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granular lock stage 2 - TCB data group change#97

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chinglee-iot wants to merge 64 commits intodev/update_for_granular_lock_demofrom
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granular lock stage 2 - TCB data group change#97
chinglee-iot wants to merge 64 commits intodev/update_for_granular_lock_demofrom
dev/update_for_granular_lock_demo_TCB_lock

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Description

Test Steps

Checklist:

  • I have tested my changes. No regression in existing tests.
  • I have modified and/or added unit-tests to cover the code changes in this Pull Request.

Related Issue

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

Dazza0 and others added 30 commits May 23, 2025 08:49
…herit()

xTaskPriorityInherit() is called inside a critical section from queue.c. This
commit moves the critical section into xTaskPriorityInherit().

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Changed xPreemptionDisable to be a count rather than a pdTRUE/pdFALSE. This
allows nested calls to vTaskPreemptionEnable(), where a yield only occurs when
xPreemptionDisable is 0.

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Adds the required checks for granular locking port macros.

Port Config:

- portUSING_GRANULAR_LOCKS to enable granular locks
- portCRITICAL_NESTING_IN_TCB should be disabled

Granular Locking Port Macros:

- Spinlocks
        - portSPINLOCK_TYPE
        - portINIT_SPINLOCK( pxSpinlock )
        - portINIT_SPINLOCK_STATIC
- Locking
        - portGET_SPINLOCK()
        - portRELEASE_SPINLOCK()

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
- Updated prvCheckForRunStateChange() for granular locks
- Updated vTaskSuspendAll() and xTaskResumeAll()
    - Now holds the xTaskSpinlock during kernel suspension
    - Increments/decrements xPreemptionDisable. Only yields when 0, thus allowing
    for nested suspensions across different data groups

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Updated critical section macros with granular locks.

Some tasks.c API relied on their callers to enter critical sections. This
assumption no longer works under granular locking. Critical sections added to
the following functions:

- `vTaskInternalSetTimeOutState()`
- `xTaskIncrementTick()`
- `vTaskSwitchContext()`
- `xTaskRemoveFromEventList()`
- `vTaskInternalSetTimeOutState()`
- `eTaskConfirmSleepModeStatus()`
- `xTaskPriorityDisinherit()`
- `pvTaskIncrementMutexHeldCount()`

Added missing suspensions to the following functions:

- `vTaskPlaceOnEventList()`
- `vTaskPlaceOnUnorderedEventList()`
- `vTaskPlaceOnEventListRestricted()`

Fixed the locking in vTaskSwitchContext()

vTaskSwitchContext() must aquire both kernel locks, viz., task lock and
ISR lock. This is because, vTaskSwitchContext() can be called from
either task context or ISR context. Also, vTaskSwitchContext() must not
alter the interrupt state prematurely.

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Updated queue.c to use granular locking

- Added xTaskSpinlock and xISRSpinlock
- Replaced  critical section macros with data group critical section macros
such as taskENTER/EXIT_CRITICAL/_FROM_ISR() with queueENTER/EXIT_CRITICAL_FROM_ISR().
- Added vQueueEnterCritical/FromISR() and vQueueExitCritical/FromISR()
  which map to the data group critical section macros.
- Added prvLockQueueForTasks() and prvUnlockQueueForTasks() as the granular locking equivalents
to prvLockQueue() and prvUnlockQueue() respectively

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Updated event_groups.c to use granular locking

- Added xTaskSpinlock and xISRSpinlock
- Replaced critical section macros with data group critical section macros
such as taskENTER/EXIT_CRITICAL/_FROM_ISR() with event_groupsENTER/EXIT_CRITICAL/_FROM_ISR().
- Added vEventGroupsEnterCritical/FromISR() and
  vEventGroupsExitCriti/FromISR() functions that map to the data group
critical section macros.
- Added prvLockEventGroupForTasks() and prvUnlockEventGroupForTasks() to suspend the event
group when executing non-deterministic code.
- xEventGroupSetBits() and vEventGroupDelete() accesses the kernel data group
directly. Thus, added vTaskSuspendAll()/xTaskResumeAll() to these fucntions.

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Updated stream_buffer.c to use granular locking

- Added xTaskSpinlock and xISRSpinlock
- Replaced critical section macros with data group critical section macros
such as taskENTER/EXIT_CRITICAL/_FROM_ISR() with sbENTER/EXIT_CRITICAL_FROM_ISR().
- Added vStreambuffersEnterCritical/FromISR() and
  vStreambuffersExitCritical/FromISR() to map to the data group critical
section macros.
- Added prvLockStreamBufferForTasks() and prvUnlockStreamBufferForTasks() to suspend the stream
buffer when executing non-deterministic code.

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Updated timers.c to use granular locking

- Added xTaskSpinlock and xISRSpinlock
- Replaced critical section macros with data group critical section macros
such as taskENTER/EXIT_CRITICAL() with tmrENTER/EXIT_CRITICAL().
- Added vTimerEnterCritical() and vTimerExitCritical() to map to the
  data group critical section macros.

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
…herit()

xTaskPriorityInherit() is called inside a critical section from queue.c. This
commit moves the critical section into xTaskPriorityInherit().

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Changed xPreemptionDisable to be a count rather than a pdTRUE/pdFALSE. This
allows nested calls to vTaskPreemptionEnable(), where a yield only occurs when
xPreemptionDisable is 0.

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Adds the required checks for granular locking port macros.

