Time and priorities

Ticks, timeouts and thread priorities shared by every kernel object. More...

Data Structures
struct	pbl_timeout_t
	Timeout of a blocking call. More...

Macros
#define	PBL_TICK_HZ   CONFIG_KERNEL_TICK_HZ
	Tick rate in Hz, from CONFIG_KERNEL_TICK_HZ.
#define	PBL_TICK_FOREVER   UINT32_MAX
	Tick count that stands for an infinite timeout.
#define	PBL_NO_WAIT   ((pbl_timeout_t){.ticks = 0})
	Do not wait: fail with -EBUSY if the call would block.
#define	PBL_FOREVER   ((pbl_timeout_t){.ticks = PBL_TICK_FOREVER})
	Wait without a time limit.
#define	PBL_TICKS(t)   ((pbl_timeout_t){.ticks = (t)})
	Timeout in ticks.
#define	PBL_MSEC(ms)   ((pbl_timeout_t){.ticks = pbl_ms_to_ticks(ms)})
	Timeout in milliseconds, rounded down to whole ticks.
#define	PBL_SEC(s)   PBL_MSEC((s) * 1000U)
	Timeout in seconds.
#define	PBL_PRIO_IDLE   ((pbl_prio_t)0)
	Lowest priority, the one of the idle thread.
#define	PBL_PRIO_MAX   ((pbl_prio_t)(CONFIG_KERNEL_NUM_PRIORITIES - 1))
	Highest priority, CONFIG_KERNEL_NUM_PRIORITIES - 1.

Typedefs
typedef uint32_t	pbl_tick_t
	Kernel tick count.
typedef uint8_t	pbl_prio_t
	Thread priority.

Functions
pbl_tick_t	pbl_ms_to_ticks (uint32_t ms)
	Convert milliseconds to ticks, rounding down.
uint32_t	pbl_ticks_to_ms (pbl_tick_t ticks)
	Convert ticks to milliseconds, rounding down.
static bool	pbl_timeout_is_forever (pbl_timeout_t t)
	Check whether a timeout is PBL_FOREVER.
static bool	pbl_timeout_is_no_wait (pbl_timeout_t t)
	Check whether a timeout is PBL_NO_WAIT.

Detailed Description

Ticks, timeouts and thread priorities shared by every kernel object.

Blocking calls take a pbl_timeout_t built with one of the timeout macros, so ticks and milliseconds cannot be mixed up:

pbl_sem_take(&sem, PBL_NO_WAIT);    // poll
pbl_sem_take(&sem, PBL_MSEC(100));  // wait up to 100 ms
pbl_sem_take(&sem, PBL_FOREVER);    // wait indefinitely

---

Data Structure Documentation

pbl_timeout_t

struct pbl_timeout_t

Timeout of a blocking call.

A distinct type so ticks and milliseconds cannot be mixed; build it with PBL_NO_WAIT, PBL_FOREVER, PBL_TICKS, PBL_MSEC or PBL_SEC.

Data Fields
pbl_tick_t	ticks	Ticks to wait, 0 for no wait or PBL_TICK_FOREVER for no limit.

Macro Definition Documentation

PBL_FOREVER

#define PBL_FOREVER   ((pbl_timeout_t){.ticks = PBL_TICK_FOREVER})

Wait without a time limit.

PBL_MSEC

#define PBL_MSEC

(

ms

)

((pbl_timeout_t){.ticks = pbl_ms_to_ticks(ms)})

Timeout in milliseconds, rounded down to whole ticks.

Parameters

ms	Number of milliseconds.

PBL_NO_WAIT

#define PBL_NO_WAIT   ((pbl_timeout_t){.ticks = 0})

Do not wait: fail with -EBUSY if the call would block.

PBL_PRIO_IDLE

#define PBL_PRIO_IDLE   ((pbl_prio_t)0)

Lowest priority, the one of the idle thread.

PBL_PRIO_MAX

#define PBL_PRIO_MAX   ((pbl_prio_t)(CONFIG_KERNEL_NUM_PRIORITIES - 1))

Highest priority, CONFIG_KERNEL_NUM_PRIORITIES - 1.

PBL_SEC

#define PBL_SEC

(

s

)

PBL_MSEC((s) * 1000U)

Timeout in seconds.

Parameters

s	Number of seconds.

PBL_TICK_FOREVER

#define PBL_TICK_FOREVER   UINT32_MAX

Tick count that stands for an infinite timeout.

PBL_TICK_HZ

#define PBL_TICK_HZ   CONFIG_KERNEL_TICK_HZ

Tick rate in Hz, from CONFIG_KERNEL_TICK_HZ.

Matches the RTC tick rate.

PBL_TICKS

#define PBL_TICKS

(

t

)

((pbl_timeout_t){.ticks = (t)})

Timeout in ticks.

Parameters

t	Number of ticks.

Typedef Documentation

pbl_prio_t

typedef uint8_t pbl_prio_t

Thread priority.

Higher value = more urgent.

pbl_tick_t

typedef uint32_t pbl_tick_t

Kernel tick count.

Wraps around; compare differences, not absolute values.

Function Documentation

pbl_ms_to_ticks()

pbl_tick_t pbl_ms_to_ticks

(

uint32_t

ms

)

Convert milliseconds to ticks, rounding down.

Parameters

ms	Milliseconds.

Returns

Ticks.

pbl_ticks_to_ms()

uint32_t pbl_ticks_to_ms

(

pbl_tick_t

ticks

)

Convert ticks to milliseconds, rounding down.

Parameters

ticks

Ticks.

Returns

Milliseconds.

pbl_timeout_is_forever()

static bool pbl_timeout_is_forever ( pbl_timeout_t  t )

inlinestatic

Check whether a timeout is PBL_FOREVER.

Parameters

t

Timeout.

Returns

true if t never expires.

References PBL_TICK_FOREVER, and pbl_timeout_t::ticks.

pbl_timeout_is_no_wait()

static bool pbl_timeout_is_no_wait ( pbl_timeout_t  t )

inlinestatic

Check whether a timeout is PBL_NO_WAIT.

Parameters

t

Timeout.

Returns

true if t does not wait.

References pbl_timeout_t::ticks.