Add SIGTERM signal handler, for slurm preemption.

Makefile

@@ -80,6 +80,10 @@ COMPFLAGS += -DACC_SEMILAG_PQM -DTRANS_SEMILAG_PPM
 #May cause problems
 #COMPFLAGS += -DCATCH_FPE
 
+#Add -DCATCH_SIGTERM to make the simulation bail out gracefully on SIGTERM (for
+# example on slurm preemption)
+COMPFLAGS += -DCATCH_SIGTERM
+
 #Define MESH=VAMR if you want to use adaptive mesh refinement in velocity space
 #MESH = VAMR
 

vlasiator.cpp

@@ -55,9 +55,10 @@
 #include "fieldsolver/gridGlue.hpp"
 #include "fieldsolver/derivatives.hpp"
 
+#include <signal.h>
+
 #ifdef CATCH_FPE
 #include <fenv.h>
-#include <signal.h>
 /*! Function used to abort the program upon detecting a floating point exception. Which exceptions are caught is defined using the function feenableexcept.
  */
 void fpehandler(int sig_num)
@@ -81,6 +82,17 @@ bool globalflags::balanceLoad = 0;
 bool globalflags::doRefine=0;
 bool globalflags::ionosphereJustSolved = false;
 
+#ifdef CATCH_SIGTERM
+// The normal behaviour on SIGTERM is to simply abort the simulation in place.
+// This implementation instead attempts to write a restart file and then quit,
+// to work nicely with slurm's job preemption mechanism.
+void termhandler(int sig_num) {
+   logFile << "Caught SIGTERM. Initiating bailout." << endl << flush;
+   globalflags::bailingOut = 1;
+   globalflags::writeRestart = 1;
+}
+#endif
+
 ObjectWrapper objectWrapper;
 
 void addTimedBarrier(string name){
@@ -311,6 +323,10 @@ int simulate(int argn,char* args[]) {
    signal(SIGFPE, fpehandler);
    #endif
 
+   #ifdef CATCH_SIGTERM
+   signal(SIGTERM, termhandler);
+   #endif
+
    // Initialize memory allocator configuration.
    memory_configurator();