📄 os_mbox.lst
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C51 COMPILER V8.02 OS_MBOX 05/22/2008 18:01:51 PAGE 1
C51 COMPILER V8.02, COMPILATION OF MODULE OS_MBOX
OBJECT MODULE PLACED IN OS_MBOX.obj
COMPILER INVOKED BY: C:\Keil\C51\BIN\C51.EXE ucos\OS_MBOX.C LARGE BROWSE INCDIR(.\dataflash;.\lcd;.\task;.\uart;.\ucos;.
-\key) DEBUG OBJECTEXTEND PRINT(.\OS_MBOX.lst) OBJECT(OS_MBOX.obj)
line level source
1 /*
2 *********************************************************************************************************
3 * uC/OS-II
4 * The Real-Time Kernel
5 * MESSAGE MAILBOX MANAGEMENT
6 *
7 * (c) Copyright 1992-2002, Jean J. Labrosse, Weston, FL
8 * All Rights Reserved
9 *
10 * File : OS_MBOX.C
11 * By : Jean J. Labrosse
12 *********************************************************************************************************
13 */
14
15 #ifndef OS_MASTER_FILE
16 #include "includes.h"
17 #endif
18
19 #if OS_MBOX_EN > 0
20 /*
21 *********************************************************************************************************
22 * ACCEPT MESSAGE FROM MAILBOX
23 *
24 * Description: This function checks the mailbox to see if a message is available. Unlike OSMboxPend(),
25 * OSMboxAccept() does not suspend the calling task if a message is not available.
26 *
27 * Arguments : pevent is a pointer to the event control block
28 *
29 * Returns : != (void *)0 is the message in the mailbox if one is available. The mailbox is cleared
30 * so the next time OSMboxAccept() is called, the mailbox will be empty.
31 * == (void *)0 if the mailbox is empty or,
32 * if 'pevent' is a NULL pointer or,
33 * if you didn't pass the proper event pointer.
34 *********************************************************************************************************
35 */
36
37 #if OS_MBOX_ACCEPT_EN > 0
38 void *OSMboxAccept (OS_EVENT *pevent) KCREENTRANT
39 {
40 1 #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
41 1 OS_CPU_SR cpu_sr;
42 1 #endif
43 1 void *msg;
44 1
45 1
46 1 #if OS_ARG_CHK_EN > 0
47 1 if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
48 2 return ((void *)0);
49 2 }
50 1 if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) { /* Validate event block type */
51 2 return ((void *)0);
52 2 }
53 1 #endif
54 1 OS_ENTER_CRITICAL();
C51 COMPILER V8.02 OS_MBOX 05/22/2008 18:01:51 PAGE 2
55 1 msg = pevent->OSEventPtr;
56 1 pevent->OSEventPtr = (void *)0; /* Clear the mailbox */
57 1 OS_EXIT_CRITICAL();
58 1 return (msg); /* Return the message received (or NULL) */
59 1 }
60 #endif
61 /*$PAGE*/
62 /*
63 *********************************************************************************************************
64 * CREATE A MESSAGE MAILBOX
65 *
66 * Description: This function creates a message mailbox if free event control blocks are available.
67 *
68 * Arguments : msg is a pointer to a message that you wish to deposit in the mailbox. If
69 * you set this value to the NULL pointer (i.e. (void *)0) then the mailbox
70 * will be considered empty.
