Pass multisim record to Colvars for mwABF

src/external/colvars/colvarbias_abf.cpp

@@ -99,14 +99,16 @@ int colvarbias_abf::init(std::string const &conf)
   get_keyval(conf, "shared", shared_on, false);
   if (shared_on) {
     cvm::main()->cite_feature("Multiple-walker ABF implementation");
-    if ((proxy->replica_enabled() != COLVARS_OK) ||
-        (proxy->num_replicas() <= 1)) {
-      return cvm::error("Error: shared ABF requires more than one replica.",
-                        COLVARS_INPUT_ERROR);
+    // Do not check for replicas in Gromacs preprocessing, in VMD, etc.
+    if (proxy->simulation_running()) {
+      if (proxy->replica_enabled() != COLVARS_OK || proxy->num_replicas() <= 1) {
+        return cvm::error("Error: shared ABF requires more than one replica.",
+                          COLVARS_INPUT_ERROR);
+      } else {
+        cvm::log("shared ABF will be applied among "+
+                 cvm::to_str(proxy->num_replicas()) + " replicas.\n");
+      }
     }
-    cvm::log("shared ABF will be applied among "+
-             cvm::to_str(proxy->num_replicas()) + " replicas.\n");
-
     // If shared_freq is not set, we default to output_freq
     get_keyval(conf, "sharedFreq", shared_freq, output_freq);
   }

src/gromacs/applied_forces/colvars/colvarproxygromacs.cpp

@@ -40,6 +40,7 @@
  */
 
 #include "colvarproxygromacs.h"
+#include "gromacs/mdrunutility/multisim.h"
 
 #include <sstream>
 
@@ -56,7 +57,9 @@ ColvarProxyGromacs::ColvarProxyGromacs(const std::string& colvarsConfigString,
                                        bool               doParsing,
                                        const std::map<std::string, std::string>& inputStrings,
                                        real ensembleTemperature,
-                                       int  seed) :
+                                       int  seed,
+                                       const gmx_multisim_t* ms,
+                                       bool simRunning) :
     gmxAtoms_(atoms), pbcType_(pbcType), logger_(logger), doParsing_(doParsing)
 {
     engine_name_ = "GROMACS";
@@ -77,6 +80,9 @@ ColvarProxyGromacs::ColvarProxyGromacs(const std::string& colvarsConfigString,
     // $ units -ts 'k' 'kJ/mol/K/avogadro'
     boltzmann_ = 0.0083144621;
 
+    // False in grompp but true in mdrun
+    b_simulation_running = simRunning;
+
     // Get the thermostat temperature.
     set_target_temperature(ensembleTemperature);
 
@@ -92,7 +98,6 @@ ColvarProxyGromacs::ColvarProxyGromacs(const std::string& colvarsConfigString,
         rng_.seed(seed);
     }
 
-
     // Read configuration file and set up the proxy during pre-processing
     // and during simulation phase but only on the master node.
     if (doParsing)
@@ -119,6 +124,18 @@ ColvarProxyGromacs::ColvarProxyGromacs(const std::string& colvarsConfigString,
             cvm::log("Initializing the colvars proxy object.\n");
         }
 
+        if (isMultiSim(ms)) {
+            inter_me = ms->simulationIndex_;
+            inter_num = ms->numSimulations_;
+            inter_comm = ms->mainRanksComm_;
+            cvm::log("Multiple-replica simulation: this is replica " + cvm::to_str(inter_me + 1)
+                    + " of " + cvm::to_str(inter_num));
+        } else {
+            inter_me = 0;
+            inter_num = 0;
+            inter_comm = MPI_COMM_NULL;
+        }
+
         int errorCode = colvarproxy::setup();
         errorCode |= colvars->read_config_string(colvarsConfigString);
         errorCode |= colvars->update_engine_parameters();
@@ -242,6 +259,59 @@ void ColvarProxyGromacs::updateAtomProperties(int index)
     atoms_charges[index] = gmxAtoms_.atom[atoms_ids[index]].q;
 }
 
