#include <qk.hpp>

Collaboration diagram for QK:

Static Public Member Functions
static QSchedStatus	schedLock (std::uint_fast8_t const ceiling) noexcept
	QK selective scheduler lock. More...

static void	schedUnlock (QSchedStatus const stat) noexcept
	QK selective scheduler unlock. More...

static void	onIdle (void)
	QK idle callback (customized in BSPs for QK) More...

static char_t const *	getVersion (void) noexcept
	get the current QK version number string of the form X.Y.Z More...

Detailed Description

QK services.

Description: This class groups together QK services. It has only static members and should not be instantiated.

Note: The QK scheduler, QK priority, QK ready set, etc. belong conceptually to the QK class (as static class members). However, to avoid potential C++ name-mangling problems in assembly language, these elements are defined outside of the QK class and use the extern "C" linkage.

Definition at line 132 of file qk.hpp.

Member Function Documentation

◆ schedLock()

QSchedStatus schedLock ( std::uint_fast8_t const ceiling )

staticnoexcept

QK selective scheduler lock.

Description: This function locks the QK scheduler to the specified ceiling.

Parameters

[in] ceiling priority ceiling to which the QK scheduler needs to be locked

Returns: The previous QK Scheduler lock status, which is to be used to unlock the scheduler by restoring its previous lock status in QP::QK::schedUnlock().

Note: QP::QK::schedLock() must be always followed by the corresponding QP::QK::schedUnlock().

See also: QK_schedUnlock()

Usage: The following example shows how to lock and unlock the QK scheduler:
std::uint32_t BSP::random(void) {

// lock the scheduler around l_rnd up to the (N_PHILO + 1U) ceiling

QP::QSchedStatus lockStat = QP::QK::schedLock(N_PHILO + 1U);

// "Super-Duper" Linear Congruential Generator (LCG)

// LCG(2^32, 3*7*11*13*23, 0, seed)

//

uint32_t rnd = l_rnd * (3U*7U*11U*13U*23U);

l_rnd = rnd; // set for the next time

QP::QK::schedUnlock(lockStat); // unlock sched after accessing l_rnd

return (rnd >> 8);

}

uint32_t
unsigned long int uint32_t
exact-width 32-bit unsigned int
Definition: 16bit/stdint.h:31

QP::QK::schedLock
static QSchedStatus schedLock(std::uint_fast8_t const ceiling) noexcept
QK selective scheduler lock.
Definition: qk.cpp:227

QP::QK::schedUnlock
static void schedUnlock(QSchedStatus const stat) noexcept
QK selective scheduler unlock.
Definition: qk.cpp:277

QP::QSchedStatus
std::uint_fast16_t QSchedStatus
The scheduler lock status.
Definition: qk.hpp:119

Precondition

The QK scheduler lock:

cannot be called from an ISR;

Definition at line 227 of file qk.cpp.

◆ schedUnlock()

void schedUnlock ( QSchedStatus const stat )

staticnoexcept

QK selective scheduler unlock.

Description: This function unlocks the QK scheduler to the previous status.

Parameters

[in] stat previous QK Scheduler lock status returned from QP::QK::schedLock()

Note: QP::QK::schedUnlock() must always follow the corresponding QP::QK::schedLock().

See also: QP::QK::schedLock()

Usage: The following example shows how to lock and unlock the QK scheduler:
std::uint32_t BSP::random(void) {

// lock the scheduler around l_rnd up to the (N_PHILO + 1U) ceiling

QP::QSchedStatus lockStat = QP::QK::schedLock(N_PHILO + 1U);

// "Super-Duper" Linear Congruential Generator (LCG)

// LCG(2^32, 3*7*11*13*23, 0, seed)

//

uint32_t rnd = l_rnd * (3U*7U*11U*13U*23U);

l_rnd = rnd; // set for the next time

QP::QK::schedUnlock(lockStat); // unlock sched after accessing l_rnd

return (rnd >> 8);

}

Precondition

The scheduler cannot be unlocked:

from the ISR context; and
the current lock priority must be greater than the previous

Definition at line 277 of file qk.cpp.

◆ onIdle()

static void onIdle ( void )

static

QK idle callback (customized in BSPs for QK)

Description: QP::QK::onIdle() is called continously by the QK idle loop. This callback gives the application an opportunity to enter a power-saving CPU mode, or perform some other idle processing.

Note: QP::QK::onIdle() is invoked with interrupts enabled and must also return with interrupts enabled.

See also: QP::QF::onIdle()

◆ getVersion()

static char_t const* getVersion ( void )

inlinestaticnoexcept

get the current QK version number string of the form X.Y.Z

Definition at line 155 of file qk.hpp.