* Bert Wesarg | 2008-12-22 08:32:15 [+0100]:
>> +static int open_existing_lock(void)
>> +{
>> + int fd;
>> + int ret;
>> + struct stat buf;
>> + int retry = 5;
>> +
>> + fd = open(lock_name, O_RDWR);
>> + if (fd < 0)
>> + return fd;
>> + do {
>> + ret = fstat(fd, &buf);
>> + if (ret < 0)
>Isn't here a close(2) missing?
yes it is. Thx.
>> + return ret;
>> +
>> + if (buf.st_size == sizeof(*limi_mutex))
>> + return fd;
>> +
>> + close(fd);
>Isn't this close(2) wrong here?
uhhh. Actually I wanted to have the open() within the do while loop. So
I move that and this will be fine then.
>> + sleep(1);
>> + retry\-\-;
>> + } while (retry);
>> +
>> + close(fd);
>> + return \-1;
>> +}
>> +
>> +static int create_new_lock(void)
>> +{
>> + int fd;
>> + pthread_mutex_t cmutex = PTHREAD_MUTEX_INITIALIZER;
>> + pthread_mutexattr_t attr;
>> + int ret;
>> +
>> + pthread_mutexattr_init(&attr);
>> + pthread_mutexattr_setrobust_np(&attr, PTHREAD_MUTEX_ROBUST_NP);
>> + pthread_mutex_init(&cmutex, &attr);
>> +
>> + fd = open(lock_name, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR |
>> + S_IRGRP | S_IWGRP);
>> + if (fd < 0)
>> + return fd;
>> +
>> + ret = write(fd, &cmutex, sizeof(cmutex));
>I think its undefined behavior if you copy a struct pthread_mutex. You
>should use mmap here too.
Why should be this undefined? Is there something special about this
struct? And why should this behave different with mmap() ?
Sebastian
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