Port Config:

- portUSING_GRANULAR_LOCKS to enable granular locks
- portCRITICAL_NESTING_IN_TCB should be disabled

Granular Locking Port Macros:

- Spinlocks
        - portSPINLOCK_TYPE
        - portINIT_SPINLOCK( pxSpinlock )
        - portINIT_SPINLOCK_STATIC
- Locking
        - portGET_SPINLOCK()
        - portRELEASE_SPINLOCK()

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
- Updated prvCheckForRunStateChange() for granular locks
- Updated vTaskSuspendAll() and xTaskResumeAll()
    - Now holds the xTaskSpinlock during kernel suspension
    - Increments/decrements xPreemptionDisable. Only yields when 0, thus allowing
    for nested suspensions across different data groups

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Updated critical section macros with granular locks.

Some tasks.c API relied on their callers to enter critical sections. This
assumption no longer works under granular locking. Critical sections added to
the following functions:

- `vTaskInternalSetTimeOutState()`
- `xTaskIncrementTick()`
- `vTaskSwitchContext()`
- `xTaskRemoveFromEventList()`
- `vTaskInternalSetTimeOutState()`
- `eTaskConfirmSleepModeStatus()`
- `xTaskPriorityDisinherit()`
- `pvTaskIncrementMutexHeldCount()`

Added missing suspensions to the following functions:

- `vTaskPlaceOnEventList()`
- `vTaskPlaceOnUnorderedEventList()`
- `vTaskPlaceOnEventListRestricted()`

Fixed the locking in vTaskSwitchContext()

vTaskSwitchContext() must aquire both kernel locks, viz., task lock and
ISR lock. This is because, vTaskSwitchContext() can be called from
either task context or ISR context. Also, vTaskSwitchContext() must not
alter the interrupt state prematurely.

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Updated queue.c to use granular locking

- Added xTaskSpinlock and xISRSpinlock
- Replaced  critical section macros with data group critical section macros
such as taskENTER/EXIT_CRITICAL/_FROM_ISR() with queueENTER/EXIT_CRITICAL_FROM_ISR().
- Added vQueueEnterCritical/FromISR() and vQueueExitCritical/FromISR()
  which map to the data group critical section macros.
- Added prvLockQueueForTasks() and prvUnlockQueueForTasks() as the granular locking equivalents
to prvLockQueue() and prvUnlockQueue() respectively

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Updated event_groups.c to use granular locking

- Added xTaskSpinlock and xISRSpinlock
- Replaced critical section macros with data group critical section macros
such as taskENTER/EXIT_CRITICAL/_FROM_ISR() with event_groupsENTER/EXIT_CRITICAL/_FROM_ISR().
- Added vEventGroupsEnterCritical/FromISR() and
  vEventGroupsExitCriti/FromISR() functions that map to the data group
critical section macros.
- Added prvLockEventGroupForTasks() and prvUnlockEventGroupForTasks() to suspend the event
group when executing non-deterministic code.
- xEventGroupSetBits() and vEventGroupDelete() accesses the kernel data group
directly. Thus, added vTaskSuspendAll()/xTaskResumeAll() to these fucntions.

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Updated stream_buffer.c to use granular locking

- Added xTaskSpinlock and xISRSpinlock
- Replaced critical section macros with data group critical section macros
such as taskENTER/EXIT_CRITICAL/_FROM_ISR() with sbENTER/EXIT_CRITICAL_FROM_ISR().
- Added vStreambuffersEnterCritical/FromISR() and
  vStreambuffersExitCritical/FromISR() to map to the data group critical
section macros.
- Added prvLockStreamBufferForTasks() and prvUnlockStreamBufferForTasks() to suspend the stream
buffer when executing non-deterministic code.

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Updated timers.c to use granular locking

- Added xTaskSpinlock and xISRSpinlock
- Replaced critical section macros with data group critical section macros
such as taskENTER/EXIT_CRITICAL() with tmrENTER/EXIT_CRITICAL().
- Added vTimerEnterCritical() and vTimerExitCritical() to map to the
  data group critical section macros.

Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
Co-authored-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>
chinglee-iot and others added 30 commits August 20, 2025 16:40
This commit removes the need for suspending the scheduler when calling
some event_groups.c APIs as the non-deterministic operations are
happening with the event group being locked and the preemption being
disabled from the current task.
prvLockQueue() and prvUnlockQueue() helper functions now only take the
ISR locks because they are always called with the task lock already
taken. However, these functions must also increment and decrement the
critical nesting count as both locks get taken eventually. This commit
fixes it.
…itical sections

Stream buffer task lists (xTaskWaitingToSend and xTaskWaitingToReceive)
are updated without critical sections. These objects are shared objects
and can be updated from an ISR context as well. Hence, these lists must
always be updated in critical sections.
This commit adds support for direct transfer for queue operations. A ew
config option configQUEUE_DIRECT_TRANSFER is introduced to enable this
option. With this feature, we enable directly copying data to a waiting
task's buffer and avoid copying data to the queue buffer. This helps in
avoiding priority inversions where a lower priority task can steal
a data from a higher priority task blocked on the queue. This also
reduces a copy operation and helps with the queue performance.
…ask TCB

This commit adds support for queue direct transfer buffer being owned by
the task's TCB. This inherently solves some design issues with the
buffer being owned by the queue's object. On the flip side, this adds
memory cost to the task's TCB.
… locks

- Convert taskDATA_GROUP_ENTER_CRITICAL macro to function to enable run state checks
- Add prvTaskDataGroupCheckForRunStateChange() to handle yield requests during critical section entry
- Fix prvYieldCore() to properly set xTaskRunState for both current and other cores
- Acquire TCB spinlocks before reading preemption disable count to prevent race conditions
- Handle yield requests even when scheduler is suspended
- Ensure ISR lock is acquired before checking run state in vTaskSuspendAll()
- Fix multiple race conditions in task deletion and suspension paths

These changes ensure proper priority ordering and prevent priority inversions
when tasks with preemption disabled enter critical sections while higher
priority tasks are ready to run.
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3 participants