1 files changed, 327 insertions, 0 deletions
diff --git a/nuttx/fs/fs_poll.c b/nuttx/fs/fs_poll.c
new file mode 100644
index 000000000..2e3adeb5d
--- /dev/null
+++ b/nuttx/fs/fs_poll.c
@@ -0,0 +1,327 @@
+/****************************************************************************
+ * fs/fs_poll.c
+ *
+ *   Copyright (C) 2008-2009, 2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <poll.h>
+#include <wdog.h>
+#include <errno.h>
+#include <assert.h>
+#include <debug.h>
+
+#include <nuttx/fs/fs.h>
+#include <nuttx/sched.h>
+#include <nuttx/clock.h>
+
+#include "fs_internal.h"
+
+#ifndef CONFIG_DISABLE_POLL
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define poll_semgive(sem) sem_post(sem)
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: poll_semtake
+ ****************************************************************************/
+
+static void poll_semtake(FAR sem_t *sem)
+{
+  /* Take the semaphore (perhaps waiting) */
+
+  while (sem_wait(sem) != 0)
+    {
+      /* The only case that an error should occur here is if
+       * the wait was awakened by a signal.
+       */
+
+      ASSERT(get_errno() == EINTR);
+    }
+}
+
+/****************************************************************************
+ * Name: poll_fdsetup
+ *
+ * Description:
+ *   Configure (or unconfigure) one file/socket descriptor for the poll
+ *   operation.  If fds and sem are non-null, then the poll is being setup.
+ *   if fds and sem are NULL, then the poll is being torn down.
+ *
+ ****************************************************************************/
+
+#if CONFIG_NFILE_DESCRIPTORS > 0
+static int poll_fdsetup(int fd, FAR struct pollfd *fds, bool setup)
+{
+  FAR struct filelist *list;
+  FAR struct file     *this_file;
+  FAR struct inode    *inode;
+  int                  ret = -ENOSYS;
+
+  /* Check for a valid file descriptor */
+
+  if ((unsigned int)fd >= CONFIG_NFILE_DESCRIPTORS)
+    {
+      /* Perform the socket ioctl */
+
+#if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0
+      if ((unsigned int)fd < (CONFIG_NFILE_DESCRIPTORS+CONFIG_NSOCKET_DESCRIPTORS))
+        {
+          return net_poll(fd, fds, setup);
+        }
+      else
+#endif
+        {
+          return -EBADF;
+        }
+    }
+
+  /* Get the thread-specific file list */
+
+  list = sched_getfiles();
+  if (!list)
+    {
+      return -EMFILE;
+    }
+
+  /* Is a driver registered? Does it support the poll method?
+   * If not, return -ENOSYS
+   */
+
+  this_file = &list->fl_files[fd];
+  inode     = this_file->f_inode;
+
+  if (inode && inode->u.i_ops && inode->u.i_ops->poll)
+    {
+      /* Yes, then setup the poll */
+
+      ret = (int)inode->u.i_ops->poll(this_file, fds, setup);
+    }
+  return ret;
+}
+#endif
+
+/****************************************************************************
+ * Name: poll_setup
+ *
+ * Description:
+ *   Setup the poll operation for each descriptor in the list.
+ *
+ ****************************************************************************/
+
+#if CONFIG_NFILE_DESCRIPTORS > 0
+static inline int poll_setup(FAR struct pollfd *fds, nfds_t nfds, sem_t *sem)
+{
+  int ret;
+  int i;
+
+  /* Process each descriptor in the list */
+
+  for (i = 0; i < nfds; i++)
+    {
+      /* Setup the poll descriptor */
+
+      fds[i].sem     = sem;
+      fds[i].revents = 0;
+      fds[i].priv    = NULL;
+
+      /* Set up the poll */
+
+      ret = poll_fdsetup(fds[i].fd, &fds[i], true);
+      if (ret < 0)
+        {
+          return ret;
+        }
+    }
+  return OK;
+}
+#endif
+
+/****************************************************************************
+ * Name: poll_teardown
+ *
+ * Description:
+ *   Teardown the poll operation for each descriptor in the list and return
+ *   the count of non-zero poll events.
