ssize_t read(int fd, FAR void *buf, size_t nbytes)
{
ssize_t ret;
/* read() is a cancellation point */
(void)enter_cancellation_point();
/* Did we get a valid file descriptor? */
#if CONFIG_NFILE_DESCRIPTORS > 0
if ((unsigned int)fd >= CONFIG_NFILE_DESCRIPTORS)
#endif
{
#if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0
/* No.. If networking is enabled, read() is the same as recv() with
* the flags parameter set to zero. Note that recv() sets
* the errno variable.
*/
ret = recv(fd, buf, nbytes, 0);
#else
/* No networking... it is a bad descriptor in any event */
set_errno(EBADF);
ret = ERROR;
#endif
}
#if CONFIG_NFILE_DESCRIPTORS > 0
else
{
FAR struct file *filep;
/* The descriptor is in a valid range to file descriptor... do the
* read. First, get the file structure. Note that on failure,
* fs_getfilep() will set the errno variable.
*/
filep = fs_getfilep(fd);
if (filep == NULL)
{
/* The errno value has already been set */
ret = ERROR;
}
else
{
/* Then let file_read do all of the work. Note that file_read()
* sets the errno variable.
*/
ret = file_read(filep, buf, nbytes);
}
}
#endif
leave_cancellation_point();
return ret;
}
ssize_t sendto(int sockfd, FAR const void *buf, size_t len, int flags,
FAR const struct sockaddr *to, socklen_t tolen)
{
FAR struct socket *psock;
ssize_t ret;
/* sendto() is a cancellation point */
(void)enter_cancellation_point();
/* Get the underlying socket structure */
psock = sockfd_socket(sockfd);
/* And let psock_sendto do all of the work */
ret = psock_sendto(psock, buf, len, flags, to, tolen);
if (ret < 0)
{
set_errno((int)-ret);
ret = ERROR;
}
leave_cancellation_point();
return ret;
}
int fcntl(int fd, int cmd, ...)
{
FAR struct file *filep;
va_list ap;
int ret;
/* fcntl() is a cancellation point */
(void)enter_cancellation_point();
/* Setup to access the variable argument list */
va_start(ap, cmd);
/* Did we get a valid file descriptor? */
#if CONFIG_NFILE_DESCRIPTORS > 0
if ((unsigned int)fd < CONFIG_NFILE_DESCRIPTORS) {
/* Get the file structure corresponding to the file descriptor. */
filep = fs_getfilep(fd);
if (!filep) {
/* The errno value has already been set */
va_end(ap);
leave_cancellation_point();
return ERROR;
}
/* Let file_vfcntl() do the real work */
ret = file_vfcntl(filep, cmd, ap);
} else
#endif
{
/* No... check for operations on a socket descriptor */
#if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0
if ((unsigned int)fd < (CONFIG_NFILE_DESCRIPTORS + CONFIG_NSOCKET_DESCRIPTORS)) {
/* Yes.. defer socket descriptor operations to net_vfcntl() */
ret = net_vfcntl(fd, cmd, ap);
} else
#endif
{
/* No.. this descriptor number is out of range */
set_errno(EBADF);
ret = ERROR;
}
}
va_end(ap);
leave_cancellation_point();
return ret;
}
int sigwaitinfo(FAR const sigset_t *set, FAR struct siginfo *info)
{
int ret;
/* sigwaitinfo() is a cancellation point */
(void)enter_cancellation_point();
/* Just a wrapper around sigtimedwait() */
ret = sigtimedwait(set, info, NULL);
leave_cancellation_point();
return ret;
}
ssize_t send(int sockfd, FAR const void *buf, size_t len, int flags)
{
FAR struct socket *psock;
ssize_t ret;
/* send() is a cancellation point */
(void)enter_cancellation_point();
/* Get the underlying socket structure */
psock = sockfd_socket(sockfd);
/* And let psock_send do all of the work */
ret = psock_send(psock, buf, len, flags);
leave_cancellation_point();
return ret;
}
ssize_t recvfrom(int sockfd, FAR void *buf, size_t len, int flags,
FAR struct sockaddr *from, FAR socklen_t *fromlen)
