Fix synchronization issue at thread start

If a newly started thread immediately exits then m_running would
immediately be set to false again and the caller would be stuck
waiting for m_running to become true forever.
Since a mutex for synchronizing startup already exists we can
simply move the while loop into it.

see also: #5134 which introduced m_start_finished_mutex

diff --git a/src/threading/thread.cpp b/src/threading/thread.cpp
index 5cfc609957eb5ed999afddb932c634a4f3f39be4..ef025ac1d0ea72e29808f5df61b4672149c35aab 100644 (file)
--- a/src/threading/thread.cpp
+++ b/src/threading/thread.cpp
@@ -121,12 +121,12 @@ bool Thread::start()
                return false;
        }
 
-       // Allow spawned thread to continue
-       m_start_finished_mutex.unlock();
-
        while (!m_running)
                sleep_ms(1);
 
+       // Allow spawned thread to continue
+       m_start_finished_mutex.unlock();
+
        m_joinable = true;
 
        return true;