📄 os_mutex.s43
字号:
NAME os_mutex(16)
RSEG CODE(1)
EXTERN OSEventFreeList
EXTERN OSIntNesting
EXTERN OSMapTbl
PUBLIC OSMutexAccept
PUBLIC OSMutexCreate
PUBLIC OSMutexDel
PUBLIC OSMutexPend
PUBLIC OSMutexPost
PUBLIC OSMutexQuery
EXTERN OSRdyGrp
EXTERN OSRdyTbl
EXTERN OSTCBCur
EXTERN OSTCBPrioTbl
EXTERN OS_EventTO
EXTERN OS_EventTaskRdy
EXTERN OS_EventTaskWait
EXTERN OS_EventWaitListInit
EXTERN OS_Sched
EXTERN ?CL430_1_26_L08
RSEG CODE
OSMutexAccept:
; 1. /*
; 2. *********************************************************************************************************
; 3. * uC/OS-II
; 4. * The Real-Time Kernel
; 5. * MUTUAL EXCLUSION SEMAPHORE MANAGEMENT
; 6. *
; 7. * (c) Copyright 1992-2002, Jean J. Labrosse, Weston, FL
; 8. * All Rights Reserved
; 9. *
; 10. * File : OS_MUTEX.C
; 11. * By : Jean J. Labrosse
; 12. *********************************************************************************************************
; 13. */
; 14.
; 15. #ifndef OS_MASTER_FILE
; 16. #include "includes.h"
; 17. #endif
; 18.
; 19. /*
; 20. *********************************************************************************************************
; 21. * LOCAL CONSTANTS
; 22. *********************************************************************************************************
; 23. */
; 24.
; 25. #define OS_MUTEX_KEEP_LOWER_8 0x00FF
; 26. #define OS_MUTEX_KEEP_UPPER_8 0xFF00
; 27.
; 28. #define OS_MUTEX_AVAILABLE 0x00FF
; 29.
; 30.
; 31. #if OS_MUTEX_EN > 0
; 32. /*
; 33. *********************************************************************************************************
; 34. * ACCEPT MUTUAL EXCLUSION SEMAPHORE
; 35. *
; 36. * Description: This function checks the mutual exclusion semaphore to see if a resource is available.
; 37. * Unlike OSMutexPend(), OSMutexAccept() does not suspend the calling task if the resource is
; 38. * not available or the event did not occur.
; 39. *
; 40. * Arguments : pevent is a pointer to the event control block
; 41. *
; 42. * err is a pointer to an error code which will be returned to your application:
; 43. * OS_NO_ERR if the call was successful.
; 44. * OS_ERR_EVENT_TYPE if 'pevent' is not a pointer to a mutex
; 45. * OS_ERR_PEVENT_NULL 'pevent' is a NULL pointer
; 46. * OS_ERR_PEND_ISR if you called this function from an ISR
; 47. *
; 48. * Returns : == 1 if the resource is available, the mutual exclusion semaphore is acquired
; 49. * == 0 a) if the resource is not available
; 50. * b) you didn't pass a pointer to a mutual exclusion semaphore
; 51. * c) you called this function from an ISR
; 52. *
; 53. * Warning(s) : This function CANNOT be called from an ISR because mutual exclusion semaphores are
; 54. * intended to be used by tasks only.
; 55. *********************************************************************************************************
; 56. */
; 57.
; 58. #if OS_MUTEX_ACCEPT_EN > 0
; 59. INT8U OSMutexAccept (OS_EVENT *pevent, INT8U *err)
; 60. {
; 61. #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
; 62. OS_CPU_SR cpu_sr;
; 63. #endif
; 64.
; 65.
