Add infrastructure to support poll()

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1258 42af7a65-404d-4744-a932-0658087f49c3

16 files changed, 336 insertions, 16 deletions

diff --git a/nuttx/ChangeLog b/nuttx/ChangeLog
index 250d6b7d1..53ea69079 100644
--- a/nuttx/ChangeLog
+++ b/nuttx/ChangeLog
@@ -564,3 +564,4 @@
 	  types.
 
 0.3.19 2008-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
+	* Add the basic infrastructure for support the poll() API
diff --git a/nuttx/Documentation/NuttX.html b/nuttx/Documentation/NuttX.html
index 79420fa15..98920305b 100644
--- a/nuttx/Documentation/NuttX.html
+++ b/nuttx/Documentation/NuttX.html
@@ -1200,6 +1200,7 @@ buildroot-0.1.2 2007-11-06 &lt;spudmonkey@racsa.co.cr&gt
 
 <pre><ul>
 nuttx-0.3.19 2008-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
+	* Add the basic infrastructure for support the poll() API
 
 pascal-0.1.3 2008-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
 
diff --git a/nuttx/drivers/bch/bchdev_driver.c b/nuttx/drivers/bch/bchdev_driver.c
index 9f579bbab..98c7f2991 100644
--- a/nuttx/drivers/bch/bchdev_driver.c
+++ b/nuttx/drivers/bch/bchdev_driver.c
@@ -85,7 +85,8 @@ struct file_operations bch_fops =
   bch_read,  /* read */
   bch_write, /* write */
   0,         /* seek */
-  bch_ioctl  /* ioctl */
+  bch_ioctl, /* ioctl */
+  0          /* poll */
 };
 
 /****************************************************************************
diff --git a/nuttx/drivers/can.c b/nuttx/drivers/can.c
index e68bfd94d..72e3fdd64 100644
--- a/nuttx/drivers/can.c
+++ b/nuttx/drivers/can.c
@@ -87,8 +87,9 @@ struct file_operations g_canops =
   can_close, /* close */
   can_read,  /* read */
   can_write, /* write */
-  0,          /* seek */
-  can_ioctl  /* ioctl */
+  0,         /* seek */
+  can_ioctl, /* ioctl */
+  0          /* poll */
 };
 
 /****************************************************************************
diff --git a/nuttx/drivers/dev_null.c b/nuttx/drivers/dev_null.c
index 5c495451b..f097f76c9 100644
--- a/nuttx/drivers/dev_null.c
+++ b/nuttx/drivers/dev_null.c
@@ -66,7 +66,8 @@ static struct file_operations devnull_fops =
   devnull_read,  /* read */
   devnull_write, /* write */
   0,             /* seek */
-  0              /* ioctl */
+  0,             /* ioctl */
+  0              /* poll */
 };
 
 /****************************************************************************
diff --git a/nuttx/drivers/dev_zero.c b/nuttx/drivers/dev_zero.c
index a18509415..876734770 100644
--- a/nuttx/drivers/dev_zero.c
+++ b/nuttx/drivers/dev_zero.c
@@ -66,7 +66,8 @@ static struct file_operations devzero_fops =
   devzero_read,  /* read */
   devzero_write, /* write */
   0,             /* seek */
-  0              /* ioctl */
+  0,             /* ioctl */
+  0              /* poll */
 };
 
 /****************************************************************************
diff --git a/nuttx/drivers/fifo.c b/nuttx/drivers/fifo.c
index 2465d41dc..fb17e3461 100644
--- a/nuttx/drivers/fifo.c
+++ b/nuttx/drivers/fifo.c
@@ -74,7 +74,8 @@ static struct file_operations fifo_fops =
   pipecommon_read,  /* read */
   pipecommon_write, /* write */
   0,                /* seek */
-  0                 /* ioctl */
+  0,                /* ioctl */
+  0                 /* poll */
 };
 
