int main(int argc, char *argv[])
{
int fd;
long i, seqno;
pid_t pid;
ssize_t n;
char line[MAXLINE + 1];
pid = getpid();
fd = Open(SEQFILE, O_RDWR, FILE_MODE);/*以读写模式打开文件*/
for(i = 0; i < 20; ++i){
my_lock(fd);/*对指定文件进行加锁*/
Lseek(fd, 0L, SEEK_SET);
n = Read(fd, line, MAXLINE);
line[n] = '\0';
n = sscanf(line, "%ld\n", &seqno);/*将line中的序列号保存到seqno中*/
printf("%s: pid = %ld, seq# = %ld\n", argv[0], (long)pid, seqno);
seqno++;/*序列号加1*/
snprintf(line, sizeof(line), "%ld\n", seqno);/*将序列号保存到line缓冲区中*/
Lseek(fd, 0L, SEEK_SET);
Write(fd, line, strlen(line));/*将line缓冲区中的内容写到指定的文件中*/
my_unlock(fd);/*释放锁*/
}
n exit(0);
}
int main(int argc, char **argv)
{
int fd;
long i= 0;
long seqno = 0;
pid_t pid;
ssize_t n;
char line[MAX_LINE+1];
pid =getpid();
fd = open(SWQFILE, O_RDWR, "ab" );
for(i = 0 ; i< 20 ; i++ )
{
my_lock(fd);
lseek(fd, 0L, SEEK_SET);
n = read(fd, line, MAX_LINE);
line[n] = '\0';
n = sscanf(line, "%ld\n" , &seqno);
printf("%s: pid = %ld, seq# = %ld\n", argv[0], (long)pid, seqno);
seqno++;
snprintf(line, sizeof(line), "%ld\n",seqno);
lseek(fd, 0L, SEEK_SET);
write(fd, line, strlen(line));
my_unlock(fd);
}
exit(0);
}
main()
{
int fd, i, n, pid, seqno;
char buff[MAXBUFF + 1];
pid = getpid();
if ( (fd = open(SEQFILE, 2) ) < 0)
err_sys("can't open %s", SEQFILE);
for (i=0 ; i<20 ; i++) {
my_lock(fd); /* lock the file */
lseek(fd, 0L, 0); /* rewind before read */
if ( (n = read(fd, buff, MAXBUFF)) <= 0 )
err_sys("read error");
buff[n] = '\0'; /* null terminate for sscanf */
if ( (n = sscanf(buff, "%d\n", &seqno)) != 1)
err_sys("sscanf error");
printf("pid = %d, seq# = %d\n", pid, seqno);
seqno++; /* increment the sequence number */
sprintf(buff, "%03d\n", seqno);
n = strlen(buff);
lseek(fd, 0L, 0); /* rewind before write */
if (write(fd, buff, n) != n)
err_sys("write error");
my_unlock(fd); /* unlick the file */
}
}
int main(int argc, char*argv[]) {
int fd;
long i, seqno;
pid_t pid;
ssize_t n;
char line[MAXLINE + 1];
int result;
pid = getpid();
fd = open(SEQFILE, O_CREAT | O_RDWR, FILE_MODE);
for (i = 0; i < 20; i++) {
my_lock(fd);
if ((result = lseek(fd, 0, SEEK_SET)) == -1) {
printf("lseek error ...\n");
return -1;
}
n = read(fd, line, MAXLINE);
line[n] = '\0';
n = sscanf(line, "%ld\n", &seqno);
printf("%s: pid = %ld, seq# = %ld\n", argv[0], (long)pid, seqno);
seqno++;
snprintf(line, sizeof(line), "%ld\n", seqno);
lseek(fd, 0L, SEEK_SET);
write(fd, line, strlen(line));
my_unlock(fd);
}
}
int
main(int argc, char **argv)
{
int fd;
long i, seqno;
pid_t pid;
ssize_t n;
char line[MAXLINE + 1];
pid = getpid();
fd = open(SEQFILE, O_RDWR, FILE_MODE);
for (i = 0; i < 20; i++) {
my_lock(fd); /* lock the file */
lseek(fd, 0L, SEEK_SET); /* rewind before read */
n = read(fd, line, MAXLINE);
line[n] = '\0'; /* null terminate for sscanf */
n = sscanf(line, "%ld\n", &seqno);
printf("%s: pid = %ld, seq# = %ld\n", argv[0], (long) pid, seqno);
seqno++; /* increment sequence number */
snprintf(line, sizeof(line), "%ld\n", seqno);
lseek(fd, 0L, SEEK_SET); /* rewind before write */
write(fd, line, strlen(line));
my_unlock(fd); /* unlock the file */
}
exit(0);
}
int
main(int argc, char **argv)
{
int fd;
long i, nloop, seqno;
ssize_t n;
char line[MAXLINE + 1];
if (argc != 2)
err_quit("usage: loopmain <loopcount>");
nloop = atol(argv[1]);
fd = Open(SEQFILE, O_RDWR, FILE_MODE);
for (i = 0; i < nloop; i++) {
my_lock(fd); /* lock the file */
Lseek(fd, 0L, SEEK_SET); /* rewind before read */
n = Read(fd, line, MAXLINE);
line[n] = '\0'; /* null terminate for sscanf */
n = sscanf(line, "%ld\n", &seqno);
seqno++; /* increment sequence number */
snprintf(line, sizeof(line), "%ld\n", seqno);
Lseek(fd, 0L, SEEK_SET); /* rewind before write */
Write(fd, line, strlen(line));
my_unlock(fd); /* unlock the file */
}
exit(0);
}
int main(int argc, char **argv)