; 66. if (OSIntNesting > 0) { /* Make sure it's not called from an ISR */
CMP.B #0,&OSIntNesting
JEQ (?0057)
; 67. *err = OS_ERR_PEND_ISR;
MOV.B #2,0(R14)
; 68. return (0);
MOV.B #0,R12
; 69. }
RET
?0057:
; 70. #if OS_ARG_CHK_EN > 0
; 71. if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
CMP #0,R12
JNE (?0059)
; 72. *err = OS_ERR_PEVENT_NULL;
MOV.B #4,0(R14)
; 73. return (0);
; 74. }
RET
?0059:
; 75. if (pevent->OSEventType != OS_EVENT_TYPE_MUTEX) { /* Validate event block type */
MOV.B #4,R13
CMP.B @R12,R13
JEQ (?0061)
; 76. *err = OS_ERR_EVENT_TYPE;
MOV.B #1,0(R14)
; 77. return (0);
MOV.B #0,R12
; 78. }
RET
?0061:
; 79. #endif
; 80. OS_ENTER_CRITICAL(); /* Get value (0 or 1) of Mutex */
DINT
; 81. if ((pevent->OSEventCnt & OS_MUTEX_KEEP_LOWER_8) == OS_MUTEX_AVAILABLE) {
MOV 2(R12),R13
AND #255,R13
CMP #255,R13
JNE (?0063)
; 82. pevent->OSEventCnt &= OS_MUTEX_KEEP_UPPER_8; /* Mask off LSByte (Acquire Mutex) */
AND #65280,2(R12)
; 83. pevent->OSEventCnt |= OSTCBCur->OSTCBPrio; /* Save current task priority in LSByte */
MOV &OSTCBCur,R13
MOV.B 29(R13),R13
BIS R13,2(R12)
; 84. pevent->OSEventPtr = (void *)OSTCBCur; /* Link TCB of task owning Mutex */
MOV &OSTCBCur,4(R12)
; 85. OS_EXIT_CRITICAL();
EINT
; 86. *err = OS_NO_ERR;
MOV.B #0,0(R14)
; 87. return (1);
MOV.B #1,R12
; 88. }
RET
?0063:
; 89. OS_EXIT_CRITICAL();
EINT
; 90. *err = OS_NO_ERR;
MOV.B #0,0(R14)
; 91. return (0);
MOV.B #0,R12
; 92. }
RET
OSMutexCreate:
; 93. #endif
; 94.
; 95. /*$PAGE*/
; 96. /*
; 97. *********************************************************************************************************
; 98. * CREATE A MUTUAL EXCLUSION SEMAPHORE
; 99. *
; 100. * Description: This function creates a mutual exclusion semaphore.
; 101. *
; 102. * Arguments : prio is the priority to use when accessing the mutual exclusion semaphore. In
; 103. * other words, when the semaphore is acquired and a higher priority task
; 104. * attempts to obtain the semaphore then the priority of the task owning the
; 105. * semaphore is raised to this priority. It is assumed that you will specify
; 106. * a priority that is LOWER in value than ANY of the tasks competing for the
; 107. * mutex.
; 108. *
; 109. * err is a pointer to an error code which will be returned to your application:
; 110. * OS_NO_ERR if the call was successful.
; 111. * OS_ERR_CREATE_ISR if you attempted to create a MUTEX from an ISR
; 112. * OS_PRIO_EXIST if a task at the priority inheritance priority
; 113. * already exist.
; 114. * OS_ERR_PEVENT_NULL No more event control blocks available.
; 115. * OS_PRIO_INVALID if the priority you specify is higher that the
; 116. * maximum allowed (i.e. > OS_LOWEST_PRIO)
; 117. *
; 118. * Returns : != (void *)0 is a pointer to the event control clock (OS_EVENT) associated with the
; 119. * created mutex.
; 120. * == (void *)0 if an error is detected.
; 121. *
; 122. * Note(s) : 1) The LEAST significant 8 bits of '.OSEventCnt' are used to hold the priority number
; 123. * of the task owning the mutex or 0xFF if no task owns the mutex.
; 124. * 2) The MOST significant 8 bits of '.OSEventCnt' are used to hold the priority number
; 125. * to use to reduce priority inversion.
; 126. *********************************************************************************************************
; 127. */
; 128.
; 129. OS_EVENT *OSMutexCreate (INT8U prio, INT8U *err)
; 130. {
PUSH R10
PUSH R11
MOV R14,R10
; 131. #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
; 132. OS_CPU_SR cpu_sr;
; 133. #endif
; 134. OS_EVENT *pevent;
; 135.
; 136.
