/************************************************************
* function: dequeueing.
* item: a pointer to the element to dequeue
* size: the size of the element
* return: 0, correct; others, error number.
***********************************************************/
int shmmq_dequeue(void* item, int size)
{
int ret = 0;
if (!item || size <= 0 || size > g_s_itemsize) {
return ERROR_INVALID_ARGUMENT;
}
if (-1 == semaphore_p(g_s_semid)) {
return ERROR_SEMAPHORE_P;
}
if (g_s_phead->enq_pos == g_s_phead->deq_pos) {
ret = ERROR_MSGQUEUE_FULL;
goto queue_full;
}
unsigned int pos = (g_s_phead->deq_pos+1) % g_s_mqsize;
memcpy(item, g_s_pcontent + pos * g_s_itemsize, size);
g_s_phead->deq_pos++;
queue_full:
if (-1 == semaphore_v(g_s_semid)) {
return ERROR_SEMAPHORE_V;
}
return ret;
}
/************************************************************
* function: clear the overdue items from the queue.
* sf: a pointer to function which can calculate the critical index
* return: 0, correct; others, error number.
***********************************************************/
int shmmq_clear(SF sf)
{
int ret = 0;
int begin;
int end;
if (sf == NULL) {
return ERROR_INVALID_ARGUMENT;
}
if (-1 == semaphore_p(g_s_semid)) {
return ERROR_SEMAPHORE_P;
}
begin = g_s_phead->deq_pos % g_s_mqsize;
end = g_s_phead->enq_pos % g_s_mqsize;
begin = (*sf)(begin, end);
if (begin < 0 || begin >= g_s_mqsize) {
ret = ERROR_INVALID_ARGUMENT;
}
if (-1 == semaphore_v(g_s_semid)) {
return ERROR_SEMAPHORE_V;
}
return ret;
}
int main(int argc,char *argv)
{
pid_t pid;
int i;
int value;
key_t key;
int status;
if((pid=fork())==-1)
{
perror("fork");
exit(EXIT_FAILURE);
}
else if(pid==0)
{
if((sem_id=semget((key_t)123456,1,IPC_CREAT|0770))==-1)
{
perror("semget");
exit(EXIT_FAILURE);
}
if (!set_semvalue())
{
fprintf(stderr, "Failed to initialize semaphore\n");
exit(EXIT_FAILURE);
}
value=get_semvalue();
printf("this is child,the current value is %d\n",value);
if(!semaphore_v())
{
fprintf(stderr, "Failed to v operator\n");
exit(EXIT_FAILURE);
}
value=get_semvalue();
printf("the child %d V operator,value=%d\n",i,value);
printf("child exit success\n");
exit(EXIT_SUCCESS);
}
else //parent
{
sleep(3);
if((sem_id=semget((key_t)123456,1,IPC_CREAT|0770))==-1)
{
perror("semget");
exit(EXIT_FAILURE);
}
value=get_semvalue();
printf("this is parent ,the current value is %d\n",value);
printf("the parent will remove the sem\n");
if(semctl(sem_id,0, IPC_RMID,(struct msquid_ds*)0)==-1)
{
perror("semctl");
exit(EXIT_FAILURE);
}
return 0;
}
}
int main(int argc,char **argv)
{
int i ;
int pause_time;
char op_char = 'O';
srand((unsigned int)getpid());
//create semaphore
sem_id = semget((key_t)1234,1,0666|IPC_CREAT);
if (argc >1)
{
//set sempvalue 初始化信号量
if (!set_semvalue())
{
fprintf(stderr,"Failed to initialize semaphore");
exit(EXIT_FAILURE);
}
op_char = 'X';
sleep(2);
}
for (i = 0; i < 10; ++i)
{
//设置信号量 等待进入
if (!semaphore_p())
{
exit(EXIT_FAILURE);
}
printf("%c",op_char);
fflush(stdout);
pause_time = rand() % 3;
sleep(pause_time);
printf("%c",op_char);
fflush(stdout);
//退出临界区，信号量设置为可用
if (!semaphore_v())
{
exit(EXIT_FAILURE);
}
pause_time = rand() % 3;
sleep(pause_time);
}
printf("\n%d - finished \n",getpid());
if (argc>1)
{
sleep(10);
//删除信号量
del_semvalue();
}
exit(EXIT_SUCCESS);
}
int main(int argc, char *argv[])
{
