##synchronized锁异常 java代码demo
public class ThreadTest {
public int mul = 1;
public static void main(String[] args) {
ThreadTest threadTest = new ThreadTest();
Thread yym_user_thread1 = new Thread() {
public void run() {
System.out.println("yym_user_thread1");
threadTest.resources(0);
}
};
yym_user_thread1.setName("yym_user_thread1");
yym_user_thread1.start();
//
//
Thread.yield();Thread.yield();Thread.yield();
Thread.yield();Thread.yield();Thread.yield();
Thread yym_user_thread2 = new Thread() {
public void run() {
System.out.println("yym_user_thread2");
threadTest.resources(1);
}
};
yym_user_thread2.setName("yym_user_thread2");
yym_user_thread2.start();
}
public void resources(int number) {
synchronized(this) {
for (int i = 0; i < 10000; i++) {
mul++;
}
int result = mul / number;
System.out.println("resources" + result);
}
}
}##javap -v ThreadTest 查看monitorenter monitorexit字节码
major version: 55
flags: (0x0021) ACC_PUBLIC, ACC_SUPER
this_class: #3 // ThreadTest
super_class: #17 // java/lang/Object
interfaces: 0, fields: 1, methods: 3, attributes: 4
{0x0000000705f0f9a0}Constant pool:
{0x0000000705f2dd10} #1 = Methodref #17.#34 // java/lang/Object."<init>":()V
#2 = Fieldref #3.#35 // ThreadTest.mul:I
{0x0000000705fc52e0} #3 = Class #36 // ThreadTest
#4 = Methodref #3.#34 // ThreadTest."<init>":()V
#5 = Class #37 // ThreadTest$1
#6 = Methodref #5.#38 // ThreadTest$1."<init>":(LThreadTest;)V
#7 = String #39 // yym_user_thread1
#8 = Methodref #40.#41 // java/lang/Thread.setName:(Ljava/lang/String;)V
#9 = Methodref #40.#42 // java/lang/Thread.start:()V
#10 = Methodref #40.#43 // java/lang/Thread.yield:()V
#11 = Class #44 // ThreadTest$2
#12 = Methodref #11.#38 // ThreadTest$2."<init>":(LThreadTest;)V
#13 = String #45 // yym_user_thread2
#14 = Fieldref #46.#47 // java/lang/System.out:Ljava/io/PrintStream;
{0x000000070610aa38}{0x0000000706114b80}{0x000000070613dfd0} #15 = InvokeDynamic #0:#51 // #0:makeConcatWithConstants:(I)Ljava/lang/String;
#16 = Methodref #52.#53 // java/io/PrintStream.println:(Ljava/lang/String;)V
#17 = Class #54 // java/lang/Object
#18 = Utf8 InnerClasses
#19 = Utf8 mul
#20 = Utf8 I
#21 = Utf8 <init>
#22 = Utf8 ()V
#23 = Utf8 Code
#24 = Utf8 LineNumberTable
#25 = Utf8 main
#26 = Utf8 ([Ljava/lang/String;)V
#27 = Utf8 resources
#28 = Utf8 (I)V
#29 = Utf8 StackMapTable
#30 = Class #55 // java/lang/Throwable
#31 = Utf8 SourceFile
#32 = Utf8 ThreadTest.java
#33 = Utf8 NestMembers
#34 = NameAndType #21:#22 // "<init>":()V
#35 = NameAndType #19:#20 // mul:I
#36 = Utf8 ThreadTest
#37 = Utf8 ThreadTest$1
#38 = NameAndType #21:#56 // "<init>":(LThreadTest;)V
#39 = Utf8 yym_user_thread1
#40 = Class #57 // java/lang/Thread
#41 = NameAndType #58:#59 // setName:(Ljava/lang/String;)V
#42 = NameAndType #60:#22 // start:()V
#43 = NameAndType #61:#22 // yield:()V
#44 = Utf8 ThreadTest$2
#45 = Utf8 yym_user_thread2
#46 = Class #62 // java/lang/System
#47 = NameAndType #63:#64 // out:Ljava/io/PrintStream;
#48 = Utf8 BootstrapMethods
{0x0000000706184b20} #49 = MethodHandle 6:#65 // REF_invokeStatic java/lang/invoke/StringConcatFactory.makeConcatWithConstants:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/String;[Ljava/lang/Object;)Ljava/lang/invoke/CallSite;