+
+// multi-replica support
+
+int ColvarProxyGromacs::replica_enabled()
+{
+  return (inter_comm != MPI_COMM_NULL) ? COLVARS_OK : COLVARS_NOT_IMPLEMENTED;
+}
+
+
+int ColvarProxyGromacs::replica_index()
+{
+  return inter_me;
+}
+
+
+int ColvarProxyGromacs::num_replicas()
+{
+  return inter_num;
+}
+
+
+void ColvarProxyGromacs::replica_comm_barrier()
+{
+  MPI_Barrier(inter_comm);
+}
+
+
+int ColvarProxyGromacs::replica_comm_recv(char* msg_data,
+                                          int buf_len, int src_rep)
+{
+  MPI_Status status;
+  int retval;
+
+  retval = MPI_Recv(msg_data,buf_len,MPI_CHAR,src_rep,0,inter_comm,&status);
+  if (retval == MPI_SUCCESS) {
+    MPI_Get_count(&status, MPI_CHAR, &retval);
+  } else retval = 0;
+  return retval;
+}
+
+
+int ColvarProxyGromacs::replica_comm_send(char* msg_data,
+                                          int msg_len, int dest_rep)
+{
+  int retval;
+  retval = MPI_Send(msg_data,msg_len,MPI_CHAR,dest_rep,0,inter_comm);
+  if (retval == MPI_SUCCESS) {
+    retval = msg_len;
+  } else retval = 0;
+  return retval;
+}
+
+
 ColvarProxyGromacs::~ColvarProxyGromacs()
 {
     if (colvars != nullptr)

src/gromacs/applied_forces/colvars/colvarproxygromacs.h

@@ -53,7 +53,8 @@
 #include "gromacs/random/threefry.h"
 #include "gromacs/topology/atoms.h"
 #include "gromacs/utility/logger.h"
-
+#include "gromacs/utility/gmxmpi.h"
+struct gmx_multisim_t;
 
 namespace gmx
 {
@@ -83,6 +84,8 @@ class ColvarProxyGromacs : public colvarproxy
     //! Activate or not the parsing of the Colvars config file
     bool doParsing_;
 
+    MPI_Comm inter_comm;        // MPI comm with 1 root proc from each world
+    int inter_me, inter_num;    // rank for the inter replica comm
 
     // GROMACS random number generation.
     DefaultRandomEngine           rng_; // gromacs random number generator
@@ -102,6 +105,8 @@ class ColvarProxyGromacs : public colvarproxy
      * \param[in] inputStrings Input files stored as string in the TPR's KVT
      * \param[in] ensembleTemperature the constant ensemble temperature
      * \param[in] seed the colvars seed for random number generator
+     * \param[in] ms the multisim record
+     * \param[in] simRunning whether we are in mdrun (as opposed to grompp)
      */
     ColvarProxyGromacs(const std::string&                        colvarsConfigString,
                        t_atoms                                   atoms,
@@ -110,7 +115,9 @@ class ColvarProxyGromacs : public colvarproxy
                        bool                                      doParsing,
                        const std::map<std::string, std::string>& inputStrings,
                        real                                      ensembleTemperature,
-                       int                                       seed);
+                       int                                       seed,
+                       const gmx_multisim_t*                     ms,
+                       bool                                      simRunning);
     ~ColvarProxyGromacs() override;
 
     //! Update colvars topology of one atom mass and charge from the GROMACS topology
@@ -138,6 +145,20 @@ class ColvarProxyGromacs : public colvarproxy
 
     //! Compute the minimum distance with respect to the PBC between 2 atoms.
     cvm::rvector position_distance(cvm::atom_pos const& pos1, cvm::atom_pos const& pos2) const override;
+
+    //! Are we running a multi-replica simulation? (multisim in gromacs)
+    int replica_enabled() override;
+    //! Index of the local replica in the array
+    int replica_index() override;
+    //! Total number of replicas
+    int num_replicas() override;
+
+    //! Communication barrier between replicas
+    void replica_comm_barrier() override;
+    //! MPI receive between replicas
+    int replica_comm_recv(char *msg_data, int buf_len, int src_rep) override;
+    //! MPI send between replicas
+    int replica_comm_send(char *msg_data, int msg_len, int dest_rep) override;
 };
 
