📄 os_task.lst
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C51 COMPILER V7.06 OS_TASK 01/08/2008 20:10:17 PAGE 1
C51 COMPILER V7.06, COMPILATION OF MODULE OS_TASK
OBJECT MODULE PLACED IN OS_TASK.OBJ
COMPILER INVOKED BY: C:\Keil\C51\BIN\C51.EXE OS_TASK.C LARGE BROWSE DEBUG OBJECTEXTEND
stmt level source
1 /*
2 *********************************************************************************************************
3 * uC/OS-II
4 * The Real-Time Kernel
5 * TASK MANAGEMENT
6 *
7 * (c) Copyright 1992-1998, Jean J. Labrosse, Plantation, FL
8 * All Rights Reserved
9 *
10 * V2.00
11 *
12 * File : OS_TASK.C
13 * By : Jean J. Labrosse
14 *********************************************************************************************************
15 */
16
17 #ifndef OS_MASTER_FILE
18 #include "includes.h"
19 #endif
20
21 /*
22 *********************************************************************************************************
23 * LOCAL FUNCTION PROTOTYPES
24 *********************************************************************************************************
25 */
26
27
28 static void OSDummy(void) reentrant;
29
30 /*
31 *********************************************************************************************************
32 * DUMMY FUNCTION
33 *
34 * Description: This function doesn't do anything. It is called by OSTaskDel() to ensure that interrupts
35 * are disabled immediately after they are enabled.
36 *
37 * Arguments : none
38 *
39 * Returns : none
40 *********************************************************************************************************
41 */
42
43 static void OSDummy (void) reentrant
44 {
45 1 }
46
47 /*$PAGE*/
48 /*
49 *********************************************************************************************************
50 * CHANGE PRIORITY OF A TASK
51 *
52 * Description: This function allows you to change the priority of a task dynamically. Note that the new
53 * priority MUST be available.
54 *
55 * Arguments : oldp is the old priority
C51 COMPILER V7.06 OS_TASK 01/08/2008 20:10:17 PAGE 2
56 *
57 * newp is the new priority
58 *
59 * Returns : OS_NO_ERR is the call was successful
60 * OS_PRIO_INVALID if the priority you specify is higher that the maximum allowed
61 * (i.e. >= OS_LOWEST_PRIO)
62 * OS_PRIO_EXIST if the new priority already exist.
63 * OS_PRIO_ERR there is no task with the specified OLD priority (i.e. the OLD task does
64 * not exist.
65 *********************************************************************************************************
66 */
67
68 #if OS_TASK_CHANGE_PRIO_EN
INT8U OSTaskChangePrio (INT8U oldprio, INT8U newprio) reentrant
{
OS_TCB *ptcb;
OS_EVENT *pevent;
INT8U x;
INT8U y;
INT8U bitx;
INT8U bity;
if ((oldprio >= OS_LOWEST_PRIO && oldprio != OS_PRIO_SELF) ||
newprio >= OS_LOWEST_PRIO) {
return (OS_PRIO_INVALID);
}
OS_ENTER_CRITICAL();
if (OSTCBPrioTbl[newprio] != (OS_TCB *)0) { /* New priority must not already exist */
OS_EXIT_CRITICAL();
return (OS_PRIO_EXIST);
} else {
OSTCBPrioTbl[newprio] = (OS_TCB *)1; /* Reserve the entry to prevent others */
OS_EXIT_CRITICAL();
y = newprio >> 3; /* Precompute to reduce INT. latency */
bity = OSMapTbl[y];
x = newprio & 0x07;
bitx = OSMapTbl[x];
OS_ENTER_CRITICAL();
if (oldprio == OS_PRIO_SELF) { /* See if changing self */
oldprio = OSTCBCur->OSTCBPrio; /* Yes, get priority */
