Repartition work queue code. Move kernel-specific parts from libc/wqueue to sched/wqueue

10 files changed, 523 insertions, 152 deletions

diff --git a/nuttx/include/nuttx/wqueue.h b/nuttx/include/nuttx/wqueue.h
index 036ea0da3..cad35a56d 100644
--- a/nuttx/include/nuttx/wqueue.h
+++ b/nuttx/include/nuttx/wqueue.h
@@ -366,24 +366,34 @@ EXTERN struct wqueue_s g_work[NWORKERS];
  ****************************************************************************/
 
 /****************************************************************************
- * Name: work_hpthread, work_lpthread, and work_usrthread
+ * Name: work_process
  *
  * Description:
- *   These are the worker threads that performs actions placed on the work
- *   lists.
+ *   This is the logic that performs actions placed on any work list.  This
+ *   logic is the common underlying logic to all work queues.  This logic is
+ *   part of the internal implementation of each work queue; it should not
+ *   be called from application level logic.
  *
- *   work_hpthread and work_lpthread:  These are the kernel mode work queues
- *     (also build in the flat build).  One of these threads also performs
- *     periodic garbage collection (that is otherwise performed by the idle
- *     thread if CONFIG_SCHED_WORKQUEUE is not defined).
+ * Input parameters:
+ *   wqueue - Describes the work queue to be processed
  *
- *     These worker threads are started by the OS during normal bringup.
+ * Returned Value:
+ *   None
  *
- *   work_usrthread:  This is a user mode work queue.  It must be started
- *     by application code by calling work_usrstart().
+ ****************************************************************************/
+
+void work_process(FAR struct wqueue_s *wqueue);
+
+/****************************************************************************
+ * Name: work_usrthread
  *
- *   All of these entrypoints are referenced by OS internally and should not
- *   not be accessed by application logic.
+ * Description:
+ *   This is the worker thread that performs the actions placed on the user
+ *   work queue.
+ *
+ *   This is a user mode work queue.  It must be used by applications for
+ *   miscellaneous operations.  The user work thread must be started by
+ *   application start-up logic by calling work_usrstart().
  *
  * Input parameters:
  *   argc, argv (not used)
@@ -393,14 +403,6 @@ EXTERN struct wqueue_s g_work[NWORKERS];
  *
  ****************************************************************************/
 
-#ifdef CONFIG_SCHED_HPWORK
-int work_hpthread(int argc, char *argv[]);
-#endif
-
-#ifdef CONFIG_SCHED_LPWORK
-int work_lpthread(int argc, char *argv[]);
-#endif
-
 #if defined(CONFIG_SCHED_USRWORK) && !defined(__KERNEL__)
 int work_usrthread(int argc, char *argv[]);
 #endif
diff --git a/nuttx/libc/wqueue/Make.defs b/nuttx/libc/wqueue/Make.defs
index 3f1303d7a..87c5437e3 100644
--- a/nuttx/libc/wqueue/Make.defs
+++ b/nuttx/libc/wqueue/Make.defs
@@ -37,10 +37,14 @@ ifeq ($(CONFIG_SCHED_WORKQUEUE),y)
 
 # Add the work queue C files to the build
 
-CSRCS += work_thread.c work_queue.c work_cancel.c work_signal.c
+CSRCS += work_process.c work_queue.c work_cancel.c work_signal.c
 
 ifeq ($(CONFIG_BUILD_PROTECTED),y)
-CSRCS += work_usrstart.c
+CSRCS += work_usrstart.c work_usrthread.c
+else
+ifeq ($(CONFIG_BUILD_KERNEL),y)
+CSRCS += work_usrstart.c work_usrthread.c
+endif
 endif
 
 # Add the wqueue directory to the build
diff --git a/nuttx/libc/wqueue/work_thread.c b/nuttx/libc/wqueue/work_process.c
index 657fe9d10..fb0ecfaa8 100644
--- a/nuttx/libc/wqueue/work_thread.c
+++ b/nuttx/libc/wqueue/work_process.c
@@ -1,7 +1,7 @@
 /****************************************************************************
- * libc/wqueue/work_thread.c
+ * libc/wqueue/work_process.c
  *
- *   Copyright (C) 2009-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2009-2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -42,14 +42,11 @@
 #include <stdint.h>
 #include <unistd.h>
 #include <queue.h>
-#include <assert.h>
-#include <errno.h>
-#include <debug.h>
 
