殺死-15后為什么java進程不退出？

Question

我通過kill -15 $PID殺死java程序，從日志中我發現ShutdownHook被調用並完成。 但這個過程仍在運行。

所以我轉儲線程並找到大部分是守護程序線程，但以下內容：

[xiafei.qiuxf@dwbasis130009 tesla]$ grep prio stack  | grep -v daemon
"DestroyJavaVM" prio=10 tid=0x00002aaaab072000 nid=0x79d3 waiting for monitor entry [0x0000000041da4000]
"VM Thread" prio=10 tid=0x00002aaaab112000 nid=0x79e6 runnable 
"Gang worker#0 (Parallel GC Threads)" prio=10 tid=0x00002aaaab105800 nid=0x79d4 runnable 
"Gang worker#1 (Parallel GC Threads)" prio=10 tid=0x00002aaaab106800 nid=0x79d5 runnable 
"Gang worker#2 (Parallel GC Threads)" prio=10 tid=0x00002aaaab107000 nid=0x79d6 runnable 
"Gang worker#3 (Parallel GC Threads)" prio=10 tid=0x00002aaaab107800 nid=0x79d7 runnable 
"Gang worker#4 (Parallel GC Threads)" prio=10 tid=0x00002aaaab108000 nid=0x79d8 runnable 
"Gang worker#5 (Parallel GC Threads)" prio=10 tid=0x00002aaaab109000 nid=0x79d9 runnable 
"Gang worker#6 (Parallel GC Threads)" prio=10 tid=0x00002aaaab109800 nid=0x79da runnable 
"Gang worker#7 (Parallel GC Threads)" prio=10 tid=0x00002aaaab10a000 nid=0x79db runnable 
"Gang worker#8 (Parallel GC Threads)" prio=10 tid=0x00002aaaab10a800 nid=0x79dc runnable 
"Gang worker#9 (Parallel GC Threads)" prio=10 tid=0x00002aaaab10b800 nid=0x79dd runnable 
"Gang worker#10 (Parallel GC Threads)" prio=10 tid=0x00002aaaab10c000 nid=0x79de runnable 
"Gang worker#11 (Parallel GC Threads)" prio=10 tid=0x00002aaaab10c800 nid=0x79df runnable 
"Gang worker#12 (Parallel GC Threads)" prio=10 tid=0x00002aaaab10d000 nid=0x79e0 runnable 
"Concurrent Mark-Sweep GC Thread" prio=10 tid=0x00002aaaab111000 nid=0x79e5 runnable 
"Gang worker#0 (Parallel CMS Threads)" prio=10 tid=0x00002aaaab10e800 nid=0x79e1 runnable 
"Gang worker#1 (Parallel CMS Threads)" prio=10 tid=0x00002aaaab10f000 nid=0x79e2 runnable 
"Gang worker#2 (Parallel CMS Threads)" prio=10 tid=0x00002aaaab10f800 nid=0x79e3 runnable 
"Gang worker#3 (Parallel CMS Threads)" prio=10 tid=0x00002aaaab110800 nid=0x79e4 runnable 
"VM Periodic Task Thread" prio=10 tid=0x00002aaaab118000 nid=0x79f1 waiting on condition 

它們似乎是GC線程或jvm的線程，但它們都不是我的（我的線程都已完成。），為什么jvm進程仍然在運行？

Answer 1

轉儲說：

"DestroyJavaVM" prio=10 tid=0x00002aaaab072000 nid=0x79d3 
    waiting for monitor entry [0x0000000041da4000] <<------------

這意味着終止應用程序的過程無法繼續，因為有人擁有監視器0x0000000041da4000 。

查看轉儲以找出哪個線程擁有此監視器。 這應該會讓你知道如何繼續。