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/**************************************************************************/
/* */
/* Copyright (c) Microsoft Corporation. All rights reserved. */
/* */
/* This software is licensed under the Microsoft Software License */
/* Terms for Microsoft Azure RTOS. Full text of the license can be */
/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
/* and in the root directory of this software. */
/* */
/**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** ThreadX Component */
/** */
/** Event Flags */
/** */
/**************************************************************************/
/**************************************************************************/
#define TX_SOURCE_CODE
/* Include necessary system files. */
#include "tx_api.h"
#include "tx_trace.h"
#include "tx_thread.h"
#include "tx_event_flags.h"
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _tx_event_flags_set PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* William E. Lamie, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function sets the specified flags in the event group based on */
/* the set option specified. All threads suspended on the group whose */
/* get request can now be satisfied are resumed. */
/* */
/* INPUT */
/* */
/* group_ptr Pointer to group control block */
/* flags_to_set Event flags to set */
/* set_option Specified either AND or OR */
/* operation on the event flags */
/* */
/* OUTPUT */
/* */
/* TX_SUCCESS Always returns success */
/* */
/* CALLS */
/* */
/* _tx_thread_system_preempt_check Check for preemption */
/* _tx_thread_system_resume Resume thread service */
/* _tx_thread_system_ni_resume Non-interruptable resume thread */
/* */
/* CALLED BY */
/* */
/* Application Code */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 05-19-2020 William E. Lamie Initial Version 6.0 */
/* 09-30-2020 Yuxin Zhou Modified comment(s), */
/* resulting in version 6.1 */
/* */
/**************************************************************************/
UINT _tx_event_flags_set(TX_EVENT_FLAGS_GROUP *group_ptr, ULONG flags_to_set, UINT set_option)
{
TX_INTERRUPT_SAVE_AREA
TX_THREAD *thread_ptr;
TX_THREAD *next_thread_ptr;
TX_THREAD *next_thread;
TX_THREAD *previous_thread;
TX_THREAD *satisfied_list;
TX_THREAD *last_satisfied;
TX_THREAD *suspended_list;
UINT suspended_count;
ULONG current_event_flags;
ULONG requested_flags;
ULONG flags_satisfied;
ULONG *suspend_info_ptr;
UINT and_request;
UINT get_option;
UINT clear_request;
UINT preempt_check;
#ifndef TX_NOT_INTERRUPTABLE
UINT interrupted_set_request;
#endif
#ifndef TX_DISABLE_NOTIFY_CALLBACKS
VOID (*events_set_notify)(struct TX_EVENT_FLAGS_GROUP_STRUCT *notify_group_ptr);
#endif
/* Disable interrupts to remove the semaphore from the created list. */
TX_DISABLE
#ifdef TX_EVENT_FLAGS_ENABLE_PERFORMANCE_INFO
/* Increment the total event flags set counter. */
_tx_event_flags_performance_set_count++;
/* Increment the number of event flags sets on this semaphore. */
group_ptr -> tx_event_flags_group_performance_set_count++;
#endif
/* If trace is enabled, insert this event into the trace buffer. */
TX_TRACE_IN_LINE_INSERT(TX_TRACE_EVENT_FLAGS_SET, group_ptr, flags_to_set, set_option, group_ptr -> tx_event_flags_group_suspended_count, TX_TRACE_EVENT_FLAGS_EVENTS)
/* Log this kernel call. */
TX_EL_EVENT_FLAGS_SET_INSERT
/* Determine how to set this group's event flags. */
if ((set_option & TX_EVENT_FLAGS_AND_MASK) == TX_AND)
{
#ifndef TX_NOT_INTERRUPTABLE
/* Set interrupted set request flag to false. */
interrupted_set_request = TX_FALSE;
/* Determine if the suspension list is being processed by an interrupted
set request. */
if (group_ptr -> tx_event_flags_group_suspended_count != TX_NO_SUSPENSIONS)
{
if (group_ptr -> tx_event_flags_group_suspension_list == TX_NULL)
{
/* Set the interrupted set request flag. */
interrupted_set_request = TX_TRUE;
}
}
/* Was a set request interrupted? */
if (interrupted_set_request == TX_TRUE)
{
/* A previous set operation was interrupted, we need to defer the
