From 9353004e3e7e34346db9c21d15b0d1478fce6c0b Mon Sep 17 00:00:00 2001
From: Axel Kohlmeyer <akohlmey@gmail.com>
Date: Sun, 4 Oct 2020 11:23:49 -0400
Subject: [PATCH] add APIs to determine of LAMMPS is running and to interrupt a
 run cleanly

---
 src/library.cpp | 28 ++++++++++++++++++++++++++++
 src/library.h   |  3 +++
 2 files changed, 31 insertions(+)

diff --git a/src/library.cpp b/src/library.cpp
index d8ec849f49..ebbebff2c1 100644
--- a/src/library.cpp
+++ b/src/library.cpp
@@ -38,6 +38,7 @@
 #include "region.h"
 #include "output.h"
 #include "thermo.h"
+#include "timer.h"
 #include "universe.h"
 #include "update.h"
 #include "variable.h"
@@ -4619,6 +4620,33 @@ void lammps_decode_image_flags(imageint image, int *flags)
   flags[2] = (image >> IMG2BITS) - IMGMAX;
 }
 
+/** Check if LAMMPS is currently inside a run or minimization
+ *
+ * This function can be used from signal handlers or multi-threaded
+ * applications to determine if the LAMMPS instance is currently active.
+ *
+ * \param  handle pointer to a previously created LAMMPS instance cast to ``void *``.
+ * \return        0 if idle or >0 if active */
+
+int lammps_is_running(void *handle)
+{
+  LAMMPS *  lmp = (LAMMPS *) handle;
+  return lmp->update->whichflag;
+}
+
+/** Force a timeout to cleanly stop an ongoing run
+ *
+ * This function can be used from signal handlers or multi-threaded
+ * applications to cleanly terminate an ongoing run.
+ *
+ * \param  handle pointer to a previously created LAMMPS instance cast to ``void *`` */
+
+void lammps_force_timeout(void *handle)
+{
+  LAMMPS *  lmp = (LAMMPS *) handle;
+  return lmp->timer->force_timeout();
+}
+
 // ----------------------------------------------------------------------
 // Library functions for error handling with exceptions enabled
 // ----------------------------------------------------------------------
diff --git a/src/library.h b/src/library.h
index 2ac0997487..c365bd9210 100644
--- a/src/library.h
+++ b/src/library.h
@@ -226,6 +226,9 @@ void lammps_set_fix_external_callback(void *, char *, FixExternalFnPtr, void*);
 void lammps_fix_external_set_energy_global(void *, char *, double);
 void lammps_fix_external_set_virial_global(void *, char *, double *);
 
+int lammps_is_running(void *handle);
+void lammps_force_timeout(void *handle);
+
 int lammps_has_error(void *handle);
 int lammps_get_last_error_message(void *handle, char *buffer, int buf_size);