#50 = String #66 // resources\u0001
#51 = NameAndType #67:#68 // makeConcatWithConstants:(I)Ljava/lang/String;
#52 = Class #69 // java/io/PrintStream
#53 = NameAndType #70:#59 // println:(Ljava/lang/String;)V
#54 = Utf8 java/lang/Object
#55 = Utf8 java/lang/Throwable
#56 = Utf8 (LThreadTest;)V
#57 = Utf8 java/lang/Thread
#58 = Utf8 setName
#59 = Utf8 (Ljava/lang/String;)V
#60 = Utf8 start
#61 = Utf8 yield
#62 = Utf8 java/lang/System
#63 = Utf8 out
#64 = Utf8 Ljava/io/PrintStream;
#65 = Methodref #71.#72 // java/lang/invoke/StringConcatFactory.makeConcatWithConstants:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/String;[Ljava/lang/Object;)Ljava/lang/invoke/CallSite;
#66 = Utf8 resources\u0001
#67 = Utf8 makeConcatWithConstants
#68 = Utf8 (I)Ljava/lang/String;
#69 = Utf8 java/io/PrintStream
#70 = Utf8 println
#71 = Class #73 // java/lang/invoke/StringConcatFactory
#72 = NameAndType #67:#76 // makeConcatWithConstants:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/String;[Ljava/lang/Object;)Ljava/lang/invoke/CallSite;
#73 = Utf8 java/lang/invoke/StringConcatFactory
#74 = Class #78 // java/lang/invoke/MethodHandles$Lookup
#75 = Utf8 Lookup
#76 = Utf8 (Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/String;[Ljava/lang/Object;)Ljava/lang/invoke/CallSite;
#77 = Class #79 // java/lang/invoke/MethodHandles
#78 = Utf8 java/lang/invoke/MethodHandles$Lookup
#79 = Utf8 java/lang/invoke/MethodHandles
{
public int mul;
{0x00000007061ad120} descriptor: I
flags: (0x0001) ACC_PUBLIC
public ThreadTest();
descriptor: ()V
flags: (0x0001) ACC_PUBLIC
Code:
{0x00000007061d5a80}{0x000000070601ee30} stack=2, locals=1, args_size=1
0: aload_0
1: invokespecial #1 // Method java/lang/Object."<init>":()V
4: aload_0
5: iconst_1
6: putfield #2 // Field mul:I
9: return
LineNumberTable:
line 1: 0
line 3: 4
public static void main(java.lang.String[]);
descriptor: ([Ljava/lang/String;)V
flags: (0x0009) ACC_PUBLIC, ACC_STATIC
Code:
stack=3, locals=4, args_size=1
0: new #3 // class ThreadTest
3: dup
4: invokespecial #4 // Method "<init>":()V
7: astore_1
8: new #5 // class ThreadTest$1
11: dup
12: aload_1
13: invokespecial #6 // Method ThreadTest$1."<init>":(LThreadTest;)V
16: astore_2
17: aload_2
18: ldc #7 // String yym_user_thread1
20: invokevirtual #8 // Method java/lang/Thread.setName:(Ljava/lang/String;)V
23: aload_2
24: invokevirtual #9 // Method java/lang/Thread.start:()V
27: invokestatic #10 // Method java/lang/Thread.yield:()V
30: invokestatic #10 // Method java/lang/Thread.yield:()V
33: invokestatic #10 // Method java/lang/Thread.yield:()V
36: invokestatic #10 // Method java/lang/Thread.yield:()V
39: invokestatic #10 // Method java/lang/Thread.yield:()V
42: invokestatic #10 // Method java/lang/Thread.yield:()V
45: new #11 // class ThreadTest$2
48: dup
49: aload_1
50: invokespecial #12 // Method ThreadTest$2."<init>":(LThreadTest;)V
53: astore_3
54: aload_3
55: ldc #13 // String yym_user_thread2
57: invokevirtual #8 // Method java/lang/Thread.setName:(Ljava/lang/String;)V
60: aload_3
61: invokevirtual #9 // Method java/lang/Thread.start:()V
64: return
LineNumberTable:
line 6: 0
line 7: 8
line 13: 17
line 14: 23
