From 6ef228fc0de1d5fb43ebfef039563d39a3a37067 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 9 May 2012 16:09:46 +0200 Subject: stream: move rate limiting to a separate header file Make the code reusable. Signed-off-by: Paolo Bonzini Signed-off-by: Kevin Wolf --- include/qemu/ratelimit.h | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 include/qemu/ratelimit.h (limited to 'include') diff --git a/include/qemu/ratelimit.h b/include/qemu/ratelimit.h new file mode 100644 index 0000000000..c6ac281141 --- /dev/null +++ b/include/qemu/ratelimit.h @@ -0,0 +1,48 @@ +/* + * Ratelimiting calculations + * + * Copyright IBM, Corp. 2011 + * + * Authors: + * Stefan Hajnoczi + * + * 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_get_clock_ns(rt_clock); + + 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 * 1000000000ULL) / slice_ns; +} + +#endif -- cgit v1.2.3-55-g7522