made it work better for GC languages

src/luaarch.c

@@ -792,7 +792,7 @@ static void luaArch_loadEnv(lua_State *L) {
 static nn_Exit luaArch_handler(nn_ArchitectureRequest *req) {
 	nn_Computer *computer = req->computer;
 	luaArch *arch = req->localState;
-	nn_Context *ctx = nn_getComputerContext(computer);
+	nn_Context *ctx = computer == NULL ? NULL : nn_getComputerContext(computer);
 	// the memory scale, used to give Lua extra memory in 64-bit systems
 	// due to it also using more memory.
 	double memScale = sizeof(void *) > 4 ? 1.8 : 1;
@@ -857,6 +857,10 @@ static nn_Exit luaArch_handler(nn_ArchitectureRequest *req) {
 	case NN_ARCH_DESERIALIZE:
 		// do nothing
 		return NN_OK;
+	case NN_ARCH_RETAIN:
+		return NN_OK;
+	case NN_ARCH_DROP:
+		return NN_OK;
 	}
 	return NN_OK;
 }

src/neonucleus.c

@@ -1229,6 +1229,8 @@ nn_Computer *nn_createComputer(nn_Universe *universe, void *userdata, const char
 	c->signalCount = 0;
 	c->userCount = 0;
 	c->idleTimestamp = 0;
+	c->arch.handler = NULL;
+	c->desiredArch.handler = NULL;
 	// set to empty string
 	c->errorBuffer[0] = '\0';
 	for(size_t i = 0; i < NN_MAX_USERDATA; i++) c->uservals[i].state = NULL;
@@ -1314,9 +1316,29 @@ bool nn_isComputerOn(nn_Computer *computer) {
 }
 
 void nn_setComputerEnvironment(nn_Computer *computer, nn_Environment env) {
+	nn_retainComputerEnvironment(env);
+	nn_dropComputerEnvironment(computer->env);
 	computer->env = env;
 }
 
+void nn_retainComputerEnvironment(nn_Environment env) {
+	if(env.handler == NULL) return;
+	nn_EnvironmentRequest req;
+	req.userdata = env.userdata;
+	req.computer = NULL;
+	req.action = NN_ENV_RETAIN;
+	env.handler(&req);
+}
+
+void nn_dropComputerEnvironment(nn_Environment env) {
+	if(env.handler == NULL) return;
+	nn_EnvironmentRequest req;
+	req.userdata = env.userdata;
+	req.computer = NULL;
+	req.action = NN_ENV_DROP;
+	env.handler(&req);
+}
+
 void nn_setDirectCost(nn_Computer *computer, double directCost) {
 	computer->directCost = directCost;
 }
@@ -1465,6 +1487,12 @@ void nn_destroyComputerN(nn_Computer *computer, size_t n) {
 	for(size_t i = 0; i < computer->userCount; i++) {
 		nn_strfree(ctx, computer->users[i]);
 	}
+	
+	nn_dropArchitecture(computer->arch);
+	for(size_t i = 0; i < computer->archCount; i++) {
+		nn_dropArchitecture(computer->archs[i]);
+	}
+	nn_dropComputerEnvironment(computer->env);
 
 	for(size_t i = 0; i < NN_MAX_USERDATA; i++) nn_freeUserdata(computer, i);
 
@@ -1571,6 +1599,8 @@ bool nn_hasUser(nn_Computer *computer, const char *user) {
 }
 
 void nn_setArchitecture(nn_Computer *computer, const nn_Architecture *arch) {
+	nn_retainArchitecture(*arch);
+	nn_dropArchitecture(computer->arch);
 	computer->arch = *arch;
 }
 
@@ -1578,7 +1608,29 @@ nn_Architecture nn_getArchitecture(nn_Computer *computer) {
 	return computer->arch;
 }
 
+void nn_retainArchitecture(nn_Architecture arch) {
+	if(arch.handler == NULL) return;
+	nn_ArchitectureRequest req;
+	req.computer = NULL;
+	req.action = NN_ARCH_RETAIN;
+	req.globalState = arch.state;
+	req.localState = NULL;
+	arch.handler(&req);
+}
+
+void nn_dropArchitecture(nn_Architecture arch) {
+	if(arch.handler == NULL) return;
+	nn_ArchitectureRequest req;
+	req.computer = NULL;
+	req.action = NN_ARCH_DROP;
+	req.globalState = arch.state;
+	req.localState = NULL;
+	arch.handler(&req);
+}
+
 void nn_setDesiredArchitecture(nn_Computer *computer, const nn_Architecture *arch) {
+	nn_retainArchitecture(*arch);
+	nn_dropArchitecture(computer->desiredArch);
 	computer->desiredArch = *arch;
 }
 
@@ -1588,6 +1640,7 @@ nn_Architecture nn_getDesiredArchitecture(nn_Computer *computer) {
 
 nn_Exit nn_addSupportedArchitecture(nn_Computer *computer, const nn_Architecture *arch) {
 	if(computer->archCount == NN_MAX_ARCHITECTURES) return NN_ELIMIT;
+	nn_retainArchitecture(*arch);
 	computer->archs[computer->archCount++] = *arch;
 	return NN_OK;
 }

src/neonucleus.h

@@ -354,6 +354,10 @@ typedef enum nn_ArchitectureAction {
 	NN_ARCH_DESERIALIZE,
 	// serialize to an encoded state, pushed it as a string
 	NN_ARCH_SERIALIZE,
+	// information about usage, for GC languages to know when it is safe to reclaim references.
+	// computer and localState are both NULL when these are emitted.
+	NN_ARCH_RETAIN,
+	NN_ARCH_DROP,
 } nn_ArchitectureAction;
 
 typedef struct nn_ArchitectureRequest {
@@ -423,6 +427,9 @@ typedef enum nn_EnvironmentAction {
 	NN_ENV_CRASHED,
 	NN_ENV_BEEP,
 	NN_ENV_BEEPMORSE,
+	// information about usage, for GC languages to know when it is safe to reclaim references
+	NN_ENV_RETAIN,
+	NN_ENV_DROP,
 } nn_EnvironmentAction;
 
 typedef struct nn_EnvironmentRequest {
@@ -473,6 +480,8 @@ void nn_forceCrashComputer(nn_Computer *computer, const char *s);
 // returns whether an architecture state is present
 bool nn_isComputerOn(nn_Computer *computer);
 void nn_setComputerEnvironment(nn_Computer *computer, nn_Environment env);
+void nn_retainComputerEnvironment(nn_Environment env);
+void nn_dropComputerEnvironment(nn_Environment env);
 
 void nn_setDirectCost(nn_Computer *computer, double directCost);
 double nn_getDirectCost(nn_Computer *computer);
@@ -601,6 +610,12 @@ bool nn_hasUser(nn_Computer *computer, const char *user);
 void nn_setArchitecture(nn_Computer *computer, const nn_Architecture *arch);
 // Gets the current architecture.
 nn_Architecture nn_getArchitecture(nn_Computer *computer);
+// Notify the architecture it is being retained. This is to help GC'd languages that provide architectures know
+// when the garbage collector can safely reclaim the memory again.
+void nn_retainArchitecture(nn_Architecture arch);
+// Notify the architecture it is being dropped. This is to help GC'd languages that provide architectures know
+// when the garbage collector can safely reclaim the memory again.
+void nn_dropArchitecture(nn_Architecture arch);
 // Sets the computer's desired architecture.
 // The desired architecture indicates, when the computer state is CHARCH, what the new architecture should be.
 // This is set even if it is not in the supported architecture list, *you must check if it is in that list first.*