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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 */
/** */
/** Byte Memory */
/** */
/**************************************************************************/
/**************************************************************************/
#define TX_SOURCE_CODE
/* Include necessary system files. */
#include "tx_api.h"
#include "tx_trace.h"
#include "tx_thread.h"
#include "tx_byte_pool.h"
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _tx_byte_release PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* William E. Lamie, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function returns previously allocated memory to its */
/* associated memory byte pool. */
/* */
/* INPUT */
/* */
/* memory_ptr Pointer to allocated memory */
/* */
/* OUTPUT */
/* */
/* [TX_PTR_ERROR | TX_SUCCESS] Completion status */
/* */
/* 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 */
/* _tx_byte_pool_search Search the byte pool for memory */
/* */
/* 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_byte_release(VOID *memory_ptr)
{
TX_INTERRUPT_SAVE_AREA
UINT status;
TX_BYTE_POOL *pool_ptr;
TX_THREAD *thread_ptr;
UCHAR *work_ptr;
UCHAR *temp_ptr;
UCHAR *next_block_ptr;
TX_THREAD *susp_thread_ptr;
UINT suspended_count;
TX_THREAD *next_thread;
TX_THREAD *previous_thread;
ULONG memory_size;
ALIGN_TYPE *free_ptr;
TX_BYTE_POOL **byte_pool_ptr;
UCHAR **block_link_ptr;
UCHAR **suspend_info_ptr;
/* Default to successful status. */
status = TX_SUCCESS;
/* Set the pool pointer to NULL. */
pool_ptr = TX_NULL;
/* Lockout interrupts. */
TX_DISABLE
/* Determine if the memory pointer is valid. */
work_ptr = TX_VOID_TO_UCHAR_POINTER_CONVERT(memory_ptr);
if (work_ptr != TX_NULL)
{
/* Back off the memory pointer to pickup its header. */
work_ptr = TX_UCHAR_POINTER_SUB(work_ptr, ((sizeof(UCHAR *)) + (sizeof(ALIGN_TYPE))));
/* There is a pointer, pickup the pool pointer address. */
temp_ptr = TX_UCHAR_POINTER_ADD(work_ptr, (sizeof(UCHAR *)));
free_ptr = TX_UCHAR_TO_ALIGN_TYPE_POINTER_CONVERT(temp_ptr);
if ((*free_ptr) != TX_BYTE_BLOCK_FREE)
{
/* Pickup the pool pointer. */
temp_ptr = TX_UCHAR_POINTER_ADD(work_ptr, (sizeof(UCHAR *)));
byte_pool_ptr = TX_UCHAR_TO_INDIRECT_BYTE_POOL_POINTER(temp_ptr);
pool_ptr = *byte_pool_ptr;
/* See if we have a valid pool pointer. */
if (pool_ptr == TX_NULL)
{
/* Return pointer error. */
status = TX_PTR_ERROR;
}
else
{
/* See if we have a valid pool. */
if (pool_ptr -> tx_byte_pool_id != TX_BYTE_POOL_ID)
{
/* Return pointer error. */
status = TX_PTR_ERROR;
/* Reset the pool pointer is NULL. */
pool_ptr = TX_NULL;
}
}
}
else
{
/* Return pointer error. */
status = TX_PTR_ERROR;
}
}
else
{
/* Return pointer error. */
status = TX_PTR_ERROR;
}
/* Determine if the pointer is valid. */
if (pool_ptr == TX_NULL)
{
/* Restore interrupts. */
TX_RESTORE
}
else
{
/* At this point, we know that the pointer is valid. */
/* Pickup thread pointer. */
TX_THREAD_GET_CURRENT(thread_ptr)
/* Indicate that this thread is the current owner. */
pool_ptr -> tx_byte_pool_owner = thread_ptr;
#ifdef TX_BYTE_POOL_ENABLE_PERFORMANCE_INFO
/* Increment the total release counter. */
_tx_byte_pool_performance_release_count++;
/* Increment the number of releases on this pool. */
pool_ptr -> tx_byte_pool_performance_release_count++;
#endif
/* If trace is enabled, insert this event into the trace buffer. */
TX_TRACE_IN_LINE_INSERT(TX_TRACE_BYTE_RELEASE, pool_ptr, TX_POINTER_TO_ULONG_CONVERT(memory_ptr), pool_ptr -> tx_byte_pool_suspended_count, pool_ptr -> tx_byte_pool_available, TX_TRACE_BYTE_POOL_EVENTS)
/* Log this kernel call. */
TX_EL_BYTE_RELEASE_INSERT
/* Release the memory. */
temp_ptr = TX_UCHAR_POINTER_ADD(work_ptr, (sizeof(UCHAR *)));
free_ptr = TX_UCHAR_TO_ALIGN_TYPE_POINTER_CONVERT(temp_ptr);
*free_ptr = TX_BYTE_BLOCK_FREE;
/* Update the number of available bytes in the pool. */
block_link_ptr = TX_UCHAR_TO_INDIRECT_UCHAR_POINTER_CONVERT(work_ptr);
next_block_ptr = *block_link_ptr;
pool_ptr -> tx_byte_pool_available =
pool_ptr -> tx_byte_pool_available + TX_UCHAR_POINTER_DIF(next_block_ptr, work_ptr);
/* Determine if the free block is prior to current search pointer. */
if (work_ptr < (pool_ptr -> tx_byte_pool_search))
{
/* Yes, update the search pointer to the released block. */