event clearing until the set operation is complete. */
/* Remember the events to clear. */
group_ptr -> tx_event_flags_group_delayed_clear =
group_ptr -> tx_event_flags_group_delayed_clear | ~flags_to_set;
}
else
{
#endif
/* Previous set operation was not interrupted, simply clear the
specified flags by "ANDing" the flags into the current events
of the group. */
group_ptr -> tx_event_flags_group_current =
group_ptr -> tx_event_flags_group_current & flags_to_set;
#ifndef TX_NOT_INTERRUPTABLE
}
#endif
/* Restore interrupts. */
TX_RESTORE
}
else
{
#ifndef TX_DISABLE_NOTIFY_CALLBACKS
/* Pickup the notify callback routine for this event flag group. */
events_set_notify = group_ptr -> tx_event_flags_group_set_notify;
#endif
/* "OR" the flags into the current events of the group. */
group_ptr -> tx_event_flags_group_current =
group_ptr -> tx_event_flags_group_current | flags_to_set;
#ifndef TX_NOT_INTERRUPTABLE
/* Determine if there are any delayed flags to clear. */
if (group_ptr -> tx_event_flags_group_delayed_clear != ((ULONG) 0))
{
/* Yes, we need to neutralize the delayed clearing as well. */
group_ptr -> tx_event_flags_group_delayed_clear =
group_ptr -> tx_event_flags_group_delayed_clear & ~flags_to_set;
}
#endif
/* Clear the preempt check flag. */
preempt_check = TX_FALSE;
/* Pickup the thread suspended count. */
suspended_count = group_ptr -> tx_event_flags_group_suspended_count;
/* Determine if there are any threads suspended on the event flag group. */
if (group_ptr -> tx_event_flags_group_suspension_list != TX_NULL)
{
/* Determine if there is just a single thread waiting on the event
flag group. */
if (suspended_count == ((UINT) 1))
{
/* Single thread waiting for event flags. Bypass the multiple thread
logic. */
/* Setup thread pointer. */
thread_ptr = group_ptr -> tx_event_flags_group_suspension_list;
/* Pickup the current event flags. */
current_event_flags = group_ptr -> tx_event_flags_group_current;
/* Pickup the suspend information. */
requested_flags = thread_ptr -> tx_thread_suspend_info;
/* Pickup the suspend option. */
get_option = thread_ptr -> tx_thread_suspend_option;
/* Isolate the AND selection. */
and_request = (get_option & TX_AND);
/* Check for AND condition. All flags must be present to satisfy request. */
if (and_request == TX_AND)
{
/* AND request is present. */
/* Calculate the flags present. */
flags_satisfied = (current_event_flags & requested_flags);
/* Determine if they satisfy the AND request. */
if (flags_satisfied != requested_flags)
{
/* No, not all the requested flags are present. Clear the flags present variable. */
flags_satisfied = ((ULONG) 0);
}
}
else
{
/* OR request is present. Simply or the requested flags and the current flags. */
flags_satisfied = (current_event_flags & requested_flags);
}
/* Determine if the request is satisfied. */
if (flags_satisfied != ((ULONG) 0))
{
/* Yes, resume the thread and apply any event flag
clearing. */
/* Set the preempt check flag. */
preempt_check = TX_TRUE;
/* Return the actual event flags that satisfied the request. */
suspend_info_ptr = TX_VOID_TO_ULONG_POINTER_CONVERT(thread_ptr -> tx_thread_additional_suspend_info);
*suspend_info_ptr = current_event_flags;
/* Pickup the clear bit. */
clear_request = (get_option & TX_EVENT_FLAGS_CLEAR_MASK);
/* Determine whether or not clearing needs to take place. */
if (clear_request == TX_TRUE)
{
/* Yes, clear the flags that satisfied this request. */
group_ptr -> tx_event_flags_group_current = group_ptr -> tx_event_flags_group_current & (~requested_flags);
}
/* Clear the suspension information in the event flag group. */
group_ptr -> tx_event_flags_group_suspension_list = TX_NULL;
group_ptr -> tx_event_flags_group_suspended_count = TX_NO_SUSPENSIONS;
/* Clear cleanup routine to avoid timeout. */
thread_ptr -> tx_thread_suspend_cleanup = TX_NULL;
/* Put return status into the thread control block. */
thread_ptr -> tx_thread_suspend_status = TX_SUCCESS;
#ifdef TX_NOT_INTERRUPTABLE
/* Resume the thread! */
_tx_thread_system_ni_resume(thread_ptr);
#else
/* Temporarily disable preemption. */
