SP_MIDI - add new API fns is_nif_loaded and is_nif_initialized

useful for runtime checks

Author: samaaron

app/external/sp_midi/src/sp_midi.cpp

@@ -33,9 +33,11 @@
 #include "monitorlogger.h"
 #include "midi_port_info.h"
 
+using namespace std;
+
 static int g_monitor_level = 6;
+static mutex g_init_mutex;
 
-using namespace std;
 
 // FIXME: need to test what happens when MIDI devices are already in use by another application
 // and sp_midi cannot open them
@@ -119,6 +121,7 @@ int sp_midi_send(const char* device_name, const unsigned char* c_message, unsign
 
 int sp_midi_init()
 {
+    lock_guard<std::mutex> lock (g_init_mutex);
     if (g_already_initialized){
         return 0;
     }
@@ -150,6 +153,7 @@ int sp_midi_init()
 
 void sp_midi_deinit()
 {
+    lock_guard<std::mutex> lock (g_init_mutex);
     if (!g_already_initialized){
         return;
     }
@@ -167,6 +171,18 @@ void sp_midi_deinit()
     midiSendProcessor.reset(nullptr);
 }
 
+int sp_midi_is_nif_initialized(bool* is_nif_initialized)
+{
+    *is_nif_initialized = g_already_initialized ? 1 : 0;
+    return 0;
+}
+
+int sp_midi_is_nif_loaded(bool* is_nif_loaded)
+{
+    *is_nif_loaded = true;
+    return 0;
+}
+
 static char **vector_str_to_c(const vector<string>& vector_str)
 {
     char **c_str_list;
@@ -226,6 +242,27 @@ ERL_NIF_TERM c_str_list_to_erlang(ErlNifEnv *env, int n, char **c_str_list)
 
 
 // NIF functions
+
+ERL_NIF_TERM sp_midi_is_nif_loaded_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+    bool loaded;
+    int rc = sp_midi_is_nif_loaded(&loaded);
+    if (rc < 0){
+        return enif_make_atom(env, "error");
+    }
+    return enif_make_atom(env, loaded ? "true" : "false");
+}
+
+ERL_NIF_TERM sp_midi_is_nif_initialized_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+    bool initialized;
+    int rc = sp_midi_is_nif_initialized(&initialized);
+    if (rc < 0){
+        return enif_make_atom(env, "error");
+    }
+    return enif_make_atom(env, initialized ? "true" : "false");
+}
+
 ERL_NIF_TERM sp_midi_init_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
     int ret = sp_midi_init();
@@ -357,6 +394,8 @@ int send_midi_data_to_erlang(const char *device_name, const unsigned char *data,
 
 
 static ErlNifFunc nif_funcs[] = {
+    {"is_nif_loaded", 0, sp_midi_is_nif_loaded_nif},
+    {"is_nif_initialized", 0, sp_midi_is_nif_initialized_nif},
     {"midi_init", 0, sp_midi_init_nif},
     {"midi_deinit", 0, sp_midi_deinit_nif},
     {"midi_send", 2, sp_midi_send_nif},

app/external/sp_midi/src/sp_midi.erl

@@ -1,5 +1,5 @@
 -module(sp_midi).
--export([midi_init/0, midi_deinit/0, midi_send/2, midi_flush/0, midi_ins/0, midi_outs/0, midi_refresh_devices/0,
+-export([is_nif_loaded/0, is_nif_initialized/0, midi_init/0, midi_deinit/0, midi_send/2, midi_flush/0, midi_ins/0, midi_outs/0, midi_refresh_devices/0,
         have_my_pid/0, set_this_pid/1, set_log_level/1, get_current_time_microseconds/0]).
 -on_load(init/0).
 
@@ -11,6 +11,10 @@ init() ->
         ok = erlang:load_nif("/home/luis/projects/sp_midi/build/libsp_midi", 0)
     end.
 
+is_nif_loaded() ->
+    exit(nif_library_not_loaded).
+is_nif_initialized() ->
+    exit(nif_library_not_loaded).
 midi_init() ->
     exit(nif_library_not_loaded).
 midi_deinit() ->

app/external/sp_midi/src/sp_midi.h

@@ -22,6 +22,7 @@
 
 #pragma once
 
+#include <stdbool.h>
 #include <erl_nif.h>
 
 #ifdef WIN32
@@ -34,6 +35,11 @@
 extern "C" {
 #endif
 
+
+
+    DllExport int sp_midi_is_nif_loaded(bool* is_nif_loaded);
+    DllExport int sp_midi_is_nif_initialized(bool* is_nif_initialized);
+
     // TODO: These are exported for C tests. Once we are happy that it's working they should not be exported
     /**
      * Initialize the spmidi library. Must be called before anything else.
@@ -91,6 +97,9 @@ extern "C" {
     // Erlang NIFs. The NIF parameters are always the same, I will only explain the parameters as unpacked from erlang.
     // Note that the only NIF that passes data is sp_midi_send_nif(), the rest do not pass anything, and are simple
     // wrappers for the C functions that do the real work.
+    DllExport ERL_NIF_TERM sp_midi_is_nif_loaded_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]);
+    DllExport ERL_NIF_TERM sp_midi_is_nif_initialized_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]);
+
     /**
      * Initialize the spmidi library. Must be called before anything else.
      *
@@ -126,7 +135,7 @@ extern "C" {
 
     /**
      * Trigger a refresh of the MIDI devices. This is triggered from erlang when it a change in the topology is detected
-     * 
+     *
      */
     DllExport ERL_NIF_TERM sp_midi_refresh_devices(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]);