{
ssize_t ret;
/* recvfrom() is a cancellation point */
(void)enter_cancellation_point();
/* Let nx_recvfrom and psock_recvfrom() do all of the work */
ret = nx_recvfrom(sockfd, buf, len, flags, from, fromlen);
if (ret < 0)
{
set_errno(-ret);
ret = ERROR;
}
leave_cancellation_point();
return ret;
}
ssize_t psock_send(FAR struct socket *psock, FAR const void *buf, size_t len,
int flags)
{
int ret;
/* Treat as a cancellation point */
(void)enter_cancellation_point();
switch (psock->s_type)
{
#if defined(CONFIG_NET_PKT)
case SOCK_RAW:
{
ret = psock_pkt_send(psock, buf, len);
}
break;
#endif
#if defined(CONFIG_NET_TCP) || defined(CONFIG_NET_LOCAL_STREAM)
case SOCK_STREAM:
{
#ifdef CONFIG_NET_LOCAL_STREAM
#ifdef CONFIG_NET_TCP
if (psock->s_domain == PF_LOCAL)
#endif
{
ret = psock_local_send(psock, buf, len, flags);
}
#endif /* CONFIG_NET_LOCAL_STREAM */
#ifdef CONFIG_NET_TCP
#ifdef CONFIG_NET_LOCAL_STREAM
else
#endif
{
ret = psock_tcp_send(psock, buf, len);
}
#endif /* CONFIG_NET_TCP */
}
break;
#endif /* CONFIG_NET_TCP || CONFIG_NET_LOCAL_STREAM */
#ifdef CONFIG_NET_UDP
case SOCK_DGRAM:
{
#ifdef CONFIG_NET_LOCAL_DGRAM
#ifdef CONFIG_NET_UDP
if (psock->s_domain == PF_LOCAL)
#endif
{
#warning Missing logic
ret = -ENOSYS;
}
#endif /* CONFIG_NET_LOCAL_DGRAM */
#ifdef CONFIG_NET_UDP
#ifdef CONFIG_NET_LOCAL_DGRAM
else
#endif
{
ret = psock_udp_send(psock, buf, len);
}
#endif /* CONFIG_NET_UDP */
}
break;
#endif /* CONFIG_NET_UDP */
default:
{
/* EDESTADDRREQ. Signifies that the socket is not connection-mode
* and no peer address is set.
*/
ret = -EDESTADDRREQ;
}
break;
}
leave_cancellation_point();
return ret;
}
int close(int fd)
{
int errcode;
#if CONFIG_NFILE_DESCRIPTORS > 0
int ret;
#endif
/* close() is a cancellation point */
(void)enter_cancellation_point();
#if CONFIG_NFILE_DESCRIPTORS > 0
/* Did we get a valid file descriptor? */
if ((unsigned int)fd >= CONFIG_NFILE_DESCRIPTORS)
#endif
{
/* Close a socket descriptor */
#if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0
if ((unsigned int)fd < (CONFIG_NFILE_DESCRIPTORS+CONFIG_NSOCKET_DESCRIPTORS))
{
ret = net_close(fd);
leave_cancellation_point();
return ret;
}
else
#endif
{
errcode = EBADF;
goto errout;
}
}
#if CONFIG_NFILE_DESCRIPTORS > 0
/* Close the driver or mountpoint. NOTES: (1) there is no
* exclusion mechanism here, the driver or mountpoint must be
* able to handle concurrent operations internally, (2) The driver
* may have been opened numerous times (for different file
* descriptors) and must also handle being closed numerous times.
* (3) for the case of the mountpoint, we depend on the close
* methods bing identical in signature and position in the operations
* vtable.
*/
ret = files_close(fd);
if (ret < 0)
{
/* An error occurred while closing the driver */
errcode = -ret;
goto errout;
}
leave_cancellation_point();
return OK;
#endif
errout:
set_errno(errcode);
leave_cancellation_point();
return ERROR;
}
int fcntl(int fd, int cmd, ...)
{
FAR struct file *filep;
va_list ap;
int ret;
/* fcntl() is a cancellation point */
(void)enter_cancellation_point();
/* Setup to access the variable argument list */
va_start(ap, cmd);
/* Did we get a valid file descriptor? */
#if CONFIG_NFILE_DESCRIPTORS > 0
if ((unsigned int)fd < CONFIG_NFILE_DESCRIPTORS)
{
/* Get the file structure corresponding to the file descriptor. */
ret = fs_getfilep(fd, &filep);
if (ret >= 0)
{
DEBUGASSERT(filep != NULL);
/* Let file_vfcntl() do the real work. The errno is not set on
* failures.
