When many threds concurrently print you need to serialize
the access to std::cout to avoid output lines are intermixed
with the contents of each thread.
This is not strictly needed at the moment because
only main thread prints out, although some ad-hoc
test could trigger UCI::loop() printing while searching.
Anyhow we want to lift this pretty avoidable constrain
also as a prerequisite for future work.
This patch just introduces the support, next one will enable
the serialization.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
+/// Used to serialize access to std::cout to avoid multiple threads to write at
+/// the same time.
+
+std::ostream& operator<<(std::ostream& os, SyncCout sc) {
+
+ static Mutex m;
+
+ if (sc == io_lock)
+ m.lock();
+
+ if (sc == io_unlock)
+ m.unlock();
+
+ return os;
+}
+
+
/// Trampoline helper to avoid moving Logger to misc.h
void start_logger(bool b) { Logger::start(b); }
/// Trampoline helper to avoid moving Logger to misc.h
void start_logger(bool b) { Logger::start(b); }
+
+enum SyncCout { io_lock, io_unlock };
+std::ostream& operator<<(std::ostream&, SyncCout);
+
+#define sync_cout std::cout << io_lock
+#define sync_endl std::endl << io_unlock
+
#endif // !defined(MISC_H_INCLUDED)
#endif // !defined(MISC_H_INCLUDED)