1 files changed, 64 insertions, 0 deletions
diff --git a/include/qemu/timed-average.h b/include/qemu/timed-average.h
new file mode 100644
index 0000000000..364bf88f70
--- /dev/null
+++ b/include/qemu/timed-average.h
@@ -0,0 +1,64 @@
+/*
+ * QEMU timed average computation
+ *
+ * Copyright (C) Nodalink, EURL. 2014
+ * Copyright (C) Igalia, S.L. 2015
+ *
+ * Authors:
+ *   Benoît Canet <benoit.canet@nodalink.com>
+ *   Alberto Garcia <berto@igalia.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) version 3 or any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TIMED_AVERAGE_H
+#define TIMED_AVERAGE_H
+
+#include <stdint.h>
+
+#include "qemu/timer.h"
+
+typedef struct TimedAverageWindow TimedAverageWindow;
+typedef struct TimedAverage TimedAverage;
+
+/* All fields of both structures are private */
+
+struct TimedAverageWindow {
+    uint64_t      min;             /* minimum value accounted in the window */
+    uint64_t      max;             /* maximum value accounted in the window */
+    uint64_t      sum;             /* sum of all values */
+    uint64_t      count;           /* number of values */
+    int64_t       expiration;      /* the end of the current window in ns */
+};
+
+struct TimedAverage {
+    uint64_t           period;     /* period in nanoseconds */
+    TimedAverageWindow windows[2]; /* two overlapping windows of with
+                                    * an offset of period / 2 between them */
+    unsigned           current;    /* the current window index: it's also the
+                                    * oldest window index */
+    QEMUClockType      clock_type; /* the clock used */
+};
+
+void timed_average_init(TimedAverage *ta, QEMUClockType clock_type,
+                        uint64_t period);
+
+void timed_average_account(TimedAverage *ta, uint64_t value);
+
+uint64_t timed_average_min(TimedAverage *ta);
+uint64_t timed_average_avg(TimedAverage *ta);
+uint64_t timed_average_max(TimedAverage *ta);
+uint64_t timed_average_sum(TimedAverage *ta, uint64_t *elapsed);
+
+#endif