*/
ret = file_vfcntl(filep, cmd, ap);
}
}
else
#endif
{
/* No... check for operations on a socket descriptor */
#if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0
if ((unsigned int)fd < (CONFIG_NFILE_DESCRIPTORS+CONFIG_NSOCKET_DESCRIPTORS))
{
/* Yes.. defer socket descriptor operations to net_vfcntl(). The
* errno is not set on failures.
*/
ret = net_vfcntl(fd, cmd, ap);
}
else
#endif
{
/* No.. this descriptor number is out of range */
ret = -EBADF;
}
}
va_end(ap);
if (ret < 0)
{
set_errno(-ret);
ret = ERROR;
}
leave_cancellation_point();
return ret;
}
int nanosleep(FAR const struct timespec *rqtp, FAR struct timespec *rmtp)
{
irqstate_t flags;
systime_t starttick;
sigset_t set;
struct siginfo value;
int errval;
#ifdef CONFIG_DEBUG_ASSERTIONS /* Warning avoidance */
int ret;
#endif
/* nanosleep() is a cancellation point */
(void)enter_cancellation_point();
if (!rqtp || rqtp->tv_nsec < 0 || rqtp->tv_nsec >= 1000000000)
{
errval = EINVAL;
goto errout;
}
/* Get the start time of the wait. Interrupts are disabled to prevent
* timer interrupts while we do tick-related calculations before and
* after the wait.
*/
flags = enter_critical_section();
starttick = clock_systimer();
/* Set up for the sleep. Using the empty set means that we are not
* waiting for any particular signal. However, any unmasked signal can
* still awaken sigtimedwait().
*/
(void)sigemptyset(&set);
/* nanosleep is a simple application of sigtimedwait. */
#ifdef CONFIG_DEBUG_ASSERTIONS /* Warning avoidance */
ret = sigtimedwait(&set, &value, rqtp);
#else
(void)sigtimedwait(&set, &value, rqtp);
#endif
/* sigtimedwait() cannot succeed. It should always return error with
* either (1) EAGAIN meaning that the timeout occurred, or (2) EINTR
* meaning that some other unblocked signal was caught.
*/
errval = get_errno();
DEBUGASSERT(ret < 0 && (errval == EAGAIN || errval == EINTR));
if (errval == EAGAIN)
{
/* The timeout "error" is the normal, successful result */
leave_critical_section(flags);
leave_cancellation_point();
return OK;
}
/* If we get there, the wait has failed because we were awakened by a
* signal. Return the amount of "unwaited" time if rmtp is non-NULL.
*/
if (rmtp)
{
systime_t elapsed;
systime_t remaining;
int ticks;
/* REVISIT: The conversion from time to ticks and back could
* be avoided. clock_timespec_subtract() would be used instead
* to get the time difference.
*/
/* First get the number of clock ticks that we were requested to
* wait.
*/
(void)clock_time2ticks(rqtp, &ticks);
/* Get the number of ticks that we actually waited */
elapsed = clock_systimer() - starttick;
/* The difference between the number of ticks that we were requested
* to wait and the number of ticks that we actualy waited is that
* amount of time that we failed to wait.
*/
if (elapsed >= (uint32_t)ticks)
{
remaining = 0;
}
else
{
remaining = (uint32_t)ticks - elapsed;
}
(void)clock_ticks2time((int)remaining, rmtp);
}
leave_critical_section(flags);
errout:
set_errno(errval);
leave_cancellation_point();
return ERROR;
}
pid_t waitpid(pid_t pid, int *stat_loc, int options)
{
FAR struct tcb_s *rtcb = this_task();
FAR struct tcb_s *ctcb;
#ifdef CONFIG_SCHED_CHILD_STATUS
FAR struct child_status_s *child;
bool retains;
#endif
FAR struct siginfo info;
sigset_t set;
int errcode;
int ret;
DEBUGASSERT(stat_loc);
/* waitpid() is a cancellation point */
(void)enter_cancellation_point();
/* None of the options are supported */
#ifdef CONFIG_DEBUG_FEATURES
if (options != 0)
{
set_errno(ENOSYS);
leave_cancellation_point();
return ERROR;
}
#endif
/* Create a signal set that contains only SIGCHLD */
(void)sigemptyset(&set);
(void)sigaddset(&set, SIGCHLD);
/* Disable pre-emption so that nothing changes while the loop executes */
sched_lock();
/* Verify that this task actually has children and that the requested PID
* is actually a child of this task.
