- New MCA option: opal_stacktrace_output
- Specifies where the stack trace output stream goes.
- Accepts: none, stdout, stderr, file[:filename]
- Default filename 'stacktrace'
- Filename will be `stacktrace.PID`, or if VPID is available,
then the filename will be `stacktrace.VPID.PID`
- Update util/stacktrace to allow for different output avenues
including files. Previously this was hardcoded to 'stderr'.
- Since opal_backtrace_print needs to be signal safe, passing it a
FILE object that actually represents a file stream is difficult. This
is because we cannot open the file in the signal handler using
`fopen` (not safe), but have to use `open` (safe). Additionally, we
cannot use `fdopen` to convert the `int fd` to a `FILE *fh` since it
is also not signal safe.
- I did not want to break the backtrace.h API so I introduced a new
rule (documented in `backtrace.c`) that if the `FILE *file`
argument is `NULL` then look for the `opal_stacktrace_output_fileno`
variable to tell you which file descriptor to use for output.
Signed-off-by: Joshua Hursey <jhursey@us.ibm.com>
