Fwd: RFR(s): 8153330: deprecate Runtime.traceInstructions & traceMethodCalls for removal

[David Holmes]

Hi Stuart,

On 20/04/2016 8:21 AM, Stuart Marks wrote:
> I just posted this to core-libs-dev, and I figured I should run this by
> Hotspot-land. There isn't any double-secret-intrinsic magic that Hotspot
> does with these methods, is there? Anybody see any issue with
> deprecating and eventually removing these methods?

I can't see any references in hotspot.

Dasvid

> They won't be removed immediately, but the proposal is to deprecate them
> in JDK 9, marked for removal in a future release.
>
> Thanks,
>
> s'marks
>
>
> -------- Forwarded Message --------
> Subject: RFR(s): 8153330: deprecate Runtime.traceInstructions &
> traceMethodCalls for removal
> Date: Tue, 19 Apr 2016 15:11:38 -0700
> From: Stuart Marks <stuart.marks at oracle.com>
> To: core-libs-dev <core-libs-dev at openjdk.java.net>
>
> Hi all,
>
> I missed a couple bits of cruft in the previous round of java.lang
> deprecations:
> the Runtime.traceInstructions() and traceMethodCalls() methods.
>
> Their implementations are empty. That is, they do absolutely nothing.
>
> They're only mentioned a couple times in the JDK, in CORBA (!) and in
> some RMI
> tests (!), and in a few symbol files. On grepcode.com, there are a
> couple uses,
> mainly attempting to enable these in response to some debugging flag
> being given.
>
> Thus, I propose these be deprecated for removal. Please review diff below.
>
> Thanks,
>
> s'marks
>
>
>
> diff -r 92280897299f src/java.base/share/classes/java/lang/Runtime.java
> --- a/src/java.base/share/classes/java/lang/Runtime.java    Mon Apr 18
> 14:10:14
> 2016 -0700
> +++ b/src/java.base/share/classes/java/lang/Runtime.java    Tue Apr 19
> 15:04:25
> 2016 -0700
> @@ -718,41 +718,27 @@
>       }
>
>       /**
> -     * Enables/Disables tracing of instructions.
> -     * If the {@code boolean} argument is {@code true}, this
> -     * method suggests that the Java virtual machine emit debugging
> -     * information for each instruction in the virtual machine as it
> -     * is executed. The format of this information, and the file or other
> -     * output stream to which it is emitted, depends on the host
> environment.
> -     * The virtual machine may ignore this request if it does not support
> -     * this feature. The destination of the trace output is system
> -     * dependent.
> -     * <p>
> -     * If the {@code boolean} argument is {@code false}, this
> -     * method causes the virtual machine to stop performing the
> -     * detailed instruction trace it is performing.
> -     *
> -     * @param   on   {@code true} to enable instruction tracing;
> -     *               {@code false} to disable this feature.
> +     * Not implemented.
> +     *
> +     * @deprecated
> +     * This method was intended to control instruction tracing.
> +     * It has been superseded by JVM-specific tracing mechanisms.
> +     *
> +     * @param on ignored
>        */
> +    @Deprecated(since="9", forRemoval=true)
>       public void traceInstructions(boolean on) { }
>
>       /**
> -     * Enables/Disables tracing of method calls.
> -     * If the {@code boolean} argument is {@code true}, this
> -     * method suggests that the Java virtual machine emit debugging
> -     * information for each method in the virtual machine as it is
> -     * called. The format of this information, and the file or other
> output
> -     * stream to which it is emitted, depends on the host environment. The
> -     * virtual machine may ignore this request if it does not support
> -     * this feature.
> -     * <p>
> -     * Calling this method with argument false suggests that the
> -     * virtual machine cease emitting per-call debugging information.
> -     *
> -     * @param   on   {@code true} to enable instruction tracing;
> -     *               {@code false} to disable this feature.
> +     * Not implemented.
> +     *
> +     * @deprecated
> +     * This method was intended to control method call tracing.
> +     * It has been superseded by JVM-specific tracing mechanisms.
> +     *
> +     * @param on ignored
>        */
> +    @Deprecated(since="9", forRemoval=true)
>       public void traceMethodCalls(boolean on) { }
>
>       /**
>
>
>