line 17: 27
line 18: 36
line 19: 45
line 25: 54
line 26: 60
line 27: 64
public void resources(int);
descriptor: (I)V
flags: (0x0001) ACC_PUBLIC
Code:
stack=3, locals=5, args_size=2
0: aload_0
1: dup
2: astore_2
3: monitorenter
4: iconst_0
5: istore_3
6: iload_3
7: sipush 10000
10: if_icmpge 29
13: aload_0
14: dup
15: getfield #2 // Field mul:I
18: iconst_1
19: iadd
20: putfield #2 // Field mul:I
23: iinc 3, 1
26: goto 6
29: aload_0
30: getfield #2 // Field mul:I
33: iload_1
34: idiv
35: istore_3
36: getstatic #14 // Field java/lang/System.out:Ljava/io/PrintStream;
39: iload_3
40: invokedynamic #15, 0 // InvokeDynamic #0:makeConcatWithConstants:(I)Ljava/lang/String;
45: invokevirtual #16 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
48: aload_2
49: monitorexit
50: goto 60
53: astore 4
55: aload_2
56: monitorexit
57: aload 4
59: athrow
60: return
Exception table:
from to target type
4 50 53 any
53 57 53 any
LineNumberTable:
line 30: 0
line 31: 4
line 32: 13
line 31: 23
line 34: 29
line 35: 36
line 36: 48
line 37: 60
StackMapTable: number_of_entries = 4
frame_type = 253 /* append */
offset_delta = 6
locals = [ class java/lang/Object, int ]
frame_type = 250 /* chop */
offset_delta = 22
frame_type = 87 /* same_locals_1_stack_item */
stack = [ class java/lang/Throwable ]
frame_type = 250 /* chop */
offset_delta = 6
}
SourceFile: "ThreadTest.java"
NestMembers:
ThreadTest$2
ThreadTest$1
InnerClasses:
#11; // class ThreadTest$2
#5; // class ThreadTest$1
public static final #75= #74 of #77; // Lookup=class java/lang/invoke/MethodHandles$Lookup of class java/lang/invoke/MethodHandles
BootstrapMethods:
0: #49 REF_invokeStatic java/lang/invoke/StringConcatFactory.makeConcatWithConstants:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/String;[Ljava/lang/Object;)Ljava/lang/invoke/CallSite;
Method arguments:
#50 resources\u0001##gdb线程栈 异常处理
(gdb) c
Continuing.
@@@@-yym-Thread PID: 4160
@@@@-yym-Thread NAME: yym_user_thread2
yym_user_thread2
[Switching to Thread 0x7fffc9d6c700 (LWP 4157)]
Thread 18 "C2 CompilerThre" hit Breakpoint 4, JavaThread::exit (this=0x7fffa4220800, destroy_vm=false, exit_type=JavaThread::normal_exit)
at /home/yym/code/jdk11u-master/src/hotspot/share/runtime/thread.cpp:1917
1917 this->clear_pending_exception();
(gdb) c
Continuing.
[Switching to Thread 0x7fffc9b6a700 (LWP 4159)]
Thread 20 "yym_user_thread" hit Breakpoint 4, JavaThread::exit (this=0x7ffff07bd800, destroy_vm=false, exit_type=JavaThread::normal_exit)
at /home/yym/code/jdk11u-master/src/hotspot/share/runtime/thread.cpp:1917
1917 this->clear_pending_exception();
(gdb) s
ThreadShadow::clear_pending_exception (this=0x7ffff07bd800) at /home/yym/code/jdk11u-master/src/hotspot/share/utilities/exceptions.cpp:59
59 void ThreadShadow::clear_pending_exception() {
(gdb) list
54 _pending_exception = exception;
55 _exception_file = file;
56 _exception_line = line;
57 }
58
59 void ThreadShadow::clear_pending_exception() {
60 LogTarget(Debug, exceptions) lt;
61 if (_pending_exception != NULL && lt.is_enabled()) {
62 ResourceMark rm;
63 LogStream ls(lt);
(gdb) n
60 LogTarget(Debug, exceptions) lt;
(gdb) p exception
No symbol "exception" in current context.
