Handle fork in target application (#191)

* Always print PID in log messages

* omnitrace-dl updates

- omnitrace_preload does not call omnitrace_init or omnitrace_init_tooling
- omnitrace_preload will call omnitrace_set_mpi if OMNITRACE_USE_MPI
  or OMNITRACE_USE_MPIP in the env is true but not call it otherwise
  because doing so either overrides OMNITRACE_USE_PID (when true) or
  disable mpip from initialization (when false) and the MPI
  init can be caught later and override OMNITRACE_USE_PID

* config updates

- set_setting_value sets user update type
- remove volatile from get_settings_configured
- don't override settings::default_process_suffix
- don't kill process in omnitrace_exit_action
- set_state ignores updating state if >= State::Finalized

* Handle state > State::Finalized

* fork gotcha updates

- unsets LD_PRELOAD
- sets OMNITRACE_ROOT_PROCESS
- sets OMNITRACE_CHILD_PROCESS

* libomnitrace library.cpp updates

- basic_bundle for fini metrics
- handle finalization from child process

* sampling updates

- sampling::shutdown handles when child process

* Add example and test using fork

* Update run-ci script to support not submitting

* Tweak test envs

* Update build flags when codecov enabled

* remove unnecessary includes of sampling header

* Replace mpi copy/fini static lambda with free-funcs

* Update codecov job

* Fix OMPT segfaults after finalization

* Miscellaneous updates after rebase

* fixes for causal profiling

* revert some run-ci.sh changes

* Disable storing env in sampling::shutdown

* formatting fix

* Update timemory submodule

- fixed occasional synchronization issues with allocator offloading
- exclude protozero:: from internal samples

* improve root/child process detection

- avoid omnitrace_finalize in MPI when child process
- revert some testing tweaks

source/lib/core/config.cpp

@@ -227,20 +227,18 @@ finalize()
 bool
 settings_are_configured()
 {
-    volatile bool _v = _settings_are_configured();
-    return _v;
+    return _settings_are_configured();
 }
 
 void
 configure_settings(bool _init)
 {
-    volatile bool _v = _settings_are_configured();
-    if(_v) return;
-
     static bool _once = false;
     if(_once) return;
     _once = true;
 
+    if(settings_are_configured()) return;
+
     if(get_is_continuous_integration() && get_state() < State::Init)
     {
         timemory_print_demangled_backtrace<64>();
@@ -2192,9 +2190,11 @@ get_perfetto_output_filename()
         _ext = _val.substr(_pos_ext + 1);
         _val = _val.substr(0, _pos_ext);
     }
-    _val = settings::compose_output_filename(_val, _ext, settings::use_output_suffix(),
-                                             settings::default_process_suffix(), false,
-                                             _dir);
+
+    auto _cfg = settings::compose_filename_config{ settings::use_output_suffix(),
+                                                   settings::default_process_suffix(),
+                                                   false, _dir };
+    _val      = settings::compose_output_filename(_val, _ext, _cfg);
     if(!_val.empty() && _val.at(0) != '/')
         return settings::format(JOIN('/', "%env{PWD}%", _val), get_config()->get_tag());
     return _val;