c source code as below:
#include<stdlib.h>
#include<stdio.h>
#include "demo_c.h"
void func(data_pair* pair) {
printf("func called");
pair->len=4;
pair->data = (char*)malloc(pair->len + 1);
memset(pair->data, 0, pair->len + 1);
memcpy(pair->data, "test", 4);
return;
}
gcc -fpic -c demo_c.c -fno-omit-frame-pointer -fsanitize=address -fsanitize-recover=address
gcc --share demo_c.o -o libdemo_c.so
then I import this library in python like this:
from ctypes import *
demo_c = CDLL('/xxx/libdemo_c.so', RTLD_GLOBAL)
libc = CDLL('libc.so.6')
libc.free.argtypes = [c_void_p]
class entry(Structure):
_fields_ = [('len',c_int),
('data', c_void_p)]
v = entry()
demo_c.func.argtypes = [c_void_p]
demo_c.func(byref(v))
libc.free(v.data)
then I run:
LD_PRELOAD=/lib64/libasan.so.5 python demo.py
output is:
AddressSanitizer:DEADLYSIGNAL
=================================================================
==432489==ERROR: AddressSanitizer: BUS on unknown address 0x000000000000 (pc 0x7f281c9c90fe bp 0x200000000000003 sp 0x7ffe0c369b20 T0)
#0 0x7f281c9c90fd in _int_free (/lib64/libc.so.6+0x810fd)
#1 0x7f281356cdcb in ffi_call_unix64 (/lib64/libffi.so.6+0x5dcb)
#2 0x7f281356c6f4 in ffi_call (/lib64/libffi.so.6+0x56f4)
#3 0x7f281377fc6a in _ctypes_callproc (/usr/lib64/python2.7/lib-dynload/_ctypes.so+0x10c6a)
#4 0x7f2813779a64 (/usr/lib64/python2.7/lib-dynload/_ctypes.so+0xaa64)
#5 0x7f281d687072 in PyObject_Call (/lib64/libpython2.7.so.1.0+0x4c072)
#6 0x7f281d71b845 in PyEval_EvalFrameEx (/lib64/libpython2.7.so.1.0+0xe0845)
#7 0x7f281d72264c in PyEval_EvalCodeEx (/lib64/libpython2.7.so.1.0+0xe764c)
#8 0x7f281d722751 in PyEval_EvalCode (/lib64/libpython2.7.so.1.0+0xe7751)
#9 0x7f281d73bb8e (/lib64/libpython2.7.so.1.0+0x100b8e)
#10 0x7f281d73cd5d in PyRun_FileExFlags (/lib64/libpython2.7.so.1.0+0x101d5d)
#11 0x7f281d73dfe8 in PyRun_SimpleFileExFlags (/lib64/libpython2.7.so.1.0+0x102fe8)
#12 0x7f281d74f19e in Py_Main (/lib64/libpython2.7.so.1.0+0x11419e)
#13 0x7f281c96a554 in __libc_start_main (/lib64/libc.so.6+0x22554)
#14 0x40068d (/usr/bin/python2.7+0x40068d)
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: BUS (/lib64/libc.so.6+0x810fd) in _int_free
==432489==ABORTING
But if I wrap libc.so's free in demo_c.c and call it instead of directly calling free directly in python code, it works fine.
Problem is that you allocate your memory with Asan's malloc and later try to release it with libc's free. This is not going to work as different allocators are generally incompatible.
when i run this command:
./vendor/bin/phpunit --coverage-html testResult
it is runing, but export an error:
No code coverage driver is available
and this is php.ini:
[xdebug]
zend_extension = "E:\wamp64\bin\php\php7.2.4\ext\php_xdebug-2.6.1-7.2-vc15-x86_64.dll"
xdebug.remote_autostart=1
xdebug.remote_enable=1
xdebug.remote_connect_back = 1
xdebug.profiler_enable = 1
xdebug.profiler_enable_trigger = 1
xdebug.profiler_output_name = "cachegrind.out.%t.%p"
xdebug.profiler_output_dir ="E:\wamp64\tmp"
xdebug.remote_handler = dbgp
xdebug.remote_port = 9000
xdebug.show_local_vars = 1
I dont know what is my problem. please help
I'm developing a program using Android Studio that runs as expected when the normal APK is run, but if I compile it for Debugging, it crashes before the 1st line of code executes, so setting a brake-point on the 1st line of my code to execute, never trips.