char message = 'X';
int i = 0;
/* 创建信号量 */
sem_id = semget((key_t)1234, 1, 0666 | IPC_CREAT);
if(argc > 1)
{
/* 程序第一次被调用，初始化信号量 */
if(!set_semvalue())
{
fprintf(stderr, "Failed to initialize semaphore\n");
exit(EXIT_FAILURE);
}
/* 设置要输出到屏幕中的信息，即其参数的第一个字符 */
message = argv[1][0];
sleep(2);
}
for(i = 0; i < 10; ++i)
{
/* 进入临界区 */
if(!semaphore_p())
{
exit(EXIT_FAILURE);
}
/* 向屏幕中输出数据 */
printf("%c", message);
/* 清理缓冲区，然后休眠随机时间 */
fflush(stdout);
sleep(rand() % 3);
/* 离开临界区前再一次向屏幕输出数据 */
printf("%c", message);
fflush(stdout);
/* 离开临界区，休眠随机时间后继续循环 */
if(!semaphore_v())
{
exit(EXIT_FAILURE);
}
sleep(rand() % 2);
}
sleep(10);
printf("\n%d - finished\n", getpid());
if(argc > 1)
{
/* 如果程序是第一次被调用，则在退出前删除信号量 */
sleep(3);
del_semvalue();
}
exit(EXIT_SUCCESS);
}
int main ()
{
int i;
int pause_time;
int status;
char op_char = 'O';
srand((unsigned int)getpid());
sem_id = semget((key_t)1234, 1, 0666 | IPC_CREAT);
sleep(2);
//if (!set_semvalue())
//{
// fprintf(stderr, "Failed to initialize semaphore\n");
// exit(EXIT_FAILURE);
//}
//op_char = 'X';
//sleep(2);
char *argc[] = {"./printer","Process_Read",NULL};
for(i = 0; i < 10; i++)
{
if (!semaphore_p())
exit(EXIT_FAILURE);
pid_t pid = fork();
if(pid == (pid_t)0)
{
execv("./printer",argc);
}
//fflush(stdout);
//pause_time = rand() % 3;
sleep(1);
//printf("%c", op_char);
//fflush(stdout);
pid_t pid_second = fork();
if(pid_second == (pid_t)0)
{
execv("./printer",argc);
}
int ret_child = waitpid(pid,&status,0);
int ret_s_child = waitpid(pid_second,&status,0);
printf("Getting Second Here \n");
if (!semaphore_v())
exit(EXIT_FAILURE);
pause_time = rand() % 2;
sleep(pause_time);
}
printf("\n%d - finished\n", getpid());
//if (argc > 1)
//{
// sleep(4);
//del_semvalue();
//}
exit(EXIT_SUCCESS);
}
int main(int argc, char* argv[]) {
int i;
int pause_time;
char op_char = 'O';
srand((unsigned int)getpid());
sem_id = semget((key_t)1234, 1, 0666 | IPC_CREAT);
if (argc > 1) {
if (!set_semvalue()) {
fprintf(stderr, "Failed to initialize semaphore\n");
exit(EXIT_FAILURE);
}
op_char = 'X';
sleep(2);
}
/* Then we have a loop which enters and leaves the critical section ten times.
There, we first make a call to semaphore_p which sets the semaphore to wait, as
this program is about to enter the critical section. */
for (i = 0; i < 10; i++) {
if (!semaphore_p()) {
exit(EXIT_FAILURE);
}
printf("%c", op_char);
fflush(stdout);
pause_time = rand() % 3;
sleep(pause_time);
printf("%c", op_char);
fflush(stdout);
/* After the critical section, we call semaphore_v, setting the semaphore available,
before going through the for loop again after a random wait. After the loop, the call
to del_semvalue is made to clean up the code. */
if (!semaphore_v()) {
exit(EXIT_FAILURE);
}
pause_time = rand() % 2;
sleep(pause_time);
}
printf("\n%d - finished\n", getpid());
if (argc > 1) {
sleep(10);
del_semvalue();
}
exit(EXIT_SUCCESS);
}
int main(int argc, char *argv[])
{
char message = 'X';
int i = 0;
key_t key;
key = ftok("/var/httcsec",IPC_ID);
//创建信号量
printf("key:%d\n", (int)key);
sem_id = semget(key, 1, 0666 | IPC_CREAT);
if(argc > 1)
{
//程序第一次被调用，初始化信号量
if(!set_semvalue())
{
fprintf(stderr, "Failed to initialize semaphore\n");
exit(EXIT_FAILURE);
}
//设置要输出到屏幕中的信息，即其参数的第一个字符
message = argv[1][0];
sleep(2);
}
for(i = 0; i < 3; ++i)
{
//进入临界区
if(!semaphore_p())
