-/*
- * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
+/* Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
#include "para.h"
/** \file time.c Helper functions for dealing with time values. */
*
* \param tv The time value value to convert.
*
- * \return The number off milliseconds in \a tv.
+ * \return The number of milliseconds in \a tv.
*/
long unsigned tv2ms(const struct timeval *tv)
{
tv->tv_usec = (n % 1000) * 1000;
}
-/**
- * Convert a double to a struct timeval.
- *
- * \param x The value to convert.
- * \param tv Result pointer.
- */
-void d2tv(double x, struct timeval *tv)
-{
- tv->tv_sec = x;
- tv->tv_usec = (x - (double)tv->tv_sec) * 1000.0 * 1000.0 + 0.5;
-}
-
/**
* Compute the difference of two time values.
*
*
* \return If \a b < \a a, this function returns -1, otherwise it returns 1.
*/
-int tv_diff(const struct timeval *b, const struct timeval *a, struct timeval *diff)
+int tv_diff(const struct timeval *b, const struct timeval *a,
+ struct timeval *diff)
{
int ret = 1;
*
* \param a First addend.
* \param b Second addend.
- * \param sum Contains the sum \a + \a b on return.
+ * \param sum Contains the sum \a a + \a b on return.
*/
void tv_add(const struct timeval *a, const struct timeval *b,
- struct timeval *sum)
+ struct timeval *sum)
{
sum->tv_sec = a->tv_sec + b->tv_sec;
if (a->tv_usec + b->tv_usec >= 1000 * 1000) {
* \param result Contains \a mult * \a tv on return.
*/
void tv_scale(const unsigned long mult, const struct timeval *tv,
- struct timeval *result)
+ struct timeval *result)
{
uint64_t x = ((uint64_t)tv->tv_sec * 1000 * 1000 + tv->tv_usec) * mult;
* \param result Contains (1 / mult) * tv on return.
*/
void tv_divide(const unsigned long divisor, const struct timeval *tv,
- struct timeval *result)
+ struct timeval *result)
{
uint64_t x = ((uint64_t)tv->tv_sec * 1000 * 1000 + tv->tv_usec) / divisor;
/**
* Compute a convex combination of two time values.
*
- * \param a The first coefiicent.
+ * \param a The first coefficient.
* \param tv1 The first time value.
- * \param b The second coefiicent.
+ * \param b The second coefficient.
* \param tv2 The second time value.
* \param result Contains the convex combination upon return.
*
- * compute x := (a * tv1 + b * tv2) / (|a| + |b|) and store |x| in \a result.
+ * Compute x := (a * tv1 + b * tv2) / (|a| + |b|) and store |x| in \a result.
* Both \a a and \a b may be negative.
*
- * \return One if \a x is positive, -1 otherwise.
+ * \return Zero, 1 or -1, if \a x is zero, positive or negative, respectively.
*/
int tv_convex_combination(const long a, const struct timeval *tv1,
const long b, const struct timeval *tv2,
struct timeval *result)
{
struct timeval tmp1, tmp2, tmp3;
- int ret = 1, subtract = ((a > 0 && b < 0) || (a < 0 && b > 0));
- unsigned long a1 = PARA_ABS(a), b1 = PARA_ABS(b);
+ int ret = 1;
+ unsigned long a1, b1;
+ if (a == 0 && b == 0) {
+ result->tv_sec = 0;
+ result->tv_usec = 0;
+ return 0;
+ }
+ a1 = PARA_ABS(a);
+ b1 = PARA_ABS(b);
tv_scale(a1, tv1, &tmp1);
tv_scale(b1, tv2, &tmp2);
- if (subtract)
+ if ((a > 0 && b < 0) || (a < 0 && b > 0)) /* subtract */
ret = tv_diff(&tmp1, &tmp2, &tmp3);
else
tv_add(&tmp1, &tmp2, &tmp3);
- if (a1 + b1)
- tv_divide(a1 + b1, &tmp3, result);
- else {
- result->tv_sec = 0;
- result->tv_usec = 0;
- }
+ tv_divide(a1 + b1, &tmp3, result);
if (!a || !b) {
if (a + b < 0)
ret = -1;
- } else
- if (a < 0)
- ret = -ret;
+ } else if (a < 0)
+ ret = -ret;
return ret;
}
* \param stream_start When the first chunk was sent.
* \param result The time when to send chunk number \a chunk_num.
*
- * This function computes stream_start + chunk_num * chunk_time.
+ * This function computes \a stream_start + \a chunk_num * \a chunk_time.
*/
void compute_chunk_time(long unsigned chunk_num,
struct timeval *chunk_tv, struct timeval *stream_start,
tv_scale(chunk_num, chunk_tv, &tmp);
tv_add(&tmp, stream_start, result);
}
+
+/**
+ * Retrieve the time of the realtime clock.
+ *
+ * \param tv Where to store the result.
+ *
+ * Gets the current value of the system-wide real-time clock (identified by id
+ * \p CLOCK_REALTIME). If \a tv is \p NULL, the value is stored in a static
+ * buffer, otherwise it is stored at the location given by \a tv.
+ *
+ * \return This function aborts on errors. On success it returns a pointer to
+ * memory containing the current time.
+ *
+ * \sa clock_gettime(2), gettimeofday(2).
+ */
+struct timeval *clock_get_realtime(struct timeval *tv)
+{
+ static struct timeval user_friendly;
+ struct timespec t;
+ int ret;
+
+ if (!tv)
+ tv = &user_friendly;
+ ret = clock_gettime(CLOCK_REALTIME, &t);
+ assert(ret == 0);
+ tv->tv_sec = t.tv_sec;
+ tv->tv_usec = t.tv_nsec / 1000;
+ return tv;
+}
projects / paraslash.git / blobdiff