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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_timer.h"
#include "tx_thread.h"
#include "tx_trace.h"
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _tx_thread_time_slice PORTABLE SMP */
/* 6.1 */
/* AUTHOR */
/* */
/* William E. Lamie, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function moves the currently executing thread to the end of */
/* the threads ready at the same priority level as a result of a */
/* time-slice interrupt. If no other thread of the same priority is */
/* ready, this function simply returns. */
/* */
/* INPUT */
/* */
/* None */
/* */
/* OUTPUT */
/* */
/* None */
/* */
/* CALLS */
/* */
/* _tx_thread_smp_rebalance_execute_list Rebalance the execution list */
/* */
/* CALLED BY */
/* */
/* _tx_timer_interrupt Timer interrupt handling */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 09-30-2020 William E. Lamie Initial Version 6.1 */
/* */
/**************************************************************************/
VOID _tx_thread_time_slice(VOID)
{
ULONG core_index, current_core;
UINT priority;
TX_THREAD *thread_ptr;
TX_THREAD *next_thread;
TX_THREAD *previous_thread;
TX_THREAD *head_ptr;
TX_THREAD *tail_ptr;
UINT loop_finished;
UINT rebalance;
ULONG excluded;
#ifdef TX_ENABLE_EVENT_TRACE
ULONG system_state;
UINT preempt_disable;
#endif
/* Quick check for expiration. */
#if TX_THREAD_SMP_MAX_CORES == 1
if (_tx_timer_time_slice[0] != 0)
{
#endif
#if TX_THREAD_SMP_MAX_CORES == 2
if ((_tx_timer_time_slice[0] != ((ULONG) 0)) || (_tx_timer_time_slice[1] != ((ULONG) 0)))
{
#endif
#if TX_THREAD_SMP_MAX_CORES == 3
if ((_tx_timer_time_slice[0] != ((ULONG) 0)) || (_tx_timer_time_slice[1] != ((ULONG) 0)) || (_tx_timer_time_slice[2] != ((ULONG) 0)))
{
#endif
#if TX_THREAD_SMP_MAX_CORES == 4
if ((_tx_timer_time_slice[0] != ((ULONG) 0)) || (_tx_timer_time_slice[1] != ((ULONG) 0)) || (_tx_timer_time_slice[2] != ((ULONG) 0)) || (_tx_timer_time_slice[3] != ((ULONG) 0)))
{
#endif
/* Initialize the rebalance flag to false. */
rebalance = TX_FALSE;
/* Get the core index. */
current_core = TX_SMP_CORE_ID;
/* Loop to process all time-slices. */
#ifndef TX_THREAD_SMP_DYNAMIC_CORE_MAX
for (core_index = ((ULONG) 0); core_index < ((ULONG) TX_THREAD_SMP_MAX_CORES); core_index++)
#else
for (core_index = ((ULONG) 0); core_index < _tx_thread_smp_max_cores; core_index++)
#endif
{
/* Determine if there is a time-slice active on this core. */
if (_tx_timer_time_slice[core_index] != ((ULONG) 0))
{
/* Time-slice is active, decrement it for this core. */
_tx_timer_time_slice[core_index]--;
/* Has the time-slice expired? */
if (_tx_timer_time_slice[core_index] == ((ULONG) 0))
{
/* Yes, time-slice on this core has expired. */
/* Pickup the current thread pointer. */
thread_ptr = _tx_thread_current_ptr[core_index];
/* Make sure the thread is still active, i.e. not suspended. */
if ((thread_ptr != TX_NULL) && (thread_ptr -> tx_thread_state == TX_READY) && (thread_ptr -> tx_thread_time_slice != ((ULONG) 0)))
{
/* Yes, thread is still active and time-slice has expired. */
/* Setup a fresh time-slice for the thread. */
thread_ptr -> tx_thread_time_slice = thread_ptr -> tx_thread_new_time_slice;
/* Reset the actual time-slice variable. */
_tx_timer_time_slice[core_index] = thread_ptr -> tx_thread_time_slice;
#ifdef TX_THREAD_SMP_DEBUG_ENABLE
/* Debug entry. */
_tx_thread_smp_debug_entry_insert(10, 0, thread_ptr);
#endif
#ifdef TX_ENABLE_STACK_CHECKING
/* Check this thread's stack. */
TX_THREAD_STACK_CHECK(thread_ptr)
#endif
#ifdef TX_THREAD_ENABLE_PERFORMANCE_INFO
/* Increment the thread's time-slice counter. */
thread_ptr -> tx_thread_performance_time_slice_count++;
/* Increment the total number of thread time-slice operations. */
_tx_thread_performance_time_slice_count++;
#endif
/* Setup the priority. */
priority = thread_ptr -> tx_thread_priority;
/* Determine if preemption-threshold is set. If so, don't time-slice. */
if (priority == thread_ptr -> tx_thread_preempt_threshold)
{
/* Preemption-threshold is not set. */
/* Pickup the next thread. */
next_thread = thread_ptr -> tx_thread_ready_next;
/* Pickup the head of the list. */
