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|
/***************************************************************************
* Copyright (c) 2024 Microsoft Corporation
*
* This program and the accompanying materials are made available under the
* terms of the MIT License which is available at
* https://opensource.org/licenses/MIT.
*
* SPDX-License-Identifier: MIT
**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** ThreadX Component */
/** */
/** Thread */
/** */
/**************************************************************************/
/**************************************************************************/
#define TX_SOURCE_CODE
#define TX_THREAD_SMP_SOURCE_CODE
/* Include necessary system files. */
#include "tx_api.h"
#include "tx_trace.h"
#include "tx_thread.h"
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _tx_thread_priority_change PORTABLE SMP */
/* 6.1 */
/* AUTHOR */
/* */
/* William E. Lamie, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function changes the priority of the specified thread. It */
/* also returns the old priority and handles preemption if the calling */
/* thread is currently executing and the priority change results in a */
/* higher priority thread ready for execution. */
/* */
/* Note: the preemption-threshold is automatically changed to the new */
/* priority. */
/* */
/* INPUT */
/* */
/* thread_ptr Pointer to thread to suspend */
/* new_priority New thread priority */
/* old_priority Old thread priority */
/* */
/* OUTPUT */
/* */
/* status Completion status */
/* */
/* CALLS */
/* */
/* _tx_thread_smp_rebalance_execute_list Rebalance the execution list */
/* _tx_thread_smp_simple_priority_change Change priority */
/* _tx_thread_system_resume Resume thread */
/* _tx_thread_system_ni_resume Non-interruptable resume */
/* _tx_thread_system_suspend Suspend thread */
/* _tx_thread_system_ni_suspend Non-interruptable suspend */
/* _tx_thread_system_preempt_check Check for preemption */
/* */
/* CALLED BY */
/* */
/* Application Code */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 09-30-2020 William E. Lamie Initial Version 6.1 */
/* */
/**************************************************************************/
UINT _tx_thread_priority_change(TX_THREAD *thread_ptr, UINT new_priority, UINT *old_priority)
{
TX_INTERRUPT_SAVE_AREA
TX_THREAD *execute_ptr;
UINT core_index;
UINT original_priority;
UINT lowest_priority;
TX_THREAD *original_pt_thread;
#ifndef TX_DISABLE_PREEMPTION_THRESHOLD
TX_THREAD *new_pt_thread;
UINT priority;
ULONG priority_bit;
#if TX_MAX_PRIORITIES > 32
UINT map_index;
#endif
#endif
UINT status;
/* Default status to not done. */
status = TX_NOT_DONE;
/* Lockout interrupts while the thread is being suspended. */
TX_DISABLE
/* If trace is enabled, insert this event into the trace buffer. */
TX_TRACE_IN_LINE_INSERT(TX_TRACE_THREAD_PRIORITY_CHANGE, thread_ptr, new_priority, thread_ptr -> tx_thread_priority, thread_ptr -> tx_thread_state, TX_TRACE_THREAD_EVENTS)
/* Log this kernel call. */
TX_EL_THREAD_PRIORITY_CHANGE_INSERT
/* Save the previous priority. */
*old_priority = thread_ptr -> tx_thread_user_priority;
/* Determine if the new priority is the same as the last requested priority. */
if ((thread_ptr -> tx_thread_user_priority == new_priority) &&
(thread_ptr -> tx_thread_user_preempt_threshold == new_priority))
{
/* Nothing to do at this point, simply return. */
/* Restore interrupts. */
TX_RESTORE
/* Done, return success. */
status = TX_SUCCESS;
}
/* Determine if the inherit priority is in effect and there is no preemption-threshold in force. */