*/
#ifdef CONFIG_SCHED_CHILD_STATUS
/* Does this task retain child status? */
retains = ((rtcb->group->tg_flags && GROUP_FLAG_NOCLDWAIT) == 0);
if (rtcb->group->tg_children == NULL && retains)
{
errcode = ECHILD;
goto errout_with_errno;
}
else if (pid != (pid_t)-1)
{
/* Get the TCB corresponding to this PID and make sure that the
* thread it is our child.
*/
ctcb = sched_gettcb(pid);
#ifdef HAVE_GROUP_MEMBERS
if (ctcb == NULL || ctcb->group->tg_pgid != rtcb->group->tg_gid)
#else
if (ctcb == NULL || ctcb->group->tg_ppid != rtcb->pid)
#endif
{
errcode = ECHILD;
goto errout_with_errno;
}
/* Does this task retain child status? */
if (retains)
{
/* Check if this specific pid has allocated child status? */
if (group_findchild(rtcb->group, pid) == NULL)
{
errcode = ECHILD;
goto errout_with_errno;
}
}
}
#else /* CONFIG_SCHED_CHILD_STATUS */
if (rtcb->group->tg_nchildren == 0)
{
/* There are no children */
errcode = ECHILD;
goto errout_with_errno;
}
else if (pid != (pid_t)-1)
{
/* Get the TCB corresponding to this PID and make sure that the
* thread it is our child.
*/
ctcb = sched_gettcb(pid);
#ifdef HAVE_GROUP_MEMBERS
if (ctcb == NULL || ctcb->group->tg_pgid != rtcb->group->tg_gid)
#else
if (ctcb == NULL || ctcb->group->tg_ppid != rtcb->pid)
#endif
{
errcode = ECHILD;
goto errout_with_errno;
}
}
#endif /* CONFIG_SCHED_CHILD_STATUS */
/* Loop until the child that we are waiting for dies */
for (; ; )
{
#ifdef CONFIG_SCHED_CHILD_STATUS
/* Check if the task has already died. Signals are not queued in
* NuttX. So a possibility is that the child has died and we
* missed the death of child signal (we got some other signal
* instead).
*/
if (pid == (pid_t)-1)
{
/* We are waiting for any child, check if there are still
* chilren.
*/
DEBUGASSERT(!retains || rtcb->group->tg_children);
if (retains && (child = group_exitchild(rtcb->group)) != NULL)
{
/* A child has exited. Apparently we missed the signal.
* Return the saved exit status.
*/
/* The child has exited. Return the saved exit status */
*stat_loc = child->ch_status << 8;
/* Discard the child entry and break out of the loop */
(void)group_removechild(rtcb->group, child->ch_pid);
group_freechild(child);
break;
}
}
/* We are waiting for a specific PID. Does this task retain child status? */
else if (retains)
{
/* Get the current status of the child task. */
child = group_findchild(rtcb->group, pid);
DEBUGASSERT(child);
/* Did the child exit? */
if ((child->ch_flags & CHILD_FLAG_EXITED) != 0)
{
/* The child has exited. Return the saved exit status */
*stat_loc = child->ch_status << 8;
/* Discard the child entry and break out of the loop */
(void)group_removechild(rtcb->group, pid);
group_freechild(child);
break;
}
}
else
{
/* We can use kill() with signal number 0 to determine if that
* task is still alive.
*/
ret = kill(pid, 0);
if (ret < 0)
{
/* It is no longer running. We know that the child task
* was running okay when we started, so we must have lost
* the signal. In this case, we know that the task exit'ed,
* but we do not know its exit status. It would be better
* to reported ECHILD than bogus status.
*/
errcode = ECHILD;
goto errout_with_errno;
}
}
#else /* CONFIG_SCHED_CHILD_STATUS */
/* Check if the task has already died. Signals are not queued in
* NuttX. So a possibility is that the child has died and we
* missed the death of child signal (we got some other signal
* instead).
*/
if (rtcb->group->tg_nchildren == 0 ||
(pid != (pid_t)-1 && (ret = kill(pid, 0)) < 0))
{
/* We know that the child task was running okay we stared,
* so we must have lost the signal. What can we do?
