qbutil.h (3) - Linux Manuals

NAME

qbutil.h -

These are some convience functions used throughout libqb.

SYNOPSIS


#include <pthread.h>
#include <stdint.h>
#include <unistd.h>
#include <qb/qbdefs.h>

Macros


#define QB_UTIL_SW_OVERWRITE 0x01

Typedefs


typedef struct qb_thread_lock_s qb_thread_lock_t

typedef void(* qb_util_log_fn_t )(const char *file_name, int32_t file_line, int32_t severity, const char *msg)

typedef struct qb_util_stopwatch qb_util_stopwatch_t

Enumerations


enum qb_thread_lock_type_t { QB_THREAD_LOCK_SHORT, QB_THREAD_LOCK_LONG }
QB_THREAD_LOCK_SHORT is a short term lock (spinlock if available on your system) QB_THREAD_LOCK_LONG is a mutex.

Functions


qb_thread_lock_t * qb_thread_lock_create (qb_thread_lock_type_t type)
Create a new lock of the given type.
int32_t qb_thread_lock (qb_thread_lock_t *tl)
Calls either pthread_mutex_lock() or pthread_spin_lock().
int32_t qb_thread_trylock (qb_thread_lock_t *tl)
Calls either pthread_mutex_trylock() or pthread_spin_trylock().
int32_t qb_thread_unlock (qb_thread_lock_t *tl)
Calls either pthread_mutex_unlock() or pthread_spin_unlock.
int32_t qb_thread_lock_destroy (qb_thread_lock_t *tl)
Calls either pthread_mutex_destro() or pthread_spin_destroy().
void qb_util_set_log_function (qb_util_log_fn_t fn) QB_GNUC_DEPRECATED
Use this function to output libqb internal log message as you wish.
void qb_timespec_add_ms (struct timespec *ts, int32_t ms)
Add milliseconds onto the timespec.
uint64_t qb_util_nano_current_get (void)
Get the current number of nano secounds produced by the systems incrementing clock (CLOCK_MONOTOMIC if available).
uint64_t qb_util_nano_monotonic_hz (void)
Get the frequence of the clock used in qb_util_nano_current_get().
uint64_t qb_util_nano_from_epoch_get (void)
Get the time in nano seconds since epoch.
void qb_util_timespec_from_epoch_get (struct timespec *ts)
Get the time in timespec since epoch.
char * qb_strerror_r (int errnum, char *buf, size_t buflen)
strerror_r replacement.
qb_util_stopwatch_t * qb_util_stopwatch_create (void)
Create a Stopwatch (to time operations)
void qb_util_stopwatch_free (qb_util_stopwatch_t *sw)
Free the stopwatch.
void qb_util_stopwatch_start (qb_util_stopwatch_t *sw)
Start the stopwatch.
void qb_util_stopwatch_stop (qb_util_stopwatch_t *sw)
Stop the stopwatch.
uint64_t qb_util_stopwatch_us_elapsed_get (qb_util_stopwatch_t *sw)
Get the elapsed time in micro seconds.
float qb_util_stopwatch_sec_elapsed_get (qb_util_stopwatch_t *sw)
Get the elapsed time in seconds.
int32_t qb_util_stopwatch_split_ctl (qb_util_stopwatch_t *sw, uint32_t max_splits, uint32_t options)

uint64_t qb_util_stopwatch_split (qb_util_stopwatch_t *sw)
Create a new time split (or lap time)
uint32_t qb_util_stopwatch_split_last (qb_util_stopwatch_t *sw)
Get the last split index to be used by qb_util_stopwatch_time_split_get()
uint64_t qb_util_stopwatch_time_split_get (qb_util_stopwatch_t *sw, uint32_t receint, uint32_t older)
Read the time split (in us) from 'receint' to 'older'.

Detailed Description

These are some convience functions used throughout libqb.

Author:

Angus Salkeld asalkeld [at] redhat.com

Locking

•
qb_thread_lock_create()
•
qb_thread_lock()
•
qb_thread_trylock()
•
qb_thread_unlock()
•
qb_thread_lock_destroy()

Time functions

•
qb_timespec_add_ms()
•
qb_util_nano_current_get()
•
qb_util_nano_monotonic_hz()
•
qb_util_nano_from_epoch_get()
•
qb_util_timespec_from_epoch_get()

Basic Stopwatch 

* uint64_t elapsed1;
* uint64_t elapsed2;
* qb_util_stopwatch_t *sw = qb_util_stopwatch_create();
*
* qb_util_stopwatch_start(sw);
*
* usleep(sometime);
* qb_util_stopwatch_stop(sw);
* elapsed1 = qb_util_stopwatch_us_elapsed_get(sw);
*
* usleep(somemoretime);
* qb_util_stopwatch_stop(sw);
* elapsed2 = qb_util_stopwatch_us_elapsed_get(sw);
*
* qb_util_stopwatch_free(sw);
*

Stopwatch with splits

Setup a stopwatch with space for 3 splits. 