exit(EXIT_FAILURE);
//向屏幕中输出数据
printf("..[%d]..lock\n", getpid());
//清理缓冲区，然后休眠随机时间
fflush(stdout);
sleep(rand() % 5);
//离开临界区前再一次向屏幕输出数据
printf("..[%d]..unlock\n", getpid());
fflush(stdout);
//离开临界区，休眠随机时间后继续循环
if(!semaphore_v())
exit(EXIT_FAILURE);
printf("..[%d]..waiting\n", getpid());
fflush(stdout);
}
printf("\n%d - finished\n", getpid());
if(argc > 1)
{
//如果程序是第一次被调用，则在退出前删除信号量
sleep(3);
del_semvalue();
}
exit(EXIT_SUCCESS);
}
int main(int argc, char *argv[])
{
int i;
srand((unsigned int)getpid());
sem_id = semget((key_t)4321, 1, 0666);
printf("sem_id_%s = %d\n",argv[1], sem_id);
if(sem_id < 0)
{
sem_id = semget((key_t)4321, 1, 0666|IPC_CREAT);
printf("sem_id_2_%s = %d\n", argv[1] , sem_id);
}
if(argc > 1)
{
if(!set_semvalue())
{
fprintf(stderr, "Failed to initlize semaphore\n");
exit(EXIT_FAILURE);
}
op_char = argv[1];
// sleep(2);
}
for(i = 0; i< 10; i++)
{
/****************** P *********************/
if(!semaphore_p())
exit(EXIT_FAILURE);
do_my_job(); //do something
/****************** V *********************/
if(!semaphore_v())
exit(EXIT_FAILURE);
pause_time = rand()%2;
// sleep(pause_time);
}//for
printf("\n%d - finished \n", getpid());
if(argc > 1)
{
// sleep(10);
del_semvalue();
}
exit(EXIT_SUCCESS);
}
int main(int argc, char *argv[])
{
int i;
int pause_time;
char op_char='O';
srand((unsigned int)getpid());
sem_id = semget((key_t)4321, 1, 0666|IPC_CREAT);
if(argc > 1)
{
if(!set_semvalue())
{
fprintf(stderr, "Failed to initlize semaphore\n");
exit(EXIT_FAILURE);
}
op_char = 'X';
sleep(2);
}
for(i = 0; i< 10; i++)
{
if(!semaphore_p())
exit(EXIT_FAILURE);
printf("%c is doing job\n", op_char);
fflush(stdout);
pause_time = rand()%3;
sleep(pause_time);
printf("%c is done\n", op_char);
fflush(stdout);
if(!semaphore_v())
exit(EXIT_FAILURE);
pause_time = rand()%2;
sleep(pause_time);
}//for
printf("\n%d - finished \n", getpid());
if(argc > 1)
{
sleep(10);
del_semvalue();
}
exit(EXIT_SUCCESS);
}
int main(int argc, char *argv[]) {
int i;
int pause_time;
char op_char = 'O';
// initialize the random seed
srand( (unsigned int) getpid() );
// creates a new semaphore (only 1) with modes + create if doesn't ex
sem_id = semget( (key_t)1234, 1, 0666 | IPC_CREAT);
// if invoked with parameters (must be the first invocation)
if ( argc > 1 ) {
if ( ! set_semvalue() ) {
fprintf (stderr, "failed to init semaphore\n");
exit (EXIT_FAILURE);
}
op_char = 'X';
// gives time to start the second semaphore
sleep (2);
}
// normal run
for ( i = 0 ; i < 10 ; i++ ) {
if ( !semaphore_p() )
exit (EXIT_FAILURE);
printf ("%c", op_char);
fflush (stdout);
pause_time = rand() % 3;
sleep (pause_time);
printf("%c", op_char);
fflush (stdout);
if ( ! semaphore_v() )
exit (EXIT_FAILURE);
pause_time = rand() % 2;
sleep (pause_time);
}
printf ("\n%d - finished\n", getpid() );
if (argc > 1 ) {
sleep (10);
del_semvalue();
}
exit (EXIT_SUCCESS);
}
int main(int argc, char *argv[]) {
int i;
int pause_time;
char op_char = 'O';
srand((unsigned int)getpid());
sem_id = semget((key_t)1234, 1, 0666 | IPC_CREAT);
// if there's an arg, set op_char to X and create the semaphore
if (argc > 1) {
if (!set_semvalue()) {
fprintf(stderr, "Failed to initialize semaphore\n");
exit(EXIT_FAILURE);
}
op_char = 'X';
sleep(2);
}
// take turns locking, printing to stdout and flushing,
// and then unlocking and waiting.
