Implement poll/select for sockets

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1277 42af7a65-404d-4744-a932-0658087f49c3

5 files changed, 29 insertions, 27 deletions

diff --git a/nuttx/drivers/dev_null.c b/nuttx/drivers/dev_null.c
index 8db8c3cbb..cada981fe 100644
--- a/nuttx/drivers/dev_null.c
+++ b/nuttx/drivers/dev_null.c
@@ -56,7 +56,7 @@
 static ssize_t devnull_read(FAR struct file *, FAR char *, size_t);
 static ssize_t devnull_write(FAR struct file *, FAR const char *, size_t);
 #ifndef CONFIG_DISABLE_POLL
-static int     devnull_poll(FAR struct file *filp, FAR struct pollfd *poll);
+static int     devnull_poll(FAR struct file *filp, FAR struct pollfd *fds, boolean setup);
 #endif
 
 /****************************************************************************
@@ -103,9 +103,9 @@ static ssize_t devnull_write(FAR struct file *filp, FAR const char *buffer, size
  ****************************************************************************/
 
 #ifndef CONFIG_DISABLE_POLL
-static int devnull_poll(FAR struct file *filp, FAR struct pollfd *fds)
+static int devnull_poll(FAR struct file *filp, FAR struct pollfd *fds, boolean setup)
 {
-  if (fds)
+  if (setup)
     {
       fds->revents |= (fds->events & (POLLIN|POLLOUT));
       if (fds->revents != 0)
diff --git a/nuttx/drivers/dev_zero.c b/nuttx/drivers/dev_zero.c
index 08815ace5..13276ca7a 100644
--- a/nuttx/drivers/dev_zero.c
+++ b/nuttx/drivers/dev_zero.c
@@ -56,7 +56,7 @@
 static ssize_t devzero_read(FAR struct file *, FAR char *, size_t);
 static ssize_t devzero_write(FAR struct file *, FAR const char *, size_t);
 #ifndef CONFIG_DISABLE_POLL
-static int     devzero_poll(FAR struct file *filp, FAR struct pollfd *fds);
+static int     devzero_poll(FAR struct file *filp, FAR struct pollfd *fds, boolean setup);
 #endif
 
 /****************************************************************************
@@ -104,9 +104,9 @@ static ssize_t devzero_write(FAR struct file *filp, FAR const char *buffer, size
  ****************************************************************************/
 
 #ifndef CONFIG_DISABLE_POLL
-static int devzero_poll(FAR struct file *filp, FAR struct pollfd *fds)
+static int devzero_poll(FAR struct file *filp, FAR struct pollfd *fds, boolean setup)
 {
-  if (fds)
+  if (setup)
     {
       fds->revents |= (fds->events & (POLLIN|POLLOUT));
       if (fds->revents != 0)
diff --git a/nuttx/drivers/pipe_common.c b/nuttx/drivers/pipe_common.c
index 87d496f62..72fea8006 100644
--- a/nuttx/drivers/pipe_common.c
+++ b/nuttx/drivers/pipe_common.c
@@ -517,7 +517,7 @@ ssize_t pipecommon_write(FAR struct file *filep, FAR const char *buffer, size_t
  ****************************************************************************/
 
 #ifndef CONFIG_DISABLE_POLL
-int pipecommon_poll(FAR struct file *filep, FAR struct pollfd *fds)
+int pipecommon_poll(FAR struct file *filep, FAR struct pollfd *fds, boolean setup)
 {
   FAR struct inode      *inode    = filep->f_inode;
   FAR struct pipe_dev_s *dev      = inode->i_private;
@@ -539,7 +539,7 @@ int pipecommon_poll(FAR struct file *filep, FAR struct pollfd *fds)
   for (i = 0; i < CONFIG_DEV_PIPE_NPOLLWAITERS; i++)
     {
       /* Find the slot with the value equal to filep->f_priv.  If there
-       * is not previously installed poll structure, then f_priv will
+       * is no previously installed poll structure, then f_priv will
        * be NULL and we will find the first unused slot.  If f_priv is
        * is non-NULL, then we will find the slot that was used for the
        * previous setup.
@@ -547,14 +547,14 @@ int pipecommon_poll(FAR struct file *filep, FAR struct pollfd *fds)
 
       if (dev->d_fds[i] == filep->f_priv)
         {
-          dev->d_fds[i] = fds;
+          dev->d_fds[i] = (setup ? fds : NULL);
           break;
         }
     }
 
   if (i >= CONFIG_DEV_PIPE_NPOLLWAITERS)
     {
-      DEBUGASSERT(fds == NULL);
+      DEBUGASSERT(setup);
       return -EBUSY;
     }
 
