X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=qemu%2Finclude%2Fqemu%2Fratelimit.h;fp=qemu%2Finclude%2Fqemu%2Fratelimit.h;h=d413a4a696b78f79628e459395bb87dd35d681c1;hb=e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb;hp=0000000000000000000000000000000000000000;hpb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;p=kvmfornfv.git

diff --git a/qemu/include/qemu/ratelimit.h b/qemu/include/qemu/ratelimit.h
new file mode 100644
index 000000000..d413a4a69
--- /dev/null
+++ b/qemu/include/qemu/ratelimit.h
@@ -0,0 +1,48 @@
+/*
+ * Ratelimiting calculations
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#ifndef QEMU_RATELIMIT_H
+#define QEMU_RATELIMIT_H 1
+
+typedef struct {
+    int64_t next_slice_time;
+    uint64_t slice_quota;
+    uint64_t slice_ns;
+    uint64_t dispatched;
+} RateLimit;
+
+static inline int64_t ratelimit_calculate_delay(RateLimit *limit, uint64_t n)
+{
+    int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+
+    if (limit->next_slice_time < now) {
+        limit->next_slice_time = now + limit->slice_ns;
+        limit->dispatched = 0;
+    }
+    if (limit->dispatched == 0 || limit->dispatched + n <= limit->slice_quota) {
+        limit->dispatched += n;
+        return 0;
+    } else {
+        limit->dispatched = n;
+        return limit->next_slice_time - now;
+    }
+}
+
+static inline void ratelimit_set_speed(RateLimit *limit, uint64_t speed,
+                                       uint64_t slice_ns)
+{
+    limit->slice_ns = slice_ns;
+    limit->slice_quota = ((double)speed * slice_ns)/1000000000ULL;
+}
+
+#endif