for(i = 0; i < 10; i++) {
// lock around the printing and a short pause
if (!semaphore_p()) exit(EXIT_FAILURE);
printf("%c", op_char);fflush(stdout);
pause_time = rand() % 3;
sleep(pause_time);
printf("%c", op_char);fflush(stdout);
if (!semaphore_v()) exit(EXIT_FAILURE);
// then do a random pause while unlocked
pause_time = rand() % 2;
sleep(pause_time);
}
printf("\n%d - finished\n", getpid());
// it's very important to delete the semaphore you created!
if (argc > 1) {
sleep(10);
del_semvalue();
}
exit(EXIT_SUCCESS);
}
int main(int argc, char *argv[])
{
int sem_id;
char ch = 'O';
int i, pause_time;
srand((unsigned int)getpid());
sem_id = semget((key_t)1234, 1, 0666|IPC_CREAT);
if(sem_id < 0)
{
fprintf(stderr, "get semaphore id failed\n");
exit(1);
}
if(argc > 1)
{
if(!set_semvalue(sem_id))
{
fprintf(stderr, "initialize semaphore failed\n");
exit(1);
}
ch = 'X';
sleep(2);
}
for(i = 0; i < 10; ++i)
{
if(!semaphore_p(sem_id))
exit(1);
printf("%c", ch);
fflush(stdout);
pause_time = rand() % 3;
sleep(pause_time);
printf("%c", ch);
fflush(stdout);
if(!semaphore_v(sem_id))
exit(1);
}
if(argc > 1)
{
sleep(10);
del_semvalue(sem_id);
}
exit(0);
}
int main(int argc, char *argv[])
{
pid_t pid;
int value;
key_t key;
if((pid=fork()) == -1){
perror("fork");
exit(EXIT_FAILURE);
}else if (pid == 0){
if((sem_id=semget((key_t)123456, 1, 0770|IPC_CREAT)) == -1){
perror("semget");
exit(EXIT_FAILURE);
}
if(!set_semvalue()){
printf("failed initialized semaphore\n");
exit(EXIT_FAILURE);
}
value = get_semvalue();
printf("child: the current value is %d\n",value);
if(!semaphore_v()){
printf("failed to v operator\n");
exit(EXIT_FAILURE);
}
value = get_semvalue();
printf("child: v operator, value=%d\n", value);
printf("child: exit success\n");
exit(EXIT_SUCCESS);
}else{
sleep(3);
if((sem_id = semget((key_t)123456, 1, 0770|IPC_CREAT)) == -1){
perror("semget");
exit(EXIT_FAILURE);
}
value=get_semvalue();
printf("parent: the current value is %d\n", value);
printf("parent: will remove the sem\n");
if(semctl(sem_id, 0, IPC_RMID, (struct msquid_ds *)0) == -1){
perror("semclt");
exit(EXIT_FAILURE);
}
}
return 0;
}
int main(int argc,char *argv[]){
int i;
int pause_time;
char op_char='O';
srand((unsigned int)getpid());
sem_id = semget((key_t)1234,1,0666|IPC_CREAT);// 產生一個新號誌 或者根據key 取得一個已存在的號誌 666為設定權限
if(argc >1){ // 假設第一次執行時 使用參數
if(!set_semvalue()){ // setctl回傳-1時（發生錯誤）
fprintf(stderr,"Failed to initialize semaphore\n");
exit(EXIT_FAILURE);
}
op_char='X';
sleep(2);
}
/* 然後進入迴圈 進出入 "critical section" 十次
* 在那裡 首先先呼叫semaphore_p 讓即將進入critical section 的semaphore等待*/
for(i=0;i<10;i++){
if(!semaphore_p()) exit(EXIT_FAILURE);
printf("%c",op_char);fflush(stdout);
pause_time=rand()%3;
sleep(pause_time);
printf("%c",op_char);fflush(stdout);
/* 在critical section 之後 呼叫semaphore_v
* 再進去for loop 之前 等待一段亂數時間 然後del sem 結束*/
if(!semaphore_v()) exit(EXIT_FAILURE);
pause_time=rand()%2;
sleep(pause_time);
}
printf("\n%d - finished\n",getpid());
if(argc>1){
sleep(10);
del_semvalue();
}
exit(EXIT_SUCCESS);
}
int main()
{
int fd1,fd2,file1,recived,sem_id;
datavar.arry='*';
datavar.arr[0]=20;
datavar.arr[1]=20;
semaphore_p();
// recived=semop(sem_id,struct sembuf *sem,SEM_UNDO);
// printf("semid is %d\n",sem_id);
