add unload/list commands

src/input.cpp

@@ -715,10 +715,10 @@ int Input::execute_command()
   else if (!strcmp(command,"include")) include();
   else if (!strcmp(command,"jump")) jump();
   else if (!strcmp(command,"label")) label();
-  else if (!strcmp(command,"load_plugin")) load_plugin();
   else if (!strcmp(command,"log")) log();
   else if (!strcmp(command,"next")) next_command();
   else if (!strcmp(command,"partition")) partition();
+  else if (!strcmp(command,"plugin")) plugin();
   else if (!strcmp(command,"print")) print();
   else if (!strcmp(command,"python")) python();
   else if (!strcmp(command,"quit")) quit();
@@ -1031,14 +1031,6 @@ void Input::label()
 
 /* ---------------------------------------------------------------------- */
 
-void Input::load_plugin()
-{
-  if (narg != 1) error->all(FLERR,"Illegal load_plugin command");
-  lammpsplugin_load(arg[0],lmp);
-}
-
-/* ---------------------------------------------------------------------- */
-
 void Input::log()
 {
   if ((narg < 1) || (narg > 2)) error->all(FLERR,"Illegal log command");
@@ -1107,6 +1099,32 @@ void Input::partition()
 
 /* ---------------------------------------------------------------------- */
 
+void Input::plugin()
+{
+  if (narg < 1) error->all(FLERR,"Illegal plugin command");
+  std::string cmd = arg[0];
+  if (cmd == "load") {
+    if (narg < 2) error->all(FLERR,"Illegal plugin load command");
+    for (int i=1; i < narg; ++i)
+      lammpsplugin_load(arg[i],lmp);
+  } else if (cmd == "unload") {
+    if (narg != 3) error->all(FLERR,"Illegal plugin unload command");
+    lammpsplugin_unload(arg[1],arg[2],lmp);
+  } else if (cmd == "list") {
+    if (comm->me == 0) {
+      int num = lammpsplugin_get_num_plugins();
+      utils::logmesg(lmp,"Currently loaded plugins\n");
+      for (int i=0; i < num; ++i) {
+        auto entry = lammpsplugin_info(i);
+        utils::logmesg(lmp,fmt::format("{:4}: {} style plugin {}\n",
+                                       i+1,entry->style,entry->name));
+      }
+    }
+  } else error->all(FLERR,"Illegal plugin command");
+}
+
+/* ---------------------------------------------------------------------- */
+
 void Input::print()
 {
   if (narg < 1) error->all(FLERR,"Illegal print command");

src/input.h

@@ -79,10 +79,10 @@ class Input : protected Pointers {
   void include();
   void jump();
   void label();
-  void load_plugin();
   void log();
   void next_command();
   void partition();
+  void plugin();
   void print();
   void python();
   void quit();

src/lammpsplugin.cpp

@@ -18,6 +18,7 @@
 #include "lammps.h"
 #include "modify.h"
 
+#include <vector>
 
 #ifdef _WIN32
 #include <windows.h>
@@ -27,6 +28,7 @@
 
 namespace LAMMPS_NS
 {
+  static std::vector<lammpsplugin_entry_t> pluginlist;
 
   void lammpsplugin_load(const char *file, void *ptr)
   {
@@ -34,7 +36,7 @@ namespace LAMMPS_NS
 #if defined(WIN32)
     utils::logmesg(lmp,"Loading of plugins not supported on Windows yet\n");
 #else
-    void *dso = dlopen(file,RTLD_NOW);
+    void *dso = dlopen(file,RTLD_NOW|RTLD_GLOBAL);
     if (dso == nullptr) {
       utils::logmesg(lmp,fmt::format("Loading of plugin from file {} failed: "
                                      "{}", file, utils::getsyserror()));
@@ -48,6 +50,7 @@ namespace LAMMPS_NS
       return;
     }
     ((lammpsplugin_initfunc)(initfunc))(ptr);
+//    dlclose(dso);
 #endif
   }
 
@@ -61,6 +64,12 @@ namespace LAMMPS_NS
                                      "version {} loaded into LAMMPS "
                                      "version {}\n", plugin->info,
                                      plugin->version, lmp->version));
+    lammpsplugin_entry_t entry;
+    entry.style = plugin->style;
+    entry.name = plugin->name;
+    entry.handle = nullptr;
+    pluginlist.push_back(entry);
+
     std::string pstyle = plugin->style;
     if (pstyle == "pair") {
       (*(lmp->force->pair_map))[plugin->name] =
@@ -68,6 +77,41 @@ namespace LAMMPS_NS
     } else {
       utils::logmesg(lmp,fmt::format("Loading plugin for {} styles not "
                                      "yet implemented\n", pstyle));
+      pluginlist.pop_back();
+    }
+  }
+
+  int lammpsplugin_get_num_plugins() 
+  {
+    return pluginlist.size();
+  }
+
+  const lammpsplugin_entry_t *lammpsplugin_info(int idx)
+  {
+    if ((idx < 0) || idx >= pluginlist.size()) return nullptr;
+
+    return &pluginlist[idx];
+  }
+
+  int lammpsplugin_find(const char *style, const char *name)
+  {
+    for (int i=0; i < pluginlist.size(); ++i) {
+      if ((strcmp(style,pluginlist[i].style) == 0)
+          && (strcmp(name,pluginlist[i].name) == 0))
+        return i;
+    }
+    return -1;
+  }
+  
+  void lammpsplugin_unload(const char *style, const char *name, void *ptr)
+  {
+    LAMMPS *lmp = (LAMMPS *)ptr;
+    std::string pstyle = style;
+    if (pstyle == "pair") {
+      auto found = lmp->force->pair_map->find(name);
+      if (found != lmp->force->pair_map->end()) {
+        lmp->force->pair_map->erase(found);
+      }
     }
   }
 }

src/lammpsplugin.h

@@ -14,9 +14,9 @@
 #ifndef LMP_LAMMPSPLUGIN_H
 #define LMP_LAMMPSPLUGIN_H
 
-#ifdef __cplusplus
+// C style API and data structures required for dynamic loading
+
 extern "C" {
-#endif
 
   typedef void *(lammpsplugin_factory)(void *);
   typedef void (*lammpsplugin_initfunc)(void *);
@@ -29,16 +29,26 @@ extern "C" {
     lammpsplugin_factory *creator;
   } lammpsplugin_t;
 
-  void lammpsplugin_init(void *);
+  typedef struct {
+    const char *style;
+    const char *name;
+    const void *handle;
+  } lammpsplugin_entry_t;
 
-#ifdef __cplusplus
+  // prototype for initializer function required
+  // to load a plugin; uses C bindings
+
+  void lammpsplugin_init(void *);
 }
-#endif
 
 namespace LAMMPS_NS
 {
   extern void lammpsplugin_load(const char *, void *);
   extern void lammpsplugin_register(lammpsplugin_t *, void *);
+  extern int lammpsplugin_get_num_plugins();
+  extern const lammpsplugin_entry_t *lammpsplugin_info(int);
+  extern int lammpsplugin_find(const char *, const char *);
+  extern void lammpsplugin_unload(const char *, const char *, void *);
 }
 
 #endif