* Let's return ECHILD.. that is at least informative.
*/
errcode = ECHILD;
goto errout_with_errno;
}
#endif /* CONFIG_SCHED_CHILD_STATUS */
/* Wait for any death-of-child signal */
ret = sigwaitinfo(&set, &info);
if (ret < 0)
{
goto errout_with_lock;
}
/* Was this the death of the thread we were waiting for? In the of
* pid == (pid_t)-1, we are waiting for any child thread.
*/
if (info.si_signo == SIGCHLD &&
(pid == (pid_t)-1 || info.si_pid == pid))
{
/* Yes... return the status and PID (in the event it was -1) */
*stat_loc = info.si_status << 8;
pid = info.si_pid;
break;
}
}
leave_cancellation_point();
sched_unlock();
return (int)pid;
errout_with_errno:
set_errno(errcode);
errout_with_lock:
leave_cancellation_point();
sched_unlock();
return ERROR;
}
pid_t waitpid(pid_t pid, int *stat_loc, int options)
{
FAR struct tcb_s *ctcb;
FAR struct task_group_s *group;
bool mystat = false;
int errcode;
int ret;
DEBUGASSERT(stat_loc);
/* waitpid() is a cancellation point */
(void)enter_cancellation_point();
/* None of the options are supported */
#ifdef CONFIG_DEBUG_FEATURES
if (options != 0)
{
set_errno(ENOSYS);
leave_cancellation_point();
return ERROR;
}
#endif
/* Disable pre-emption so that nothing changes in the following tests */
sched_lock();
/* Get the TCB corresponding to this PID */
ctcb = sched_gettcb(pid);
if (ctcb == NULL)
{
errcode = ECHILD;
goto errout_with_errno;
}
/* Then the task group corresponding to this PID */
group = ctcb->group;
DEBUGASSERT(group);
/* Lock this group so that it cannot be deleted until the wait completes */
group_addwaiter(group);
/* "If more than one thread is suspended in waitpid() awaiting termination of
* the same process, exactly one thread will return the process status at the
* time of the target process termination." Hmmm.. what do we return to the
* others?
*/
if (stat_loc != NULL && group->tg_statloc == NULL)
{
group->tg_statloc = stat_loc;
mystat = true;
}
/* Then wait for the task to exit */
if (options & WNOHANG)
{
/* Don't wait if status is not available */
ret = sem_trywait(&group->tg_exitsem);
group_delwaiter(group);
if (ret < 0)
{
pid = 0;
}
}
else
{
/* Wait if necessary for status to become available */
ret = sem_wait(&group->tg_exitsem);
group_delwaiter(group);
if (ret < 0)
{
/* Unlock pre-emption and return the ERROR (sem_wait has already set
* the errno). Handle the awkward case of whether or not we need to
* nullify the stat_loc value.
*/
if (mystat)
{
group->tg_statloc = NULL;
}
goto errout;
}
}
/* On success, return the PID */
leave_cancellation_point();
sched_unlock();
return pid;
errout_with_errno:
set_errno(errcode);
errout:
leave_cancellation_point();
sched_unlock();
return ERROR;
}
int select(int nfds, FAR fd_set *readfds, FAR fd_set *writefds,
FAR fd_set *exceptfds, FAR struct timeval *timeout)
{
struct pollfd *pollset;
int errcode = OK;
int fd;
int npfds;
int msec;
int ndx;
int ret;
/* select() is cancellation point */
(void)enter_cancellation_point();
/* How many pollfd structures do we need to allocate? */
/* Initialize the descriptor list for poll() */
for (fd = 0, npfds = 0; fd < nfds; fd++)
{
/* Check if any monitor operation is requested on this fd */
if ((readfds && FD_ISSET(fd, readfds)) ||
(writefds && FD_ISSET(fd, writefds)) ||
(exceptfds && FD_ISSET(fd, exceptfds)))
{
/* Yes.. increment the count of pollfds structures needed */
npfds++;
}
}
/* Allocate the descriptor list for poll() */
pollset = (struct pollfd *)kmm_zalloc(npfds * sizeof(struct pollfd));
if (!pollset)
{
set_errno(ENOMEM);
leave_cancellation_point();
return ERROR;
}
/* Initialize the descriptor list for poll() */
for (fd = 0, ndx = 0; fd < nfds; fd++)
{
int incr = 0;
/* The readfs set holds the set of FDs that the caller can be assured
* of reading from without blocking. Note that POLLHUP is included as
* a read-able condition. POLLHUP will be reported at the end-of-file
* or when a connection is lost. In either case, the read() can then
* be performed without blocking.