(gdb) n
61 if (_pending_exception != NULL && lt.is_enabled()) {##抛出异常
##方法退出
##gdb调试
(gdb) b thread.cpp:1917
(gdb) p *_pending_exception
$8 = {_mark = 0x7ffff07bd805, _metadata = {_klass = 0xe294f72300014610, _compressed_klass = 83472}}
(gdb) call _pending_exception->print_on(tty)
java.lang.ArithmeticException
{0x0000000714a7b8f0} - klass: 'java/lang/ArithmeticException'
- ---- fields (total size 5 words):
- private transient 'backtrace' 'Ljava/lang/Object;' @12 a 'java/lang/Object'[5] {0x0000000714a7b918} (e294f723)
- private 'detailMessage' 'Ljava/lang/String;' @16 "/ by zero"{0x0000000714a7b8b8} (e294f717)
- private 'cause' 'Ljava/lang/Throwable;' @20 a 'java/lang/ArithmeticException'{0x0000000714a7b8f0} (e294f71e)
- private 'stackTrace' '[Ljava/lang/StackTraceElement;' @24 a 'java/lang/StackTraceElement'[0] {0x0000000715120a70} (e2a2414e)
- private strict 'suppressedExceptions' 'Ljava/util/List;' @28 a 'java/util/Collections$EmptyList'{0x000000071510bb90} (e2a21772)
- private transient 'depth' 'I' @32 2
(gdb) bt
#0 ThreadShadow::clear_pending_exception (this=0x7ffff07bd800) at /home/yym/code/jdk11u-master/src/hotspot/share/utilities/exceptions.cpp:61
#1 0x00007ffff6173b7c in JavaThread::exit (this=0x7ffff07bd800, destroy_vm=false, exit_type=JavaThread::normal_exit)
at /home/yym/code/jdk11u-master/src/hotspot/share/runtime/thread.cpp:1917
#2 0x00007ffff61738ef in JavaThread::thread_main_inner (this=0x7ffff07bd800) at /home/yym/code/jdk11u-master/src/hotspot/share/runtime/thread.cpp:1875
#3 0x00007ffff617374a in JavaThread::run (this=0x7ffff07bd800) at /home/yym/code/jdk11u-master/src/hotspot/share/runtime/thread.cpp:1850
#4 0x00007ffff616f8eb in Thread::call_run (this=0x7ffff07bd800) at /home/yym/code/jdk11u-master/src/hotspot/share/runtime/thread.cpp:387
#5 0x00007ffff5f703fd in thread_native_entry (thread=0x7ffff07bd800) at /home/yym/code/jdk11u-master/src/hotspot/os/linux/os_linux.cpp:827
#6 0x00007ffff71c56ba in start_thread (arg=0x7fffc9b6a700) at pthread_create.c:333
#7 0x00007ffff790051d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109
(gdb)##yym_user_thread1释放锁
(gdb) set args ThreadTest
(gdb) handle SIGSEGV pass noprint nostop
Signal Stop Print Pass to program Description
SIGSEGV No No Yes Segmentation fault
(gdb) handle SIGFPE pass noprint nostop
Signal Stop Print Pass to program Description
SIGFPE No No Yes Arithmetic exception
(gdb) b thread.cpp:1917
(gdb) b ObjectMonitor::exit
(gdb)b ObjectMonitor::ExitEpilog
InterpreterRuntime::monitorexit (thread=0x7ffff06c6800, elem=0x7fffc9b695d8) at /home/yym/code/jdk11u-master/src/hotspot/share/interpreter/interpreterRuntime.cpp:801
801 elem->set_obj(NULL);
(gdb) n
803 thread->last_frame().interpreter_frame_verify_monitor(elem);
(gdb) n
788 IRT_ENTRY_NO_ASYNC(void, InterpreterRuntime::monitorexit(JavaThread* thread, BasicObjectLock* elem))
(gdb) p thread->print_on(tty)
"yym_user_thread1" #12 prio=5 os_prio=0 cpu=1.74ms elapsed=132.10s tid=0x00007ffff06c6800 nid=0x2163 runnable [0x00007fffc9b69000]
java.lang.Thread.State: RUNNABLE
JavaThread state: _thread_in_vm
Thread: 0x00007ffff06c6800 [0x2163] State: _call_back _has_called_back 0 _at_poll_safepoint 0
JavaThread state: _thread_in_vm
$7 = void
(gdb)##唤醒其他线程
(gdb) n
[Switching to Thread 0x7fffc9b6a700 (LWP 9733)]
Thread 20 "yym_user_thread" hit Breakpoint 4, ObjectMonitor::ExitEpilog (this=0x7fffb0008b80, Self=0x7ffff072f000, Wakee=0x7fffc9a68600)
at /home/yym/code/jdk11u-master/src/hotspot/share/runtime/objectMonitor.cpp:1283
1283 assert(_owner == Self, "invariant");
(gdb) n
1291 _succ = Knob_SuccEnabled ? Wakee->_thread : NULL;
(gdb) n
1292 ParkEvent * Trigger = Wakee->_event;
##main释放锁-等待日后验证，现阶段不知道干啥的
(gdb) b thread.cpp:2040