+ *
+ ****************************************************************************/
+
+#if CONFIG_NFILE_DESCRIPTORS > 0
+static inline int poll_teardown(FAR struct pollfd *fds, nfds_t nfds, int *count)
+{
+  int status;
+  int ret = OK;
+  int i;
+
+  /* Process each descriptor in the list */
+
+  *count = 0;
+  for (i = 0; i < nfds; i++)
+    {
+      /* Teardown the poll */
+
+      status = poll_fdsetup(fds[i].fd, &fds[i], false);
+      if (status < 0)
+        {
+          ret = status;
+        }
+
+      /* Check if any events were posted */
+
+      if (fds[i].revents != 0)
+        {
+          (*count)++;
+        }
+
+      /* Un-initialize the poll structure */
+
+      fds[i].sem = NULL;
+    }
+
+  return ret;
+}
+#endif
+
+/****************************************************************************
+ * Name: poll_timeout
+ *
+ * Description:
+ *   The wdog expired before any other events were received.
+ *
+ ****************************************************************************/
+
+static void poll_timeout(int argc, uint32_t isem, ...)
+{
+  /* Wake up the poller */
+
+  FAR sem_t *sem = (FAR sem_t *)isem;
+  poll_semgive(sem);
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: poll
+ *
+ * Description:
+ *   poll() waits for one of a set of file descriptors to become ready to
+ *   perform I/O.  If none of the events requested (and no error) has
+ *   occurred for any of  the  file  descriptors,  then  poll() blocks until
+ *   one of the events occurs.
+ *
+ * Inputs:
+ *   fds  - List of structures describing file descriptors to be monitored
+ *   nfds - The number of entries in the list
+ *   timeout - Specifies an upper limit on the time for which poll() will
+ *     block in milliseconds.  A negative value of timeout means an infinite
+ *     timeout.
+ *
+ * Return:
+ *   On success, the number of structures that have nonzero revents fields.
+ *   A value of 0 indicates that the call timed out and no file descriptors
+ *   were ready.  On error, -1 is returned, and errno is set appropriately:
+ *
+ *   EBADF - An invalid file descriptor was given in one of the sets.
+ *   EFAULT - The fds address is invalid
+ *   EINTR - A signal occurred before any requested event.
+ *   EINVAL - The nfds value exceeds a system limit.
+ *   ENOMEM - There was no space to allocate internal data structures.
+ *   ENOSYS - One or more of the drivers supporting the file descriptor
+ *     does not support the poll method.
+ *
+ ****************************************************************************/
+
+int poll(FAR struct pollfd *fds, nfds_t nfds, int timeout)
+{
+  WDOG_ID wdog;
+  sem_t sem;
+  int count = 0;
+  int ret;
+
+  sem_init(&sem, 0, 0);
+  ret = poll_setup(fds, nfds, &sem);
+  if (ret >= 0)
+    {
+      if (timeout >= 0)
+        {
+          /* Wait for the poll event with a timeout.  Note that the
+           * millisecond timeout has to be converted to system clock
+           * ticks for wd_start
+           */
+
+          wdog = wd_create();
+          wd_start(wdog,  MSEC2TICK(timeout), poll_timeout, 1, (uint32_t)&sem);
+          poll_semtake(&sem);
+          wd_delete(wdog);
+        }
+      else
+        {
+          /* Wait for the poll event with no timeout */
+
+          poll_semtake(&sem);
+        }
+
+      /* Teardown the poll operation and get the count of events */
+
+      ret = poll_teardown(fds, nfds, &count);
+    }
+
+  sem_destroy(&sem);
+
+  /* Check for errors */
+
+  if (ret < 0)
+    {
+      set_errno(-ret);
+      return ERROR;
+    }
+
+  return count;
+}
+
+#endif /* CONFIG_DISABLE_POLL */