* uint64_t split;
* qb_util_stopwatch_t *sw = qb_util_stopwatch_create();
*
* qb_util_stopwatch_split_ctl(sw, 3, 0);
* qb_util_stopwatch_start(sw);
*
* usleep(sometime);
* qb_util_stopwatch_split(sw);
*
* usleep(somemoretime);
* qb_util_stopwatch_split(sw);
*
* usleep(somemoretime);
* qb_util_stopwatch_split(sw);
*
* idx = qb_util_stopwatch_split_last(sw);
* do {
*      split = qb_util_stopwatch_time_split_get(sw, idx, idx);
*      qb_log(LOG_INFO, "split %d is %"PRIu64"", last, split);
*      idx--;
* } while (split > 0);
*
* split = qb_util_stopwatch_time_split_get(sw, 2, 1);
* qb_log(LOG_INFO, "time between second and third split is %"PRIu64"", split);
*
* qb_util_stopwatch_free(sw);
*


 

Macro Definition Documentation

#define QB_UTIL_SW_OVERWRITE 0x01

Typedef Documentation

typedef struct qb_thread_lock_s qb_thread_lock_t

typedef void(* qb_util_log_fn_t)(const char *file_name, int32_t file_line, int32_t severity, const char *msg)

typedef struct qb_util_stopwatch qb_util_stopwatch_t

Enumeration Type Documentation

enum qb_thread_lock_type_t

QB_THREAD_LOCK_SHORT is a short term lock (spinlock if available on your system) QB_THREAD_LOCK_LONG is a mutex.

Enumerator

QB_THREAD_LOCK_SHORT
QB_THREAD_LOCK_LONG

Function Documentation

char* qb_strerror_r (interrnum, char *buf, size_tbuflen)

strerror_r replacement.

int32_t qb_thread_lock (qb_thread_lock_t *tl)

Calls either pthread_mutex_lock() or pthread_spin_lock().

qb_thread_lock_t* qb_thread_lock_create (qb_thread_lock_type_ttype)

Create a new lock of the given type.

Parameters:

type QB_THREAD_LOCK_SHORT == spinlock (where available, else mutex) QB_THREAD_LOCK_LONG == mutex

Returns:

pointer to qb_thread_lock_type_t or NULL on error.

int32_t qb_thread_lock_destroy (qb_thread_lock_t *tl)

Calls either pthread_mutex_destro() or pthread_spin_destroy().

int32_t qb_thread_trylock (qb_thread_lock_t *tl)

Calls either pthread_mutex_trylock() or pthread_spin_trylock().

int32_t qb_thread_unlock (qb_thread_lock_t *tl)

Calls either pthread_mutex_unlock() or pthread_spin_unlock.

void qb_timespec_add_ms (struct timespec *ts, int32_tms)

Add milliseconds onto the timespec.

Parameters:

ts the ts to add to
ms the amount of milliseconds to increment ts

uint64_t qb_util_nano_current_get (void)

Get the current number of nano secounds produced by the systems incrementing clock (CLOCK_MONOTOMIC if available).

uint64_t qb_util_nano_from_epoch_get (void)

Get the time in nano seconds since epoch.

uint64_t qb_util_nano_monotonic_hz (void)

Get the frequence of the clock used in qb_util_nano_current_get().

void qb_util_set_log_function (qb_util_log_fn_tfn)

Use this function to output libqb internal log message as you wish.

qb_util_stopwatch_t* qb_util_stopwatch_create (void)

Create a Stopwatch (to time operations)

void qb_util_stopwatch_free (qb_util_stopwatch_t *sw)

Free the stopwatch.

float qb_util_stopwatch_sec_elapsed_get (qb_util_stopwatch_t *sw)

Get the elapsed time in seconds. (it must have been started and stopped).

uint64_t qb_util_stopwatch_split (qb_util_stopwatch_t *sw)

Create a new time split (or lap time)

Parameters:

sw the stopwatch

Return values:

the relative split time in micro seconds
0 if no more splits available

int32_t qb_util_stopwatch_split_ctl (qb_util_stopwatch_t *sw, uint32_tmax_splits, uint32_toptions)

Parameters:

sw the stopwatch
max_splits maximum number of time splits
options (0 or QB_UTIL_SW_OVERWRITE )

Return values:

0 on success
-errno on failure

uint32_t qb_util_stopwatch_split_last (qb_util_stopwatch_t *sw)

Get the last split index to be used by qb_util_stopwatch_time_split_get()

Note:

this is zero based

Parameters:

sw the stopwatch

Returns:

the last entry index

void qb_util_stopwatch_start (qb_util_stopwatch_t *sw)

Start the stopwatch. This also acts as a reset. Essentially it sets the starting time and clears the splits.

void qb_util_stopwatch_stop (qb_util_stopwatch_t *sw)

Stop the stopwatch. This just allows you to get the elapsed time. So you can call this multiple times. Do not call qb_util_stopwatch_start() unless you want to reset the stopwatch.

uint64_t qb_util_stopwatch_time_split_get (qb_util_stopwatch_t *sw, uint32_treceint, uint32_tolder)

Read the time split (in us) from 'receint' to 'older'. If older == receint then the cumulated split will be returned (from the stopwatch start).

Parameters:

sw the stopwatch
receint split
older split

Return values:

the split time in micro seconds
0 if not a valid split

uint64_t qb_util_stopwatch_us_elapsed_get (qb_util_stopwatch_t *sw)

Get the elapsed time in micro seconds. (it must have been started and stopped).

void qb_util_timespec_from_epoch_get (struct timespec *ts)

Get the time in timespec since epoch.

Parameters:

ts (out) the timespec

Returns:

status (0 == ok, -errno on error)

Author

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