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Functions

pj_status_t pj_gettickcount (pj_time_val *tv)
 
pj_status_t pj_get_timestamp (pj_timestamp *ts)
 
pj_status_t pj_get_timestamp_freq (pj_timestamp *freq)
 
void pj_set_timestamp32 (pj_timestamp *t, pj_uint32_t hi, pj_uint32_t lo)
 
int pj_cmp_timestamp (const pj_timestamp *t1, const pj_timestamp *t2)
 
void pj_add_timestamp (pj_timestamp *t1, const pj_timestamp *t2)
 
void pj_add_timestamp32 (pj_timestamp *t1, pj_uint32_t t2)
 
void pj_sub_timestamp (pj_timestamp *t1, const pj_timestamp *t2)
 
void pj_sub_timestamp32 (pj_timestamp *t1, pj_uint32_t t2)
 
pj_int32_t pj_timestamp_diff32 (const pj_timestamp *t1, const pj_timestamp *t2)
 
pj_time_val pj_elapsed_time (const pj_timestamp *start, const pj_timestamp *stop)
 
pj_uint32_t pj_elapsed_msec (const pj_timestamp *start, const pj_timestamp *stop)
 
pj_uint64_t pj_elapsed_msec64 (const pj_timestamp *start, const pj_timestamp *stop)
 
pj_uint32_t pj_elapsed_usec (const pj_timestamp *start, const pj_timestamp *stop)
 
pj_uint32_t pj_elapsed_nanosec (const pj_timestamp *start, const pj_timestamp *stop)
 
pj_uint32_t pj_elapsed_cycle (const pj_timestamp *start, const pj_timestamp *stop)
 

Detailed Description

PJLIB provides High Resolution Timestamp API to access highest resolution timestamp value provided by the platform. The API is usefull to measure precise elapsed time, and can be used in applications such as profiling.

The timestamp value is represented in cycles, and can be related to normal time (in seconds or sub-seconds) using various functions provided.

Examples

For examples, please see:

Function Documentation

void pj_add_timestamp ( pj_timestamp t1,
const pj_timestamp t2 
)

Add timestamp t2 to t1.

Parameters
t1t1.
t2t2.
void pj_add_timestamp32 ( pj_timestamp t1,
pj_uint32_t  t2 
)

Add timestamp t2 to t1.

Parameters
t1t1.
t2t2.
int pj_cmp_timestamp ( const pj_timestamp t1,
const pj_timestamp t2 
)

Compare timestamp t1 and t2.

Parameters
t1t1.
t2t2.
Returns
-1 if (t1 < t2), 1 if (t1 > t2), or 0 if (t1 == t2)
pj_uint32_t pj_elapsed_cycle ( const pj_timestamp start,
const pj_timestamp stop 
)

Calculate the elapsed time in 32-bit cycles. This function calculates the elapsed time using highest precision calculation that is available for current platform, considering whether floating point or 64-bit precision arithmetic is available. For maximum portability, application should prefer to use this function rather than calculating the elapsed time by itself.

Parameters
startThe starting timestamp.
stopThe end timestamp.
Returns
Elapsed time in cycles.
See also
pj_elapsed_usec(), pj_elapsed_time(), pj_elapsed_nanosec()
pj_uint32_t pj_elapsed_msec ( const pj_timestamp start,
const pj_timestamp stop 
)

Calculate the elapsed time as 32-bit miliseconds. This function calculates the elapsed time using highest precision calculation that is available for current platform, considering whether floating point or 64-bit precision arithmetic is available. For maximum portability, application should prefer to use this function rather than calculating the elapsed time by itself.

Parameters
startThe starting timestamp.
stopThe end timestamp.
Returns
Elapsed time in milisecond.
See also
pj_elapsed_time(), pj_elapsed_cycle(), pj_elapsed_nanosec()
pj_uint64_t pj_elapsed_msec64 ( const pj_timestamp start,
const pj_timestamp stop 
)

Variant of pj_elapsed_msec() which returns 64bit value.

pj_uint32_t pj_elapsed_nanosec ( const pj_timestamp start,
const pj_timestamp stop 
)

Calculate the elapsed time in 32-bit nanoseconds. This function calculates the elapsed time using highest precision calculation that is available for current platform, considering whether floating point or 64-bit precision arithmetic is available. For maximum portability, application should prefer to use this function rather than calculating the elapsed time by itself.

Parameters
startThe starting timestamp.
stopThe end timestamp.
Returns
Elapsed time in nanoseconds.
See also
pj_elapsed_time(), pj_elapsed_cycle(), pj_elapsed_usec()
pj_time_val pj_elapsed_time ( const pj_timestamp start,
const pj_timestamp stop 
)

Calculate the elapsed time, and store it in pj_time_val. This function calculates the elapsed time using highest precision calculation that is available for current platform, considering whether floating point or 64-bit precision arithmetic is available. For maximum portability, application should prefer to use this function rather than calculating the elapsed time by itself.

Parameters
startThe starting timestamp.
stopThe end timestamp.
Returns
Elapsed time as pj_time_val.
See also
pj_elapsed_usec(), pj_elapsed_cycle(), pj_elapsed_nanosec()
pj_uint32_t pj_elapsed_usec ( const pj_timestamp start,
const pj_timestamp stop 
)

Calculate the elapsed time in 32-bit microseconds. This function calculates the elapsed time using highest precision calculation that is available for current platform, considering whether floating point or 64-bit precision arithmetic is available. For maximum portability, application should prefer to use this function rather than calculating the elapsed time by itself.

Parameters
startThe starting timestamp.
stopThe end timestamp.
Returns
Elapsed time in microsecond.
See also
pj_elapsed_time(), pj_elapsed_cycle(), pj_elapsed_nanosec()
pj_status_t pj_get_timestamp ( pj_timestamp ts)

Acquire high resolution timer value. The time value are stored in cycles.

Parameters
tsHigh resolution timer value.
Returns
PJ_SUCCESS or the appropriate error code.
See also
pj_get_timestamp_freq().
pj_status_t pj_get_timestamp_freq ( pj_timestamp freq)

Get high resolution timer frequency, in cycles per second.

Parameters
freqTimer frequency, in cycles per second.
Returns
PJ_SUCCESS or the appropriate error code.
pj_status_t pj_gettickcount ( pj_time_val tv)

Get monotonic time since some unspecified starting point.

Parameters
tvVariable to store the result.
Returns
PJ_SUCCESS if successful.
void pj_set_timestamp32 ( pj_timestamp t,
pj_uint32_t  hi,
pj_uint32_t  lo 
)

Set timestamp from 32bit values.

Parameters
tThe timestamp to be set.
hiThe high 32bit part.
loThe low 32bit part.
void pj_sub_timestamp ( pj_timestamp t1,
const pj_timestamp t2 
)

Substract timestamp t2 from t1.

Parameters
t1t1.
t2t2.
void pj_sub_timestamp32 ( pj_timestamp t1,
pj_uint32_t  t2 
)

Substract timestamp t2 from t1.

Parameters
t1t1.
t2t2.
pj_int32_t pj_timestamp_diff32 ( const pj_timestamp t1,
const pj_timestamp t2 
)

Get the timestamp difference between t2 and t1 (that is t2 minus t1), and return a 32bit signed integer difference.

References pj_int32_t.

 


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