*/
if (readfds && FD_ISSET(fd, readfds))
{
pollset[ndx].fd = fd;
pollset[ndx].events |= POLLIN;
incr = 1;
}
/* The writefds set holds the set of FDs that the caller can be assured
* of writing to without blocking.
*/
if (writefds && FD_ISSET(fd, writefds))
{
pollset[ndx].fd = fd;
pollset[ndx].events |= POLLOUT;
incr = 1;
}
/* The exceptfds set holds the set of FDs that are watched for exceptions */
if (exceptfds && FD_ISSET(fd, exceptfds))
{
pollset[ndx].fd = fd;
incr = 1;
}
ndx += incr;
}
DEBUGASSERT(ndx == npfds);
/* Convert the timeout to milliseconds */
if (timeout)
{
/* Calculate the timeout in milliseconds */
msec = timeout->tv_sec * 1000 + timeout->tv_usec / 1000;
}
else
{
/* Any negative value of msec means no timeout */
msec = -1;
}
/* Then let poll do all of the real work. */
ret = poll(pollset, npfds, msec);
if (ret < 0)
{
/* poll() failed! Save the errno value */
errcode = get_errno();
}
/* Now set up the return values */
if (readfds)
{
memset(readfds, 0, sizeof(fd_set));
}
if (writefds)
{
memset(writefds, 0, sizeof(fd_set));
}
if (exceptfds)
{
memset(exceptfds, 0, sizeof(fd_set));
}
/* Convert the poll descriptor list back into selects 3 bitsets */
if (ret > 0)
{
ret = 0;
for (ndx = 0; ndx < npfds; ndx++)
{
/* Check for read conditions. Note that POLLHUP is included as a
* read condition. POLLHUP will be reported when no more data will
* be available (such as when a connection is lost). In either
* case, the read() can then be performed without blocking.
*/
if (readfds)
{
if (pollset[ndx].revents & (POLLIN | POLLHUP))
{
FD_SET(pollset[ndx].fd, readfds);
ret++;
}
}
/* Check for write conditions */
if (writefds)
{
if (pollset[ndx].revents & POLLOUT)
{
FD_SET(pollset[ndx].fd, writefds);
ret++;
}
}
/* Check for exceptions */
if (exceptfds)
{
if (pollset[ndx].revents & POLLERR)
{
FD_SET(pollset[ndx].fd, exceptfds);
ret++;
}
}
}
}
kmm_free(pollset);
/* Did poll() fail above? */
if (ret < 0)
{
/* Yes.. restore the errno value */
set_errno(errcode);
}
leave_cancellation_point();
return ret;
}
int mq_waitsend(mqd_t mqdes)
{
FAR struct tcb_s *rtcb;
FAR struct mqueue_inode_s *msgq;
/* mq_waitsend() is not a cancellation point, but it is always called from
* a cancellation point.
*/
if (enter_cancellation_point())
{
#ifndef CONFIG_CANCELLATION_POINTS /* Not reachable in this case */
/* If there is a pending cancellation, then do not perform
* the wait. Exit now with ECANCELED.
*/
set_errno(ECANCELED);
leave_cancellation_point();
return ERROR;
#endif
}
/* Get a pointer to the message queue */
msgq = mqdes->msgq;
/* Verify that the queue is indeed full as the caller thinks */
if (msgq->nmsgs >= msgq->maxmsgs)
{
/* Should we block until there is sufficient space in the
* message queue?
*/
if ((mqdes->oflags & O_NONBLOCK) != 0)
{
/* No... We will return an error to the caller. */
set_errno(EAGAIN);
leave_cancellation_point();
return ERROR;
}
/* Yes... We will not return control until the message queue is
* available or we receive a signal or at timout occurs.
*/
else
{
/* Loop until there are fewer than max allowable messages in the
* receiving message queue
*/
while (msgq->nmsgs >= msgq->maxmsgs)
{
/* Block until the message queue is no longer full.
