[#56] Make mutex test more robust

iceoryx2-bb/posix/src/mutex.rs

@@ -266,7 +266,12 @@ pub enum MutexThreadTerminationBehavior {
     /// mutex owning
     /// thread/process dies the mutex is put into an inconsistent state which can be recovered with
     /// [`Mutex::make_consistent()`]. The inconsistent state is detected by the next instance which
-    /// calls [`Mutex::lock()`], [`Mutex::try_lock()`] or [`Mutex::timed_lock()`].
+    /// calls [`Mutex::try_lock()`] or [`Mutex::timed_lock()`].
+    ///
+    /// **Important:** If the owner dies after another thread has already locked the [`Mutex`] it
+    /// may become impossible to recover the [`Mutex`]. Therefore, this feature should be used
+    /// only in combination with either [`Mutex::try_lock`] or [`Mutex::timed_lock()`] and
+    /// never with [`Mutex::lock()`].
     ///
     /// This is also known as robust mutex.
     ReleaseWhenLocked = posix::PTHREAD_MUTEX_ROBUST,

iceoryx2-bb/posix/tests/mutex_tests.rs

@@ -405,14 +405,16 @@ fn mutex_can_be_recovered_when_thread_died() {
         });
     });
 
-    let guard = sut.lock();
-    assert_that!(guard, is_err);
-    match guard.as_ref().err().as_ref().unwrap() {
-        MutexLockError::LockAcquiredButOwnerDied(_) => (),
-        _ => assert_that!(true, eq false),
+    loop {
+        let guard = sut.try_lock();
+
+        if guard.is_ok() {
+            assert_that!(guard.as_ref().unwrap(), is_none);
+        } else if let Err(MutexLockError::LockAcquiredButOwnerDied(_)) = guard {
+            sut.make_consistent();
+            break;
+        }
     }
-    sut.make_consistent();
-    drop(guard);
 
     let guard = sut.try_lock();
     assert_that!(guard, is_ok);