{
int fd, i, seqno, c;
pid_t pid;
ssize_t n;
char line[MAXLINE + 1], *ptr;
pid = getpid();
if ((fd = open(SEQFILE, O_RDWR | O_CREAT, FILE_MODE)) == -1) {
printf("open error for %s: %s\n", SEQFILE, strerror(errno));
exit(1);
}
setvbuf(stdout, NULL, _IONBF, 0); /* unbuffered */
for (i = 0; i < 20; i++) {
my_lock(fd); /* lock the file */
if (lseek(fd, 0L, SEEK_SET) == (off_t) -1) { /* rewind before read */
perror("lseek error");
exit(1);
}
if ((n = read(fd, line, MAXLINE)) < 0) {
perror("read error");
exit(1);
}
line[n] = '\0'; /* null terminate for sscanf */
n = sscanf(line, "%d\n", &seqno);
snprintf(line, sizeof(line), "pid = %d, seq# = %d\n", pid, seqno);
for (ptr = line; (c = *ptr++) != 0; )
putchar(c);
seqno++; /* increment sequence number */
sprintf(line, "%03d\n", seqno);
if (lseek(fd, 0, SEEK_SET) == (off_t) -1) { /* rewind before write */
perror("lseek error");
exit(1);
}
if (write(fd, line, strlen(line)) != strlen(line)) {
perror("write error");
exit(1);
}
my_unlock(fd); /* unlock the file */
}
exit(0);
}
int
main(int argc, char **argv)
{
int fd;
long i, nloop, seqno;
ssize_t n;
char line[MAXLINE + 1];
if (argc != 2) {
fprintf(stderr, "usage: loopmain <loopcount>\n");
exit(1);
}
nloop = atol(argv[1]);
if ((fd = open(SEQFILE, O_RDWR | O_NONBLOCK, FILE_MODE)) == -1) {
fprintf(stderr, "open error for %s: %s\n", SEQFILE, strerror(errno));
exit(1);
}
for (i = 0; i < nloop; i++) {
my_lock(fd); /* lock the file */
if (lseek(fd, 0L, SEEK_SET) == (off_t) -1) { /* rewind before read */
perror("lseek error");
exit(1);
}
if ((n = read(fd, line, MAXLINE)) == -1) {
perror("read error");
exit(1);
}
line[n] = '\0'; /* null terminate for sscanf */
n = sscanf(line, "%ld\n", &seqno);
seqno++; /* increment sequence number */
snprintf(line, sizeof(line), "%ld\n", seqno);
if (lseek(fd, 0L, SEEK_SET) == (off_t) -1) { /* rewind before write */
perror("lseek error");
exit(1);
}
if (write(fd, line, strlen(line)) != strlen(line)) {
perror("write error");
exit(1);
}
my_unlock(fd); /* unlock the file */
}
exit(0);
}
static void counter_func(struct work_struct *work)
{
unsigned int cpu = smp_processor_id();
int i;
pr_info("Started job #%u\n", cpu);
for (i = 0; i < TIMES_INC; i++) {
my_lock(&count_lock);
count++;
my_unlock(&count_lock);
}
pr_info("finished job #%u\n", cpu);
}
int
main(int argc, char **argv)
{
int fd = 0, stat, nconflicts;
long i, j, nproc;
sem_t *ptr;
pid_t pid;
ssize_t n;
if (argc != 2)
err_quit("usage: locksvsemrace1 <#processes>");
nproc = atol(argv[1]);
Pipe(pipefd);
ptr = My_shm(sizeof(sem_t)); /* create memory-based semaphore */
Sem_init(ptr, 1, 0);
for (j = 0; j < nproc; j++) {
if (Fork() == 0) {
/* 4child */
Sem_wait(ptr); /* wait for parent to start children */
for (i = 0; i < 10; i++) {
my_lock(fd); /* lock the file */
my_unlock(fd); /* unlock the file */
}
exit(0);
}
/* parent loops around, creating next child */
}
for (j = 0; j < nproc; j++)
Sem_post(ptr); /* start all the children */
/* now just wait for all the children to finish */
while ( (pid = waitpid(-1, &stat, WNOHANG)) > 0)
;
Close(pipefd[1]);
nconflicts = 0;
while ( (n = Read(pipefd[0], &stat, 1)) > 0)
nconflicts += n;
printf("%d conflicts\n", nconflicts);
exit(0);
}
static void* engine_thread(void* p) {
while(!has_first_table) {}
eng_ctx_t* eng_ctx = eng_context_init(p);
while (is_thread_run) {
eng_context_config(eng_ctx);
travel_command_list(eng_ctx);
eng_context_free_rwservers(eng_ctx);
}
my_lock(&total_request_lock);
total_request += eng_ctx->stats.ninsert;
total_request += eng_ctx->stats.nupdate;
total_request += eng_ctx->stats.ndelete;
total_request += eng_ctx->stats.nselect;
my_unlock(&total_request_lock);
eng_context_destroy(eng_ctx);
return NULL;
}
void down(int me)
{
my_unlock(chopstick[me]);
my_unlock(chopstick[(me+1)%5]);
}