// sem.sem_num=0;
// sem.sem_ops=-1;
fd1=open("fifo_server",O_WRONLY);
printf("process pid is %d\n",getpid());
recived=write(fd1,&datavar,sizeof(datavar));
close(fd1);
// printf("number of written by are %d\n",recived);
// printf("writen data is %c %d %d\n",datavar.arry,datavar.arr[0],datavar.arr[1]);
if(access("fifo_client1",F_OK) == -1)
file1=mkfifo("fifo_client1",0777);
if(file1<0)
{
printf("file not created successfuly\n");
}
else
{
printf("file created successfully and pid is %d\n",getpid());
}
fd2=open("fifo_client1",O_RDONLY);
printf("file discriptor is %d\n",fd2);
recived=read(fd2,&datavar1,sizeof(datavar));
close(fd2);
//printf("number of bytes read are %d\n",recived);
printf("result of sum (20*20)= %d\n",datavar1.result);
semaphore_v();
// printf("end of program\n");
//sem.sem_ops=1;
//semop(sem_id,struct sembuf *sem_ops,SEM_UNDO);
}
/*
//------------------------------------------------------------------------------------------------------
// Allocate shraed memory ,set semaphore,wakeup audio server
//
//------------------------------------------------------------------------------------------------------
*/
static int preinit(sh_audio_t *sh)
{
#ifndef EngineMode
union smc *sc;
long curr_codec;
#endif
{
#ifndef EngineMode
if(sh->samplesize==2)
{
sh->sample_format=AF_FORMAT_S16_LE; //packing as 2 bytes
}else if(sh->samplesize==1)
{
sh->sample_format=AF_FORMAT_U8; //packing as 1 bytes
}else if(sh->samplesize==4)
{
sh->sample_format=AF_FORMAT_S32_LE; //packing as 4 bytes
}
#endif
sh->audio_out_minsize = BLOCKS_PER_LOOP*2*sh->samplesize;
}
#ifndef EngineMode
#ifdef AD_SHM_REWRITE
sm_com_id = get_first_shared_mem_id(KEY_SM_COM, SM_COM_SIZE);
if(sm_com_id < 0)
sm_com_id = get_shared_mem_id(KEY_SM_COM, SM_COM_SIZE); //get shared memory ID
if(sm_com == NULL)
{
if ((sm_com = allocate_share_mem(sm_com_id))==NULL) //allocate shared memory ( command )
return 0;
}
#else
sm_com_id = get_shared_mem_id(KEY_SM_COM, SM_COM_SIZE); //get shared memory ID
if ((sm_com = allocate_share_mem(sm_com_id))==NULL) //allocate shared memory ( command )
return 0;
#endif
id = get_semaphore_id(); //get semaphore ID
if (!reset_semvalue(id, 0)){ //reset semaphore
return 0;
}
sc = (union smc *)sm_com;
sc->magic.magic_num = PLAYER_MAGIC;
curr_codec = APE_ID; //inform server what kind of coded to be used.
sc->magic.codec_id = curr_codec;
if (!semaphore_v(id, 1)) //wakeup server!
return 0;
if (!wait_server(sc)){ //wait for server's response
deallocate_share_mem(sm_com);
#ifndef AD_SHM_REWRITE
shmctl(sm_com_id, IPC_RMID, 0);
#endif
del_semvalue(id, 0);
printf("Audio server crash \n");
return 0;
}
if (sc->magic.codec_id != curr_codec){ //check codec
printf("Unsuppoted codec\n");
return 0;
}
#endif
csd_avail_num = res_num = 0;
return 1;
}
int main()
{
signal (SIGTERM, out);
signal (SIGINT, out);
int shmid;
/* искать сегмент, соответствующий ключу key*/
shmid = shmget((key_t)1234, sizeof(struct memFormat), 0666);
if (shmid == -1) {perror("shmget");return 0;}
shared_memory = shmat(shmid, (void *)0, SHM_RDONLY);
if (shared_memory == (void *)-1) {perror("shmat");return 0;}
int sem_id = createSem(1,12345);
if(sem_id==-1) {perror("createSem"); return 0;}
if(set_semvalue(sem_id,0)==-1) {perror("set_semvalue"); return 0;}