head_ptr = _tx_thread_priority_list[priority];
/* Pickup the list tail. */
tail_ptr = head_ptr -> tx_thread_ready_previous;
/* Determine if this thread is not the tail pointer. */
if (thread_ptr != tail_ptr)
{
/* Not the tail pointer, this thread must be moved to the end of the ready list. */
/* Determine if this thread is at the head of the list. */
if (head_ptr == thread_ptr)
{
/* Simply move the head pointer to put this thread at the end of the ready list at this priority. */
_tx_thread_priority_list[priority] = next_thread;
}
else
{
/* Now we need to remove this thread from its current position and place it at the end of the list. */
/* Pickup the previous thread pointer. */
previous_thread = thread_ptr -> tx_thread_ready_previous;
/* Remove the thread from the ready list. */
next_thread -> tx_thread_ready_previous = previous_thread;
previous_thread -> tx_thread_ready_next = next_thread;
/* Insert the thread at the end of the list. */
tail_ptr -> tx_thread_ready_next = thread_ptr;
head_ptr -> tx_thread_ready_previous = thread_ptr;
thread_ptr -> tx_thread_ready_previous = tail_ptr;
thread_ptr -> tx_thread_ready_next = head_ptr;
}
/* Make sure the current core execute pointer is still this thread. If not, a higher priority thread has already
preempted it either from another ISR or from the timer processing. */
if (_tx_thread_execute_ptr[core_index] != thread_ptr)
{
/* Set the rebalance flag. */
rebalance = TX_TRUE;
}
/* Determine if the rebalance flag has been set already. If so, don't bother trying to update the
execute list from this routine. */
if (rebalance == TX_FALSE)
{
/* Set the loop finished flag to false. */
loop_finished = TX_FALSE;
/* Determine if there is a thread at the same priority that isn't currently executing. */
do
{
/* Isolate the exclusion for this core. */
excluded = (next_thread -> tx_thread_smp_cores_excluded >> core_index) & ((ULONG) 1);
/* Determine if the next thread has preemption-threshold set. */
if (next_thread -> tx_thread_preempt_threshold < next_thread -> tx_thread_priority)
{
/* Set the rebalance flag. */
rebalance = TX_TRUE;
/* Get out of the loop. */
loop_finished = TX_TRUE;
}
/* Determine if the next thread is excluded from running on this core. */
else if (excluded == ((ULONG) 1))
{
/* Set the rebalance flag. */
rebalance = TX_TRUE;
/* Get out of the loop. */
loop_finished = TX_TRUE;
}
else
{
/* Is the next thread not scheduled */
if (next_thread != _tx_thread_execute_ptr[next_thread -> tx_thread_smp_core_mapped])
{
/* Remember this index in the thread control block. */
next_thread -> tx_thread_smp_core_mapped = core_index;
/* Setup the entry in the execution list. */
_tx_thread_execute_ptr[core_index] = next_thread;
#ifdef TX_THREAD_SMP_INTER_CORE_INTERRUPT
/* Determine if we need to preempt the core. */
if (core_index != current_core)
{
/* Preempt the mapped thread. */
_tx_thread_smp_core_preempt(core_index);
}
#endif
/* Get out of the loop. */
loop_finished = TX_TRUE;
}
}
/* Is the loop fininshed? */
if (loop_finished == TX_TRUE)
{
/* Yes, break out of the loop. */
break;
}
/* Move to the next thread at this priority. */
next_thread = next_thread -> tx_thread_ready_next;
} while (next_thread != thread_ptr);
}
}
#ifdef TX_THREAD_SMP_DEBUG_ENABLE
/* Debug entry. */
_tx_thread_smp_debug_entry_insert(11, 0, thread_ptr);
#endif
}
}
}
}
}
/* Determine if rebalance was set. */
if (rebalance == TX_TRUE)
{
/* Call the rebalance routine. This routine maps cores and ready threads. */
_tx_thread_smp_rebalance_execute_list(current_core);
}
#ifdef TX_ENABLE_EVENT_TRACE
/* Pickup the volatile information. */
system_state = TX_THREAD_GET_SYSTEM_STATE();
preempt_disable = _tx_thread_preempt_disable;
/* Insert this event into the trace buffer. */
TX_TRACE_IN_LINE_INSERT(TX_TRACE_TIME_SLICE, _tx_thread_execute_ptr[0], system_state, preempt_disable, TX_POINTER_TO_ULONG_CONVERT(&thread_ptr), TX_TRACE_INTERNAL_EVENTS)
#endif
#if TX_THREAD_SMP_MAX_CORES == 1
}
#endif
#if TX_THREAD_SMP_MAX_CORES == 2
}
#endif
#if TX_THREAD_SMP_MAX_CORES == 3
}
#endif
#if TX_THREAD_SMP_MAX_CORES == 4
}
#endif
}
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