@@ -562,13 +562,16 @@ int pipecommon_poll(FAR struct file *filep, FAR struct pollfd *fds)
    * private data.
    */
 
-  filep->f_priv = fds;
+  filep->f_priv = NULL; /* Assume teardown */
+  if (setup)
+    {
+      /* Set the poll event structure reference in the 'struct file' private data.  */
 
-  /* Check if we should immediately notify on any of the requested events */
+      filep->f_priv = fds;
 
-  if (fds)
-    {
-      /* Determine how many bytes are in the buffer */
+      /* Check if we should immediately notify on any of the requested events.  First,
+       * Determine how many bytes are in the buffer
+       */
 
       if (dev->d_wrndx >= dev->d_rdndx)
         {
diff --git a/nuttx/drivers/pipe_common.h b/nuttx/drivers/pipe_common.h
index 05edd9ca2..0f2247766 100644
--- a/nuttx/drivers/pipe_common.h
+++ b/nuttx/drivers/pipe_common.h
@@ -123,7 +123,7 @@ EXTERN int     pipecommon_close(FAR struct file *filep);
 EXTERN ssize_t pipecommon_read(FAR struct file *, FAR char *, size_t);
 EXTERN ssize_t pipecommon_write(FAR struct file *, FAR const char *, size_t);
 #ifndef CONFIG_DISABLE_POLL
-EXTERN int     pipecommon_poll(FAR struct file *filep, FAR struct pollfd *fds);
+EXTERN int     pipecommon_poll(FAR struct file *filep, FAR struct pollfd *fds, boolean setup);
 #endif
 
 #undef EXTERN
diff --git a/nuttx/drivers/serial.c b/nuttx/drivers/serial.c
index 533675886..0effeff00 100644
--- a/nuttx/drivers/serial.c
+++ b/nuttx/drivers/serial.c
@@ -79,7 +79,7 @@ static ssize_t uart_read(FAR struct file *filep, FAR char *buffer, size_t buflen
 static ssize_t uart_write(FAR struct file *filep, FAR const char *buffer, size_t buflen);
 static int     uart_ioctl(FAR struct file *filep, int cmd, unsigned long arg);
 #ifndef CONFIG_DISABLE_POLL
-static int     uart_poll(FAR struct file *filep, FAR struct pollfd *fds);
+static int     uart_poll(FAR struct file *filep, FAR struct pollfd *fds, boolean setup);
 #endif
 
 /************************************************************************************
@@ -400,7 +400,7 @@ static int uart_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
  ****************************************************************************/
 
 #ifndef CONFIG_DISABLE_POLL
-int uart_poll(FAR struct file *filep, FAR struct pollfd *fds)
+int uart_poll(FAR struct file *filep, FAR struct pollfd *fds, boolean setup)
 {
   FAR struct inode *inode = filep->f_inode;
   FAR uart_dev_t   *dev   = inode->i_private;
@@ -422,7 +422,7 @@ int uart_poll(FAR struct file *filep, FAR struct pollfd *fds)
   for (i = 0; i < CONFIG_DEV_CONSOLE_NPOLLWAITERS; i++)
     {
       /* Find the slot with the value equal to filep->f_priv.  If there
-       * is not previously installed poll structure, then f_priv will
+       * is no previously installed poll structure, then f_priv will
        * be NULL and we will find the first unused slot.  If f_priv is
        * is non-NULL, then we will find the slot that was used for the
        * previous setup.
@@ -430,14 +430,14 @@ int uart_poll(FAR struct file *filep, FAR struct pollfd *fds)
 
       if (dev->fds[i] == filep->f_priv)
         {
-          dev->fds[i] = fds;
+          dev->fds[i] = (setup ? fds : NULL);
           break;
         }
     }
 
   if (i >= CONFIG_DEV_CONSOLE_NPOLLWAITERS)
     {
-      DEBUGASSERT(fds == NULL);
+      DEBUGASSERT(setup);
       return -EBUSY;
     }
 
@@ -445,13 +445,12 @@ int uart_poll(FAR struct file *filep, FAR struct pollfd *fds)
    * private data.
    */
 
-  filep->f_priv = fds;
-
-  /* Check if we should immediately notify on any of the requested events */
-
-  if (fds)
+  filep->f_priv = NULL; /* Assume teardown */
+  if (setup)
     {
-      /* Check if the xmit buffer is full. */
+      /* Check if we should immediately notify on any of the requested events.
+       * First, check if the xmit buffer is full.
+       */
 
       eventset = 0;