Unclear use of OMRSIG_SIGNAL / OMRSIG_SIGACTION

[dnakamura]

A number of places in the jvm ( eg 1 2 3 among others ), we use the macros OMRSIG_SIGNAL / OMRSIG_SIGACTION These macros are conditionally defined in omrport.h to expand to omrsig_primary_signal / omr_primary_sigaction if OMRPORT_OMRSIG_SUPPORT is defined, or signal / sigaction otherwise.

The issue is that we only define OMRPORT_OMRSIG_SUPPORT when compiling the port library. Thus these other reference are actually just calling signal/sigaction. Is this the intended behaviour? If so, shouldn't we make it more clear by avoiding the use of the macros? If not, we should be defining OMRPORT_OMRSIG_SUPPORT globally, or merging it with OMR_OMRPORT.

[babsingh]

@dnakamura OMRPORT_OMRSIG_SUPPORT should be defined globally. OpenJ9 and OMR should consistently use either omrsig_primary_signal/omr_primary_sigaction or signal/sigaction.

How should we enable OMRPORT_OMRSIG_SUPPORT globally? Can you provide details about merging with OMR_OMRPORT?

[dnakamura]

I would maybe add something to the bottom of omrcfg.h like:

#if defined(OMR_PORT) && defined(OMR_OMRSIG)
#define OMRPORT_OMRSIG_SUPPORT
#endif

[babsingh]

@dnakamura In OpenJ9, the J9VM_PORT_OMRSIG_SUPPORT flag is used to enable the OMRPORT_OMRSIG_SUPPORT flag when building the port library.

If we use the above approach to enable OMRPORT_OMRSIG_SUPPORT globally, then OMRPORT_OMRSIG_SUPPORT won't be disabled when J9VM_PORT_OMRSIG_SUPPORT is disabled.

Will the below changes work?

1. Enable OMRPORT_OMRSIG_SUPPORT in runtime/gc_glue_java/configure_includes/configure_common.mk.ftl:

<#if uma.spec.flags.port_omrsigSupport.enabled>
  --enable-OMRPORT_OMRSIG_SUPPORT \
</#if>

2. Add OMRPORT_OMRSIG_SUPPORT in
   i) omr/omrmakefiles/configure..mk.in
   ii) omr/configure.ac
   iii) omr/omrcfg.CMakeTemplate.h
   iv) omr/include_core/omrcfg.h.in
   v) omr/cmake/config.cmake

Also, did you find a fix for the linkage issue which occurs when OMRPORT_OMRSIG_SUPPORT is enabled globally?