semaphore_p(sem_id);
memcpy(&memf,shared_memory, sizeof(struct memFormat));
semaphore_v(sem_id);
if (shmdt(shared_memory) == -1) {perror("shmat"); return 0;}
int size = sizeof(struct memFormat)+(memf.max*memf.sizeItem);
printf("Moniotr attache mem size: %d + %d=%d",sizeof(struct memFormat),(memf.max*memf.sizeItem),size);
shmid = shmget((key_t)1234, size, 0666);
if (shmid == -1) {perror("shmget2");return 0;}
shared_memory = shmat(shmid, (void *)0, SHM_RDONLY);
if (shared_memory == (void *)-1) {perror("shmat2");return 0;}
pitem = (int*)shared_memory+sizeof(struct memFormat);
printf("Monitor memory attached at %p,data attached at %p\n", shared_memory,pitem);
printf("memory pid %d:\n sizeItem %d, count %d, max %d",memf.pidMaster,memf.sizeItem,memf.count,memf.max);
sleep(1);
while(bOut==false)
{
pitem = (int*)shared_memory+sizeof(struct memFormat);
delay(500);
int count1=0;
if(!semaphore_p(sem_id)) {perror("semaphore_p");break;}
memcpy(&memf,shared_memory, sizeof(struct memFormat));
for(int vi=0;vi<memf.count;vi++)
{
if(*pitem==1) count1++;
//printf("%d.",*pitem);
pitem++;
}
if(!semaphore_v(sem_id)) {perror("semaphore_v");break;}
printf("\nnumber '1': %d.",count1);
}
if (shmdt(shared_memory) == -1) {perror("shmat2");}
del_semvalue(sem_id,0);
printf("\nExit...\n");
}
/*
//------------------------------------------------------------------------------------------------------
// Allocate shraed memory ,set semaphore,wakeup audio server
//
//------------------------------------------------------------------------------------------------------
*/
static int preinit(sh_audio_t *sh)
{
aserver_pid = 0;
#ifndef EngineMode
union smc *sc;
long curr_codec;
#endif
{
sh->audio_out_minsize = 320;
}
#ifndef EngineMode
#ifdef AD_SHM_REWRITE
sm_com_id = get_first_shared_mem_id(KEY_SM_COM, SM_COM_SIZE);
if(sm_com_id < 0)
sm_com_id = get_shared_mem_id(KEY_SM_COM, SM_COM_SIZE); //get shared memory ID
if(sm_com == NULL)
{
if ((sm_com = allocate_share_mem(sm_com_id))==NULL) //allocate shared memory ( command )
return 0;
}
#else
sm_com_id = get_shared_mem_id(KEY_SM_COM, SM_COM_SIZE); //get shared memory ID
if ((sm_com = allocate_share_mem(sm_com_id))==NULL) //allocate shared memory ( command )
return 0;
#endif
id = get_semaphore_id(); //get semaphore ID
if (!reset_semvalue(id, 0)){ //reset semaphore
return 0;
}
sc = (union smc *)sm_com;
sc->magic.magic_num = PLAYER_MAGIC;
curr_codec = AMRNB_ID; //inform server what kind of coded to be used.
sc->magic.codec_id = curr_codec;
if (!semaphore_v(id, 1)) //wakeup server!
return 0;
if (!wait_server(sc)){ //wait for server's response
deallocate_share_mem(sm_com);
#ifndef AD_SHM_REWRITE
shmctl(sm_com_id, IPC_RMID, 0);
#endif
del_semvalue(id, 0);
printf("Audio server crash \n");
return 0;
}
if (sc->magic.codec_id != curr_codec){ //check codec
printf("Unsuppoted codec\n");
return 0;
}
#endif
aserver_pid = sc->pinit.pid;
return 1;
}
/************************************************************
* function: create or open the shared memory.
* iscreated: 1, to create the shm; 0, only to open the shm.
* mqsize: the count of the items
* itemsize: the size of an item (bytes)
* return: 0, correct; others, error number.
