Add select()

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1263 42af7a65-404d-4744-a932-0658087f49c3

5 files changed, 349 insertions, 8 deletions

diff --git a/nuttx/ChangeLog b/nuttx/ChangeLog
index 53ea69079..32760238a 100644
--- a/nuttx/ChangeLog
+++ b/nuttx/ChangeLog
@@ -564,4 +564,7 @@
 	  types.
 
 0.3.19 2008-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
-	* Add the basic infrastructure for support the poll() API
+	* Add poll() and select() APIs (in the initial check-in, these work only with character devices) 
+	* Add poll() methods to /dev/null, /dev/zero, pipes, and fifos.
+	* Add examples/poll for testing poll() and select()
+
diff --git a/nuttx/Documentation/NuttX.html b/nuttx/Documentation/NuttX.html
index 98920305b..e149f42a8 100644
--- a/nuttx/Documentation/NuttX.html
+++ b/nuttx/Documentation/NuttX.html
@@ -8,7 +8,7 @@
   <tr align="center" bgcolor="#e4e4e4">
     <td>
       <h1><big><font color="#3c34ec"><i>NuttX RTOS</i></font></big></h1>
-      <p>Last Updated: November 16, 2008</p>
+      <p>Last Updated: November 17, 2008</p>
     </td>
   </tr>
 </table>
@@ -1200,7 +1200,9 @@ 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
+	* Add poll() and select() APIs (in the initial check-in, these work only with character devices) 
+	* Add poll() methods to /dev/null, /dev/zero, pipes, and fifos.
+	* Add examples/poll for testing poll() and select()
 
