1 files changed, 101 insertions, 0 deletions
diff --git a/src/thread/Util.cxx b/src/thread/Util.cxx
new file mode 100644
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--- /dev/null
+++ b/src/thread/Util.cxx
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2014-2016 Max Kellermann <max@duempel.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "Util.hxx"
+#include "util/Error.hxx"
+
+#ifdef __linux__
+#include <sched.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#elif defined(WIN32)
+#include <windows.h>
+#endif
+
+#ifdef __linux__
+
+static int
+ioprio_set(int which, int who, int ioprio)
+{
+	return syscall(__NR_ioprio_set, which, who, ioprio);
+}
+
+static void
+ioprio_set_idle()
+{
+	static constexpr int _IOPRIO_WHO_PROCESS = 1;
+	static constexpr int _IOPRIO_CLASS_IDLE = 3;
+	static constexpr int _IOPRIO_CLASS_SHIFT = 13;
+	static constexpr int _IOPRIO_IDLE =
+		(_IOPRIO_CLASS_IDLE << _IOPRIO_CLASS_SHIFT) | 7;
+
+	ioprio_set(_IOPRIO_WHO_PROCESS, 0, _IOPRIO_IDLE);
+}
+
+#endif
+
+void
+SetThreadIdlePriority()
+{
+#ifdef __linux__
+#ifdef SCHED_IDLE
+	static struct sched_param sched_param;
+	sched_setscheduler(0, SCHED_IDLE, &sched_param);
+#endif
+
+	ioprio_set_idle();
+
+#elif defined(WIN32)
+	SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_IDLE);
+#endif
+};
+
+bool
+SetThreadRealtime(Error& error)
+{
+#ifdef __linux__
+	struct sched_param sched_param;
+	sched_param.sched_priority = 50;
+
+	int policy = SCHED_FIFO;
+#ifdef SCHED_RESET_ON_FORK
+	policy |= SCHED_RESET_ON_FORK;
+#endif
+
+	if(sched_setscheduler(0, policy, &sched_param)==0) {
+		return true;
+	} else {
+		error.FormatErrno("sched_setscheduler failed");
+		return false;
+	}
+#else
+	return true; // on non-linux systems, we pretend it worked
+#endif	// __linux__
+};