***********************************************************/
int shmmq_open(int iscreated, int mqsize, int itemsize)
{
int nflag;
int ret = 0;
/* Initial semaphore */
g_s_semid = get_semvalue((key_t)SEM_KEY);
if (-1 == g_s_semid) {
return ERROR_GET_SEMVALUE;
}
if (iscreated && -1 == set_semvalue(g_s_semid)) {
return ERROR_SET_SEMVALUE;
}
if (-1 == semaphore_p(g_s_semid)) {
return ERROR_SEMAPHORE_P;
}
while (1)
{
if (iscreated) {
nflag = 0666 | IPC_CREAT;
} else {
nflag = 0666;
}
g_s_mqsize = (mqsize <= 0) ? DEFAULT_MQ_SIZE : mqsize;
g_s_itemsize = (itemsize <= 0) ? DEFAULT_ITEM_SIZE : itemsize;
/* Initial shared memory */
g_s_shmid = shmget((key_t)SHM_KEY,
g_s_mqsize * g_s_itemsize + DEFAULT_HEAD_SIZE,
nflag);
if (-1 == g_s_shmid) {
ret = ERROR_SHMGET;
break;
}
g_s_pbase = shmat(g_s_shmid, NULL, 0);
if ((void *)-1 == g_s_pbase) {
g_s_pbase = NULL;
ret = ERROR_SHMAT;
break;
}
g_s_phead = (shmmq_head*)g_s_pbase;
g_s_pcontent = g_s_pbase + DEFAULT_HEAD_SIZE;
/* Initial head of the shared memory */
if (iscreated) {
g_s_phead->enq_pos = -1;
g_s_phead->deq_pos = -1;
}
break;
}
if (ret && iscreated) {
if (g_s_shmid >= 0) shmctl(g_s_shmid, IPC_RMID, 0);
semaphore_v(g_s_semid);
del_semvalue(g_s_semid);
return ret;
}
if (-1 == semaphore_v(g_s_semid)) {
return ERROR_SEMAPHORE_V;
}
return ret;
}
int main() {
//counters and size variables
int nread;
int n = 0;
//buffer to read in from the file
char buffer[BUFSIZ];
//declaring shared memory space and message
void *shared_memory = (void *)0;
struct buffer_msg *msg;
int id;
//declaring the necessary semaphore ids
int sem_id_s;
int sem_id_n;
int sem_id_e;
//creating the semaphores and setting their values
sem_id_n = semget((key_t)key_n, 1, 0666 | IPC_CREAT);
sem_id_s = semget((key_t)key_s, 1, 0666 | IPC_CREAT);
sem_id_e = semget((key_t)key_e, 1, 0666 | IPC_CREAT);
if (!set_semvalue(1, sem_id_s)) {
fprintf(stderr, "Failed to initialize semaphore\n");
exit(EXIT_FAILURE);
}
if (!set_semvalue(0, sem_id_n)) {
fprintf(stderr, "Failed to initialize semaphore\n");
exit(EXIT_FAILURE);
}
if (!set_semvalue(NBUFFER, sem_id_e)) {
fprintf(stderr, "Failed to initialize semaphore\n");
exit(EXIT_FAILURE);
}
//creating and attaching the shared memory with its address space
id = shmget((key_t)key, MEMSIZE, 0666|IPC_CREAT);
if(id==-1) {
fprintf(stderr, "shmget failed\n");
exit(EXIT_FAILURE);
}
shared_memory = shmat(id, (void *)0, 0);
if(shared_memory == (void *)-1) {
fprintf(stderr, "shmat failed\n");
exit(EXIT_FAILURE);
}
//reading in the message from the file
nread = read(0, buffer, BUFSIZ); //BUFSIZ is from stdio.h
if(nread==-1) {
fprintf(stderr, "nread failed\n");
exit(EXIT_FAILURE);
}
//iterate through the read in message
int i = 0;
int count = 0;
msg = (struct buffer_msg *)shared_memory;
while(n<nread) {
//wait to be able to add something into the shared memory buffer (so it does not overflow) and ensure mutual exclusion is held
semaphore_p(sem_id_e);
semaphore_p(sem_id_s); //these can be commented out to achieve the same result if there is only one producer and one consumer
//copy what is in the read in buffer to shared memory
strncpy(msg->buffer[i].msg, buffer+n, TEXTSIZE);
//put the size of the message in shared memory
msg->buffer[i].size = strlen(msg->buffer[i].msg);
count+=msg->buffer[i].size;
//signal that something is in the shared memory buffer and that it has left the critical section
semaphore_v(sem_id_s); //these can be commented out to achieve the same result if there is only one producer and one consumer
semaphore_v(sem_id_n);
i = (i + 1) % NBUFFER;
n += TEXTSIZE;
}
printf("Read in %i bytes\n", count);
}
int main()
{
int ret,result,fd;
req cli;
union semun sem_union;
signal(SIGUSR1,sig_hand);
cli.opr = '-';
cli.opr1= 10;
cli.opr2= 5;
cli.pid = getpid();
if(make_fifo("Wfifo") == -1){
