Mutual-exclusion critical section for protecting shared resources between tasks. More...

#include <nbrtos.h>

Inherits OS_TASK_DLY_OBJ.

Public Member Functions
	OS_CRIT ()
	Construct and initialize the OS_CRIT object.

uint8_t	Init ()
	Reset the OS_CRIT object to its initial (unclaimed) state.

uint8_t	LockAndEnter (uint32_t timeoutTicks=WAIT_FOREVER)
	Disable task switching (lock) and then claim the critical section.

uint8_t	Enter (TickTimeout &t)
	Claim the critical section, using a TickTimeout to limit waiting.

uint8_t	Enter (uint32_t timeoutTicks=WAIT_FOREVER)
	Claim the critical section with a timeout in system ticks.

uint8_t	EnterNoWait ()
	Attempt to claim the critical section without blocking.

uint8_t	Leave ()
	Release one level of ownership of the critical section.

uint8_t	LeaveAndUnlock ()
	Release the critical section and re-enable task switching.

bool	UsedFromISR ()
	Check whether this critical section is marked for ISR usage.

void	SetUseFromISR (bool enableFromISR)
	Enable or disable the UsedFromISR flag for this critical section.

bool	OwnedByCurTask ()
	Check whether the calling task currently owns this critical section.

uint32_t	CurDepth ()
	Get the current recursive entry depth of this critical section.

Friends
class	fifo_buffer_storage

void	ForceReboot (bool fromIRQ=false)
	Friend declaration allowing ForceReboot() to access critical section internals.

Detailed Description

Mutual-exclusion critical section for protecting shared resources between tasks.

An OS_CRIT ensures that only one task at a time can execute a protected code region. Tasks that attempt to enter a critical section already owned by another task will block until the owning task calls Leave(). Critical sections support recursive (nested) entry by the same task – each Enter() must be paired with a Leave().

For RAII-style usage, see OSCriticalSectionObj, OSLockAndCritObj, or OSSpinCrit.

See also: OSCriticalSectionObj, OSLockAndCritObj, OSSpinCrit

Expand for Example Usage

Examples

Protect Shared Data: OS_CRIT gDataCrit;

int gSharedCounter;

void IncrementCounter()

{

gDataCrit.Enter();

gSharedCounter++;

gDataCrit.Leave();

}

OS_CRIT
Mutual-exclusion critical section for protecting shared resources between tasks.
Definition nbrtos.h:1391

OS_CRIT::Enter
uint8_t Enter(TickTimeout &t)
Claim the critical section, using a TickTimeout to limit waiting.

OS_CRIT::Leave
uint8_t Leave()
Release one level of ownership of the critical section.

RAII Usage with OSCriticalSectionObj: void SafeAccess()

{

OSCriticalSectionObj lock(gDataCrit);

// gDataCrit is held until lock goes out of scope

gSharedCounter++;

}

OSCriticalSectionObj
RAII wrapper for OS_CRIT that automatically enters and leaves a critical section.
Definition nbrtos.h:3022

Constructor & Destructor Documentation

◆ OS_CRIT()

OS_CRIT::OS_CRIT ( )

inline

Construct and initialize the OS_CRIT object.

See also: Init()

Member Function Documentation

◆ CurDepth()

uint32_t OS_CRIT::CurDepth ( )

inline

Get the current recursive entry depth of this critical section.

A depth of 0 means the section is not currently claimed.

Returns: The current nesting depth count.

◆ Enter() [1/2]

uint8_t OS_CRIT::Enter ( TickTimeout & t )

Claim the critical section, using a TickTimeout to limit waiting.

The section supports recursive entry: if the calling task already owns it, this call succeeds immediately and increments the depth count. Each successful Enter() must be paired with a corresponding Leave().

Parameters

t	TickTimeout controlling the maximum wait duration.

Return values

OS_NO_ERR	The section was claimed (or already owned by this task).
OS_TIMEOUT	The section could not be claimed before the timeout.

See also: EnterNoWait(), Leave(), NBRTOS Error Codes

◆ Enter() [2/2]

uint8_t OS_CRIT::Enter ( uint32_t timeoutTicks = WAIT_FOREVER )

inline

Claim the critical section with a timeout in system ticks.

Each successful Enter() must be paired with a corresponding Leave().

Parameters

timeoutTicks Maximum system ticks to wait. A value of 0 (default) waits forever.

Return values

OS_NO_ERR	The section was claimed (or already owned by this task).
OS_TIMEOUT	The section could not be claimed before the timeout.

