Use StackWalker to extract caller data when using J9+ to improve cpu performance

[qsLI]

Logback uses Throwable.getStackTrace() method to calculate caller info which will get all stacktraces and causing performance issue.

code location:

logback/logback-classic/src/main/java/ch/qos/logback/classic/spi/CallerData.java

Line 58 in 5bde644

StackTraceElement[] steArray = t.getStackTrace();

some discussion:

• java - Access stacktraces with good performance? - Stack Overflow

jdk9 introduces a new api ( StackWalker JEP 259: Stack-Walking API ) allows to get only needed StackTraceElement. LOG4J already supported StackWalker:

• [LOG4J2-1359] Add support for Java 9 StackWalker API in ReflectionUtil - ASF JIRA

Do we have any plan to support StackWalker?

[be-hase]

I also feel that this point is an issue. Since StackWalker is more efficient, I believe this is a meaningful improvement.

[ceki]

In several tests I performed, StackWalker was not faster. However, I will look into this again.