working on thread safety, preparing for static RTOS

mission/freeRTOS_rust_helper.c

@@ -4,6 +4,29 @@
 
 // TODO namespace the names
 
+SemaphoreHandle_t * global_threading_semaphore = NULL;
+
+uint8_t global_threading_available_c() {
+  if (global_threading_semaphore == NULL) {
+    
+    global_threading_semaphore = xSemaphoreCreateBinary();
+    //xSemaphoreGive(global_threading_semaphore);
+  }
+  if (uxSemaphoreGetCount(global_threading_semaphore) == 1) {
+    return 1;
+  } else {
+    return 0;
+  }
+}
+
+void enable_global_threading_c() {
+  xSemaphoreGive(global_threading_semaphore);
+}
+
+void disable_global_threading_c() {
+  xSemaphoreTake(global_threading_semaphore, portMAX_DELAY);
+}
+
 const char *get_task_name() { return pcTaskGetName(NULL); }
 
 void stop_it() { taskENTER_CRITICAL(); }

mission_rust/src/fsrc/datasets/mod.rs

@@ -39,7 +39,7 @@ pub struct ReferencedDataset<T: HasTypeId + Copy> {
     mutex: Option<mutex::RawMutex>,
 }
 
-impl<T: HasTypeId + Copy> DataSetIF for OwnedDataset<T> {
+impl<T: HasTypeId + Copy + Default> DataSetIF for OwnedDataset<T> {
     fn get_type_id(&self) -> TypeId {
         self.actual_data.get_type_id()
     }
@@ -49,6 +49,7 @@ impl<T: HasTypeId + Copy> DataSetIF for OwnedDataset<T> {
     }
 
     fn get_mutex(&self) -> mutex::RawMutex {
+        self.initialize();
         return self.mutex;
     }
 }
@@ -77,6 +78,10 @@ impl<T: HasTypeId + Copy + Default> OwnedDataset<T> {
         };
         self.actual_data = data;
     }
+
+    fn initialize(&mut self) {
+
+    }
 }
 
 impl<T: HasTypeId + Copy + Default> ReferencedDataset<T> {

mission_rust/src/fsrc/mutex.rs

@@ -1,10 +1,7 @@
 use super::osal;
 
-// We allow copy because we protext our pointer via a global mutex
-// when using static allocation (which is TBCoded)
-#[derive(Clone, Copy)]
 pub struct RawMutex {
-    handle: *const core::ffi::c_void,
+    handle: Option<*const core::ffi::c_void>
 }
 
 pub struct RawMutexGuard {
@@ -22,23 +19,50 @@ impl Drop for RawMutexGuard {
 // or maybe lazy later on, TBD if lazy is needed or we can guarantee init to be called
 impl RawMutex {
     pub fn new() -> Self {
-        let handle = unsafe {osal::create_mutex()};
         Self {
-            handle: handle
+            handle: None
+        }
+    }
+
+    pub fn clone(&self) -> Self {
+        let mut_self = self as *const Self as *mut Self; //oh look, a C developer wrote this
+        unsafe { (*mut_self).initialize() }; //TODO this might be safe (we are in init), but does not look very good
+        Self {
+            handle: self.handle
         }
     }
 
     pub fn take(&self) -> Result<RawMutexGuard,()> {
-        match unsafe {osal::take_mutex(self.handle)} {
-            1 => Ok(RawMutexGuard { handle: self.handle }),
+        osal::check_global_threading_available();
+        let handle = match self.handle {
+            None => return Err(()), //TODO plan was that this failes silently -> implement an empty mutex guard?
+            Some(handle) => handle
+        };
+        match unsafe {osal::take_mutex(handle)} {
+            1 => Ok(RawMutexGuard { handle: handle }),
             _ => Err(()) //TODO error code
         }
     }
 