I have already
Completely deleted the program from the test target (nexus 7)
Power offed the tablet and then restarted tablet
Power off/rebooted the development machine
Cleaned the project
Rebuilt the project.
The program still runs as expected when compiled/run without debugging.
Crashes after loading, but before running when compiled/run in debug.
Any ideas on how to try and overcome this problem would be welcome.
Android Studio 2.1.2
compileSdkVersion 21
buildToolsVersion "21.1.2
Copy of exception variable after crash
shadow$klass = {Class#613} "class java.lang.Class"
superClass = {Class#1356} "class java.lang.Exception"
2 = {ArtMethod#3613}
17 = {ArtMethod#3628}
numReferenceStaticFields = 0
verifyErrorClass = null
iFields = {ArtField[2]#3636}
stackState = {Object[22]#3602}
3 = {ArtMethod#3614}
0 = {ArtMethod#3611}
errno = 2
classLoader = null
8 = {ArtMethod#3619}
dexCache = {DexCache#3633}
functionName = "stat"
virtualMethods = {ArtMethod[3]#3639}
shadow$monitor = -1294973706
primitiveType = 0
Exception = {ErrnoException#3590}
16 = {ArtMethod#3627}
value = {char[4]#3607}
ifTable = {Object[2]#3637}
vtable = null
4 = {ArtMethod#3615}
suppressedExceptions = {Collections$EmptyList#3604} size = 0
classSize = 468
functionName = "stat"
6 = {ArtMethod#3617}
errno = 2
hashCode = 3540564
referenceStaticOffsets = 0
1 = {ArtMethod#3612}
13 = {ArtMethod#3624}
detailMessage = null
18 = {ArtMethod#3629}
stackTrace = {StackTraceElement[0]#3603}
sFields = null
dexClassDefIndex = 4
componentType = null
15 = {ArtMethod#3626}
status = 10
10 = {ArtMethod#3621}
shadow$klass = {Class#3428} "class java.lang.String"
shadow$klass = {Class#183} "class android.system.ErrnoException"
19 = {ArtMethod#3630}
12 = {ArtMethod#3623}
5 = {ArtMethod#3616}
referenceInstanceOffsets = -1090519040
cause = {ErrnoException#3590} "android.system.ErrnoException: stat failed: ENOENT (No such file or directory)"
suppressedExceptions = {Collections$EmptyList#3604} size = 0
objectSize = 36
detailMessage = null
shadow$klass = {Class#183} "class android.system.ErrnoException"
dexCacheStrings = {String[23663]#3634}
dexTypeIndex = 6
shadow$monitor = -1665173294
offset = 0
14 = {ArtMethod#3625}
numReferenceInstanceFields = 1
Variables debug info not available
21 = {int[21]#3632}
name = "android.system.ErrnoException"
stackState = {Object[22]#3602}
clinitThreadId = 456
directMethods = {ArtMethod[2]#3635}
7 = {ArtMethod#3618}
20 = {ArtMethod#3631}
9 = {ArtMethod#3620}
11 = {ArtMethod#3622}
count = 4
shadow$monitor = -1353303322
cause = {ErrnoException#3590} "android.system.ErrnoException: stat failed:
ENOENT (No such file or directory)"
stackTrace = {StackTraceElement[0]#3603}
accessFlags = 524305
Well, I solved the problem myself. NOT in a way that I'd like to have solved it, or that in any way explained what caused the problem, but the problem was corrected. - I've been in IT long enough to know you need to do backups, and once I remembered I had them, I pulled the backup of a day before the problem surfaced, restored the entire directory tree when the project resided and PUFF, everything worked. Re-applied any code changes I made in the day after the backup (I keep pretty good paper notes on changes) and away I went.
- BUT -
This doesn't explain why the system was working one day and after a night of sleep, the system wouldn't work the next day. And I still have no idea how a person who received the error message I received would go about debugging/fixing the problem if he/she didn't have a good set of backups.