_tx_thread_preempt_disable++;
/* Restore interrupts. */
TX_RESTORE
/* Resume thread. */
_tx_thread_system_resume(thread_ptr);
/* Disable interrupts to remove the semaphore from the created list. */
TX_DISABLE
#endif
}
}
else
{
/* Otherwise, the event flag requests of multiple threads must be
examined. */
/* Setup thread pointer, keep a local copy of the head pointer. */
suspended_list = group_ptr -> tx_event_flags_group_suspension_list;
thread_ptr = suspended_list;
/* Clear the suspended list head pointer to thwart manipulation of
the list in ISR's while we are processing here. */
group_ptr -> tx_event_flags_group_suspension_list = TX_NULL;
/* Setup the satisfied thread pointers. */
satisfied_list = TX_NULL;
last_satisfied = TX_NULL;
/* Pickup the current event flags. */
current_event_flags = group_ptr -> tx_event_flags_group_current;
/* Disable preemption while we process the suspended list. */
_tx_thread_preempt_disable++;
/* Loop to examine all of the suspended threads. */
do
{
#ifndef TX_NOT_INTERRUPTABLE
/* Restore interrupts temporarily. */
TX_RESTORE
/* Disable interrupts again. */
TX_DISABLE
#endif
/* Determine if we need to reset the search. */
if (group_ptr -> tx_event_flags_group_reset_search != TX_FALSE)
{
/* Clear the reset search flag. */
group_ptr -> tx_event_flags_group_reset_search = TX_FALSE;
/* Move the thread pointer to the beginning of the search list. */
thread_ptr = suspended_list;
/* Reset the suspended count. */
suspended_count = group_ptr -> tx_event_flags_group_suspended_count;
/* Update the current events with any new ones that might
have been set in a nested set events call from an ISR. */
current_event_flags = current_event_flags | group_ptr -> tx_event_flags_group_current;
}
/* Save next thread pointer. */
next_thread_ptr = thread_ptr -> tx_thread_suspended_next;
/* Pickup the suspend information. */
requested_flags = thread_ptr -> tx_thread_suspend_info;
/* Pickup this thread's suspension get option. */
get_option = thread_ptr -> tx_thread_suspend_option;
/* Isolate the AND selection. */
and_request = (get_option & TX_AND);
/* Check for AND condition. All flags must be present to satisfy request. */
if (and_request == TX_AND)
{
/* AND request is present. */
/* Calculate the flags present. */
flags_satisfied = (current_event_flags & requested_flags);
/* Determine if they satisfy the AND request. */
if (flags_satisfied != requested_flags)
{
/* No, not all the requested flags are present. Clear the flags present variable. */
flags_satisfied = ((ULONG) 0);
}
}
else
{
/* OR request is present. Simply or the requested flags and the current flags. */
flags_satisfied = (current_event_flags & requested_flags);
}
/* Check to see if the thread had a timeout or wait abort during the event search processing.
If so, just set the flags satisfied to ensure the processing here removes the thread from
the suspension list. */
if (thread_ptr -> tx_thread_state != TX_EVENT_FLAG)
{
/* Simply set the satisfied flags to 1 in order to remove the thread from the suspension list. */
flags_satisfied = ((ULONG) 1);
}
/* Determine if the request is satisfied. */
if (flags_satisfied != ((ULONG) 0))
{
/* Yes, this request can be handled now. */
/* Set the preempt check flag. */
preempt_check = TX_TRUE;
/* Determine if the thread is still suspended on the event flag group. If not, a wait
abort must have been done from an ISR. */
if (thread_ptr -> tx_thread_state == TX_EVENT_FLAG)
{
/* Return the actual event flags that satisfied the request. */
suspend_info_ptr = TX_VOID_TO_ULONG_POINTER_CONVERT(thread_ptr -> tx_thread_additional_suspend_info);
*suspend_info_ptr = current_event_flags;
/* Pickup the clear bit. */
clear_request = (get_option & TX_EVENT_FLAGS_CLEAR_MASK);
/* Determine whether or not clearing needs to take place. */
if (clear_request == TX_TRUE)
{
/* Yes, clear the flags that satisfied this request. */
group_ptr -> tx_event_flags_group_current = group_ptr -> tx_event_flags_group_current & ~requested_flags;
}
/* Prepare for resumption of the first thread. */
