1 // InterfaceMethod org/apache/derbyTesting/system/oe/client/Load.populateAllTables:()V
8: return
Exceptions:
throws java.lang.Exception
public static org.dacapo.h2.TPCC make(org.dacapo.parser.Config, java.io.File, java.lang.Boolean, java.lang.Boolean) throws java.lang.Exception;
descriptor: (Lorg/dacapo/parser/Config;Ljava/io/File;Ljava/lang/Boolean;Ljava/lang/Boolean;)Lorg/dacapo/h2/TPCC;
flags: ACC_PUBLIC, ACC_STATIC
Code:
stack=6, locals=4, args_size=4
0: new #2 // class org/dacapo/h2/TPCC
3: dup
4: aload_0
5: aload_1
6: iconst_1
7: iconst_1
8: invokespecial #28 // Method "<init>":(Lorg/dacapo/parser/Config;Ljava/io/File;ZZ)V
11: areturn
Exceptions:
throws java.lang.Exception
public void postIteration(java.lang.String) throws java.lang.Exception;
descriptor: (Ljava/lang/String;)V
flags: ACC_PUBLIC
Code:
stack=0, locals=2, args_size=2
0: return
Exceptions:
throws java.lang.Exception
public void preIteration(java.lang.String) throws java.lang.Exception;
descriptor: (Ljava/lang/String;)V
flags: ACC_PUBLIC
Code:
stack=0, locals=2, args_size=2
0: return
Exceptions:
throws java.lang.Exception
}
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