ALSO – it seems that someone downgraded my question. Maybe it did deserve to be downgraded, but I have no idea why it was downgraded. The question seemed reasonable to me. One day late in the evening the system worked, and the next day it didn't and the information the system offered was posted in the question.
I'd be very happy if anyone could explain to me how a person could extract information from the posted log, to find out what was wrong – or – at least explain why the question was improper enough to warrant a downgrade ?
any reasonable comments would be welcome.
Joe Cullity
i am new to flume. My flume agent is not writing data to HDFS. Please help. Here is the code. The purpose of the code is to get the data from apache and park it to HDFS.
#identify the components on agent a1
a1.sources = apache_server
a1.sinks = hdfs_sink
a1.channels = c1
# Configure the source:
a1.sources.apache_server.type = exec
a1.sources.apache_server.command = tail -f /var/log/httpd/error_log
# Describe the sink:
a1.sinks.hdfs_sink.type = hdfs
a1.sinks.hdfs_sink.hdfs.path = hdfs://hadoop1.example.com:9000/Apache_Logs
a1.sinks.hdfs_sink.hdfs.writeFormat = Text
a1.sinks.hdfs_sink.hdfs.fileType = DataStream
a1.sinks.hdfs-sink.hdfs.rollInterval = 10
a1.sinks.hdfs_sink.hdfs.rollSize = 0
a1.sinks.hdfs-sink.hdfs.filePrefix=apacheaccess
# Configure a channel that buffers events in memory:
a1.channels.c1.type = memory
a1.channels.c1.capacity = 20000
a1.channels.c1.transactionCapacity = 100
# Bind the source and sink to the channel:
a1.sources.apache_server.channels = c1
a1.sinks.hdfs_sink.channel = c1
Loop.times(5, () -> {
System.out.println("looping");
});
Which of these would it effectively compile to?
for(int i = 0; i < 5; i++)
System.out.println("looping");
or something like
new CallableInterfaceImpl(){
public void call(){
for(int i = 0; i < 5; i++)
System.out.println("looping");
}
}.call();
So would it replace (kind of inline), or actually create an anonymous class?
The VM decides how to implement lambda, not a compiler.
See Translation strategy section in Translation of Lambda Expressions.
Instead of generating bytecode to create the object that implements the lambda expression (such as calling a constructor for an inner class), we describe a recipe for constructing the lambda, and delegate the actual construction to the language runtime. That recipe is encoded in the static and dynamic argument lists of an invokedynamic instruction.
for construction from your example is most effective way in terms of simple compiling or perfomance (but the performance differences are very small, by the tests).
Addon:
I created and disassemble two examples:
for (String string: Arrays.asList("hello")) {
System.out.println(string);
}
Disassembled bytecode, constants and other information:
Classfile LambdaCode.class
Last modified 30.05.2013; size 771 bytes
MD5 checksum 79bf2821b5a14485934e5cebb60c99d6
Compiled from "LambdaCode.java"
public class test.lambda.LambdaCode
SourceFile: "LambdaCode.java"
minor version: 0
major version: 52
flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
#1 = Methodref #11.#22 // java/lang/Object."<init>":()V
#2 = Class #23 // java/lang/String
#3 = String #24 // hello
#4 = Methodref #25.#26 // java/util/Arrays.asList:([Ljava/lang/Object;)Ljava/util/List;
#5 = InterfaceMethodref #27.#28 // java/util/List.iterator:()Ljava/util/Iterator;
#6 = InterfaceMethodref #29.#30 // java/util/Iterator.hasNext:()Z
#7 = InterfaceMethodref #29.#31 // java/util/Iterator.next:()Ljava/lang/Object;
