RFR: 8319554: Select LogOutput* directly for stdout and stderr

[Xin Liu]

On Wed, 8 Nov 2023 09:57:45 GMT, Johan Sjölen <jsjolen at openjdk.org> wrote:

>> This patch skips allocation on C heap and invoking jio_snprintf for stdout and stderr. 
>> They are 2 predefined LogOuptuts and can't be deleted. 
>> 
>> We also check the return value of set_log_config in test_asynclog.cpp. if configuration fails,
>> the test will be skipped. We expect tot fix the flaky failures(JDK-8309067).
>
> src/hotspot/share/logging/logConfiguration.cpp line 513:
> 
>> 511:   } else if (0 == strcmp(outputstr, StderrLog->name())) { // stderr
>> 512:     idx = 1;
>> 513:     assert(find_output(outputstr) == idx, "sanity check");
> 
> This is the first time I see [Yoda conditions](https://en.wikipedia.org/wiki/Yoda_conditions) in HotSpot :-), maybe do `strcmp(...) == 0` instead?

oh, I don't know there's a term for that. 

I guess I derive this from java. "stdout".equals(name) can compare name == null whereas name.equals("stdout") will throw NPE. 
 
okay. I will flip them.

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PR Review Comment: https://git.openjdk.org/jdk/pull/16543#discussion_r1387085419