See also: EnterNoWait(), Leave(), NBRTOS Error Codes

◆ EnterNoWait()

uint8_t OS_CRIT::EnterNoWait ( )

Attempt to claim the critical section without blocking.

Returns immediately whether or not the section was claimed. Each successful call must be paired with a corresponding Leave().

Return values

OS_NO_ERR	The section was claimed (or already owned by this task).
OS_TIMEOUT	The section is owned by another task.

See also: Enter(), Leave(), NBRTOS Error Codes

◆ Init()

uint8_t OS_CRIT::Init ( )

Reset the OS_CRIT object to its initial (unclaimed) state.

Return values

OS_NO_ERR If successful.

See also: NBRTOS Error Codes

◆ Leave()

uint8_t OS_CRIT::Leave ( )

Release one level of ownership of the critical section.

Must be called once for each successful Enter() or EnterNoWait(). When the depth count reaches zero, the section is released and the highest-priority waiting task (if any) is made ready.

Return values

OS_NO_ERR	The depth count was decremented (or the section was fully released).
OS_CRIT_ERR	The calling task does not own this critical section.

See also: Enter(), EnterNoWait(), NBRTOS Error Codes

◆ LeaveAndUnlock()

uint8_t OS_CRIT::LeaveAndUnlock ( )

Release the critical section and re-enable task switching.

Must be called once for each successful LockAndEnter() call to release both the critical section and the scheduler lock.

Return values

OS_NO_ERR If successful.

See also: LockAndEnter(), NBRTOS Error Codes

◆ LockAndEnter()

uint8_t OS_CRIT::LockAndEnter ( uint32_t timeoutTicks = WAIT_FOREVER )

Disable task switching (lock) and then claim the critical section.

Combines OSLock() with Enter() in a single call. If the section cannot be claimed before the timeout, the lock is automatically released. On success, you must call LeaveAndUnlock() once for each LockAndEnter() call.

Parameters

timeoutTicks Maximum ticks to wait. A value of 0 (default) waits forever.

Return values

OS_NO_ERR	The section was claimed (or was already owned by this task).
OS_TIMEOUT	The section could not be claimed before the timeout.

See also: LeaveAndUnlock(), Enter(), NBRTOS Error Codes

◆ SetUseFromISR()

void OS_CRIT::SetUseFromISR ( bool enableFromISR )

inline

Enable or disable the UsedFromISR flag for this critical section.

When set, the critical section uses interrupt-safe operations suitable for use from interrupt service routines.

Parameters

enableFromISR Set to true to enable ISR usage, false to disable.

See also: UsedFromISR()

◆ UsedFromISR()

bool OS_CRIT::UsedFromISR ( )

inline

Check whether this critical section is marked for ISR usage.

Return values

true	The UsedFromISR flag is set.
false	The flag is not set.

See also: SetUseFromISR()

Friends And Related Symbol Documentation

◆ ForceReboot

void ForceReboot ( bool fromIRQ = false )

friend

Friend declaration allowing ForceReboot() to access critical section internals.

This function triggers a complete system restart by directly commanding the hardware reset mechanisms. The reset is immediate and unconditional - all running processes are terminated, memory contents are cleared, and the system restarts from the boot sequence. This is equivalent to a power cycle but is performed through software control. The function never returns to the calling code as the system undergoes a complete restart.

Parameters

fromIRQ Optional parameter indicating the reset context true: reset is being triggered from within an interrupt service routine or exception handler, which may require special handling procedures false: reset is being triggered from normal application code (default)

Note: This function never returns - execution does not continue after this call. All unsaved data, network connections, and application state will be lost. File systems and persistent storage should be properly synchronized before calling. The fromIRQ parameter ensures proper reset handling when called from interrupt contexts. After reset, the system will restart from the beginning of the boot sequence. Use this function only when a complete system restart is absolutely necessary.

Warning: This function immediately terminates all system operations without cleanup. Ensure critical data is saved and network connections are properly closed before use.

See also: attribute((noreturn)) indicates this function never returns to the caller

The documentation for this struct was generated from the following file:

nbrtos.h

Public Member Functions

Friends

Detailed Description

Constructor & Destructor Documentation

◆ OS_CRIT()

Member Function Documentation

◆ CurDepth()

◆ Enter() [1/2]

◆ Enter() [2/2]

◆ EnterNoWait()

◆ Init()

◆ Leave()

◆ LeaveAndUnlock()

◆ LockAndEnter()

◆ SetUseFromISR()

◆ UsedFromISR()

Friends And Related Symbol Documentation

◆ ForceReboot