Looking through a thread dump I see several BLOCKED threads but some have "waiting to lock " and some have "waiting on " while there is only one RUNNABLE thread that has presumably acquired the lock. The question I have is why are some "waiting to lock" and others "waiting on"? Also the thread that is "waiting on" appears to have the lock but is not the RUNNABLE thread that actually holds the lock as it says it locked the object at address lower in the stack trace, so why is it blocking if it has the lock (or does it not have the lock)?
Examples below: The locked object is at 0x00000000c2ad4be8
waiting on
"ajp-bio-10032-exec-15" daemon prio=10 tid=0x00007f888c02d000 nid=0x74c8 in Object.wait() [0x00007f8821792000]
java.lang.Thread.State: BLOCKED (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x00000000c2ad4be8> (a java.lang.Object)
at java.lang.Object.wait(Object.java:503)
at com.tibco.tibjms.TibjmsxLinkTcp.disconnect(TibjmsxLinkTcp.java:1026)
waiting to lock
"ajp-bio-10032-exec-95" daemon prio=10 tid=0x00007f888c089800 nid=0x1e66 in Object.wait() [0x00007f881df4b000]
java.lang.Thread.State: BLOCKED (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x00000000c2ad4be8> (a java.lang.Object)
at java.lang.Object.wait(Object.java:503)
at com.tibco.tibjms.TibjmsxLinkTcp.disconnect(TibjmsxLinkTcp.java:1026)
- locked <0x00000000c2ad4be8> (a java.lang.Object)
at com.tibco.tibjms.TibjmsConnection._close(TibjmsConnection.java:2430)
and finally the RUNNABLE thread
"ajp-bio-10032-exec-142" daemon prio=10 tid=0x00007f888c0b7000 nid=0x3657 runnable [0x00007f88167d4000]
java.lang.Thread.State: RUNNABLE
at java.lang.Thread.start0(Native Method)
at java.lang.Thread.start(Thread.java:713)
- locked <0x00000000f022c5e0> (a com.tibco.tibjms.TibjmsxLinkTcp$LinkReader)
at com.tibco.tibjms.TibjmsxLinkTcp.start(TibjmsxLinkTcp.java:968)
- locked <0x00000000c2ad4be8> (a java.lang.Object)
