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authorYang Zhang <yang.z.zhang@intel.com>2015-08-28 09:58:54 +0800
committerYang Zhang <yang.z.zhang@intel.com>2015-09-01 12:44:00 +0800
commite44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch)
tree66b09f592c55df2878107a468a91d21506104d3f /qemu/include/qemu/ratelimit.h
parent9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff)
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5 Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/include/qemu/ratelimit.h')
-rw-r--r--qemu/include/qemu/ratelimit.h48
1 files changed, 48 insertions, 0 deletions
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