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/omnitrace/library.cpp

@@ -68,6 +68,7 @@
 #include <timemory/signals/signal_mask.hpp>
 #include <timemory/signals/types.hpp>
 #include <timemory/utility/backtrace.hpp>
+#include <timemory/utility/join.hpp>
 #include <timemory/utility/procfs/maps.hpp>
 
 #include <atomic>
@@ -679,6 +680,8 @@ omnitrace_finalize_hidden(void)
     // disable initialization callback
     threading::remove_callback(&ensure_initialization);
 
+    bool _is_child = is_child_process();
+
     set_thread_state(ThreadState::Completed);
 
     // return if not active
@@ -688,6 +691,12 @@ omnitrace_finalize_hidden(void)
                                 std::to_string(get_state()).c_str());
         return;
     }
+    else if(_is_child)
+    {
+        set_state(State::Finalized);
+        std::quick_exit(EXIT_SUCCESS);
+        return;
+    }
 
     if(get_verbose() >= 0 || get_debug()) fprintf(stderr, "\n");
     OMNITRACE_VERBOSE_F(0, "finalizing...\n");
@@ -1104,9 +1113,14 @@ omnitrace_finalize_hidden(void)
                       _push_count, "vs. popped:", _pop_count)
             .c_str());
 
+    debug::close_file();
     config::finalize();
 
     OMNITRACE_VERBOSE_F(0, "Finalized: %s\n", _finalization.as_string().c_str());
+
+    tim::signals::enable_signal_detection(
+        { tim::signals::sys_signal::SegFault, tim::signals::sys_signal::Stop },
+        [](int) {});
 }
 
 //======================================================================================//