> `jcmd` provides great diagnostics but many commands lack a timestamp in their > output. > Adding a timestamp to the output of some would add value for those debugging > JVM data. > > Some diagnostic commands already provide timestamps. For example > `Thread.print` already prints one of "yyyy-MM-dd HH:mm:ss" format. > > With this MR I propose to introduce time-stamping to all diagnostic `jcmd` > commands in a form of an additional common flag "-T": > > jcmd [pid | main-class] [-T] command... | PerfCounter.print | -f filename > ^^^^ > > * The choice for time format is "yyyy-MM-dd HH:mm:ss" as it is already used > in `Thread.print`. > * `Thread.print` prints timestamp irrespectively from "-T" flag presence to > preserve backwards compatibility. > > I haven't added a timestamp to the following diagnostic command: > * `VM.uptime` - command run with `-date` argument will also print a timestamp; > * `VM.system_properties` - as the output already lists a timestamp. Not sure > if we need more timestamps here. > * `Thread.dump_to_file` - the content dumped to a file already has a > timestamp;
Ivan Bereziuk has updated the pull request incrementally with two additional commits since the last revision: - improve test. Assert new ISO 8601 format - handle timestamp in parse_and_execute(). Thread.print is exceptional. Add default initialation to JcmdOptions ------------- Changes: - all: https://git.openjdk.org/jdk/pull/27368/files - new: https://git.openjdk.org/jdk/pull/27368/files/5f1cefe0..c702901d Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=27368&range=02 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27368&range=01-02 Stats: 133 lines in 4 files changed: 19 ins; 101 del; 13 mod Patch: https://git.openjdk.org/jdk/pull/27368.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/27368/head:pull/27368 PR: https://git.openjdk.org/jdk/pull/27368
