timespec: Pull in timespec.h from weston

Signed-off-by: Sebastian Wick <sebastian.wick@redhat.com>

1 files changed, 259 insertions, 0 deletions

diff --git a/src/timespec-util.h b/src/timespec-util.h
new file mode 100644
index 0000000..f79969b
--- /dev/null
+++ b/src/timespec-util.h
@@ -0,0 +1,259 @@
+/*
+ * Copyright © 2014 - 2015 Collabora, Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef TIMESPEC_UTIL_H
+#define TIMESPEC_UTIL_H
+
+#include <stdint.h>
+#include <assert.h>
+#include <time.h>
+#include <stdbool.h>
+
+#define NSEC_PER_SEC 1000000000
+
+/* Subtract timespecs
+ *
+ * \param r[out] result: a - b
+ * \param a[in] operand
+ * \param b[in] operand
+ */
+static inline void
+timespec_sub(struct timespec *r,
+	     const struct timespec *a, const struct timespec *b)
+{
+	r->tv_sec = a->tv_sec - b->tv_sec;
+	r->tv_nsec = a->tv_nsec - b->tv_nsec;
+	if (r->tv_nsec < 0) {
+		r->tv_sec--;
+		r->tv_nsec += NSEC_PER_SEC;
+	}
+}
+
+/* Add a nanosecond value to a timespec
+ *
+ * \param r[out] result: a + b
+ * \param a[in] base operand as timespec
+ * \param b[in] operand in nanoseconds
+ */
+static inline void
+timespec_add_nsec(struct timespec *r, const struct timespec *a, int64_t b)
+{
+	r->tv_sec = a->tv_sec + (b / NSEC_PER_SEC);
+	r->tv_nsec = a->tv_nsec + (b % NSEC_PER_SEC);
+
+	if (r->tv_nsec >= NSEC_PER_SEC) {
+		r->tv_sec++;
+		r->tv_nsec -= NSEC_PER_SEC;
+	} else if (r->tv_nsec < 0) {
+		r->tv_sec--;
+		r->tv_nsec += NSEC_PER_SEC;
+	}
+}
+
+/* Add a millisecond value to a timespec
+ *
+ * \param r[out] result: a + b
+ * \param a[in] base operand as timespec
+ * \param b[in] operand in milliseconds
+ */
+static inline void
+timespec_add_msec(struct timespec *r, const struct timespec *a, int64_t b)
+{
+	timespec_add_nsec(r, a, b * 1000000);
+}
+
+/* Convert timespec to nanoseconds
+ *
+ * \param a timespec
+ * \return nanoseconds
+ */
+static inline int64_t
+timespec_to_nsec(const struct timespec *a)
+{
+	return (int64_t)a->tv_sec * NSEC_PER_SEC + a->tv_nsec;
+}
+
+/* Subtract timespecs and return result in nanoseconds
+ *
+ * \param a[in] operand
+ * \param b[in] operand
+ * \return to_nanoseconds(a - b)
+ */
+static inline int64_t
+timespec_sub_to_nsec(const struct timespec *a, const struct timespec *b)
+{
+	struct timespec r;
+	timespec_sub(&r, a, b);
+	return timespec_to_nsec(&r);
+}
+
+/* Convert timespec to milliseconds
+ *
+ * \param a timespec
+ * \return milliseconds
+ *
+ * Rounding to integer milliseconds happens always down (floor()).
+ */
+static inline int64_t
+timespec_to_msec(const struct timespec *a)
+{
+	return (int64_t)a->tv_sec * 1000 + a->tv_nsec / 1000000;
+}
+
+/* Subtract timespecs and return result in milliseconds
+ *
+ * \param a[in] operand
+ * \param b[in] operand
+ * \return to_milliseconds(a - b)
+ */
+static inline int64_t
+timespec_sub_to_msec(const struct timespec *a, const struct timespec *b)
+{
+	return timespec_sub_to_nsec(a, b) / 1000000;