pool_ptr -> tx_byte_pool_search = work_ptr;
}
/* Determine if there are threads suspended on this byte pool. */
if (pool_ptr -> tx_byte_pool_suspended_count != TX_NO_SUSPENSIONS)
{
/* Now examine the suspension list to find threads waiting for
memory. Maybe it is now available! */
while (pool_ptr -> tx_byte_pool_suspended_count != TX_NO_SUSPENSIONS)
{
/* Pickup the first suspended thread pointer. */
susp_thread_ptr = pool_ptr -> tx_byte_pool_suspension_list;
/* Pickup the size of the memory the thread is requesting. */
memory_size = susp_thread_ptr -> tx_thread_suspend_info;
/* Restore interrupts. */
TX_RESTORE
/* See if the request can be satisfied. */
work_ptr = _tx_byte_pool_search(pool_ptr, memory_size);
/* Optional processing extension. */
TX_BYTE_RELEASE_EXTENSION
/* Disable interrupts. */
TX_DISABLE
/* Indicate that this thread is the current owner. */
pool_ptr -> tx_byte_pool_owner = thread_ptr;
/* If there is not enough memory, break this loop! */
if (work_ptr == TX_NULL)
{
/* Break out of the loop. */
break;
}
/* Check to make sure the thread is still suspended. */
if (susp_thread_ptr == pool_ptr -> tx_byte_pool_suspension_list)
{
/* Also, makes sure the memory size is the same. */
if (susp_thread_ptr -> tx_thread_suspend_info == memory_size)
{
/* Remove the suspended thread from the list. */
/* Decrement the number of threads suspended. */
pool_ptr -> tx_byte_pool_suspended_count--;
/* Pickup the suspended count. */
suspended_count = pool_ptr -> tx_byte_pool_suspended_count;
/* See if this is the only suspended thread on the list. */
if (suspended_count == TX_NO_SUSPENSIONS)
{
/* Yes, the only suspended thread. */
/* Update the head pointer. */
pool_ptr -> tx_byte_pool_suspension_list = TX_NULL;
}
else
{
/* At least one more thread is on the same expiration list. */
/* Update the list head pointer. */
next_thread = susp_thread_ptr -> tx_thread_suspended_next;
pool_ptr -> tx_byte_pool_suspension_list = next_thread;
/* Update the links of the adjacent threads. */
previous_thread = susp_thread_ptr -> tx_thread_suspended_previous;
next_thread -> tx_thread_suspended_previous = previous_thread;
previous_thread -> tx_thread_suspended_next = next_thread;
}
/* Prepare for resumption of the thread. */
/* Clear cleanup routine to avoid timeout. */
susp_thread_ptr -> tx_thread_suspend_cleanup = TX_NULL;
/* Return this block pointer to the suspended thread waiting for
a block. */
suspend_info_ptr = TX_VOID_TO_INDIRECT_UCHAR_POINTER_CONVERT(susp_thread_ptr -> tx_thread_additional_suspend_info);
*suspend_info_ptr = work_ptr;
/* Clear the memory pointer to indicate that it was given to the suspended thread. */
work_ptr = TX_NULL;
/* Put return status into the thread control block. */
susp_thread_ptr -> tx_thread_suspend_status = TX_SUCCESS;
#ifdef TX_NOT_INTERRUPTABLE
/* Resume the thread! */
_tx_thread_system_ni_resume(susp_thread_ptr);
/* Restore interrupts. */
TX_RESTORE
#else
/* Temporarily disable preemption. */
_tx_thread_preempt_disable++;
/* Restore interrupts. */
TX_RESTORE
/* Resume thread. */
_tx_thread_system_resume(susp_thread_ptr);
#endif
/* Lockout interrupts. */
TX_DISABLE
}
}
/* Determine if the memory was given to the suspended thread. */
if (work_ptr != TX_NULL)
{
/* No, it wasn't given to the suspended thread. */
/* Put the memory back on the available list since this thread is no longer
suspended. */
work_ptr = TX_UCHAR_POINTER_SUB(work_ptr, (((sizeof(UCHAR *)) + (sizeof(ALIGN_TYPE)))));
temp_ptr = TX_UCHAR_POINTER_ADD(work_ptr, (sizeof(UCHAR *)));
free_ptr = TX_UCHAR_TO_ALIGN_TYPE_POINTER_CONVERT(temp_ptr);
*free_ptr = TX_BYTE_BLOCK_FREE;
/* Update the number of available bytes in the pool. */
block_link_ptr = TX_UCHAR_TO_INDIRECT_UCHAR_POINTER_CONVERT(work_ptr);
next_block_ptr = *block_link_ptr;
pool_ptr -> tx_byte_pool_available =
pool_ptr -> tx_byte_pool_available + TX_UCHAR_POINTER_DIF(next_block_ptr, work_ptr);
/* Determine if the current pointer is before the search pointer. */
if (work_ptr < (pool_ptr -> tx_byte_pool_search))
{
/* Yes, update the search pointer. */
pool_ptr -> tx_byte_pool_search = work_ptr;
}
}
}
/* Restore interrupts. */
TX_RESTORE
/* Check for preemption. */
_tx_thread_system_preempt_check();
}
else
{
/* No, threads suspended, restore interrupts. */
TX_RESTORE
}
}
/* Return completion status. */
return(status);
}