}
if ((ptcb = OSTCBPrioTbl[oldprio]) != (OS_TCB *)0) { /* Task to change must exist */
OSTCBPrioTbl[oldprio] = (OS_TCB *)0; /* Remove TCB from old priority */
if (OSRdyTbl[ptcb->OSTCBY] & ptcb->OSTCBBitX) { /* If task is ready make it not ready */
if ((OSRdyTbl[ptcb->OSTCBY] &= ~ptcb->OSTCBBitX) == 0) {
OSRdyGrp &= ~ptcb->OSTCBBitY;
}
OSRdyGrp |= bity; /* Make new priority ready to run */
OSRdyTbl[y] |= bitx;
} else {
if ((pevent = ptcb->OSTCBEventPtr) != (OS_EVENT *)0) { /* Remove from event wait list */
if ((pevent->OSEventTbl[ptcb->OSTCBY] &= ~ptcb->OSTCBBitX) == 0) {
pevent->OSEventGrp &= ~ptcb->OSTCBBitY;
}
pevent->OSEventGrp |= bity; /* Add new priority to wait list */
pevent->OSEventTbl[y] |= bitx;
}
}
OSTCBPrioTbl[newprio] = ptcb; /* Place pointer to TCB @ new priority */
ptcb->OSTCBPrio = newprio; /* Set new task priority */
ptcb->OSTCBY = y;
C51 COMPILER V7.06 OS_TASK 01/08/2008 20:10:17 PAGE 3
ptcb->OSTCBX = x;
ptcb->OSTCBBitY = bity;
ptcb->OSTCBBitX = bitx;
OS_EXIT_CRITICAL();
OSSched(); /* Run highest priority task ready */
return (OS_NO_ERR);
} else {
OSTCBPrioTbl[newprio] = (OS_TCB *)0; /* Release the reserved prio. */
OS_EXIT_CRITICAL();
return (OS_PRIO_ERR); /* Task to change didn't exist */
}
}
}
#endif
132 /*$PAGE*/
133 /*
134 *********************************************************************************************************
135 * CREATE A TASK
136 *
137 * Description: This function is used to have uC/OS-II manage the execution of a task. Tasks can either
138 * be created prior to the start of multitasking or by a running task. A task cannot be
139 * created by an ISR.
140 *
141 * Arguments : task is a pointer to the task's code
142 *
143 * pdata is a pointer to an optional data area which can be used to pass parameters to
144 * the task when the task first executes. Where the task is concerned it thinks
145 * it was invoked and passed the argument 'pdata' as follows:
146 *
147 * void Task (void *pdata)
148 * {
149 * for (;;) {
150 * Task code;
151 * }
152 * }
153 *
154 * ptos is a pointer to the task's top of stack. If the configuration constant
155 * OS_STK_GROWTH is set to 1, the stack is assumed to grow downward (i.e. from high
156 * memory to low memory). 'pstk' will thus point to the highest (valid) memory
157 * location of the stack. If OS_STK_GROWTH is set to 0, 'pstk' will point to the
158 * lowest memory location of the stack and the stack will grow with increasing
159 * memory locations.
160 *
161 * prio is the task's priority. A unique priority MUST be assigned to each task and the
162 * lower the number, the higher the priority.
163 *
164 * Returns : OS_NO_ERR if the function was successful.
165 * OS_PRIO_EXIT if the task priority already exist
166 * (each task MUST have a unique priority).
167 * OS_PRIO_INVALID if the priority you specify is higher that the maximum allowed
168 * (i.e. >= OS_LOWEST_PRIO)
169 *********************************************************************************************************
170 */
171
172 #if OS_TASK_CREATE_EN
173 INT8U OSTaskCreate (void (*task)(void *pd), void *ppdata, OS_STK *ptos, INT8U prio) reentrant
174 {
175 1 void *psp;
176 1 INT8U err;
177 1
178 1
179 1 if (prio > OS_LOWEST_PRIO) { /* Make sure priority is within allowable range */
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