+    // Mutex guard takes care of this in its drop
+    // Do not offer this in API to avoid duplicate give
     // pub fn give(&self) -> Result<(),()> {
-    //     match unsafe {osal::give_mutex(self.handle)} {
+    //     osal::check_global_threading_available();
+    //     let handle = match self.handle {
+    //         None => return Ok(()),
+    //         Some(handle) => handle
+    //     };
+    //     match unsafe {osal::give_mutex(handle)} {
     //         1 => Ok(()),
     //         _ => Err(()) //TODO error code
     //     }
     // }
+
+    pub fn initialize(&mut self) {
+        let handle = unsafe {osal::create_mutex()};
+        if handle == 0 as *const core::ffi::c_void {
+            panic!("Could not create mutex")
+        }
+        self.handle = Some(handle);
+    }
 }

mission_rust/src/fsrc/osal/mod.rs

@@ -1,6 +1,7 @@
 type TaskFunction = unsafe extern "C" fn(*mut core::ffi::c_void);
 
 //TODO verify uXX == uintXX_t
+//TODO safe API
 
 extern "C" {
     pub fn outbyte(c: u8);
@@ -30,4 +31,26 @@ extern "C" {
     pub fn take_mutex(mutex: *const core::ffi::c_void) -> u8;
     pub fn give_mutex(mutex: *const core::ffi::c_void) -> u8;
 
+    fn global_threading_available_c() -> u8;
+    fn enable_global_threading_c();
+    fn disable_global_threading_c();
+
+}
+
+pub fn global_threading_available() -> bool {
+    unsafe{global_threading_available_c() == 1}
+}
+
+pub fn check_global_threading_available() {
+    if !global_threading_available() {
+        panic!("using queue outside of threading environment")
+    }
+}
+
+pub fn enable_global_threading(){
+    unsafe{enable_global_threading_c()};
+}
+
+pub fn disable_global_threading(){
+    unsafe{disable_global_threading_c()};
 }

mission_rust/src/fsrc/queues/mod.rs

@@ -1,46 +1,63 @@
-pub struct MessageQueue {
-    queue_id: *const core::ffi::c_void,
+use crate::osal;
+
+pub struct MessageQueue<const DEPTH: usize> {
+    queue_data: [Message; DEPTH],
+    queue_id: Option<*const core::ffi::c_void>,
 }
 
 pub struct MessageQueueSender {
     queue_id: Option<*const core::ffi::c_void>,
 }
 
-impl MessageQueue {
-    pub fn new(depth: usize) -> Self {
-        unsafe {
-            //TODO check cast of depth
-            let cast_depth: u32 = u32::try_from(depth).unwrap(); //TODO check these
-            let element_size: u32 = u32::try_from(core::mem::size_of::<Message>()).unwrap();
-            let queue_id = crate::fsrc::osal::create_queue(cast_depth, element_size);
-
-            if queue_id == 0 as *mut core::ffi::c_void {
-                panic!("could not create Queue");
-            }
-
-            Self { queue_id: queue_id }
+impl<const DEPTH: usize> MessageQueue<DEPTH> {
+    pub fn new() -> Self {
+        Self {
+            queue_data: [Message::default(); DEPTH],
+            queue_id: None,
         }
     }
 