#8 = Fieldref #32.#33 // java/lang/System.out:Ljava/io/PrintStream;
#9 = Methodref #34.#35 // java/io/PrintStream.println:(Ljava/lang/String;)V
#10 = Class #36 // test/lambda/LambdaCode
#11 = Class #37 // java/lang/Object
#12 = Utf8 <init>
#13 = Utf8 ()V
#14 = Utf8 Code
#15 = Utf8 LineNumberTable
#16 = Utf8 main
#17 = Utf8 ([Ljava/lang/String;)V
#18 = Utf8 StackMapTable
#19 = Class #38 // java/util/Iterator
#20 = Utf8 SourceFile
#21 = Utf8 LambdaCode.java
#22 = NameAndType #12:#13 // "<init>":()V
#23 = Utf8 java/lang/String
#24 = Utf8 hello
#25 = Class #39 // java/util/Arrays
#26 = NameAndType #40:#41 // asList:([Ljava/lang/Object;)Ljava/util/List;
#27 = Class #42 // java/util/List
#28 = NameAndType #43:#44 // iterator:()Ljava/util/Iterator;
#29 = Class #38 // java/util/Iterator
#30 = NameAndType #45:#46 // hasNext:()Z
#31 = NameAndType #47:#48 // next:()Ljava/lang/Object;
#32 = Class #49 // java/lang/System
#33 = NameAndType #50:#51 // out:Ljava/io/PrintStream;
#34 = Class #52 // java/io/PrintStream
#35 = NameAndType #53:#54 // println:(Ljava/lang/String;)V
#36 = Utf8 test/lambda/LambdaCode
#37 = Utf8 java/lang/Object
#38 = Utf8 java/util/Iterator
#39 = Utf8 java/util/Arrays
#40 = Utf8 asList
#41 = Utf8 ([Ljava/lang/Object;)Ljava/util/List;
#42 = Utf8 java/util/List
#43 = Utf8 iterator
#44 = Utf8 ()Ljava/util/Iterator;
#45 = Utf8 hasNext
#46 = Utf8 ()Z
#47 = Utf8 next
#48 = Utf8 ()Ljava/lang/Object;
#49 = Utf8 java/lang/System
#50 = Utf8 out
#51 = Utf8 Ljava/io/PrintStream;
#52 = Utf8 java/io/PrintStream
#53 = Utf8 println
#54 = Utf8 (Ljava/lang/String;)V
{
public test.lambda.LambdaCode();
descriptor: ()V
flags: ACC_PUBLIC
Code:
stack=1, locals=1, args_size=1
0: aload_0
1: invokespecial #1 // Method java/lang/Object."<init>":()V
4: return
LineNumberTable:
line 15: 0
public static void main(java.lang.String[]);
descriptor: ([Ljava/lang/String;)V
flags: ACC_PUBLIC, ACC_STATIC
Code:
stack=4, locals=3, args_size=1
0: iconst_1
1: anewarray #2 // class java/lang/String
4: dup
5: iconst_0
6: ldc #3 // String hello
8: aastore
9: invokestatic #4 // Method java/util/Arrays.asList:([Ljava/lang/Object;)Ljava/util/List;
12: invokeinterface #5, 1 // InterfaceMethod java/util/List.iterator:()Ljava/util/Iterator;
17: astore_1
18: aload_1
19: invokeinterface #6, 1 // InterfaceMethod java/util/Iterator.hasNext:()Z
24: ifeq 47
27: aload_1
28: invokeinterface #7, 1 // InterfaceMethod java/util/Iterator.next:()Ljava/lang/Object;
33: checkcast #2 // class java/lang/String
36: astore_2
37: getstatic #8 // Field java/lang/System.out:Ljava/io/PrintStream;
40: aload_2
41: invokevirtual #9 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
44: goto 18
47: return
LineNumberTable:
line 35: 0
line 36: 37
line 37: 44
line 38: 47
StackMapTable: number_of_entries = 2
frame_type = 252 /* append */
offset_delta = 18
locals = [ class java/util/Iterator ]
frame_type = 250 /* chop */
offset_delta = 28
}
and
Arrays.asList("hello").forEach(p -> {System.out.println(p);});
Disassembled bytecode, constants and other information:
Classfile LambdaCode.class
Last modified 30.05.2013; size 1262 bytes
MD5 checksum 4804e0a37b73141d5791cc39d51d649c
Compiled from "LambdaCode.java"
public class test.lambda.LambdaCode
SourceFile: "LambdaCode.java"
InnerClasses:
public static final #64= #63 of #70; //Lookup=class java/lang/invoke/MethodHandles$Lookup of class java/lang/invoke/MethodHandles
BootstrapMethods:
0: #27 invokestatic java/lang/invoke/LambdaMetafactory.metaFactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