fprintf(stderr,"Wfifo fails\n");
exit(EXIT_FAILURE);
}
if(make_fifo("Rfifo") == -1){
fprintf(stderr,"Rfifo fails\n");
exit(EXIT_FAILURE);
}
sem_id = semget((key_t)123,1,0666|IPC_CREAT);
sem_union.val = 1;
if(semctl(sem_id,0,SETVAL,sem_union) == -1)
{
printf("ERROR: semctl fails\n");
exit(EXIT_FAILURE);
}
semaphore_p();
fd = open("Wfifo",O_WRONLY);
if(fd == -1)
{
printf("ERROR: Wfifo open fails\n");
exit(EXIT_FAILURE);
}
ret = write(fd,&cli,sizeof(cli));
printf("%d bytes write %d: %d\n",getpid(),fd,ret);
close(fd);
semaphore_v();
//semaphore_p();
pause();
fd = open("Rfifo",O_RDONLY);
if(fd == -1)
{
printf("ERROR: Rfifo open fails\n");
exit(EXIT_FAILURE);
}
ret = read(fd,&cli,sizeof(cli));
printf("%d bytes read: %d & GOT: %d %c %d = %d\n",getpid(),ret,cli.opr1,cli.opr,cli.opr2,cli.result);
close(fd);
//semaphore_v();
/* if(semctl(sem_id,0,IPC_RMID,sem_union) == -1)
{
printf("ERROR: semctl fails\n");
exit(EXIT_FAILURE);
}
*/
//unlink("Wfifo");
return 0;
}
static int basic_test(void)
{
pid_t pid;
int fd, sem_id, status, ret = 0;
unsigned long i, j, chunk_no = 0, num_chunks = 0;
struct write_unit wu;
sem_id = semaphore_init(1);
if (sem_id < 0)
return sem_id;
num_chunks = file_size / CHUNK_SIZE;
open_rw_flags |= O_DIRECT;
open_ro_flags |= O_DIRECT;
if (test_flags & BASC_TEST) {
fprintf(stdout, "# Prepare file in %lu length.\n", file_size);
ret = prep_orig_file_in_chunks(workfile, file_size);
if (ret)
return ret;
}
fflush(stderr);
fflush(stdout);
signal(SIGCHLD, sigchld_handler);
fd = open_file(workfile, open_rw_flags);
if (fd < 0)
return fd;
if (test_flags & FIHL_TEST) {
fprintf(stdout, "# Reserve a hole by truncating file to %lu.\n",
file_size);
ret = ftruncate(fd, file_size);
if (ret) {
ret = errno;
fprintf(stderr, "ftruncate faile:%d,%s\n",
ret, strerror(ret));
return ret;
}
}
fprintf(stdout, "# Fork %lu processes performing writes.\n",
num_children);
for (i = 0; i < num_children; i++) {
pid = fork();
if (pid < 0) {
fprintf(stderr, "Fork process error!\n");
return pid;
}
if (pid == 0) {
srand(getpid());
for (j = 0; j < num_chunks; j++) {
if (verbose)
fprintf(stdout, " #%d process writes "
"#%lu chunk\n", getpid(),
chunk_no);
if (semaphore_p(sem_id) < 0) {
ret = -1;
goto child_bail;
}
if (test_flags & APPD_TEST)
chunk_no = j;
else
chunk_no = get_rand_ul(0, num_chunks - 1);
prep_rand_dest_write_unit(&wu, chunk_no);
ret = do_write_chunk(fd, wu);
if (ret < 0)
goto child_bail;
ret = log_write(&wu, log);
if (ret < 0)
goto child_bail;
if (semaphore_v(sem_id) < 0) {
ret = -1;
goto child_bail;
}
usleep(10000);
if (!(test_flags & DSCV_TEST))
continue;
/*
* Are you ready to crash the machine?
*/
if ((j > 1) && (j < num_chunks - 1)) {
if (get_rand_ul(1, num_chunks) == num_chunks / 2) {
if (semaphore_p(sem_id) < 0) {
ret = -1;
goto child_bail;
}
fprintf(stdout, "#%d process "
"tries to crash the "
"box.\n", getpid());
if (system("echo b>/proc/sysrq-trigger") < 0) {
fprintf(stderr, "#%d process "
"tries to enable sysrq-trigger "
"but failed.\n", getpid());
goto child_bail;
}
}
} else if (j == num_chunks - 1) {
if (semaphore_p(sem_id) < 0) {
ret = -1;
goto child_bail;
}
fprintf(stdout, "#%d process "
"tries to crash the "
"box.\n", getpid());
if (system("echo b>/proc/sysrq-trigger") < 0) {
fprintf(stderr, "#%d process "
"tries to enable sysrq-trigger "
"but failed.\n", getpid());
goto child_bail;
}
}
}
child_bail:
if (fd)
close(fd);
if (ret > 0)
ret = 0;
exit(ret);
}
if (pid > 0)
child_pid_list[i] = pid;
}
signal(SIGINT, sigint_handler);
signal(SIGTERM, sigterm_handler);
for (i = 0; i < num_children; i++) {
waitpid(child_pid_list[i], &status, 0);
ret = WEXITSTATUS(status);
if (ret) {
fprintf(stderr, "Child %d exits abnormally with "
"RC=%d\n", child_pid_list[i], ret);
}
}
if (fd)
close(fd);
if (sem_id)
semaphore_close(sem_id);
return ret;
}