/* Clear cleanup routine to avoid timeout. */
thread_ptr -> tx_thread_suspend_cleanup = TX_NULL;
/* Put return status into the thread control block. */
thread_ptr -> tx_thread_suspend_status = TX_SUCCESS;
}
/* We need to remove the thread from the suspension list and place it in the
expired list. */
/* See if this is the only suspended thread on the list. */
if (thread_ptr == thread_ptr -> tx_thread_suspended_next)
{
/* Yes, the only suspended thread. */
/* Update the head pointer. */
suspended_list = TX_NULL;
}
else
{
/* At least one more thread is on the same expiration list. */
/* Update the links of the adjacent threads. */
next_thread = thread_ptr -> tx_thread_suspended_next;
previous_thread = thread_ptr -> tx_thread_suspended_previous;
next_thread -> tx_thread_suspended_previous = previous_thread;
previous_thread -> tx_thread_suspended_next = next_thread;
/* Update the list head pointer, if removing the head of the
list. */
if (suspended_list == thread_ptr)
{
/* Yes, head pointer needs to be updated. */
suspended_list = thread_ptr -> tx_thread_suspended_next;
}
}
/* Decrement the suspension count. */
group_ptr -> tx_event_flags_group_suspended_count--;
/* Place this thread on the expired list. */
if (satisfied_list == TX_NULL)
{
/* First thread on the satisfied list. */
satisfied_list = thread_ptr;
last_satisfied = thread_ptr;
/* Setup initial next pointer. */
thread_ptr -> tx_thread_suspended_next = TX_NULL;
}
else
{
/* Not the first thread on the satisfied list. */
/* Link it up at the end. */
last_satisfied -> tx_thread_suspended_next = thread_ptr;
thread_ptr -> tx_thread_suspended_next = TX_NULL;
last_satisfied = thread_ptr;
}
}
/* Copy next thread pointer to working thread ptr. */
thread_ptr = next_thread_ptr;
/* Decrement the suspension count. */
suspended_count--;
} while (suspended_count != TX_NO_SUSPENSIONS);
/* Setup the group's suspension list head again. */
group_ptr -> tx_event_flags_group_suspension_list = suspended_list;
#ifndef TX_NOT_INTERRUPTABLE
/* Determine if there is any delayed event clearing to perform. */
if (group_ptr -> tx_event_flags_group_delayed_clear != ((ULONG) 0))
{
/* Perform the delayed event clearing. */
group_ptr -> tx_event_flags_group_current =
group_ptr -> tx_event_flags_group_current & ~(group_ptr -> tx_event_flags_group_delayed_clear);
/* Clear the delayed event flag clear value. */
group_ptr -> tx_event_flags_group_delayed_clear = ((ULONG) 0);
}
#endif
/* Restore interrupts. */
TX_RESTORE
/* Walk through the satisfied list, setup initial thread pointer. */
thread_ptr = satisfied_list;
while(thread_ptr != TX_NULL)
{
/* Get next pointer first. */
next_thread_ptr = thread_ptr -> tx_thread_suspended_next;
/* Disable interrupts. */
TX_DISABLE
#ifdef TX_NOT_INTERRUPTABLE
/* Resume the thread! */
_tx_thread_system_ni_resume(thread_ptr);
/* Restore interrupts. */
TX_RESTORE
#else
/* Disable preemption again. */
_tx_thread_preempt_disable++;
/* Restore interrupt posture. */
TX_RESTORE
/* Resume the thread. */
_tx_thread_system_resume(thread_ptr);
#endif
/* Move next thread to current. */
thread_ptr = next_thread_ptr;
}
/* Disable interrupts. */
TX_DISABLE
/* Release thread preemption disable. */
_tx_thread_preempt_disable--;
}
}
else
{
/* Determine if we need to set the reset search field. */
if (group_ptr -> tx_event_flags_group_suspended_count != TX_NO_SUSPENSIONS)
{
/* We interrupted a search of an event flag group suspension
list. Make sure we reset the search. */
group_ptr -> tx_event_flags_group_reset_search = TX_TRUE;
}
}
/* Restore interrupts. */
TX_RESTORE
#ifndef TX_DISABLE_NOTIFY_CALLBACKS
/* Determine if a notify callback is required. */
if (events_set_notify != TX_NULL)
{
/* Call application event flags set notification. */
(events_set_notify)(group_ptr);
}
#endif
/* Determine if a check for preemption is necessary. */
if (preempt_check == TX_TRUE)
{
/* Yes, one or more threads were resumed, check for preemption. */
_tx_thread_system_preempt_check();
}
}
/* Return completion status. */
return(TX_SUCCESS);
}
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