; 137. if (OSIntNesting > 0) { /* See if called from ISR ... */
CMP.B #0,&OSIntNesting
JEQ (?0066)
; 138. *err = OS_ERR_CREATE_ISR; /* ... can't CREATE mutex from an ISR */
MOV.B #141,0(R10)
; 139. return ((OS_EVENT *)0);
MOV #0,R12
; 140. }
JMP (?0073)
?0066:
; 141. #if OS_ARG_CHK_EN > 0
; 142. if (prio >= OS_LOWEST_PRIO) { /* Validate PIP */
CMP.B #12,R12
JNC (?0068)
; 143. *err = OS_PRIO_INVALID;
MOV.B #42,0(R10)
; 144. return ((OS_EVENT *)0);
MOV #0,R12
; 145. }
JMP (?0073)
?0068:
; 146. #endif
; 147. OS_ENTER_CRITICAL();
DINT
; 148. if (OSTCBPrioTbl[prio] != (OS_TCB *)0) { /* Mutex priority must not already exist */
MOV.B R12,R13
ADD R13,R13
CMP #0,OSTCBPrioTbl(R13)
JEQ (?0070)
; 149. OS_EXIT_CRITICAL(); /* Task already exist at priority ... */
EINT
; 150. *err = OS_PRIO_EXIST; /* ... inheritance priority */
MOV.B #40,0(R10)
; 151. return ((OS_EVENT *)0);
MOV #0,R12
; 152. }
JMP (?0073)
?0070:
; 153. OSTCBPrioTbl[prio] = (OS_TCB *)1; /* Reserve the table entry */
MOV.B R12,R13
ADD R13,R13
MOV #1,OSTCBPrioTbl(R13)
; 154. pevent = OSEventFreeList; /* Get next free event control block */
MOV &OSEventFreeList,R11
; 155. if (pevent == (OS_EVENT *)0) { /* See if an ECB was available */
CMP #0,R11
JNE (?0072)
; 156. OSTCBPrioTbl[prio] = (OS_TCB *)0; /* No, Release the table entry */
AND.B #-1,R12
ADD R12,R12
MOV #0,OSTCBPrioTbl(R12)
; 157. OS_EXIT_CRITICAL();
EINT
; 158. *err = OS_ERR_PEVENT_NULL; /* No more event control blocks */
MOV.B #4,0(R10)
; 159. return (pevent);
MOV #0,R12
; 160. }
JMP (?0073)
?0072:
; 161. OSEventFreeList = (OS_EVENT *)OSEventFreeList->OSEventPtr; /* Adjust the free list */
MOV &OSEventFreeList,R13
MOV 4(R13),&OSEventFreeList
; 162. OS_EXIT_CRITICAL();
EINT
; 163. pevent->OSEventType = OS_EVENT_TYPE_MUTEX;
MOV.B #4,0(R11)
; 164. pevent->OSEventCnt = (prio << 8) | OS_MUTEX_AVAILABLE;/* Resource is available */
AND.B #-1,R12
SWPB R12
BIS #255,R12
MOV R12,2(R11)
; 165. pevent->OSEventPtr = (void *)0; /* No task owning the mutex */
MOV #0,4(R11)
; 166. OS_EventWaitListInit(pevent);
MOV R11,R12
CALL #OS_EventWaitListInit
; 167. *err = OS_NO_ERR;
MOV.B #0,0(R10)
; 168. return (pevent);
MOV R11,R12
; 169. }
?0073:
POP R11
POP R10
RET
OSMutexDel:
; 170.
; 171. /*$PAGE*/
; 172. /*
; 173. *********************************************************************************************************
; 174. * DELETE A MUTEX
; 175. *
; 176. * Description: This function deletes a mutual exclusion semaphore and readies all tasks pending on the it.
; 177. *
; 178. * Arguments : pevent is a pointer to the event control block associated with the desired mutex.
; 179. *
; 180. * opt determines delete options as follows:
; 181. * opt == OS_DEL_NO_PEND Delete mutex ONLY if no task pending
; 182. * opt == OS_DEL_ALWAYS Deletes the mutex even if tasks are waiting.
; 183. * In this case, all the tasks pending will be readied.
; 184. *
; 185. * err is a pointer to an error code that can contain one of the following values:
; 186. * OS_NO_ERR The call was successful and the mutex was deleted
; 187. * OS_ERR_DEL_ISR If you attempted to delete the MUTEX from an ISR
; 188. * OS_ERR_INVALID_OPT An invalid option was specified
; 189. * OS_ERR_TASK_WAITING One or more tasks were waiting on the mutex
; 190. * OS_ERR_EVENT_TYPE If you didn't pass a pointer to a mutex
; 191. * OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer.
; 192. *
; 193. * Returns : pevent upon error
; 194. * (OS_EVENT *)0 if the mutex was successfully deleted.
; 195. *
; 196. * Note(s) : 1) This function must be used with care. Tasks that would normally expect the presence of
; 197. * the mutex MUST check the return code of OSMutexPend().
; 198. * 2) This call can potentially disable interrupts for a long time. The interrupt disable
; 199. * time is directly proportional to the number of tasks waiting on the mutex.
; 200. * 3) Because ALL tasks pending on the mutex will be readied, you MUST be careful because the
; 201. * resource(s) will no longer be guarded by the mutex.
; 202. *********************************************************************************************************
; 203. */
; 204.
; 205. #if OS_MUTEX_DEL_EN
; 206. OS_EVENT *OSMutexDel (OS_EVENT *pevent, INT8U opt, INT8U *err)
; 207. {
PUSH R10
PUSH R11
PUSH R8
MOV R12,R11
MOV 8(SP),R8
; 208. #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
; 209. OS_CPU_SR cpu_sr;
; 210. #endif
; 211. BOOLEAN tasks_waiting;
; 212. INT8U pip;
; 213.
; 214.
; 215. if (OSIntNesting > 0) { /* See if called from ISR ... */
CMP.B #0,&OSIntNesting
⌨️ 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 + -