-#include <nuttx/arch.h>
-#include <nuttx/wqueue.h>
 #include <nuttx/clock.h>
-#include <nuttx/kmalloc.h>
+#include <nuttx/wqueue.h>
+
+#include <arch/irq.h>
 
 #ifdef CONFIG_SCHED_WORKQUEUE
 
@@ -62,7 +59,7 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Public Variables
+ * Public Data
  ****************************************************************************/
 
 /* The state of each work queue. */
@@ -90,7 +87,7 @@ struct wqueue_s g_work[NWORKERS];
 #endif /* CONFIG_BUILD_PROTECTED */
 
 /****************************************************************************
- * Private Variables
+ * Private Data
  ****************************************************************************/
 
 /****************************************************************************
@@ -98,10 +95,17 @@ struct wqueue_s g_work[NWORKERS];
  ****************************************************************************/
 
 /****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
  * Name: work_process
  *
  * Description:
- *   This is the logic that performs actions placed on any work list.
+ *   This is the logic that performs actions placed on any work list.  This
+ *   logic is the common underlying logic to all work queues.  This logic is
+ *   part of the internal implementation of each work queue; it should not
+ *   be called from application level logic.
  *
  * Input parameters:
  *   wqueue - Describes the work queue to be processed
@@ -111,7 +115,7 @@ struct wqueue_s g_work[NWORKERS];
  *
  ****************************************************************************/
 
-static void work_process(FAR struct wqueue_s *wqueue)
+void work_process(FAR struct wqueue_s *wqueue)
 {
   volatile FAR struct work_s *work;
   worker_t  worker;
@@ -215,117 +219,4 @@ static void work_process(FAR struct wqueue_s *wqueue)
   irqrestore(flags);
 }
 