else if ((thread_ptr -> tx_thread_inherit_priority < new_priority) &&
(thread_ptr -> tx_thread_user_preempt_threshold == thread_ptr -> tx_thread_user_priority))
{
/* In this case, simply setup the user priority and preemption-threshold and return. */
/* Setup the new priority for this thread. */
thread_ptr -> tx_thread_user_priority = new_priority;
thread_ptr -> tx_thread_user_preempt_threshold = new_priority;
/* Restore interrupts. */
TX_RESTORE
/* Done, return success. */
status = TX_SUCCESS;
}
else
{
/* Default the execute pointer to NULL. */
execute_ptr = TX_NULL;
/* Determine if this thread is currently ready. */
if (thread_ptr -> tx_thread_state != TX_READY)
{
/* Setup the user priority and threshold in the thread's control
block. */
thread_ptr -> tx_thread_user_priority = new_priority;
thread_ptr -> tx_thread_user_preempt_threshold = new_priority;
/* Determine if the actual thread priority should be setup, which is the
case if the new priority is higher than the priority inheritance. */
if (new_priority < thread_ptr -> tx_thread_inherit_priority)
{
/* Change thread priority to the new user's priority. */
thread_ptr -> tx_thread_priority = new_priority;
thread_ptr -> tx_thread_preempt_threshold = new_priority;
}
else
{
/* Change thread priority to the priority inheritance. */
thread_ptr -> tx_thread_priority = thread_ptr -> tx_thread_inherit_priority;
thread_ptr -> tx_thread_preempt_threshold = thread_ptr -> tx_thread_inherit_priority;
}
/* Restore interrupts. */
TX_RESTORE
/* Done, return success. */
status = TX_SUCCESS;
}
else
{
/* Pickup the core index. */
core_index = thread_ptr -> tx_thread_smp_core_mapped;
/* Save the original priority. */
original_priority = thread_ptr -> tx_thread_priority;
/* Determine if this thread is the currently scheduled thread. */
if (thread_ptr == _tx_thread_execute_ptr[core_index])
{
/* Yes, this thread is scheduled. */
/* Remember this thread as the currently executing thread. */
execute_ptr = thread_ptr;
/* Determine if the thread is being set to a higher-priority and it does't have
preemption-threshold set. */
if ((new_priority < thread_ptr -> tx_thread_priority) &&
(thread_ptr -> tx_thread_user_priority == thread_ptr -> tx_thread_user_preempt_threshold))
{
/* Simple case, remove the thread from the current priority list and place in
the higher priority list. */
_tx_thread_smp_simple_priority_change(thread_ptr, new_priority);
/* Setup the new priority for this thread. */
thread_ptr -> tx_thread_user_priority = new_priority;
thread_ptr -> tx_thread_user_preempt_threshold = new_priority;
/* Restore interrupts. */
TX_RESTORE
/* Return a successful completion. */
status = TX_SUCCESS;
}
}
else
{
/* Thread is not currently executing, so it can just be moved to the lower priority in the list. */
/* Determine if the thread is being set to a lower-priority and it does't have
preemption-threshold set. */
if ((new_priority > thread_ptr -> tx_thread_priority) &&
(thread_ptr -> tx_thread_user_priority == thread_ptr -> tx_thread_user_preempt_threshold))
{
/* Simple case, remove the thread from the current priority list and place in
the lower priority list. */
_tx_thread_smp_simple_priority_change(thread_ptr, new_priority);
/* Setup the new priority for this thread. */
thread_ptr -> tx_thread_user_priority = new_priority;
thread_ptr -> tx_thread_user_preempt_threshold = new_priority;
/* Restore interrupts. */
TX_RESTORE
/* Return a successful completion. */
status = TX_SUCCESS;
}
}
/* Determine if we are done. */
if (status == TX_NOT_DONE)
{
/* Yes, more to do. */
/* Default the status to success. */
status = TX_SUCCESS;