Method arguments:
#28 invokeinterface java/util/function/Consumer.accept:(Ljava/lang/Object;)V
#29 invokestatic test/lambda/LambdaCode.lambda$0:(Ljava/lang/String;)V
#30 (Ljava/lang/String;)V
minor version: 0
major version: 52
flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
#1 = Methodref #10.#21 // java/lang/Object."<init>":()V
#2 = Class #22 // java/lang/String
#3 = String #23 // hello
#4 = Methodref #24.#25 // java/util/Arrays.asList:([Ljava/lang/Object;)Ljava/util/List;
#5 = InvokeDynamic #0:#31 // #0:lambda$:()Ljava/util/function/Consumer;
#6 = InterfaceMethodref #32.#33 // java/util/List.forEach:(Ljava/util/function/Consumer;)V
#7 = Fieldref #34.#35 // java/lang/System.out:Ljava/io/PrintStream;
#8 = Methodref #36.#37 // java/io/PrintStream.println:(Ljava/lang/String;)V
#9 = Class #38 // test/lambda/LambdaCode
#10 = Class #39 // java/lang/Object
#11 = Utf8 <init>
#12 = Utf8 ()V
#13 = Utf8 Code
#14 = Utf8 LineNumberTable
#15 = Utf8 main
#16 = Utf8 ([Ljava/lang/String;)V
#17 = Utf8 lambda$0
#18 = Utf8 (Ljava/lang/String;)V
#19 = Utf8 SourceFile
#20 = Utf8 LambdaCode.java
#21 = NameAndType #11:#12 // "<init>":()V
#22 = Utf8 java/lang/String
#23 = Utf8 hello
#24 = Class #40 // java/util/Arrays
#25 = NameAndType #41:#42 // asList:([Ljava/lang/Object;)Ljava/util/List;
#26 = Utf8 BootstrapMethods
#27 = MethodHandle #6:#43 // invokestatic java/lang/invoke/LambdaMetafactory.metaFactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#28 = MethodHandle #9:#44 // invokeinterface java/util/function/Consumer.accept:(Ljava/lang/Object;)V
#29 = MethodHandle #6:#45 // invokestatic test/lambda/LambdaCode.lambda$0:(Ljava/lang/String;)V
#30 = MethodType #18 // (Ljava/lang/String;)V
#31 = NameAndType #46:#47 // lambda$:()Ljava/util/function/Consumer;
#32 = Class #48 // java/util/List
#33 = NameAndType #49:#50 // forEach:(Ljava/util/function/Consumer;)V
#34 = Class #51 // java/lang/System
#35 = NameAndType #52:#53 // out:Ljava/io/PrintStream;
#36 = Class #54 // java/io/PrintStream
#37 = NameAndType #55:#18 // println:(Ljava/lang/String;)V
#38 = Utf8 test/lambda/LambdaCode
#39 = Utf8 java/lang/Object
#40 = Utf8 java/util/Arrays
#41 = Utf8 asList
#42 = Utf8 ([Ljava/lang/Object;)Ljava/util/List;
#43 = Methodref #56.#57 // java/lang/invoke/LambdaMetafactory.metaFactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#44 = InterfaceMethodref #58.#59 // java/util/function/Consumer.accept:(Ljava/lang/Object;)V
#45 = Methodref #9.#60 // test/lambda/LambdaCode.lambda$0:(Ljava/lang/String;)V
#46 = Utf8 lambda$
#47 = Utf8 ()Ljava/util/function/Consumer;
#48 = Utf8 java/util/List
#49 = Utf8 forEach
#50 = Utf8 (Ljava/util/function/Consumer;)V
#51 = Utf8 java/lang/System
#52 = Utf8 out
#53 = Utf8 Ljava/io/PrintStream;
#54 = Utf8 java/io/PrintStream
#55 = Utf8 println
#56 = Class #61 // java/lang/invoke/LambdaMetafactory
#57 = NameAndType #62:#66 // metaFactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#58 = Class #67 // java/util/function/Consumer
#59 = NameAndType #68:#69 // accept:(Ljava/lang/Object;)V
#60 = NameAndType #17:#18 // lambda$0:(Ljava/lang/String;)V
#61 = Utf8 java/lang/invoke/LambdaMetafactory
#62 = Utf8 metaFactory
#63 = Class #71 // java/lang/invoke/MethodHandles$Lookup
#64 = Utf8 Lookup
#65 = Utf8 InnerClasses
#66 = Utf8 (Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
#67 = Utf8 java/util/function/Consumer
#68 = Utf8 accept
#69 = Utf8 (Ljava/lang/Object;)V
#70 = Class #72 // java/lang/invoke/MethodHandles