* When we are unblocked, we will try again
*/
rtcb = this_task();
rtcb->msgwaitq = msgq;
msgq->nwaitnotfull++;
set_errno(OK);
up_block_task(rtcb, TSTATE_WAIT_MQNOTFULL);
/* When we resume at this point, either (1) the message queue
* is no longer empty, or (2) the wait has been interrupted by
* a signal. We can detect the latter case be examining the
* errno value (should be EINTR or ETIMEOUT).
*/
if (get_errno() != OK)
{
leave_cancellation_point();
return ERROR;
}
}
}
}
leave_cancellation_point();
return OK;
}
int pthread_join(pthread_t thread, FAR pthread_addr_t *pexit_value)
{
FAR struct tcb_s *rtcb = this_task();
FAR struct task_group_s *group = rtcb->group;
FAR struct join_s *pjoin;
int ret;
sinfo("thread=%d group=%p\n", thread, group);
DEBUGASSERT(group);
/* pthread_join() is a cancellation point */
(void)enter_cancellation_point();
/* First make sure that this is not an attempt to join to
* ourself.
*/
if ((pid_t)thread == getpid())
{
leave_cancellation_point();
return EDEADLK;
}
/* Make sure no other task is mucking with the data structures
* while we are performing the following operations. NOTE:
* we can be also sure that pthread_exit() will not execute
* because it will also attempt to get this semaphore.
*/
(void)pthread_takesemaphore(&group->tg_joinsem);
/* Find the join information associated with this thread.
* This can fail for one of three reasons: (1) There is no
* thread associated with 'thread,' (2) the thread is a task
* and does not have join information, or (3) the thread
* was detached and has exited.
*/
pjoin = pthread_findjoininfo(group, (pid_t)thread);
if (!pjoin)
{
/* Determine what kind of error to return */
FAR struct tcb_s *tcb = sched_gettcb((pthread_t)thread);
serr("ERROR: Could not find thread data\n");
/* Case (1) or (3) -- we can't tell which. Assume (3) */
if (!tcb)
{
ret = ESRCH;
}
/* The thread is still active but has no join info. In that
* case, it must be a task and not a pthread.
*/
else
{
ret = EINVAL;
}
(void)pthread_givesemaphore(&group->tg_joinsem);
}
else
{
/* We found the join info structure. Increment for the reference
* to the join structure that we have. This will keep things
* stable for we have to do
*/
sched_lock();
pjoin->crefs++;
/* Check if the thread is still running. If not, then things are
* simpler. There are still race conditions to be concerned with.
* For example, there could be multiple threads executing in the
* 'else' block below when we enter!
*/
if (pjoin->terminated)
{
sinfo("Thread has terminated\n");
/* Get the thread exit value from the terminated thread. */
if (pexit_value)
{
sinfo("exit_value=0x%p\n", pjoin->exit_value);
*pexit_value = pjoin->exit_value;
}
}
else
{
sinfo("Thread is still running\n");
/* Relinquish the data set semaphore. Since pre-emption is
* disabled, we can be certain that no task has the
* opportunity to run between the time we relinquish the
* join semaphore and the time that we wait on the thread exit
* semaphore.
*/
(void)pthread_givesemaphore(&group->tg_joinsem);
/* Take the thread's thread exit semaphore. We will sleep here
* until the thread exits. We need to exercise caution because
* there could be multiple threads waiting here for the same
* pthread to exit.
*/
(void)pthread_takesemaphore(&pjoin->exit_sem);
/* The thread has exited! Get the thread exit value */
if (pexit_value)
{
*pexit_value = pjoin->exit_value;
sinfo("exit_value=0x%p\n", pjoin->exit_value);
}
/* Post the thread's data semaphore so that the exiting thread
* will know that we have received the data.
*/
(void)pthread_givesemaphore(&pjoin->data_sem);
/* Retake the join semaphore, we need to hold this when
* pthread_destroyjoin is called.
*/
(void)pthread_takesemaphore(&group->tg_joinsem);
}
/* Pre-emption is okay now. The logic still cannot be re-entered
* because we hold the join semaphore
*/
sched_unlock();
/* Release our reference to the join structure and, if the reference
* count decrements to zero, deallocate the join structure.