/* Save the original preemption-threshold thread. */
original_pt_thread = _tx_thread_preemption__threshold_scheduled;
#ifdef TX_NOT_INTERRUPTABLE
/* Increment the preempt disable flag. */
_tx_thread_preempt_disable++;
/* Set the state to priority change. */
thread_ptr -> tx_thread_state = TX_PRIORITY_CHANGE;
/* Call actual non-interruptable thread suspension routine. */
_tx_thread_system_ni_suspend(thread_ptr, ((ULONG) 0));
/* At this point, the preempt disable flag is still set, so we still have
protection against all preemption. */
/* Setup the new priority for this thread. */
thread_ptr -> tx_thread_user_priority = new_priority;
thread_ptr -> tx_thread_user_preempt_threshold = new_priority;
/* Determine if the actual thread priority should be setup, which is the
case if the new priority is higher than the priority inheritance. */
if (new_priority < thread_ptr -> tx_thread_inherit_priority)
{
/* Change thread priority to the new user's priority. */
thread_ptr -> tx_thread_priority = new_priority;
thread_ptr -> tx_thread_preempt_threshold = new_priority;
}
else
{
/* Change thread priority to the priority inheritance. */
thread_ptr -> tx_thread_priority = thread_ptr -> tx_thread_inherit_priority;
thread_ptr -> tx_thread_preempt_threshold = thread_ptr -> tx_thread_inherit_priority;
}
/* Resume the thread with the new priority. */
_tx_thread_system_ni_resume(thread_ptr);
/* Decrement the preempt disable flag. */
_tx_thread_preempt_disable--;
#else
/* Increment the preempt disable flag. */
_tx_thread_preempt_disable = _tx_thread_preempt_disable + ((UINT) 3);
/* Set the state to priority change. */
thread_ptr -> tx_thread_state = TX_PRIORITY_CHANGE;
/* Set the suspending flag. */
thread_ptr -> tx_thread_suspending = TX_TRUE;
/* Setup the timeout period. */
thread_ptr -> tx_thread_timer.tx_timer_internal_remaining_ticks = ((ULONG) 0);
/* Restore interrupts. */
TX_RESTORE
/* The thread is ready and must first be removed from the list. Call the
system suspend function to accomplish this. */
_tx_thread_system_suspend(thread_ptr);
/* Lockout interrupts again. */
TX_DISABLE
/* At this point, the preempt disable flag is still set, so we still have
protection against all preemption. */
/* Setup the new priority for this thread. */
thread_ptr -> tx_thread_user_priority = new_priority;
thread_ptr -> tx_thread_user_preempt_threshold = new_priority;
/* Determine if the actual thread priority should be setup, which is the
case if the new priority is higher than the priority inheritance. */
if (new_priority < thread_ptr -> tx_thread_inherit_priority)
{
/* Change thread priority to the new user's priority. */
thread_ptr -> tx_thread_priority = new_priority;
thread_ptr -> tx_thread_preempt_threshold = new_priority;
}
else
{
/* Change thread priority to the priority inheritance. */
thread_ptr -> tx_thread_priority = thread_ptr -> tx_thread_inherit_priority;
thread_ptr -> tx_thread_preempt_threshold = thread_ptr -> tx_thread_inherit_priority;
}
/* Restore interrupts. */
TX_RESTORE
/* Resume the thread with the new priority. */
_tx_thread_system_resume(thread_ptr);
#endif
/* Optional processing extension. */
TX_THREAD_PRIORITY_CHANGE_EXTENSION
#ifndef TX_NOT_INTERRUPTABLE
/* Disable interrupts. */
TX_DISABLE
/* Decrement the preemption-threshold flag. */
_tx_thread_preempt_disable--;
#endif
/* Determine if the thread was previously executing. */
if (thread_ptr == execute_ptr)
{
/* Make sure the thread is still ready. */
if (thread_ptr -> tx_thread_state == TX_READY)
{
#ifndef TX_DISABLE_PREEMPTION_THRESHOLD
/* Determine if preemption-threshold is in force at the new priority level. */
