On Fri, 19 May 2023 17:11:36 GMT, Alan Bateman <[email protected]> wrote:
>> This is the implementation for JEP 451. There are two parts to this:
>>
>> 1. A multi-line warning is printed when a JVM TI or Java agent is loaded
>> into a running VM. For JVM TI, the message is printed to stderr from
>> JvmtiAgent::load. For Java agents, it is printed to System.err (as that may
>> be redirected) in the JPLIS (j.l.instrumentation) implementation. This part
>> includes an update to the JVM TI spec and API docs to require the warning.
>>
>> 2. If running with -Djdk.instrument.traceUsage or
>> -Djdk.instrument.traceUsage=true, the calls to the Instrumentation API print
>> a trace message and stack trace.
>
> Alan Bateman has updated the pull request with a new target base due to a
> merge or a rebase. The incremental webrev excludes the unrelated changes
> brought in by the merge/rebase. The pull request contains 10 additional
> commits since the last revision:
>
> - Merge
> - Refresh package description
> - Merge
> - Tweak docs
> - Merge
> - Draft docs changes
> - Merge
> - Rename/cleanup
> - Merge
> - Initial commit
src/java.instrument/share/classes/java/lang/instrument/package-info.java line
61:
> 59: * manifest attributes for standalone applications that are packaged as
> <em>executable
> 60: * JAR files</em>. If an implementation supports a mechanism to start an
> application as
> 61: * an executable JAR then the main manifest of the JAR file can include
> the
Suggestion:
* JAR files</em>. If an implementation supports a mechanism to start an
application as
* an executable JAR, then the main manifest of the JAR file can include the
src/java.instrument/share/classes/java/lang/instrument/package-info.java line
65:
> 63: * class that is packaged with the application. If the attribute is
> present then the
> 64: * JVM starts the agent, by loading the agent class and invoking its
> {@code agentmain}
> 65: * method, before the application {@code main} method is invoked.
Suggestion:
* class that is packaged with the application. If the attribute is present,
then the
* JVM starts the agent by loading the agent class and invoking its {@code
agentmain}
* method before the application {@code main} method is invoked.
src/java.instrument/share/classes/java/lang/instrument/package-info.java line
73:
> 71: * }</blockquote>
> 72: *
> 73: * <p> If the agent class does not define this method then the JVM will
> attempt
Suggestion:
* <p> If the agent class does not define this method, then the JVM will attempt
src/java.instrument/share/classes/java/lang/instrument/package-info.java line
106:
> 104: * Premain-Class}. The value of this attribute is the binary name of the
> agent class
> 105: * in the JAR file. The JVM starts the agent, by loading the agent class
> and invoking
> 106: * its {@code premain} method, before the application {@code main}
> method is invoked.
Suggestion:
* in the JAR file. The JVM starts the agent by loading the agent class and
invoking
* its {@code premain} method before the application {@code main} method is
invoked.
src/java.instrument/share/classes/java/lang/instrument/package-info.java line
146:
> 144: * <p> An implementation may provide a mechanism to start agents in a
> running VM (meaning
> 145: * after JVM startup). The details as to how this is initiated are
> implementation specific
> 146: * but typically the application has already started and its {@code
> main} method has
Suggestion:
* after JVM startup). The details as to how this is initiated are
implementation specific,
* but typically the application has already started and its {@code main}
method has
src/java.instrument/share/classes/java/lang/instrument/package-info.java line
194:
> 192: * <p> The agent class may also have a {@code premain} method for use
> when the agent
> 193: * is started using a command-line option. When the agent is started in
> a running JVM
> 194: * the {@code premain} method is not invoked.
Suggestion:
* is started using a command-line option. When the agent is started in a
running JVM,
* the {@code premain} method is not invoked.
src/java.instrument/share/classes/java/lang/instrument/package-info.java line
253:
> 251: * <dt>{@code Launcher-Agent-Class}</dt>
> 252: * <dd> If an implementation supports a mechanism to start an
> application in an
> 253: * executable JAR file then this attribute, if present, specifies the
> binary name
Suggestion:
* <dd> If an implementation supports a mechanism to start an application in an
* executable JAR file, then this attribute, if present, specifies the binary
name
src/java.instrument/share/classes/java/lang/instrument/package-info.java line
256:
> 254: * of the agent class that is packaged with the application.
> 255: * The agent is started, by invoking the agent class {@code agentmain}
> method,
> 256: * before the application {@code main} method is invoked. </dd>
Suggestion:
* The agent is started by invoking the agent class {@code agentmain} method
* before the application {@code main} method is invoked. </dd>
src/java.instrument/share/classes/java/lang/instrument/package-info.java line
262:
> 260: * the binary name of the agent class in the JAR file.
> 261: * The agent is started, by invoking the agent class {@code premain}
> method,
> 262: * before the application {@code main} method is invoked.
Suggestion:
* The agent is started by invoking the agent class {@code premain} method
* before the application {@code main} method is invoked.
src/java.instrument/share/native/libinstrument/InvocationAdapter.c line 161:
> 159: }
> 160:
> 161: initerror = createNewJPLISAgent(vm, &agent, jarfile, JNI_FALSE);
No warning is ever printed in this case since this is an agent being loaded due
to -javaagent on the command line. Correct?
src/java.instrument/share/native/libinstrument/InvocationAdapter.c line 501:
> 499:
> 500: // create JPLISAgent with JVMTI environment
> 501: if (createNewJPLISAgent(vm, &agent, jarfile, JNI_FALSE) !=
> JPLIS_INIT_ERROR_NONE) {
No warning is ever printed in this case since this is an agent being loaded
from an executable JAR. Correct?
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/13899#discussion_r1201264543
PR Review Comment: https://git.openjdk.org/jdk/pull/13899#discussion_r1201266407
PR Review Comment: https://git.openjdk.org/jdk/pull/13899#discussion_r1201266670
PR Review Comment: https://git.openjdk.org/jdk/pull/13899#discussion_r1201267997
PR Review Comment: https://git.openjdk.org/jdk/pull/13899#discussion_r1201269344
PR Review Comment: https://git.openjdk.org/jdk/pull/13899#discussion_r1201270901
PR Review Comment: https://git.openjdk.org/jdk/pull/13899#discussion_r1201271453
PR Review Comment: https://git.openjdk.org/jdk/pull/13899#discussion_r1201271684
PR Review Comment: https://git.openjdk.org/jdk/pull/13899#discussion_r1201272099
PR Review Comment: https://git.openjdk.org/jdk/pull/13899#discussion_r1201293583
PR Review Comment: https://git.openjdk.org/jdk/pull/13899#discussion_r1201292355
