6875716: JLayer.remove((Component)null) should behave consistently in (not) throwing NPE
Reviewed-by: rupashka
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Using HotSpot Serviceability Agent (SA)
</title>
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<h1>Using HotSpot Serviceability Agent (SA)</h1>
<h3>HSDB GUI</h3>
<p>
The top-level GUI program using the HotSpot Serviceability Agent APIs is
called <b>HSDB</b>, the "HotSpot Debugger". To run it, type "hsdbproc.sh"
or "hsdbwindbg.bat" or 64-bit variants (on Unix, Windows platforms
respectively). More info. on HSDB GUI are in <a href="hsdb.html">hsdb.html</a>.
</p>
<h3>SA Modes</h3>
<p>
There are three modes for the SA debugger:
<ul>
<li>attaching to a local process,
<li>opening a core file, and
<li>attaching to a remote "debug server".
</ul>
<p>
The remote case requires two programs to be running on the remote machine:
the rmiregistry (see the script "start-rmiregistry.sh" in this directory;
run this in the background) and the debug server (see the script
"start-debug-server-proc.sh"), in that order. start-rmiregistry.sh takes no
arguments; start-debug-server-proc.sh (or -windbg.bat) takes as argument
the process ID or the executable and core file names to allow remote debugging
of.
</p>
<h3>Command line HSDB</h3>
<p>
There are also command line HSDB variants ("clhsdbproc.sh" or "clhsdbwindbg.bat"
or 64-bit variants). There is also a JavaScript based command line interface
called "jsdbproc.sh" [or "jsdbwindbg.bat" or 64-bit variants]. More details on
command line interfaces can be found in
<ul>
<li><a href="clhsdb.html">clhsdb.html</a>
<li><a href="jsdb.html">jsdb.html</a>
</ul>
</p>
<h3>Other command line tools</h3>
<p>
The following table lists all SA command line tools. <xxx>windbg.bat
files are for Windows. .sh files are for Solaris. <xxx>64.sh are for
64 bit debugees.
</p>
<table border="1">
<tr>
<th>
Tool
</th>
<th>
Description
</th>
</tr>
<tr>
<td>
dumpflagsproc.sh,
dumpflagsproc64.sh,
dumpflagswindbg.bat
dumpflagswindbg64.bat
</td>
<td>
dumps name and value of all -XX JVM command line arguments passed
to debuggee.
</td>
</tr>
<tr>
<td>
<a name="dumpsysprops"></a>
dumpsyspropsproc.sh,
dumpsyspropsproc64.sh,
dumpsyspropswindbg.bat
dumpsyspropswindbg64.bat
</td>
<td>
This prints name and value of Java level System properties.
</td>
</tr>
<tr>
<td>
<a name="heapdump"></a>
heapdumpproc.sh,
heapdumpproc64.sh,
heapdumpwindbg.bat
heapdumpwindbg64.bat
</td>
<td>
Dumps heap in a file in hprof binary format.
</td>
</tr>
<tr>
<td>
<a name="heapsum"></a>
heapsumproc.sh,
heapsumproc64.sh,
heapsumwindbg.bat
heapsumwindbg64.bat
</td>
<td>
Prints summary information on Java heap.
</td>
</tr>
<tr>
<td>
jcoreproc.sh,
jcoreproc64.sh,
jcorewindbg.bat
jcorewindbg64.bat
</td>
<td>
This can retrieve .class files from the debuggee.
set the environment variable <b>JCORE_PACKAGES</b> to comman separated list of
packages whose classes have to be retrieved from the core file.
</td>
</tr>
<tr>
<tr>
<td>
jstackproc.sh,
jstackproc64.sh,
jstackwindbg.bat
jstackwindbg64.bat
</td>
<td>
used to get java stack trace for all java threads.
</td>
</tr>
<tr>
<td>
jhistoproc.sh,
jhistoproc64.sh,
jhistowindbg.bat
jhistowindbg64.bat
</td>
<td>
used to get object histogram of java heap.
</td>
</tr>
<tr>
<td>
permstatproc.sh,
permstatproc64.sh,
permstatwindbg.bat
permstatwindbg64.bat
</td>
<td>
To gather statistics on perm. generation.
</td>
</tr>
<a name="mixed_pstack"></a>
<tr>
<tr>
<td>
pstackproc.sh,
pstackproc64.sh,
pstackwindbg.bat
pstackwindbg64.bat
</td>
<td>
This is cross platform mixed mode pstack utility. This works on any (non-java as well) process, core dump. For java process and core dumps, this prints both java and C/C++ frames.
</td>
</tr>
<tr>
<td>
pmapproc.sh,
pmapproc64.sh,
pmapwindbg.bat
pmapwindbg64.bat
</td>
<td>
This is cross platform Solaris pmap-like utility.
</td>
</tr>
<tr>
<td>
soqlproc.sh,
soqlproc64.sh,
soqlwindbg.bat
soqlwindbg64.bat
</td>
<td>
This is command line SOQL - Simple Object Query Language tool.
SOQL is SQL-like query language to query Java heap.
</td>
<tr>
<td>
start-debug-server-proc.sh,
start-debug-server-proc64.sh,
start-debug-server-windbg.bat,
start-debug-server-windbg64.bat,
start-rmiregistry.bat,
start-rmiregistry64.bat,
start-rmiregistry.sh
start-rmiregistry64.sh
</td>
<td>
These scripts are used to run SA remotely.
</td>
</tr>
</table>
<h3>Debugging transported core dumps</h3>
<p>
When a core dump is moved from the machine where it was produced to a
difference machine, it may not always be possible for SA to debug the same.
More info. on debugging on transported core dumps is in
<a href="transported_core.html">transported_core.html</a>.
</p>
<h3>SA Bugs</h3>
<p>
Not all of the possible states of target VMs have been tested (or
supportable) with SA. For example, the SA will probably not work at all
if it freezes the target VM during certain phases of GC. When filing bugs
a pointer to a core file (see gcore(1)) which the SA can not handle well
is best.
</p>
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