#71 = Utf8 java/lang/invoke/MethodHandles$Lookup
#72 = Utf8 java/lang/invoke/MethodHandles
{
public test.lambda.LambdaCode();
descriptor: ()V
flags: ACC_PUBLIC
Code:
stack=1, locals=1, args_size=1
0: aload_0
1: invokespecial #1 // Method java/lang/Object."<init>":()V
4: return
LineNumberTable:
line 15: 0
public static void main(java.lang.String[]);
descriptor: ([Ljava/lang/String;)V
flags: ACC_PUBLIC, ACC_STATIC
Code:
stack=4, locals=1, args_size=1
0: iconst_1
1: anewarray #2 // class java/lang/String
4: dup
5: iconst_0
6: ldc #3 // String hello
8: aastore
9: invokestatic #4 // Method java/util/Arrays.asList:([Ljava/lang/Object;)Ljava/util/List;
12: invokedynamic #5, 0 // InvokeDynamic #0:lambda$:()Ljava/util/function/Consumer;
17: invokeinterface #6, 2 // InterfaceMethod java/util/List.forEach:(Ljava/util/function/Consumer;)V
22: return
LineNumberTable:
line 28: 0
line 38: 22
}
Compiler generated class-file is more complicated and larger (771b vs 1262b) for Lambda example.
Java compiler will generate synthetic methods for the code construct that is neither explicitly nor implicitly declared.
As we are aware, lambda expression/function is an anonymous class method implementation for abstract method in functional interface and if we see the byte code of a compiled class file with lambda expression, Instead of creating a new object that will wrap the Lambda function, it uses the new INVOKEDYNAMIC instruction to dynamically link this call site to the actual Lambda function which is converted to private static synthetic lambda$0(Ljava/lang/String;)V which will accept string as a parameter.
private static synthetic lambda$0(Ljava/lang/String;)V
GETSTAIC java/lang/System.out: Ljava/io/PrintStream;
ALOAD 0
INVOKEVIRTUAL java/io/PrintStream.println(Ljava/lang/String;)V
RETURN
Example: list.forEach(x-> System.out.println(x));
This lambda expression x-> System.out.println(x) is converted to private static synthetic block as mentioned above. But how this will be invoked for each element in the list when we run java Class? Refer the below byte code of lambda expression linkage as forEach accepts Consumer functional interface object.
INVOKEDYNAMIC accept()Ljava/util/function/Consumer;
[
java/lang/invoke/LambdaMetaFactory.metafactory(Ljava/lang/invokeMethodHandler$Lookup.Ljava/lang/invoke/CallSite..
//arguments
(Ljava/lang/Object;)V
//INVOKESTATIC
com/<Classname>.lambda$)(Ljava/lang/String;)V,
(Ljava/lang/String;)V
]
java.lang.invoke.LambdaMetaFactory: This class provides two forms of linkage methods:
A standard version (metafactory(MethodHandles.Lookup, String, MethodType, MethodType, MethodHandle, MethodType)) using an optimized protocol,
An alternate version altMetafactory(MethodHandles.Lookup, String, MethodType, Object...)).
These linkage methods are designed to support the evaluation of lambda expressions and method references in the Java Language.
For every lambda expressions or method reference in the source code, there is a target type which is a functional interface.
Evaluating a lambda expression produces an object of its target type. The recommended mechanism for evaluating lambda expressions is to desugar the lambda body to a method, invoke an invokedynamic call site whose static argument list describes the sole method of the functional interface and the desugared implementation method, and returns an object (the lambda object) that implements the target type.
Note(For method references, the implementation method is simply the referenced method; no desugaring is needed.)