 } // namespace gmx

src/gromacs/applied_forces/colvars/colvarsMDModule.cpp

@@ -55,6 +55,11 @@
 #include "colvarsoptions.h"
 #include "colvarssimulationsparameters.h"
 
+#include <iostream>
+
+//struct gmx_multisim_t;
+#include "gromacs/mdrunutility/multisim.h"
+
 
 namespace gmx
 {
@@ -87,7 +92,7 @@ class ColvarsMDModule final : public IMDModule
      *     KeyValueTreeObjectBuilder as parameter
      *   - Acess topology using gmx_mtop_t notification
      *   - Access MDLogger for notifications output
-     *   - Access warninp for for grompp warnings output
+     *   - Access warning for for grompp warnings output
      *   - Coordinates, PBC and box for setting up the proxy
      */
     void subscribeToPreProcessingNotifications(MDModulesNotifiers* notifier) override
@@ -182,6 +187,13 @@ class ColvarsMDModule final : public IMDModule
         };
         notifier->simulationSetupNotifier_.subscribe(setCommFunction);
 
+        // Retrieve the Multisim Record during simulations setup
+        const auto setMultisimFunction = [this](const gmx_multisim_t *ms) {
+            std::cout << "GETTING MULTISIM: " << ms->numSimulations_ << "simulations\n";
+            this->ColvarsSimulationsParameters_.setMultisim(ms);
+        };
+        notifier->simulationSetupNotifier_.subscribe(setMultisimFunction);
+
         // setting the simulation time step
         const auto setSimulationTimeStepFunction = [this](const SimulationTimeStep& simulationTimeStep) {
             this->ColvarsSimulationsParameters_.setSimulationTimeStep(simulationTimeStep.delta_t);
@@ -241,6 +253,7 @@ class ColvarsMDModule final : public IMDModule
                     colvarsOptions_.colvarsSeed(),
                     ColvarsSimulationsParameters_.localAtomSetManager(),
                     ColvarsSimulationsParameters_.comm(),
+                    ColvarsSimulationsParameters_.ms(),
                     ColvarsSimulationsParameters_.simulationTimeStep(),
                     colvarsOptions_.colvarsAtomCoords(),
                     colvarsOptions_.colvarsOutputPrefix(),

src/gromacs/applied_forces/colvars/colvarsforceprovider.cpp

@@ -53,6 +53,7 @@
 #include "gromacs/mdtypes/commrec.h"
 #include "gromacs/mdtypes/enerdata.h"
 #include "gromacs/mdtypes/forceoutput.h"
+#include "gromacs/mdrunutility/multisim.h"
 
 
 namespace gmx
@@ -155,11 +156,12 @@ ColvarsForceProvider::ColvarsForceProvider(const std::string& colvarsConfigStrin
                                            int                              seed,
                                            LocalAtomSetManager*             localAtomSetManager,
                                            const t_commrec*                 cr,
+                                           const gmx_multisim_t*            ms,
                                            double                           simulationTimeStep,
                                            const std::vector<RVec>&         colvarsCoords,
                                            const std::string&               outputPrefix,
                                            const ColvarsForceProviderState& state) :
-    ColvarProxyGromacs(colvarsConfigString, atoms, pbcType, logger, MAIN(cr), inputStrings, ensembleTemperature, seed),
+    ColvarProxyGromacs(colvarsConfigString, atoms, pbcType, logger, MAIN(cr), inputStrings, ensembleTemperature, seed, ms, true),
     stateToCheckpoint_(state)
 {
 

src/gromacs/applied_forces/colvars/colvarsforceprovider.h

@@ -49,7 +49,7 @@
 
 #include "colvarproxygromacs.h"
 