 /****************************************************************************
diff --git a/nuttx/drivers/lowconsole.c b/nuttx/drivers/lowconsole.c
index 0dcfe72b3..8b776da19 100755
--- a/nuttx/drivers/lowconsole.c
+++ b/nuttx/drivers/lowconsole.c
@@ -75,7 +75,8 @@ struct file_operations g_serialops =
   lowconsole_read,  /* read */
   lowconsole_write, /* write */
   0,                /* seek */
-  lowconsole_ioctl  /* ioctl */
+  lowconsole_ioctl, /* ioctl */
+  0                 /* poll */
 };
 
 /****************************************************************************
diff --git a/nuttx/drivers/pipe.c b/nuttx/drivers/pipe.c
index 677bcfe4c..7e4581c8a 100644
--- a/nuttx/drivers/pipe.c
+++ b/nuttx/drivers/pipe.c
@@ -82,7 +82,8 @@ static struct file_operations pipe_fops =
   pipecommon_read,   /* read */
   pipecommon_write,  /* write */
   0,                 /* seek */
-  0                  /* ioctl */
+  0,                 /* ioctl */
+  0,                 /* pipe */
 };
 
 static sem_t  g_pipesem     = { 1 };
diff --git a/nuttx/drivers/serial.c b/nuttx/drivers/serial.c
index bd4ca33e7..366c7a208 100644
--- a/nuttx/drivers/serial.c
+++ b/nuttx/drivers/serial.c
@@ -89,7 +89,8 @@ struct file_operations g_serialops =
   uart_read,  /* read */
   uart_write, /* write */
   0,          /* seek */
-  uart_ioctl  /* ioctl */
+  uart_ioctl, /* ioctl */
+  0           /* poll */
 };
 
 /************************************************************************************
diff --git a/nuttx/examples/pashello/device.c b/nuttx/examples/pashello/device.c
index b6db1db5c..fb2deff65 100644
--- a/nuttx/examples/pashello/device.c
+++ b/nuttx/examples/pashello/device.c
@@ -68,7 +68,8 @@ static struct file_operations hello_fops =
   hello_read,    /* read */
   0,             /* write */
   0,             /* seek */
-  0              /* ioctl */
+  0,             /* ioctl */
+  0              /* poll */
 };
 
 /****************************************************************************
diff --git a/nuttx/fs/fs_poll.c b/nuttx/fs/fs_poll.c
index 7b1db1f41..2f585d818 100644
--- a/nuttx/fs/fs_poll.c
+++ b/nuttx/fs/fs_poll.c
@@ -41,16 +41,200 @@
 
 #include <sys/types.h>
 #include <poll.h>
+#include <wdog.h>
 #include <errno.h>
+#include <assert.h>
+#include <debug.h>
 
 #include <nuttx/fs.h>
+#include <nuttx/sched.h>
+
 #include "fs_internal.h"
 
 /****************************************************************************
+ * 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(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)
+{
+  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(fds->fd, fds);
+        }
+      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);
+    }
+  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->sem     = sem;
+      fds->revents = 0;
+
+      /* Set up the poll */
+
+      ret = poll_fdsetup(fds->fd, fds);
+      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 */
+
+  for (i = 0; i < nfds; i++)
+    {
+      /* Teardown the poll */
+
+      status = poll_fdsetup(fds->fd, NULL);
+      if (status < 0)
+        {
+          ret = status;
+        }
+
+      /* Check if any events were posted */
+
+      if (fds->revents != 0)
+        {
+          (*count)++;
+        }
+
+      /* Un-initialize the poll structure */
+
+      fds->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 isem)
+{
+  /* Wake up the poller */
+
+  FAR sem_t *sem = (FAR sem_t *)isem;
+  poll_semgive(sem);
+}
+
+/****************************************************************************
  * Public Functions
  ****************************************************************************/
 
@@ -87,11 +271,45 @@
 
 int poll(FAR struct pollfd *fds, nfds_t nfds, int timeout)
 {
-#ifdef CONFIG_CPP_HAVE_WARNING
-#  warning To be provided
-#endif
+  WDOG_ID wdog;
+  sem_t sem;
+  int count;
+  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 */
+
+          wdog = wd_create();
+          wd_start(wdog, poll_timeout, 1, (uint32)&sem);
+          poll_semtake(&sem);
+          wd_delete(wdog);
+        }
+      else
+        {
+          /* Wait for the poll event with not timeout */
+
+          poll_semtake(&sem);
+        }
+
+      /* Teardown the the poll operation and get the count of events */
+
+      ret = poll_teardown(fds, nfds, &count);
+    }
+  sem_destroy(&sem);
+
+  /* Check for errors */
+
+  if (ret < 0)
+    {
+      errno = -ret;
+      return ERROR;
+    }
 