-    pub fn get_sender(&self) -> MessageQueueSender {
-        let instance: MessageQueueSender = MessageQueueSender {
-            queue_id: Some(self.queue_id),
+    pub fn receive(&self) -> Option<Message> {
+        osal::check_global_threading_available();
+        let actual_id = match self.queue_id {
+            None => return None,
+            Some(id) => id,
         };
-        instance
-    }
-
-    pub fn receive(&self) -> Result<Message, ()> {
         let mut message: Message = Message::default();
         let res: u8;
         unsafe {
             //message = core::mem::MaybeUninit::zeroed().assume_init(); // We only return it if the queue received something
-            let message_pointer: *mut core::ffi::c_void = &mut message as *mut _ as *mut core::ffi::c_void;
-            res = crate::fsrc::osal::queue_receive(self.queue_id, message_pointer);
+            let message_pointer: *mut core::ffi::c_void =
+                &mut message as *mut _ as *mut core::ffi::c_void;
+            res = osal::queue_receive(actual_id, message_pointer);
         }
         if res == 1 {
-            Ok(message)
+            Some(message)
         } else {
-            Err(())
+            None
+        }
+    }
+
+    fn initialize(&mut self) {
+        if self.queue_id != None {
+            return;
+        }
+        let cast_depth: u32 = u32::try_from(DEPTH).unwrap(); //TODO check these
+        let element_size: u32 = u32::try_from(core::mem::size_of::<Message>()).unwrap();
+        let queue_id = unsafe { osal::create_queue(cast_depth, element_size) };
+
+        if queue_id == 0 as *mut core::ffi::c_void {
+            panic!("could not create Queue");
+        }
+        self.queue_id = Some(queue_id);
+    }
+
+    pub fn get_sender(&self) -> MessageQueueSender {
+        let mut_self = self as *const Self as *mut Self; //oh look, a C developer wrote this
+        unsafe { (*mut_self).initialize() }; //TODO this might be safe (we are in init), but does not look very good
+        let queue_id = self.queue_id.expect("Queue uninitialized");
+        MessageQueueSender {
+            queue_id: Some(queue_id),
         }
     }
 }
@@ -51,11 +68,16 @@ impl MessageQueueSender {
     }
 
     pub fn send(&self, message: Message) -> Result<(), ()> {
-        let queue_id = self.queue_id.expect("unitialized Message Queue");
+        osal::check_global_threading_available();
+        let queue_id = match self.queue_id {
+            None => return Err(()),
+            Some(id) => id,
+        };
         let res: u8;
         unsafe {
-            let message_pointer: *const core::ffi::c_void = &message as *const _ as *const core::ffi::c_void;
-            res = crate::fsrc::osal::queue_send(queue_id, message_pointer);
+            let message_pointer: *const core::ffi::c_void =
+                &message as *const _ as *const core::ffi::c_void;
+            res = osal::queue_send(queue_id, message_pointer);
         }
         if res == 1 {
             Ok(())

mission_rust/src/lib.rs

@@ -1,6 +1,5 @@
 #![no_std]
 
-//TODO look into using core::ffi (some types do not seem to work)
 //TODO os errors in API calls
 //TODO look into a pattern for late initialized stuff, currently using Option (can we make it compile time safe?)
 
@@ -60,7 +59,7 @@ impl datasets::HasTypeId for HandlerData {}
 
 struct Handler {
     id: objectmanager::ObjectId,
-    command_queue: queues::MessageQueue,
+    command_queue: queues::MessageQueue<10>,
     data: datasets::OwnedDataset<HandlerData>
 }
 
@@ -94,8 +93,8 @@ impl tasks::ExecutableObjectIF for Handler {
         sifln!("Handler {} performs", self.id);
         let result = self.command_queue.receive();
         match result {
-            Ok(message) => self.handle_message(message),
-            Err(_) => {
+            Some(message) => self.handle_message(message),
+            None => {
                 sifln!("Handler {} got nothing", self.id);
             }
         }
@@ -149,8 +148,9 @@ impl DatapoolOwnerIF for HandlerSender {}
 
 impl SystemObjectIF for HandlerSender {
     fn get_command_queue(&self) -> crate::fsrc::queues::MessageQueueSender {
-        queues::MessageQueueSender::new()
+        queues::MessageQueueSender::new() //TODO
     }
+
     fn get_id(&self) -> objectmanager::ObjectId {
         self.id
     }
@@ -173,7 +173,7 @@ fn mission() {
 
     let mut h1 = Handler {
         id: 1,
-        command_queue: queues::MessageQueue::new(5),
+        command_queue: queues::MessageQueue::new(),
         data: datasets::OwnedDataset::new()
     };
     let mut h2 = HandlerSender {