-
+struct gmx_multisim_t;
 namespace gmx
 {
 
@@ -178,6 +178,7 @@ class ColvarsForceProvider final : public ColvarProxyGromacs, public IForceProvi
                          int                                       seed,
                          LocalAtomSetManager*                      localAtomSetManager,
                          const t_commrec*                          cr,
+                         const gmx_multisim_t*                     ms,
                          double                                    simulationTimeStep,
                          const std::vector<RVec>&                  colvarsCoords,
                          const std::string&                        outputPrefix,

src/gromacs/applied_forces/colvars/colvarspreprocessor.cpp

@@ -62,10 +62,11 @@ ColvarsPreProcessor::ColvarsPreProcessor(const std::string&   colvarsConfigStrin
                        true,
                        std::map<std::string, std::string>(),
                        ensembleTemperature,
-                       seed),
+                       seed,
+                       nullptr,
+                       false),
     x_(x)
 {
-
     // Initialize t_pbc struct
     set_pbc(&gmxPbc_, pbcType, box);
 

src/gromacs/applied_forces/colvars/colvarssimulationsparameters.cpp

@@ -112,6 +112,16 @@ const t_commrec* ColvarsSimulationsParameters::comm() const
     return cr_;
 }
 
+void ColvarsSimulationsParameters::setMultisim(const gmx_multisim_t *ms)
+{
+    ms_ = ms;
+}
+
+const gmx_multisim_t* ColvarsSimulationsParameters::ms() const
+{
+    return ms_;
+}
+
 
 void ColvarsSimulationsParameters::setLogger(const MDLogger& logger)
 {

src/gromacs/applied_forces/colvars/colvarssimulationsparameters.h

@@ -47,6 +47,7 @@
 #include "gromacs/pbcutil/pbc.h"
 #include "gromacs/topology/atoms.h"
 #include "gromacs/utility/logger.h"
+struct gmx_multisim_t;
 
 namespace gmx
 {
@@ -104,7 +105,12 @@ class ColvarsSimulationsParameters
     //! Return the communicator
     const t_commrec* comm() const;
 
-    /*! \brief Set the logger for QMMM during mdrun
+    //! Set the Multisim record
+    void setMultisim(const gmx_multisim_t *ms);
+    //! Return Multisim record
+    const gmx_multisim_t* ms() const;
+
+    /*! \brief Set the logger for Colvars during mdrun
      * \param[in] logger Logger instance to be used for output
      */
     void setLogger(const MDLogger& logger);
@@ -123,6 +129,8 @@ class ColvarsSimulationsParameters
     t_atoms gmxAtoms_;
     //! The communicator
     const t_commrec* cr_;
+    //! The multisim record
+    const gmx_multisim_t *ms_;
     //! MDLogger for notifications during mdrun
     const MDLogger* logger_ = nullptr;
 

src/gromacs/mdrun/runner.cpp

@@ -1795,6 +1795,7 @@ int Mdrunner::mdrunner()
     if (thisRankHasDuty(cr, DUTY_PP))
     {
         setupNotifier.notify(*cr);
+        setupNotifier.notify(ms);
         setupNotifier.notify(&atomSets);
         setupNotifier.notify(mtop);
         setupNotifier.notify(inputrec->pbcType);

src/gromacs/mdrunutility/mdmodulesnotifiers.h

@@ -58,6 +58,7 @@ struct gmx_mtop_t;
 class WarningHandler;
 enum class PbcType : int;
 struct t_inputrec;
+struct gmx_multisim_t;
 
 namespace gmx
 {
@@ -374,6 +375,7 @@ struct MDModulesNotifiers
                            SeparatePmeRanksPermitted*,
                            const PbcType&,
                            const SimulationTimeStep&,
+                           const gmx_multisim_t*,
                            const t_commrec&,
                            const MdRunInputFilename&,
                            const EdrOutputFilename&>::type simulationSetupNotifier_;