-  errno = ENOSYS;
-  return ERROR;
+  return count;
 }
 
diff --git a/nuttx/include/nuttx/fs.h b/nuttx/include/nuttx/fs.h
index 946c60589..65e033208 100644
--- a/nuttx/include/nuttx/fs.h
+++ b/nuttx/include/nuttx/fs.h
@@ -57,6 +57,8 @@
  */
 
 struct file;
+struct pollfd;
+
 struct file_operations
 {
   /* The device driver open method differs from the mountpoint open method */
@@ -73,6 +75,7 @@ struct file_operations
   ssize_t (*write)(FAR struct file *filp, FAR const char *buffer, size_t buflen);
   off_t   (*seek)(FAR struct file *filp, off_t offset, int whence);
   int     (*ioctl)(FAR struct file *filp, int cmd, unsigned long arg);
+  int     (*poll)(FAR struct file *filp, struct pollfd *poll);
 
   /* The two structures need not be common after this point */
 };
diff --git a/nuttx/include/nuttx/net.h b/nuttx/include/nuttx/net.h
index d4d7ec754..5126e7b65 100644
--- a/nuttx/include/nuttx/net.h
+++ b/nuttx/include/nuttx/net.h
@@ -153,6 +153,14 @@ EXTERN int net_close(int sockfd);
 struct ifreq; /* Forward reference -- see net/ioctls.h */
 EXTERN int netdev_ioctl(int sockfd, int cmd, struct ifreq *req);
 
+/* net-poll.c ****************************************************************/
+/* The standard poll() operation redirects operations on socket descriptors
+ * to this function.
+ */
+
+struct pollfd; /* Forward reference -- see poll.h */
+EXTERN int net_poll(int sockfd, struct pollfd *fds);
+
 /* netdev-register.c *********************************************************/
 /* This function is called by network interface device drivers to inform the
  * socket layer of their existence.  This registration is necesary to support
diff --git a/nuttx/net/Makefile b/nuttx/net/Makefile
index b43943396..97c758dd7 100644
--- a/nuttx/net/Makefile
+++ b/nuttx/net/Makefile
@@ -52,7 +52,7 @@ endif
 endif
 
 NETDEV_ASRCS	=
-NETDEV_CSRCS	= netdev-register.c netdev-ioctl.c netdev-txnotify.c \
+NETDEV_CSRCS	= netdev-register.c netdev-ioctl.c net-poll.c netdev-txnotify.c \
 		  netdev-findbyname.c netdev-findbyaddr.c netdev-count.c \
 		  netdev-foreach.c
 
diff --git a/nuttx/net/net-poll.c b/nuttx/net/net-poll.c
new file mode 100644
index 000000000..ef4ba9dd3
--- /dev/null
+++ b/nuttx/net/net-poll.c
@@ -0,0 +1,80 @@
+/****************************************************************************
+ * net/net-poll.c
+ *
+ *   Copyright (C) 2008 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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>
+#ifdef CONFIG_NET
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <poll.h>
+#include <errno.h>
+
+#include <nuttx/net.h>
+#include "net-internal.h"
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: net_poll
+ *
+ * Description:
+ *   The standard poll() operation redirects operations on socket descriptors
+ *   to this function.
+ *
+ * Parameters:
+ *   fd   - The socket descriptor of interest
+ *   fds  - The structures describing events to be monitored, OR NULL if
+ *          this is a request to stop monitoring events.
+ *
+ * Returned Value:
+ *  TBD
+ *
+ ****************************************************************************/
+
+int net_poll(int sockfd, struct pollfd *fds)
+{
+#ifdef CONFIG_CPP_HAVE_WARNING
+#  warning To be provided
+#endif
+  return -ENOSYS;
+}
+
+#endif /* CONFIG_NET */