Merge remote-tracking branch 'origin/master' into vnc

ChangeLog

@@ -11642,4 +11642,8 @@
 	* net/sockets/listen.c and accept.c and include/nuttx/net:  Separate
 	  out psock_listen() and psock_accepti() for internal OS usage
 	  (2016-04-14).
-
+	* fs/inode/, fs/vfs/, and sched/task/:  File and socket descriptors are
+	  no longer allocated for kernel threads.  They must use SYSLOG for
+	  output and the low-level psock interfaces for network I/O.  This
+	  saves a little memory which might be important for small footprint
+	  configurations (2015-04-14).

fs/inode/fs_files.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * fs/inode/fs_files.c
  *
- *   Copyright (C) 2007-2009, 2011-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011-2013, 2016 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -51,22 +51,6 @@
 
 #include "inode/inode.h"
 
-/****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
-
-/****************************************************************************
- * Private Types
- ****************************************************************************/
-
-/****************************************************************************
- * Private Data
- ****************************************************************************/
-
-/****************************************************************************
- * Private Data
- ****************************************************************************/
-
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
@@ -222,9 +206,18 @@ int file_dup2(FAR struct file *filep1, FAR struct file *filep2)
     }
 
   list = sched_getfiles();
-  DEBUGASSERT(list);
 
+  /* The file list can be NULL under two cases:  (1) One is an obscure
+   * cornercase:  When memory management debug output is enabled.  Then
+   * there may be attempts to write to stdout from malloc before the group
+   * data has been allocated.  The other other is (2) if this is a kernel
+   * thread.  Kernel threads have no allocated file descriptors.
+   */
+
+  if (list != NULL)
+    {
       _files_semtake(list);
+    }
 
   /* If there is already an inode contained in the new file structure,
    * close the file and release the inode.
@@ -278,7 +271,11 @@ int file_dup2(FAR struct file *filep1, FAR struct file *filep2)
         }
     }
 
+  if (list != NULL)
+    {
       _files_semgive(list);
+    }
+
   return OK;
 
 /* Handler various error conditions */
@@ -291,7 +288,11 @@ errout_with_inode:
 
 errout_with_ret:
   err              = -ret;
+
+  if (list != NULL)
+    {
       _files_semgive(list);
+    }
 
 errout:
   set_errno(err);
@@ -312,8 +313,10 @@ int files_allocate(FAR struct inode *inode, int oflags, off_t pos, int minfd)
   FAR struct filelist *list;
   int i;
 
+  /* Get the file descriptor list.  It should not be NULL in this context. */
+
   list = sched_getfiles();
-  DEBUGASSERT(list);
+  DEBUGASSERT(list != NULL);
 
   _files_semtake(list);
   for (i = minfd; i < CONFIG_NFILE_DESCRIPTORS; i++)
@@ -349,10 +352,12 @@ int files_close(int fd)
   FAR struct filelist *list;
   int                  ret;
 
-  /* Get the thread-specific file list */
+  /* Get the thread-specific file list.  It should never be NULL in this
+   * context.
+   */
 
   list = sched_getfiles();
-  DEBUGASSERT(list);
+  DEBUGASSERT(list != NULL);
 
   /* If the file was properly opened, there should be an inode assigned */
 

fs/inode/fs_foreachinode.c

@@ -52,6 +52,7 @@
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
+
 /* Is it better to allocate the struct inode_path_s from the heap? or
  * from the stack?  This decision depends on how often this is down and
  * how much stack space you can afford.

fs/inode/fs_inode.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * fs/inode/fs_inode.c
  *
- *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011-2012, 2016 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -57,6 +57,7 @@
 /****************************************************************************
  * Private Types
  ****************************************************************************/
+
 /* Implements a re-entrant mutex for inode access.  This must be re-entrant
  * because there can be cycles.  For example, it may be necessary to destroy
  * a block driver inode on umount() after a removable block device has been

fs/vfs/fs_getfilep.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * fs/vfs/fs_getfilep.c
  *
- *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2014, 2016 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -91,12 +91,14 @@ FAR struct file *fs_getfilep(int fd)
 
   list = sched_getfiles();
 
-  /* The file list can be NULL under one obscure cornercase:  When memory
+  /* The file list can be NULL under two cases:  (1) One is an obscure
-   * management debug output is enabled.  Then there may be attempts to
+   * cornercase:  When memory management debug output is enabled.  Then
-   * write to stdout from malloc before the group data has been allocated.
+   * there may be attempts to write to stdout from malloc before the group
+   * data has been allocated.  The other other is (2) if this is a kernel
+   * thread.  Kernel threads have no allocated file descriptors.
    */
 
-  if (!list)
+  if (list == NULL)
     {
       errcode = EAGAIN;
       goto errout;

sched/task/task_create.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * sched/task/task_create.c
  *
- *   Copyright (C) 2007-2010, 2013-2014 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2010, 2013-2014, 2016 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -85,7 +85,8 @@
  ****************************************************************************/
 
 static int thread_create(FAR const char *name, uint8_t ttype, int priority,
-                         int stack_size, main_t entry, FAR char * const argv[])
+                         int stack_size, main_t entry,
+                         FAR char * const argv[])
 {
   FAR struct task_tcb_s *tcb;
   pid_t pid;
@@ -115,15 +116,21 @@ static int thread_create(FAR const char *name, uint8_t ttype, int priority,
     }
 #endif
 
-  /* Associate file descriptors with the new task */
-
 #if CONFIG_NFILE_DESCRIPTORS > 0 || CONFIG_NSOCKET_DESCRIPTORS > 0
+  /* Associate file descriptors with the new task.  Exclude kernel threads;
+   * kernel threads do not have file or socket descriptors.  They must use
+   * SYSLOG for output and the low-level psock interfaces for network I/O.
+   */
+
+  if (ttype != TCB_FLAG_TTYPE_KERNEL)
+    {
       ret = group_setuptaskfiles(tcb);
       if (ret < OK)
         {
           errcode = -ret;
           goto errout_with_tcb;
         }
+    }
 #endif
 
   /* Allocate the stack for the TCB */
@@ -228,7 +235,8 @@ errout:
 int task_create(FAR const char *name, int priority,
                 int stack_size, main_t entry, FAR char * const argv[])
 {
-  return thread_create(name, TCB_FLAG_TTYPE_TASK, priority, stack_size, entry, argv);
+  return thread_create(name, TCB_FLAG_TTYPE_TASK, priority, stack_size,
+                       entry, argv);
 }
 #endif
 
@@ -251,5 +259,6 @@ int task_create(FAR const char *name, int priority,
 int kernel_thread(FAR const char *name, int priority,
                   int stack_size, main_t entry, FAR char * const argv[])
 {
-  return thread_create(name, TCB_FLAG_TTYPE_KERNEL, priority, stack_size, entry, argv);
+  return thread_create(name, TCB_FLAG_TTYPE_KERNEL, priority, stack_size,
+                       entry, argv);
 }