+}
+
+/* Convert timespec to microseconds
+ *
+ * \param a timespec
+ * \return microseconds
+ *
+ * Rounding to integer microseconds happens always down (floor()).
+ */
+static inline int64_t
+timespec_to_usec(const struct timespec *a)
+{
+	return (int64_t)a->tv_sec * 1000000 + a->tv_nsec / 1000;
+}
+
+/* Convert timespec to protocol data
+ *
+ * \param a timespec
+ * \param tv_sec_hi[out] the high bytes of the seconds part
+ * \param tv_sec_lo[out] the low bytes of the seconds part
+ * \param tv_nsec[out] the nanoseconds part
+ *
+ * The input timespec must be normalized (the nanoseconds part should
+ * be less than 1 second) and non-negative.
+ */
+static inline void
+timespec_to_proto(const struct timespec *a, uint32_t *tv_sec_hi,
+                  uint32_t *tv_sec_lo, uint32_t *tv_nsec)
+{
+	assert(a->tv_sec >= 0);
+	assert(a->tv_nsec >= 0 && a->tv_nsec < NSEC_PER_SEC);
+
+	uint64_t sec64 = a->tv_sec;
+
+	*tv_sec_hi = sec64 >> 32;
+	*tv_sec_lo = sec64 & 0xffffffff;
+	*tv_nsec = a->tv_nsec;
+}
+
+/* Convert nanoseconds to timespec
+ *
+ * \param a timespec
+ * \param b nanoseconds
+ */
+static inline void
+timespec_from_nsec(struct timespec *a, int64_t b)
+{
+	a->tv_sec = b / NSEC_PER_SEC;
+	a->tv_nsec = b % NSEC_PER_SEC;
+}
+
+/* Convert microseconds to timespec
+ *
+ * \param a timespec
+ * \param b microseconds
+ */
+static inline void
+timespec_from_usec(struct timespec *a, int64_t b)
+{
+	timespec_from_nsec(a, b * 1000);
+}
+
+/* Convert milliseconds to timespec
+ *
+ * \param a timespec
+ * \param b milliseconds
+ */
+static inline void
+timespec_from_msec(struct timespec *a, int64_t b)
+{
+	timespec_from_nsec(a, b * 1000000);
+}
+
+/* Convert protocol data to timespec
+ *
+ * \param a[out] timespec
+ * \param tv_sec_hi the high bytes of seconds part
+ * \param tv_sec_lo the low bytes of seconds part
+ * \param tv_nsec the nanoseconds part
+ */
+static inline void
+timespec_from_proto(struct timespec *a, uint32_t tv_sec_hi,
+                    uint32_t tv_sec_lo, uint32_t tv_nsec)
+{
+	a->tv_sec = ((uint64_t)tv_sec_hi << 32) + tv_sec_lo;
+	a->tv_nsec = tv_nsec;
+}
+
+/* Check if a timespec is zero
+ *
+ * \param a timespec
+ * \return whether the timespec is zero
+ */
+static inline bool
+timespec_is_zero(const struct timespec *a)
+{
+	return a->tv_sec == 0 && a->tv_nsec == 0;
+}
+
+/* Check if two timespecs are equal
+ *
+ * \param a[in] timespec to check
+ * \param b[in] timespec to check
+ * \return whether timespecs a and b are equal
+ */
+static inline bool
+timespec_eq(const struct timespec *a, const struct timespec *b)
+{
+	return a->tv_sec == b->tv_sec &&
+	       a->tv_nsec == b->tv_nsec;
+}
+
+/* Convert milli-Hertz to nanoseconds
+ *
+ * \param mhz frequency in mHz, not zero
+ * \return period in nanoseconds
+ */
+static inline int64_t
+millihz_to_nsec(uint32_t mhz)
+{
+	assert(mhz > 0);
+	return 1000000000000LL / mhz;
+}
+
+#endif /* TIMESPEC_UTIL_H */