Merge pull request #46 from diondokter/upchannel-flush

Add flush function to `UpChannel`

Author: noppej

rtt-target/src/lib.rs

@@ -241,6 +241,20 @@ impl UpChannel {
 
         Some(UpChannel(ptr))
     }
+
+    /// Wait until all data has been read by the debugger.
+    ///
+    /// *Note: This means that if no debugger is connected or if it isn't reading the rtt data,*
+    /// *this function will wait indefinitely.*
+    pub fn flush(&self) {
+        loop {
+            let (write, read) = self.channel().read_pointers();
+            if write == read {
+                break;
+            }
+            core::hint::spin_loop();
+        }
+    }
 }
 
 impl fmt::Write for UpChannel {

rtt-target/src/rtt.rs

@@ -146,7 +146,7 @@ impl RttChannel {
         }
     }
 
-    fn read_pointers(&self) -> (usize, usize) {
+    pub(crate) fn read_pointers(&self) -> (usize, usize) {
         let write = self.write.load(SeqCst);
         let read = self.read.load(SeqCst);