71 *
72 * Returns : != (OS_EVENT *)0 is a pointer to the event control clock (OS_EVENT) associated with the
73 * created mailbox
74 * == (OS_EVENT *)0 if no event control blocks were available
75 *********************************************************************************************************
76 */
77
78 OS_EVENT *OSMboxCreate (void *msg) KCREENTRANT
79 {
80 1 #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
81 1 OS_CPU_SR cpu_sr;
82 1 #endif
83 1 OS_EVENT *pevent;
84 1
85 1
86 1 if (OSIntNesting > 0) { /* See if called from ISR ... */
87 2 return ((OS_EVENT *)0); /* ... can't CREATE from an ISR */
88 2 }
89 1 OS_ENTER_CRITICAL();
90 1 pevent = OSEventFreeList; /* Get next free event control block */
91 1 if (OSEventFreeList != (OS_EVENT *)0) { /* See if pool of free ECB pool was empty */
92 2 OSEventFreeList = (OS_EVENT *)OSEventFreeList->OSEventPtr;
93 2 }
94 1 OS_EXIT_CRITICAL();
95 1 if (pevent != (OS_EVENT *)0) {
96 2 pevent->OSEventType = OS_EVENT_TYPE_MBOX;
97 2 pevent->OSEventCnt = 0;
98 2 pevent->OSEventPtr = msg; /* Deposit message in event control block */
99 2 OS_EventWaitListInit(pevent);
100 2 }
101 1 return (pevent); /* Return pointer to event control block */
102 1 }
103 /*$PAGE*/
104 /*
105 *********************************************************************************************************
106 * DELETE A MAIBOX
107 *
108 * Description: This function deletes a mailbox and readies all tasks pending on the mailbox.
109 *
110 * Arguments : pevent is a pointer to the event control block associated with the desired
111 * mailbox.
112 *
113 * opt determines delete options as follows:
114 * opt == OS_DEL_NO_PEND Delete the mailbox ONLY if no task pending
115 * opt == OS_DEL_ALWAYS Deletes the mailbox even if tasks are waiting.
116 * In this case, all the tasks pending will be readied.
C51 COMPILER V8.02 OS_MBOX 05/22/2008 18:01:51 PAGE 3
117 *
118 * err is a pointer to an error code that can contain one of the following values:
119 * OS_NO_ERR The call was successful and the mailbox was deleted
120 * OS_ERR_DEL_ISR If you attempted to delete the mailbox from an ISR
121 * OS_ERR_INVALID_OPT An invalid option was specified
122 * OS_ERR_TASK_WAITING One or more tasks were waiting on the mailbox
123 * OS_ERR_EVENT_TYPE If you didn't pass a pointer to a mailbox
124 * OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer.
125 *
126 * Returns : pevent upon error
127 * (OS_EVENT *)0 if the mailbox was successfully deleted.
128 *
129 * Note(s) : 1) This function must be used with care. Tasks that would normally expect the presence of
130 * the mailbox MUST check the return code of OSMboxPend().
131 * 2) OSMboxAccept() callers will not know that the intended mailbox has been deleted!
132 * 3) This call can potentially disable interrupts for a long time. The interrupt disable
133 * time is directly proportional to the number of tasks waiting on the mailbox.
134 * 4) Because ALL tasks pending on the mailbox will be readied, you MUST be careful in
135 * applications where the mailbox is used for mutual exclusion because the resource(s)
136 * will no longer be guarded by the mailbox.
137 *********************************************************************************************************
138 */
139
140 #if OS_MBOX_DEL_EN > 0
141 OS_EVENT *OSMboxDel (OS_EVENT *pevent, INT8U opt, INT8U *err) KCREENTRANT
142 {
143 1 #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
144 1 OS_CPU_SR cpu_sr;
145 1 #endif
146 1 BOOLEAN tasks_waiting;
147 1
148 1
149 1 if (OSIntNesting > 0) { /* See if called from ISR ... */
150 2 *err = OS_ERR_DEL_ISR; /* ... can't DELETE from an ISR */
151 2 return (pevent);
152 2 }
153 1 #if OS_ARG_CHK_EN > 0
154 1 if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
155 2 *err = OS_ERR_PEVENT_NULL;
156 2 return (pevent);
157 2 }
158 1 if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) { /* Validate event block type */
159 2 *err = OS_ERR_EVENT_TYPE;
160 2 return (pevent);
161 2 }
162 1 #endif
163 1 OS_ENTER_CRITICAL();
164 1 if (pevent->OSEventGrp != 0x00) { /* See if any tasks waiting on mailbox */
165 2 tasks_waiting = TRUE; /* Yes */
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