src/gallium/auxiliary/os/os_time.h

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  27
  28 /**
  29  * @file
  30  * OS independent time-manipulation functions.
  31  *
  32  * @author Jose Fonseca <jfonseca@vmware.com>
  33  */
  34
  35 #ifndef _OS_TIME_H_
  36 #define _OS_TIME_H_
  37
  38
  39 #include "pipe/p_config.h"
  40
  41 #if defined(PIPE_OS_UNIX)
  42 #  include <unistd.h> /* usleep */
  43 #endif
  44
  45 #include "pipe/p_compiler.h"
  46
  47
  48 #ifdef  __cplusplus
  49 extern "C" {
  50 #endif
  51
  52
  53 /*
  54  * Get the current time in nanoseconds from an unknown base.
  55  */
  56 int64_t
  57 os_time_get_nano(void);
  58
  59
  60 /*
  61  * Get the current time in microseconds from an unknown base.
  62  */
  63 static INLINE int64_t
  64 os_time_get(void) {
  65     return os_time_get_nano() / 1000;
  66 }
  67
  68
  69 /*
  70  * Sleep.
  71  */
  72 #if defined(PIPE_OS_UNIX)
  73 #define os_time_sleep(_usecs) usleep(_usecs)
  74 #else
  75 void
  76 os_time_sleep(int64_t usecs);
  77 #endif
  78
  79
  80 /*
  81  * Helper function for detecting time outs, taking in account overflow.
  82  *
  83  * Returns true if the current time has elapsed beyond the specified interval.
  84  */
  85 static INLINE boolean
  86 os_time_timeout(int64_t start,
  87                 int64_t end,
  88                 int64_t curr)
  89 {
  90    if(start <= end)
  91       return !(start <= curr && curr < end);
  92    else
  93       return !((start <= curr) || (curr < end));
  94 }
  95
  96
  97 /**
  98  * Convert a relative timeout in nanoseconds into an absolute timeout,
  99  * in other words, it returns current time + timeout.
 100  * os_time_get_nano() must be monotonic.
 101  * PIPE_TIMEOUT_INFINITE is passed through unchanged. If the calculation
 102  * overflows, PIPE_TIMEOUT_INFINITE is returned.
 103  */
 104 int64_t
 105 os_time_get_absolute_timeout(uint64_t timeout);
 106
 107
 108 /**
 109  * Wait until the variable at the given memory location is zero.
 110  *
 111  * \param var           variable
 112  * \param timeout       timeout in ns, can be anything from 0 (no wait) to
 113  *                      PIPE_TIME_INFINITE (wait forever)
 114  * \return     true if the variable is zero
 115  */
 116 bool
 117 os_wait_until_zero(volatile int *var, uint64_t timeout);
 118
 119
 120 /**
 121  * Wait until the variable at the given memory location is zero.
 122  * The timeout is the absolute time when the waiting should stop. If it is
 123  * less than or equal to the current time, it only returns the status and
 124  * doesn't wait. PIPE_TIME_INFINITE waits forever. This requires that
 125  * os_time_get_nano is monotonic.
 126  *
 127  * \param var       variable
 128  * \param timeout   the time in ns when the waiting should stop
 129  * \return     true if the variable is zero
 130  */
 131 bool
 132 os_wait_until_zero_abs_timeout(volatile int *var, int64_t timeout);
 133
 134 #ifdef  __cplusplus
 135 }
 136 #endif
 137
 138 #endif /* _OS_TIME_H_ */