DPDK  16.11.9
rte_time.h
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33 
34 #ifndef _RTE_TIME_H_
35 #define _RTE_TIME_H_
36 
37 #include <stdint.h>
38 #include <time.h>
39 
40 #define NSEC_PER_SEC 1000000000L
41 
48  uint64_t cycle_last;
50  uint64_t nsec;
52  uint64_t nsec_mask;
54  uint64_t nsec_frac;
56  uint64_t cc_mask;
58  uint32_t cc_shift;
59 };
60 
64 static inline uint64_t
65 rte_cyclecounter_cycles_to_ns(struct rte_timecounter *tc, uint64_t cycles)
66 {
67  uint64_t ns;
68 
69  /* Add fractional nanoseconds. */
70  ns = cycles + tc->nsec_frac;
71  tc->nsec_frac = ns & tc->nsec_mask;
72 
73  /* Shift to get only nanoseconds. */
74  return ns >> tc->cc_shift;
75 }
76 
80 static inline uint64_t
81 rte_timecounter_update(struct rte_timecounter *tc, uint64_t cycle_now)
82 {
83  uint64_t cycle_delta, ns_offset;
84 
85  /* Calculate the delta since the last call. */
86  if (tc->cycle_last <= cycle_now)
87  cycle_delta = (cycle_now - tc->cycle_last) & tc->cc_mask;
88  else
89  /* Handle cycle counts that have wrapped around . */
90  cycle_delta = (~(tc->cycle_last - cycle_now) & tc->cc_mask) + 1;
91 
92  /* Convert to nanoseconds. */
93  ns_offset = rte_cyclecounter_cycles_to_ns(tc, cycle_delta);
94 
95  /* Store current cycle counter for next call. */
96  tc->cycle_last = cycle_now;
97 
98  /* Update the nanosecond count. */
99  tc->nsec += ns_offset;
100 
101  return tc->nsec;
102 }
103 
107 static inline uint64_t
108 rte_timespec_to_ns(const struct timespec *ts)
109 {
110  return ((uint64_t) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
111 }
112 
116 static inline struct timespec
117 rte_ns_to_timespec(uint64_t nsec)
118 {
119  struct timespec ts = {0, 0};
120 
121  if (nsec == 0)
122  return ts;
123 
124  ts.tv_sec = nsec / NSEC_PER_SEC;
125  ts.tv_nsec = nsec % NSEC_PER_SEC;
126 
127  return ts;
128 }
129 
130 #endif /* _RTE_TIME_H_ */