*/
if (--pjoin->crefs <= 0)
{
(void)pthread_destroyjoin(group, pjoin);
}
(void)pthread_givesemaphore(&group->tg_joinsem);
ret = OK;
}
leave_cancellation_point();
sinfo("Returning %d\n", ret);
return ret;
}
int pthread_cond_timedwait(FAR pthread_cond_t *cond, FAR pthread_mutex_t *mutex, FAR const struct timespec *abstime)
{
FAR struct tcb_s *rtcb = this_task();
int ticks;
int mypid = (int)getpid();
irqstate_t int_state;
uint16_t oldstate;
int ret = OK;
int status;
trace_begin(TTRACE_TAG_TASK, "pthread_cond_timedwait");
svdbg("cond=0x%p mutex=0x%p abstime=0x%p\n", cond, mutex, abstime);
DEBUGASSERT(rtcb->waitdog == NULL);
/* pthread_cond_timedwait() is a cancellation point */
(void)enter_cancellation_point();
/* Make sure that non-NULL references were provided. */
if (!cond || !mutex) {
ret = EINVAL;
}
/* Make sure that the caller holds the mutex */
else if (mutex->pid != mypid) {
ret = EPERM;
}
/* If no wait time is provided, this function degenerates to
* the same behavior as pthread_cond_wait().
*/
else if (!abstime) {
ret = pthread_cond_wait(cond, mutex);
}
else {
/* Create a watchdog */
rtcb->waitdog = wd_create();
if (!rtcb->waitdog) {
ret = EINVAL;
} else {
svdbg("Give up mutex...\n");
/* We must disable pre-emption and interrupts here so that
* the time stays valid until the wait begins. This adds
* complexity because we assure that interrupts and
* pre-emption are re-enabled correctly.
*/
sched_lock();
int_state = irqsave();
/* Convert the timespec to clock ticks. We must disable pre-emption
* here so that this time stays valid until the wait begins.
*/
ret = clock_abstime2ticks(CLOCK_REALTIME, abstime, &ticks);
if (ret) {
/* Restore interrupts (pre-emption will be enabled when
* we fall through the if/then/else)
*/
irqrestore(int_state);
} else {
/* Check the absolute time to wait. If it is now or in the past, then
* just return with the timedout condition.
*/
if (ticks <= 0) {
/* Restore interrupts and indicate that we have already timed out.
* (pre-emption will be enabled when we fall through the
* if/then/else
*/
irqrestore(int_state);
ret = ETIMEDOUT;
} else {
/* Give up the mutex */
mutex->pid = -1;
ret = pthread_mutex_give(mutex);
if (ret != 0) {
/* Restore interrupts (pre-emption will be enabled when
* we fall through the if/then/else)
*/
irqrestore(int_state);
} else {
/* Start the watchdog */
wd_start(rtcb->waitdog, ticks, (wdentry_t)pthread_condtimedout, 2, (uint32_t)mypid, (uint32_t)SIGCONDTIMEDOUT);
/* Take the condition semaphore. Do not restore interrupts
* until we return from the wait. This is necessary to
* make sure that the watchdog timer and the condition wait
* are started atomically.
*/
status = sem_wait((sem_t *)&cond->sem);
/* Did we get the condition semaphore. */
if (status != OK) {
/* NO.. Handle the special case where the semaphore wait was
* awakened by the receipt of a signal -- presumably the
* signal posted by pthread_condtimedout().
*/
if (get_errno() == EINTR) {
sdbg("Timedout!\n");
ret = ETIMEDOUT;
} else {
ret = EINVAL;
}
}
/* The interrupts stay disabled until after we sample the errno.
* This is because when debug is enabled and the console is used
* for debug output, then the errno can be altered by interrupt
* handling! (bad)
*/
irqrestore(int_state);
}
/* Reacquire the mutex (retaining the ret). */
svdbg("Re-locking...\n");
oldstate = pthread_disable_cancel();
status = pthread_mutex_take(mutex, false);
pthread_enable_cancel(oldstate);
if (status == OK) {
mutex->pid = mypid;
} else if (ret == 0) {
ret = status;
}
}
/* Re-enable pre-emption (It is expected that interrupts
* have already been re-enabled in the above logic)
*/
sched_unlock();
}
/* We no longer need the watchdog */
wd_delete(rtcb->waitdog);
rtcb->waitdog = NULL;
}
}
svdbg("Returning %d\n", ret);
leave_cancellation_point();
trace_end(TTRACE_TAG_TASK);
return ret;
}