RFR: 8004095: Add support for JMX interface to Diagnostic Framework and Commands,

Frederic Parain frederic.parain at oracle.com
Mon Dec 17 07:01:04 PST 2012


Thank you for the review, I've fixed the code to address all
the issue you reported. The new webrev is here:




On 12/17/12 01:27 PM, Staffan Larsen wrote:
> Frederic,
> Looks good! Just a few small comments below.
> diagnosticCommand.cpp:255: When DisableExplicitGC is set, it would be great if the SystemGC command printed on error message so that the caller knows that the GC didn't happen as intended. I also think we should add an entry to GCCause for GCs caused by the DCmd (but that isn't new to this change).
> diagnosticFramework.hpp:423: nit: misspelled "enabled" in the method name
> diagnosticFramework.cpp:435: seems some testing code has slipped in
> diagnosticFramework.cpp:509: nit: missing spaces around '&'. (Consider adding () to clarify the precedence.)
> Thanks,
> /Staffan
> On 17 dec 2012, at 12:26, Frederic Parain <frederic.parain at oracle.com> wrote:
>> Hi,
>> Please review the following change for CR 8004095.
>> This changeset is the JDK side of two parts project.
>> The goal of this feature is to allow remote invocations of
>> Diagnostic Commands via JMX.
>> Diagnostic Commands are actually invoked from the jcmd
>> tool, which is a local tool using the attachAPI. It was
>> not possible to remotely invoke these commands.
>> This project creates a new PlatformMBean, remotely
>> accessible via the Platform MBean Server, providing
>> access to Diagnostic Commands too.
>> The JDK side of this project, including the new
>> Platform MBean, is covered in CR 7150256.
>> This changeset contains the modifications in the
>> JVM to support the new API.
>> There are two types of modifications:
>>   1 - extension of the diagnostic command framework
>>   2 - extension of existing diagnostic commands
>> Modifications of the framework:
>> The first modification of the framework is the mechanism
>> to communicate with the DiagnosticCommandsMBean defined
>> in the JDK. Communications are performed via the jmm.h
>> interface. In addition to a few new entries in the
>> jmm structure, several data structures have been declared
>> to export diagnostic command meta-data to the JDK.
>> The second modification of the framework consists in an
>> export control mechanism. Diagnostic Commands are executed
>> inside the JVM, they have access to critical information
>> and can perform very disruptive operations. Even if the
>> DiagnosticCommandsMBean includes some security checks
>> using Java Permissions, it sometime better to simply
>> make a diagnostic command not available from the JMX
>> API. The export control mechanism gives to diagnostic
>> command developers full control on how the command will
>> be accessible. When a diagnostic command is registered
>> to the framework, a list of interfaces allowed to
>> export this command must be provided. The current
>> implementation defines three interfaces: JVM internal,
>> attachAPI and JMX. A diagnostic command can be
>> exported to any combination of these interfaces.
>> Modifications of existing diagnostic commands:
>> Because this feature allows remote invocations, it
>> is important to be able to control who is invoking
>> and what is invoked. Java Permission checks have
>> been introduced in the DiagnosticCommandsMBean and
>> are performed before a remote invocation request
>> is forwarded to the JVM. So, each Diagnostic Command
>> can require a Java Permission to be invoked remotely.
>> Note that invocations from inside the JVM or via the
>> attachAPI do not check these permissions. Invocations
>> from inside the JVM are considered trusted, and the
>> attachAPI has its own security model based on EUID/
>> EGID.
>> Some existing diagnostic commands that have been
>> identified as begin potentially harmful have been
>> extended to specify the Java Permission required
>> for their execution.
>> The webrev is here:
>> http://cr.openjdk.java.net/~fparain/8004095/webrev.00/
>> Thanks,
>> Fred
>> --
>> Frederic Parain - Oracle
>> Grenoble Engineering Center - France
>> Phone: +33 4 76 18 81 17
>> Email: Frederic.Parain at Oracle.com

Frederic Parain - Oracle
Grenoble Engineering Center - France
Phone: +33 4 76 18 81 17
Email: Frederic.Parain at Oracle.com

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