Can RAJA plugins be made easier to understand and use?

[adayton1]

Is there a way to add a plugin at run time via calling a method (note that I do not want to deal with shared objects)? All I can find is a way to do it at compile time:

static RAJA::util::PluginRegistry::add<ProfilePlugin> P("Profile", "Profiles RAJA loops");

This is so convoluted to me - I don't know what in the world is safe to do inside a plugin class. Here is what I am trying to do:

class ProfilePlugin : public RAJA::util::PluginStrategy {
      public:
         ProfilePlugin(const ProfilePlugin&) = delete;

         static ProfilePlugin& getInstance() {
             static ProfilePlugin s_plugin;
             return s_plugin;
         }

         void preLaunch(const RAJA::util::PluginContext& p) override {
            if (m_active) {
               if (p.platform == RAJA::Platform::device) {
                    // start recording with nvtx or roctx using m_name as the label
               }
            }
         }
         
         void postLaunch(const RAJA::util::PluginContext& p) override {
            if (m_active) {
               if (p.platform == RAJA::Platform::device) {
                   // end recording with nvtx or roctx using m_name as the label
                   m_name = "";
               }
            }
         }

         void enable() {
             m_active = true;
         }

         void disable() {
             m_active = false;
         }

         void setName(std::string name) {
             m_name = name;
         }
      
      private:
         ProfilePlugin() = default;

         bool m_active = false;
         std::string m_name = "";
};

// It would be nice just to be able to register my plugin myself anywhere in my application.
RAJA::util::PluginRegistry::add(ProfilePlugin::getInstance(), "Profile", "Profile RAJA loops");

// Right before a RAJA loop
ProfilePlugin::getInstance().setName("My loop");

// At various points in my application
ProfilePlugin::getInstance().enable();
// Do some work
ProfilePlugin::getInstance().disable();

My guess is that this will not work with RAJA because of the singleton pattern. I can think of ways around this, but they are much more convoluted. I've been wanting to use RAJA plugins for a while and I think I could contribute some really useful ones to RAJA and or CHAI, but because it is so inflexible, I have written my own layer in CARE to do what I need to.

[rhornung67]

@adayton1 was the discussion of this at a RAJA meeting a while ago sufficient to resolve your issue? If not, do you have specific suggestions for changes you would like to see?

[adayton1]

I have not had a chance to work on this (I'm still stuck on updating BLT/RAJA/Umpire/CHAI and a host of other libraries with outdated build systems that needed to be changed to build with C++14). But what would be helpful is updating the documentation for how to use addNode manually (that way we could pass a pointer to a class that has a private constructor, e.g. a singleton, to be registered).