When debugging remote core dumps it is easier to work with command line tools instead of GUI tools. Command line HSDB (CLHSDB) tool is alternative to SA GUI tool HSDB.
There is also JavaScript based SA command line interface called jsdb. But, CLHSDB supports Unix shell-like (or dbx/gdb-like) command line interface with support for output redirection/appending (familiar >, >>), command history and so on. Each CLHSDB command can have zero or more arguments and optionally end with output redirection (or append) to a file. Commands may be stored in a file and run using source command. help command prints usage message for all supported commands (or a specific command)
Available commands:
assert true | false turn on/off asserts in SA code
attach pid | exec core attach SA to a process or core
buildreplayjars [all | boot | app] build jars for replay, boot.jar for bootclasses, app.jar for application classes
class name find a Java class from debuggee and print oop
classes print all loaded Java classes with Klass*
detach detach SA from current target
dis address [ length ] disassemble (x86) specified number of instructions from given address
dissemble address disassemble nmethod
dumpcfg -a | id Dump the PhaseCFG for every compiler thread that has one live
dumpclass { address | name } [ directory ] dump .class file for given Klass* or class name
dumpcodecache dump codecache contents
dumpheap [ file ] dump heap in hprof binary format
dumpideal -a | id dump ideal graph like debug flag -XX:+PrintIdeal
dumpilt -a | id dump inline tree for C2 compilation
dumpreplaydata <address> | -a | <thread_id> [>replay.txt] dump replay data into a file
echo [ true | false ] turn on/off command echo mode
examine [ address/count ] | [ address,address] show contents of memory from given address
field [ type [ name fieldtype isStatic offset address ] ] print info about a field of HotSpot type
findpc address print info. about pointer location
flags [ flag ] show all -XX flag name value pairs. or just show given flag
help [ command ] print help message for all commands or just given command
history show command history. usual !command-number syntax works.
inspect expression inspect a given oop
intConstant [ name [ value ] ] print out hotspot integer constant(s)
jdis address show bytecode disassembly of a given Method*
jhisto show Java heap histogram
jseval script evaluate a given string as JavaScript code
jsload file load and evaluate a JavaScript file
jstack [-v] show Java stack trace of all Java threads. -v is verbose mode
livenmethods show all live nmethods
longConstant [ name [ value ] ] print out hotspot long constant(s)s
mem address [ length ] show contents of memory -- also shows closest ELF/COFF symbol if found
pmap show Solaris pmap-like output
print expression print given Klass*, Method* or arbitrary address
printas type expression print given address as given HotSpot type. eg. print JavaThread <address>
printmdo -a | expression print method data oop
printstatics [ type ] print static fields of given HotSpot type (or all types if none specified)
pstack [-v] show mixed mode stack trace for all Java, non-Java threads. -v is verbose mode
quit quit CLHSDB tool
reattach detach and re-attach SA to current target
revptrs find liveness of oops
scanoops start end [ type ] scan a Oop from given start to end address
search [ heap | codecache | threads ] value search a value in heap or codecache or threads
source filename load and execute CLHSDB commands from given file
symbol name show address of a given ELF/COFF symbol
sysprops show all Java System properties
thread id show thread of id
threads show all Java threads
tokenize ...
type [ type [ name super isOop isInteger isUnsigned size ] ] show info. on HotSpot type
universe print gc universe
vmstructsdump dump hotspot type library in text
verbose true | false turn on/off verbose mode
versioncheck [ true | false ] turn on/off debuggee VM version check
whatis address print info about any arbitrary address
where { -a | id } print Java stack trace of given Java thread or all Java threads (-a)
Few CLHSDB commands are already implemented in JavaScript. It is possible to extend CLHSDB command set
by implementing more commands in a JavaScript file and by loading it by jsload command. jseval
command may be used to evaluate arbitrary JavaScript expression from a string. Any JavaScript function
may be exposed as a CLHSDB command by registering it using JavaScript registerCommand
function. This function accepts command name, usage and name of the JavaScript implementation function
as arguments.
function helloImpl(name) {
println("hello, " + name);
}
// register the above JavaScript function as CLHSDB command
registerCommand("hello", "hello name", "helloImpl");
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hsdb> jsload test.js
When a java process crashes in compiled method, usually a core file is saved. The replay function can reproduce the compiling process in the core. cireplay.html