📄 tx_byta.c
字号:
/**************************************************************************/
/* */
/* Copyright (c) 1996-2000 by Express Logic Inc. */
/* */
/* This software is copyrighted by and is the sole property of Express */
/* Logic, Inc. All rights, title, ownership, or other interests */
/* in the software remain the property of Express Logic, Inc. This */
/* software may only be used in accordance with the corresponding */
/* license agreement. Any unauthorized use, duplication, transmission, */
/* distribution, or disclosure of this software is expressly forbidden. */
/* */
/* This Copyright notice may not be removed or modified without prior */
/* written consent of Express Logic, Inc. */
/* */
/* Express Logic, Inc. reserves the right to modify this software */
/* without notice. */
/* */
/* Express Logic, Inc. */
/* 11440 West Bernardo Court info@expresslogic.com */
/* Suite 366 http://www.expresslogic.com */
/* San Diego, CA 92127 */
/* */
/**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** ThreadX Component */
/** */
/** Byte Memory (BYT) */
/** */
/**************************************************************************/
/**************************************************************************/
#define TX_SOURCE_CODE
/* Include necessary system files. */
#include "tx_api.h"
#include "tx_thr.h"
#include "tx_tim.h"
#include "tx_byt.h"
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _tx_byte_allocate PORTABLE C */
/* 3.0f */
/* AUTHOR */
/* */
/* William E. Lamie, Express Logic, Inc. */
/* */
/* DESCRIPTION */
/* */
/* This function allocates bytes from the specified memory byte */
/* pool. */
/* */
/* INPUT */
/* */
/* pool_ptr Pointer to pool control block */
/* memory_ptr Pointer to place allocated bytes */
/* pointer */
/* memory_size Number of bytes to allocate */
/* wait_option Suspension option */
/* */
/* OUTPUT */
/* */
/* status Completion status */
/* */
/* CALLS */
/* */
/* _tx_timer_activate Activate timer routine */
/* _tx_thread_suspend Suspend thread service */
/* _tx_byte_pool_search Search byte pool for memory */
/* */
/* CALLED BY */
/* */
/* Application Code */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 12-31-1996 William E. Lamie Initial Version 3.0 */
/* 11-11-1997 Andrea Temple Added rounding to memory size */
/* to ensure ULONG alignment */
/* and modified comments, */
/* resulting in version 3.0b. */
/* 03-01-1998 William E. Lamie Optimized post RESTORE */
/* processing, resulting in */
/* version 3.0d. */
/* 01-01-1999 William E. Lamie Modified comment(s), */
/* resulting in version 3.0e. */
/* 11-01-1999 William E. Lamie Modified comment(s), */
/* added logic to track events,*/
/* resulting in version 3.0f. */
/* */
/**************************************************************************/
UINT _tx_byte_allocate(TX_BYTE_POOL *pool_ptr, VOID **memory_ptr,
ULONG memory_size, ULONG wait_option)
{
TX_INTERRUPT_SAVE_AREA
REG_1 UINT status; /* Return status */
REG_2 TX_THREAD *thread_ptr; /* Working thread pointer */
REG_3 CHAR_PTR work_ptr; /* Working byte pointer */
/* Pickup the thread pointer. */
thread_ptr = _tx_thread_current_ptr;
/* Round the memory size up to the next size that is evenly divisable by
an ULONG. This guarantees proper alignment. */
memory_size = ((memory_size + sizeof(ULONG)-1)/sizeof(ULONG)) * sizeof(ULONG);
/* Disable interrupts. */
TX_DISABLE
/* Log this kernel call. */
TX_EL_BYTE_ALLOCATE_INSERT
/* Loop to handle cases where the owner of the pool changed. */
do
{
/* Indicate that this thread is the current owner. */
pool_ptr -> tx_byte_pool_owner = thread_ptr;
/* Restore interrupts. */
TX_RESTORE
/* At this point, the executing thread owns the pool and can perform a search
for free memory. */
work_ptr = _tx_byte_pool_search(pool_ptr, memory_size);
/* Lockout interrupts. */
TX_DISABLE
} while ((!work_ptr) && (pool_ptr -> tx_byte_pool_owner != thread_ptr));
/* Determine if memory was found. */
if (work_ptr)
{
/* Copy the pointer into the return destination. */
*memory_ptr = (VOID *) work_ptr;
/* Set the status to success. */
status = TX_SUCCESS;
}
else
{
/* No memory of sufficient size was found... */
/* Determine if the request specifies suspension. */
if (wait_option)
{
/* Prepare for suspension of this thread. */
/* Setup cleanup routine pointer. */
thread_ptr -> tx_suspend_cleanup = _tx_byte_pool_cleanup;
/* Setup cleanup information, i.e. this pool control
block. */
thread_ptr -> tx_suspend_control_block = (VOID_PTR) pool_ptr;
/* Save the return memory pointer address as well. */
thread_ptr -> tx_additional_suspend_info = (VOID_PTR) memory_ptr;
/* Save the byte size requested. */
thread_ptr -> tx_suspend_info = memory_size;
/* Setup suspension list. */
if (pool_ptr -> tx_byte_pool_suspension_list)
{
/* This list is not NULL, add current thread to the end. */
thread_ptr -> tx_suspended_next =
pool_ptr -> tx_byte_pool_suspension_list;
thread_ptr -> tx_suspended_previous =
(pool_ptr -> tx_byte_pool_suspension_list) -> tx_suspended_previous;
((pool_ptr -> tx_byte_pool_suspension_list) -> tx_suspended_previous) -> tx_suspended_next =
thread_ptr;
(pool_ptr -> tx_byte_pool_suspension_list) -> tx_suspended_previous = thread_ptr;
}
else
{
/* No other threads are suspended. Setup the head pointer and
just setup this threads pointers to itself. */
pool_ptr -> tx_byte_pool_suspension_list = thread_ptr;
thread_ptr -> tx_suspended_next = thread_ptr;
thread_ptr -> tx_suspended_previous = thread_ptr;
}
/* Increment the suspended thread count. */
pool_ptr -> tx_byte_pool_suspended_count++;
/* Set the state to suspended. */
thread_ptr -> tx_state = TX_BYTE_MEMORY;
/* Set the suspending flag. */
thread_ptr -> tx_suspending = TX_TRUE;
/* Temporarily disable preemption. */
_tx_thread_preempt_disable++;
/* Save the timeout value. */
thread_ptr -> tx_thread_timer.tx_remaining_ticks = wait_option;
/* Restore interrupts. */
TX_RESTORE
/* See if we need to start a timer. */
if (wait_option != TX_WAIT_FOREVER)
{
/* A timeout is required. */
/* Activate the thread timer for the timeout. */
_tx_timer_activate(&(thread_ptr -> tx_thread_timer));
}
/* Call actual thread suspension routine. */
_tx_thread_suspend(thread_ptr);
/* Return the completion status. */
return(thread_ptr -> tx_suspend_status);
}
else
{
/* Immediate return, return error completion. */
status = TX_NO_MEMORY;
}
}
/* Restore interrupts. */
TX_RESTORE
/* Return completion status. */
return(status);
}
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -