📄 os_sem.lst
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117 *
118 * Description: This function deletes a semaphore and readies all tasks pending on the semaphore.
119 *
120 * Arguments : pevent is a pointer to the event control block associated with the desired
121 * semaphore.
122 *
123 * opt determines delete options as follows:
124 * opt == OS_DEL_NO_PEND Delete semaphore ONLY if no task pending
125 * opt == OS_DEL_ALWAYS Deletes the semaphore even if tasks are waiting.
126 * In this case, all the tasks pending will be readied.
127 *
128 * err is a pointer to an error code that can contain one of the following values:
129 * OS_NO_ERR The call was successful and the semaphore was deleted
130 * OS_ERR_DEL_ISR If you attempted to delete the semaphore from an ISR
131 * OS_ERR_INVALID_OPT An invalid option was specified
132 * OS_ERR_TASK_WAITING One or more tasks were waiting on the semaphore
133 * OS_ERR_EVENT_TYPE If you didn't pass a pointer to a semaphore
134 * OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer.
135 *
136 * Returns : pevent upon error
137 * (OS_EVENT *)0 if the semaphore was successfully deleted.
138 *
139 * Note(s) : 1) This function must be used with care. Tasks that would normally expect the presence of
140 * the semaphore MUST check the return code of OSSemPend().
141 * 2) OSSemAccept() callers will not know that the intended semaphore has been deleted unless
142 * they check 'pevent' to see that it's a NULL pointer.
143 * 3) This call can potentially disable interrupts for a long time. The interrupt disable
144 * time is directly proportional to the number of tasks waiting on the semaphore.
145 * 4) Because ALL tasks pending on the semaphore will be readied, you MUST be careful in
146 * applications where the semaphore is used for mutual exclusion because the resource(s)
147 * will no longer be guarded by the semaphore.
148 *********************************************************************************************************
149 */
150
151 #if OS_SEM_DEL_EN > 0
\ In segment CODE, align 4, keep-with-next
152 OS_EVENT *OSSemDel (OS_EVENT *pevent, INT8U opt, INT8U *err)
153 {
\ OSSemDel:
\ 00000000 F2B5 PUSH {R1,R4-R7,LR}
\ 00000002 0400 MOVS R4,R0
\ 00000004 1500 MOVS R5,R2
154 #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
155 OS_CPU_SR cpu_sr;
156 #endif
157 BOOLEAN tasks_waiting;
158
159
160 if (OSIntNesting > 0) { /* See if called from ISR ... */
\ 00000006 .... LDR R0,??DataTable7 ;; OSIntNesting
\ 00000008 0078 LDRB R0,[R0, #+0]
\ 0000000A 0028 CMP R0,#+0
\ 0000000C 01D0 BEQ ??OSSemDel_0
161 *err = OS_ERR_DEL_ISR; /* ... can't DELETE from an ISR */
\ 0000000E 8C20 MOVS R0,#+140
\ 00000010 53E0 B.N ??OSSemDel_1
162 return (pevent);
163 }
164 #if OS_ARG_CHK_EN > 0
165 if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
\ ??OSSemDel_0:
\ 00000012 002C CMP R4,#+0
\ 00000014 03D1 BNE ??OSSemDel_2
166 *err = OS_ERR_PEVENT_NULL;
\ 00000016 0420 MOVS R0,#+4
\ 00000018 2870 STRB R0,[R5, #+0]
167 return (pevent);
\ 0000001A 0020 MOVS R0,#+0
\ 0000001C 4FE0 B ??OSSemDel_3
168 }
169 #endif
170 if (pevent->OSEventType != OS_EVENT_TYPE_SEM) { /* Validate event block type */
\ ??OSSemDel_2:
\ 0000001E 2078 LDRB R0,[R4, #+0]
\ 00000020 0328 CMP R0,#+3
\ 00000022 01D0 BEQ ??OSSemDel_4
171 *err = OS_ERR_EVENT_TYPE;
\ 00000024 0120 MOVS R0,#+1
\ 00000026 48E0 B.N ??OSSemDel_1
172 return (pevent);
173 }
174 OS_ENTER_CRITICAL();
\ ??OSSemDel_4:
\ 00000028 ........ _BLF OS_CPU_SR_Save,??OS_CPU_SR_Save??rT
\ 0000002C 0600 MOVS R6,R0
175 if (pevent->OSEventGrp != 0x00) { /* See if any tasks waiting on semaphore */
\ 0000002E 6078 LDRB R0,[R4, #+1]
\ 00000030 0028 CMP R0,#+0
\ 00000032 01D0 BEQ ??OSSemDel_5
176 tasks_waiting = TRUE; /* Yes */
\ 00000034 0127 MOVS R7,#+1
\ 00000036 00E0 B ??OSSemDel_6
177 } else {
178 tasks_waiting = FALSE; /* No */
\ ??OSSemDel_5:
\ 00000038 0027 MOVS R7,#+0
179 }
180 switch (opt) {
\ ??OSSemDel_6:
\ 0000003A 6846 MOV R0,SP
\ 0000003C 0078 LDRB R0,[R0, #+0]
\ 0000003E 0028 CMP R0,#+0
\ 00000040 02D0 BEQ ??OSSemDel_7
\ 00000042 0128 CMP R0,#+1
\ 00000044 1ED0 BEQ ??OSSemDel_8
\ 00000046 34E0 B ??OSSemDel_9
181 case OS_DEL_NO_PEND: /* Delete semaphore only if no task waiting */
182 if (tasks_waiting == FALSE) {
\ ??OSSemDel_7:
\ 00000048 002F CMP R7,#+0
\ 0000004A 11D1 BNE ??OSSemDel_10
183 #if OS_EVENT_NAME_SIZE > 1
184 pevent->OSEventName[0] = '?'; /* Unknown name */
\ 0000004C 3F20 MOVS R0,#+63
\ 0000004E 2074 STRB R0,[R4, #+16]
185 pevent->OSEventName[1] = OS_ASCII_NUL;
\ 00000050 0020 MOVS R0,#+0
\ 00000052 6074 STRB R0,[R4, #+17]
186 #endif
187 pevent->OSEventType = OS_EVENT_TYPE_UNUSED;
\ 00000054 2070 STRB R0,[R4, #+0]
188 pevent->OSEventPtr = OSEventFreeList; /* Return Event Control Block to free list */
\ 00000056 .... LDR R0,??DataTable6 ;; OSEventFreeList
\ 00000058 0068 LDR R0,[R0, #+0]
\ 0000005A 6060 STR R0,[R4, #+4]
189 pevent->OSEventCnt = 0;
\ 0000005C 0020 MOVS R0,#+0
\ 0000005E 6080 STRH R0,[R4, #+2]
190 OSEventFreeList = pevent; /* Get next free event control block */
\ 00000060 .... LDR R0,??DataTable6 ;; OSEventFreeList
\ 00000062 0460 STR R4,[R0, #+0]
191 OS_EXIT_CRITICAL();
\ 00000064 3000 MOVS R0,R6
\ 00000066 ........ _BLF OS_CPU_SR_Restore,??OS_CPU_SR_Restore??rT
192 *err = OS_NO_ERR;
\ ??OSSemDel_11:
\ 0000006A 0020 MOVS R0,#+0
\ 0000006C 2870 STRB R0,[R5, #+0]
193 return ((OS_EVENT *)0); /* Semaphore has been deleted */
\ 0000006E 26E0 B ??OSSemDel_3
194 } else {
195 OS_EXIT_CRITICAL();
\ ??OSSemDel_10:
\ 00000070 3000 MOVS R0,R6
\ 00000072 ........ _BLF OS_CPU_SR_Restore,??OS_CPU_SR_Restore??rT
196 *err = OS_ERR_TASK_WAITING;
\ 00000076 0820 MOVS R0,#+8
\ 00000078 1FE0 B.N ??OSSemDel_1
197 return (pevent);
198 }
199
200 case OS_DEL_ALWAYS: /* Always delete the semaphore */
201 while (pevent->OSEventGrp != 0x00) { /* Ready ALL tasks waiting for semaphore */
202 OS_EventTaskRdy(pevent, (void *)0, OS_STAT_SEM);
\ ??OSSemDel_12:
\ 0000007A 0122 MOVS R2,#+1
\ 0000007C 0021 MOVS R1,#+0
\ 0000007E 2000 MOVS R0,R4
\ 00000080 ........ _BLF OS_EventTaskRdy,??OS_EventTaskRdy??rT
203 }
\ ??OSSemDel_8:
\ 00000084 6078 LDRB R0,[R4, #+1]
\ 00000086 0028 CMP R0,#+0
\ 00000088 F7D1 BNE ??OSSemDel_12
204 #if OS_EVENT_NAME_SIZE > 1
205 pevent->OSEventName[0] = '?'; /* Unknown name */
\ 0000008A 3F20 MOVS R0,#+63
\ 0000008C 2074 STRB R0,[R4, #+16]
206 pevent->OSEventName[1] = OS_ASCII_NUL;
\ 0000008E 0020 MOVS R0,#+0
\ 00000090 6074 STRB R0,[R4, #+17]
207 #endif
208 pevent->OSEventType = OS_EVENT_TYPE_UNUSED;
\ 00000092 2070 STRB R0,[R4, #+0]
209 pevent->OSEventPtr = OSEventFreeList; /* Return Event Control Block to free list */
\ 00000094 .... LDR R0,??DataTable6 ;; OSEventFreeList
\ 00000096 0068 LDR R0,[R0, #+0]
\ 00000098 6060 STR R0,[R4, #+4]
210 pevent->OSEventCnt = 0;
\ 0000009A 0020 MOVS R0,#+0
\ 0000009C 6080 STRH R0,[R4, #+2]
211 OSEventFreeList = pevent; /* Get next free event control block */
\ 0000009E .... LDR R0,??DataTable6 ;; OSEventFreeList
\ 000000A0 0460 STR R4,[R0, #+0]
212 OS_EXIT_CRITICAL();
\ 000000A2 3000 MOVS R0,R6
\ 000000A4 ........ _BLF OS_CPU_SR_Restore,??OS_CPU_SR_Restore??rT
213 if (tasks_waiting == TRUE) { /* Reschedule only if task(s) were waiting */
\ 000000A8 012F CMP R7,#+1
\ 000000AA DED1 BNE ??OSSemDel_11
214 OS_Sched(); /* Find highest priority task ready to run */
\ 000000AC ........ _BLF OS_Sched,??OS_Sched??rT
215 }
216 *err = OS_NO_ERR;
\ ??OSSemDel_13:
\ 000000B0 DBE7 B.N ??OSSemDel_11
217 return ((OS_EVENT *)0); /* Semaphore has been deleted */
218
219 default:
220 OS_EXIT_CRITICAL();
\ ??OSSemDel_9:
\ 000000B2 3000 MOVS R0,R6
\ 000000B4 ........ _BLF OS_CPU_SR_Restore,??OS_CPU_SR_Restore??rT
221 *err = OS_ERR_INVALID_OPT;
\ 000000B8 0720 MOVS R0,#+7
\ ??OSSemDel_1:
\ 000000BA 2870 STRB R0,[R5, #+0]
222 return (pevent);
\ 000000BC 2000 MOVS R0,R4
\ ??OSSemDel_3:
\ 000000BE 01B0 ADD SP,SP,#+4
\ 000000C0 F0BC POP {R4-R7}
\ 000000C2 02BC POP {R1}
\ 000000C4 0847 BX R1 ;; return
223 }
224 }
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