if (_tx_thread_preemption_threshold_list[thread_ptr -> tx_thread_priority] == TX_NULL)
{
/* Ensure that this thread is placed at the front of the priority list. */
_tx_thread_priority_list[thread_ptr -> tx_thread_priority] = thread_ptr;
}
#else
/* Ensure that this thread is placed at the front of the priority list. */
_tx_thread_priority_list[thread_ptr -> tx_thread_priority] = thread_ptr;
#endif
}
}
/* Pickup the core index. */
core_index = thread_ptr -> tx_thread_smp_core_mapped;
#ifndef TX_THREAD_SMP_DYNAMIC_CORE_MAX
/* Pickup the next thread to execute. */
if (core_index < ((UINT) TX_THREAD_SMP_MAX_CORES))
#else
/* Pickup the next thread to execute. */
if (core_index < _tx_thread_smp_max_cores)
#endif
{
/* Determine if this thread is not the next thread to execute. */
if (thread_ptr != _tx_thread_execute_ptr[core_index])
{
/* Now determine if this thread was previously executing thread. */
if (thread_ptr == execute_ptr)
{
/* Determine if we moved to a lower priority. If so, move the thread to the front of the priority list. */
if (original_priority < new_priority)
{
/* Make sure the thread is still ready. */
if (thread_ptr -> tx_thread_state == TX_READY)
{
/* Determine the lowest priority scheduled thread. */
lowest_priority = _tx_thread_smp_lowest_priority_get();
/* Determine if this thread has a higher or same priority as the lowest priority
in the list. */
if (thread_ptr -> tx_thread_priority <= lowest_priority)
{
/* Yes, we need to rebalance to make it possible for this thread to execute. */
/* Determine if the thread with preemption-threshold thread has changed... and is
not the scheduled thread. */
if ((original_pt_thread != _tx_thread_preemption__threshold_scheduled) &&
(original_pt_thread != thread_ptr))
{
/* Yes, preemption-threshold has changed. Determine if it can or should
be reversed. */
#ifndef TX_DISABLE_PREEMPTION_THRESHOLD
/* Pickup the preemption-threshold thread. */
new_pt_thread = _tx_thread_preemption__threshold_scheduled;
#endif
/* Restore the original preemption-threshold thread. */
_tx_thread_preemption__threshold_scheduled = original_pt_thread;
#ifndef TX_DISABLE_PREEMPTION_THRESHOLD
/* Determine if there is a new preemption-threshold thread to reverse. */
if (new_pt_thread != TX_NULL)
{
/* Clear the information associated with the new preemption-threshold thread. */
/* Pickup the priority. */
priority = new_pt_thread -> tx_thread_priority;
/* Clear the preempted list entry. */
_tx_thread_preemption_threshold_list[priority] = TX_NULL;
#if TX_MAX_PRIORITIES > 32
/* Calculate the bit map array index. */
map_index = new_priority/((UINT) 32);
#endif
/* Ensure that this thread's priority is clear in the preempt map. */
TX_MOD32_BIT_SET(priority, priority_bit)
_tx_thread_preempted_maps[MAP_INDEX] = _tx_thread_preempted_maps[MAP_INDEX] & (~(priority_bit));
#if TX_MAX_PRIORITIES > 32
/* Determine if there are any other bits set in this preempt map. */
if (_tx_thread_preempted_maps[MAP_INDEX] == ((ULONG) 0))
{
/* No, clear the active bit to signify this preempted map has nothing set. */
TX_DIV32_BIT_SET(priority, priority_bit)
_tx_thread_preempted_map_active = _tx_thread_preempted_map_active & (~(priority_bit));
}
#endif
}
#endif
}
/* Pickup the index. */
core_index = TX_SMP_CORE_ID;
/* Call the rebalance routine. This routine maps cores and ready threads. */
_tx_thread_smp_rebalance_execute_list(core_index);
}
}
}
}
}
}
/* Restore interrupts. */
TX_RESTORE
/* Check for preemption. */
_tx_thread_system_preempt_check();
}
}
}
/* Return completion status. */
return(status);
}
|