 pascal-0.1.3 2008-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
 
diff --git a/nuttx/fs/Makefile b/nuttx/fs/Makefile
index 1ffa5b5f5..1fce0e423 100644
--- a/nuttx/fs/Makefile
+++ b/nuttx/fs/Makefile
@@ -41,14 +41,14 @@ AOBJS		= $(ASRCS:.S=$(OBJEXT))
 CSRCS		=
 ifeq ($(CONFIG_NFILE_DESCRIPTORS),0)
 ifneq ($(CONFIG_NSOCKET_DESCRIPTORS),0)
-CSRCS		+= fs_close.c fs_write.c fs_ioctl.c fs_poll.c
+CSRCS		+= fs_close.c fs_write.c fs_ioctl.c fs_poll.c fs_select.c
 endif
 else
 CSRCS		+= fs_open.c fs_close.c fs_read.c fs_write.c fs_ioctl.c fs_poll.c \
-		   fs_lseek.c fs_dup.c fs_mmap.c fs_opendir.c fs_closedir.c fs_stat.c \
-		   fs_readdir.c fs_readdirr.c fs_seekdir.c fs_telldir.c fs_rewinddir.c \
-		   fs_files.c fs_inode.c fs_inodefind.c fs_inodereserve.c fs_statfs.c \
-		   fs_inoderemove.c fs_registerdriver.c fs_unregisterdriver.c \
+		   fs_select.c fs_lseek.c fs_dup.c fs_mmap.c fs_opendir.c fs_closedir.c \
+		   fs_stat.c fs_readdir.c fs_readdirr.c fs_seekdir.c fs_telldir.c \
+		   fs_rewinddir.c fs_files.c fs_inode.c fs_inodefind.c fs_inodereserve.c \
+		   fs_statfs.c fs_inoderemove.c fs_registerdriver.c fs_unregisterdriver.c \
 		   fs_inodeaddref.c fs_inoderelease.c
 CSRCS		+= fs_registerblockdriver.c fs_unregisterblockdriver.c \
 		   fs_findblockdriver.c fs_openblockdriver.c fs_closeblockdriver.c
diff --git a/nuttx/fs/fs_select.c b/nuttx/fs/fs_select.c
new file mode 100644
index 000000000..ca2ae4027
--- /dev/null
+++ b/nuttx/fs/fs_select.c
@@ -0,0 +1,217 @@
+/****************************************************************************
+ * fs/fs_select.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>
+
+#include <sys/types.h>
+#include <sys/select.h>
+
+#include <stdlib.h>
+#include <string.h>
+#include <poll.h>
+#include <time.h>
+#include <errno.h>
+#include <assert.h>
+#include <debug.h>
+
+#include <nuttx/fs.h>
+
+#include "fs_internal.h"
+
+#ifndef CONFIG_DISABLE_POLL
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: select
+ *
+ * Description:
+ *   select() allows a program to monitor multiple file descriptors, waiting
+ *   until one or more of the file descriptors become "ready" for some class
+ *   of I/O operation (e.g., input possible).  A file descriptor is
+ *   considered  ready if it is possible to perform the corresponding I/O
+ *   operation (e.g., read(2)) without blocking.
+ *
+ *   NOTE: poll() is the fundamental API for performing such monitoring
+ *   operation under NuttX.  select() is provided for compatibility and
+ *   is simply a layer of added logic on top of poll().  As such, select()
+ *   is more wasteful of resources and poll() is the recommend API to be
+ *   used.
+ *
+ * Input parameters:
+ *   nfds - the maximum fd number (+1) of any descriptor in any of the
+ *     three sets.
+ *   readfds - the set of descriptions to monitor for read-ready events
+ *   writefds - the set of descriptions to monitor for write-ready events
+ *   exceptfds - the set of descriptions to monitor for error events
+ *   timeout - Return at this time if none of these events of interest
+ *     occur.
+ *
+ *  Return:
+ *   0: Timer expired
+ *  >0: The number of bits set in the three sets of descriptors
+ *  -1: An error occurred (errno will be set approrpiately)
+ *
+ ****************************************************************************/
+
+int select(int nfds, FAR fd_set *readfds, FAR fd_set *writefds,
+           FAR fd_set *exceptfds, FAR struct timeval *timeout)
+{
+  struct pollfd *pollset;
+  int fd;
+  int npfds;
+  int msec;
+  int ndx;
+  int ret;
+
+  /* Allocate the descriptor list for poll() */
+
+  pollset = (struct pollfd *)zalloc(nfds * sizeof(struct pollfd));
+  if (!pollset)
+    {
+      errno = ENOMEM;
+      return ERROR;
+    }
+
+  /* Initialize the descriptor list for poll() */
+
+  for (fd = 0, npfds = 0; fd < nfds; fd++)
+    {
+      int incr = 0;
+
+      if (readfds && FD_ISSET(fd, readfds))
+        {
+           pollset[npfds].fd      = fd;
+           pollset[npfds].events |= POLLIN;
+           incr                  = 1;
+        }
+
+      if (writefds && FD_ISSET(fd, writefds))
+        {
+           pollset[npfds].fd      = fd;
+           pollset[npfds].events |= POLLOUT;
+           incr                  = 1;
+        }
+
+      if (exceptfds && FD_ISSET(fd, exceptfds))
+        {
+           pollset[npfds].fd      = fd;
+           incr                  = 1;
+        }
+
+      npfds += incr;
+    }
+
+  /* Convert the timeout to milliseconds */
+
+  msec = timeout->tv_sec * 1000 + timeout->tv_usec / 1000;
+
+  /* Then let poll do all of the real work. */
+
+  ret = poll(pollset, npfds, msec);
+
+  /* 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++)
+        {
+          if (readfds)
+            {
+              if (pollset[fd].revents & POLLIN)
+                {
+                  FD_SET(pollset[ndx].fd, readfds);
+                  ret++;
+                }
+            }
+
+          if (writefds)
+            {
+              if (pollset[fd].revents & POLLOUT)
+                {
+                  FD_SET(pollset[ndx].fd, writefds);
+                  ret++;
+                }
+            }
+
+          if (exceptfds)
+            {
+              if (pollset[fd].revents & POLLERR)
+                {
+                  FD_SET(pollset[ndx].fd, exceptfds);
+                  ret++;
+                }
+            }
+        }
+    }
+
+  free(pollset);
+  return ret;
+}
+
+#endif /* CONFIG_DISABLE_POLL */
+
diff --git a/nuttx/include/sys/select.h b/nuttx/include/sys/select.h
new file mode 100644
index 000000000..a665a5882
--- /dev/null
+++ b/nuttx/include/sys/select.h
@@ -0,0 +1,119 @@
+/****************************************************************************
+ * include/sys/select.h
+ *
+ *   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.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_SYS_SELECT_H
+#define __INCLUDE_SYS_SELECT_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <time.h>
+
+#if CONFIG_NFILE_DESCRIPTORS > 0 || CONFIG_NSOCKET_DESCRIPTORS > 0
+
+/****************************************************************************
+ * Pre-Processor Definitions
+ ****************************************************************************/
+
+/* Get the total number of descriptors that we will have to support */
+
+#define __SELECT_NDESCRIPTORS (CONFIG_NFILE_DESCRIPTORS + CONFIG_NSOCKET_DESCRIPTORS)
+
+/* We will use a 32-bit bitsets to represent the set of descriptors.  How
+ * many uint32's do we need to span all descriptors?
+ */
+
+#if __SELECT_NDESCRIPTORS <= 32
+#  define __SELECT_NUINT32 1
+#elif __SELECT_NDESCRIPTORS <= 64
+#  define __SELECT_NUINT32 2
+#elif __SELECT_NDESCRIPTORS <= 96
+#  define __SELECT_NUINT32 3
+#elif __SELECT_NDESCRIPTORS <= 128
+#  define __SELECT_NUINT32 4
+#elif __SELECT_NDESCRIPTORS <= 160
+#  define __SELECT_NUINT32 5
+#elif __SELECT_NDESCRIPTORS <= 192
+#  define __SELECT_NUINT32 6
+#elif __SELECT_NDESCRIPTORS <= 224
+#  define __SELECT_NUINT32 7
+#elif __SELECT_NDESCRIPTORS <= 256
+#  define __SELECT_NUINT32 8
+#else
+#  warning "Large fd_set needed"
+#endif
+
+/* These macros map a file descripto to an index and bit number */
+
+#define _FD_NDX(fd) ((fd) >> 5)
+#define _FD_BIT(fd) ((fd) & 0x1f)
+
+/* Standard helper macros */
+
+#define FD_CLR(fd,set)    (((uint32*)(set))[_FD_NDX(fd)] &= ~(1 << _FD_BIT(fd)))
+#define FD_SET(fd,set)    (((uint32*)(set))[_FD_NDX(fd)] |= (1 << _FD_BIT(fd)))
+#define FD_ISSET(fd,set)  ((((uint32*)(set))[_FD_NDX(fd)] & (1 << _FD_BIT(fd))) != 0)
+#define FD_ZERO(set)      memset(set, 0, sizeof(fd_set))
+
+/****************************************************************************
+ * Type Definitions
+ ****************************************************************************/
+
+typedef uint32 fd_set[__SELECT_NUINT32];
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C" {
+#else
+#define EXTERN extern
+#endif
+
+EXTERN int select(int nfds, FAR fd_set *readfds, FAR fd_set *writefds,
+                  FAR fd_set *exceptfds, FAR struct timeval *timeout);
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* CONFIG_NFILE_DESCRIPTORS || CONFIG_NSOCKET_DESCRIPTORS */
+#endif /* __INCLUDE_SYS_SELECT_H */