armprog.rar_VxWorks ARM_armprog

/*优先级转置算法------ 使用互斥信号量时 high 阻塞时间长，但没有media长，low资源正常情况下会被media 占用 但是low占用信号量资源时不情愿被media抢占 这时如果high因为此信号量阻塞，就被迫延长等待时间 采用“优先级转置”　 low此时优先级与阻塞在次资源的任务的最高优先级相同 semId=semMCreate(SEM_Q_PRIORITY | SEM_INVERSION_SAFE)*/ #include "vxWorks.h" #include "taskLib.h" #include "semLib.h" void prioHigh(void); void prioMedium(void); void prioLow(void); #define ITER 3 #define HIGH 102 #define MEDIUM 103 #define LOW 104 #define LONG_TIME 3000000 SEM_ID semMutex; void inversion(void) { printf("\n\n....................#####running###..................\n\n\n"); semMutex=semMCreate(SEM_Q_PRIORITY|SEM_INVERSION_SAFE); // semMutex=semMCreate(SEM_Q_PRIORITY); if(taskSpawn("task1",LOW,0x100,20000,prioLow,0,0,0,0,0,0,0,0,0,0)==ERROR) printf("taskspawn prio low failed\n"); if(taskSpawn("task2",MEDIUM,0x100,20000,prioMedium,0,0,0,0,0,0,0,0,0,0)==ERROR) printf("taskspawn prio medium failed\n"); if(taskSpawn("task3",HIGH,0x100,20000,prioHigh,0,0,0,0,0,0,0,0,0,0)==ERROR) printf("taskspawn prio high failed\n"); } /* void timing() { FUNCPTR function_ptr=prioLow; semMutex=semMCreate(SEM_Q_PRIORITY|SEM_INVERSION_SAFE); timexN(function_ptr,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL); } //*/ void prioLow(void) { int i,j; printf("taskspawn prioLow\n"); for(i=0;i<ITER;i++) { semTake(semMutex,WAIT_FOREVER); printf("low priority task locks semaphore\n"); for(j=0;j<LONG_TIME;j++); printf("low priority task unlocks semaphore\n"); semGive(semMutex);/*give up semaphore*/ } printf(".............................low priority task exit\n"); } void prioMedium(void) { int i; printf("taskspawn prioMedium\n"); taskDelay(2); /*allow time for task with the lowest priority to seize semaphore */ for(i=0;i<LONG_TIME*10;i++) { if(i%LONG_TIME==0) printf("medium task running \n"); } printf(".............................medium priority task exit\n"); } void prioHigh(void) { int i,j; printf("taskspawn prioHigh\n"); taskDelay(3); for(i=0;i<ITER;i++) { printf("high priority task try to lock semaphore\n"); semTake(semMutex,WAIT_FOREVER); printf("high priority task locks semaphore\n"); for(j=0;j<LONG_TIME;j++) semGive(semMutex);/*give up*/ } printf(".............................high priority task exit\n"); } /* semMutex=semMCreate(SEM_Q_PRIORITY); ....................#####running###.................. taskspawn prioHigh taskspawn prioMedium taskspawn prioLow low priority task locks semaphore low priority task unlocks semaphore low priority task locks semaphore low priority task unlocks semaphore medium task running high priority task try to lock semaphore medium task running medium task running medium task running medium task running medium task running medium task running medium task running medium task running medium task running .............................medium priority task exit high priority task locks semaphore high priority task try to lock semaphore high priority task locks semaphore high priority task try to lock semaphore high priority task locks semaphore .............................high priority task exit low priority task locks semaphore low priority task unlocks semaphore .............................low priority task exit */ /* semMutex=semMCreate(SEM_Q_PRIORITY|SEM_INVERSION_SAFE); ....................#####running###.................. taskspawn prioHigh taskspawn prioMedium taskspawn prioLow low priority task locks semaphore medium task running high priority task try to lock semaphore low priority task unlocks semaphore high priority task locks semaphore high priority task try to lock semaphore high priority task locks semaphore high priority task try to lock semaphore high priority task locks semaphore .............................high priority task exit medium task running medium task running medium task running medium task running medium task running medium task running medium task running medium task running medium task running .............................medium priority task exit low priority task locks semaphore low priority task unlocks semaphore low priority task locks semaphore low priority task unlocks semaphore .............................low priority task exit */