Wakeup worker per eventfd

emper/Runtime.cpp

@@ -3,6 +3,7 @@
 #include "Runtime.hpp"
 
 #include <pthread.h>	// for pthread_t, pthread_attr_init
+#include <sys/eventfd.h>
 
 #include <cerrno>	 // for errno
 // Non portable.
@@ -72,8 +73,7 @@ Runtime::Runtime(workerid_t workerCount, RuntimeStrategyFactory& strategyFactory
 			threads(new pthread_t[workerCount]),
 			workers(new Worker*[workerCount]),
 			randomEngine(seed),
-			sleepingWorkers(0),
-			skipSleep(false) {
+			sleepingWorkers(0) {
 	const int nprocs = get_nprocs();
 
 	{
@@ -84,6 +84,12 @@ Runtime::Runtime(workerid_t workerCount, RuntimeStrategyFactory& strategyFactory
 		currentRuntime = this;
 	}
 
+	// initialize the wakeup eventfd
+	wakeup_fd = eventfd(0, EFD_SEMAPHORE);
+	if (wakeup_fd == -1) {
+		DIE_MSG_ERRNO("creating wakeup eventfd failed");
+	}
+
 	// initialize the global and all worker IoContexts
 	if constexpr (emper::IO) {
 		// The global io_uring needs at least workerCount entries in its SQ because