add needed fields for global libuv loop + bindings to manage from rust

adding two pointers fields to rust_kernel :(
.. have to do manual malloc/free for one of the fields, which feels wrong

src/rt/rust_kernel.cpp

@@ -24,6 +24,13 @@ rust_kernel::rust_kernel(rust_env *env) :
     non_weak_tasks(0),
     env(env)
 {
+    // set up storage of pointers needed to
+    // access the global loop.
+    global_loop_chan = 0;
+    global_async_handle = (void**)::malloc( // FIXME -- can use this->malloc()
+        sizeof(void*));                   // .. what do?
+    *global_async_handle = (void*)0;
+
     // Create the single threaded scheduler that will run on the platform's
     // main thread
     rust_manual_sched_launcher_factory launchfac;

src/rt/rust_kernel.h

@@ -73,6 +73,10 @@ class rust_kernel {
     rust_scheduler* get_scheduler_by_id_nolock(rust_sched_id id);
     void end_weak_tasks();
 
+	// Used to communicate with the process-side, global libuv loop
+	uintptr_t global_loop_chan;
+	void** global_async_handle;
+
 public:
     struct rust_env *env;
 
@@ -117,6 +121,11 @@ public:
     void unweaken_task(rust_port_id chan);
 
     bool send_to_port(rust_port_id chan, void *sptr);
+
+	uintptr_t* get_global_loop() { return &global_loop_chan; }
+	void** get_global_async_handle() { return global_async_handle; }
+	void set_global_async_handle(void* handle) {
+		*global_async_handle = handle; }
 };
 
 template <typename T> struct kernel_owned {

src/rt/rust_uv.cpp

@@ -425,3 +425,24 @@ rust_uv_ip4_addr(const char* ip, int port) {
     LOG(task, stdlib, "after creating .. port: %d\n", addr.sin_port);
     return addr;
 }
+
+extern "C" uintptr_t*
+rust_uv_get_kernel_global_chan_ptr() {
+	uintptr_t* result = rust_get_current_task()->kernel->get_global_loop();
+	printf("global loop: %lu\n", (unsigned long int)result);
+	printf("global loop val: %lu\n", (unsigned long int)*result);
+	return result;
+}
+
+extern "C" void**
+rust_uv_get_kernel_global_async_handle() {
+	return rust_get_current_task()->kernel->get_global_async_handle();
+}
+extern "C" void
+rust_uv_set_kernel_global_async_handle(uv_async_t* handle) {
+	rust_get_current_task()->kernel->set_global_async_handle((void*)handle);
+}
+extern "C" void
+rust_uv_free_kernel_global_async_handle() {
+	free((void*)rust_get_current_task()->kernel->get_global_async_handle());
+}

src/rt/rustrt.def.in

@@ -134,6 +134,10 @@ rust_uv_get_data_for_req
 rust_uv_set_data_for_req
 rust_uv_get_base_from_buf
 rust_uv_get_len_from_buf
+rust_uv_get_kernel_global_chan_ptr
+rust_uv_get_kernel_global_async_handle
+rust_uv_set_kernel_global_async_handle
+rust_uv_free_kernel_global_async_handle
 rust_dbg_lock_create
 rust_dbg_lock_destroy
 rust_dbg_lock_lock