-/****************************************************************************
- * Public Functions
- ****************************************************************************/
-/****************************************************************************
- * Name: work_hpthread, work_lpthread, and work_usrthread
- *
- * Description:
- *   These are the worker threads that performs actions placed on the work
- *   lists.
- *
- *   work_hpthread and work_lpthread:  These are the kernel mode work queues
- *     (also build in the flat build).  One of these threads also performs
- *     periodic garbage collection (that is otherwise performed by the idle
- *     thread if CONFIG_SCHED_WORKQUEUE is not defined).
- *
- *     These worker threads are started by the OS during normal bringup.
- *
- *   work_usrthread:  This is a user mode work queue.  It must be built into
- *     the application blob during the user phase of a kernel build.  The
- *     user work thread will then automatically be started when the system
- *     boots by calling through the pointer found in the header on the user
- *     space blob.
- *
- *   All of these entrypoints are referenced by OS internally and should not
- *   not be accessed by application logic.
- *
- * Input parameters:
- *   argc, argv (not used)
- *
- * Returned Value:
- *   Does not return
- *
- ****************************************************************************/
-
-#if defined(CONFIG_SCHED_HPWORK)
-
-int work_hpthread(int argc, char *argv[])
-{
-  /* Loop forever */
-
-  for (;;)
-    {
-      /* First, perform garbage collection.  This cleans-up memory de-allocations
-       * that were queued because they could not be freed in that execution
-       * context (for example, if the memory was freed from an interrupt handler).
-       * NOTE: If the work thread is disabled, this clean-up is performed by
-       * the IDLE thread (at a very, very low priority).
-       */
-
-#ifndef CONFIG_SCHED_LPWORK
-      sched_garbagecollection();
-#endif
-
-      /* Then process queued work.  We need to keep interrupts disabled while
-       * we process items in the work list.
-       */
-
-      work_process(&g_work[HPWORK]);
-    }
-
-  return OK; /* To keep some compilers happy */
-}
-
-#ifdef CONFIG_SCHED_LPWORK
-
-int work_lpthread(int argc, char *argv[])
-{
-  /* Loop forever */
-
-  for (;;)
-    {
-      /* First, perform garbage collection.  This cleans-up memory de-allocations
-       * that were queued because they could not be freed in that execution
-       * context (for example, if the memory was freed from an interrupt handler).
-       * NOTE: If the work thread is disabled, this clean-up is performed by
-       * the IDLE thread (at a very, very low priority).
-       */
-
-      sched_garbagecollection();
-
-      /* Then process queued work.  We need to keep interrupts disabled while
-       * we process items in the work list.
-       */
-
-      work_process(&g_work[LPWORK]);
-    }
-
-  return OK; /* To keep some compilers happy */
-}
-
-#endif /* CONFIG_SCHED_LPWORK */
-#endif /* CONFIG_SCHED_HPWORK */
-
-#if defined(CONFIG_SCHED_USRWORK) && !defined(__KERNEL__)
-
-int work_usrthread(int argc, char *argv[])
-{
-  /* Loop forever */
-
-  for (;;)
-    {
-      /* Then process queued work.  We need to keep interrupts disabled while
-       * we process items in the work list.
-       */
-
-      work_process(&g_work[USRWORK]);
-    }
-
-  return OK; /* To keep some compilers happy */
-}
-
-#endif /* CONFIG_SCHED_USRWORK */
-
 #endif /* CONFIG_SCHED_WORKQUEUE */
diff --git a/nuttx/libc/wqueue/work_usrthread.c b/nuttx/libc/wqueue/work_usrthread.c
new file mode 100644
index 000000000..b836e27ca
--- /dev/null
+++ b/nuttx/libc/wqueue/work_usrthread.c
@@ -0,0 +1,102 @@
+/****************************************************************************
+ * libc/wqueue/work_usrthread.c
+ *
+ *   Copyright (C) 2009-2014 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 <nuttx/wqueue.h>
+
+#if defined(CONFIG_SCHED_WORKQUEUE) && defined(CONFIG_SCHED_USRWORK) && \
+   !defined(__KERNEL__)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Type Declarations
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: work_usrthread
+ *
+ * Description:
+ *   This is the worker thread that performs the actions placed on the user
+ *   work queue.
+ *
+ *   This is a user mode work queue.  It must be used by applications for
+ *   miscellaneous operations.  The user work thread must be started by
+ *   application start-up logic by calling work_usrstart().
+ *
+ * Input parameters:
+ *   argc, argv (not used)
+ *
+ * Returned Value:
+ *   Does not return
+ *
+ ****************************************************************************/
+
+int work_usrthread(int argc, char *argv[])
+{
+  /* Loop forever */
+
+  for (;;)
+    {
+      /* Then process queued work.  We need to keep interrupts disabled while
+       * we process items in the work list.
+       */
+
+      work_process(&g_work[USRWORK]);
+    }
+
+  return OK; /* To keep some compilers happy */
+}
+
+#endif /* CONFIG_SCHED_WORKQUEUE && CONFIG_SCHED_USRWORK && !__KERNEL__*/
diff --git a/nuttx/sched/init/os_bringup.c b/nuttx/sched/init/os_bringup.c
index 23eaed044..751a15449 100644
--- a/nuttx/sched/init/os_bringup.c
+++ b/nuttx/sched/init/os_bringup.c
@@ -57,6 +57,7 @@
 #ifdef CONFIG_PAGING
 # include "paging/paging.h"
 #endif
+# include "wqueue/wqueue.h"
 # include "init/init.h"
 
 /****************************************************************************
diff --git a/nuttx/sched/wqueue/Make.defs b/nuttx/sched/wqueue/Make.defs
index cd1b0ddb8..86c5edc12 100644
--- a/nuttx/sched/wqueue/Make.defs
+++ b/nuttx/sched/wqueue/Make.defs
@@ -37,18 +37,24 @@
 
 ifeq ($(CONFIG_SCHED_WORKQUEUE),y)
 
+# Add high priority work queue files
+
+ifeq ($(CONFIG_SCHED_HPWORK),y)
+CSRCS += work_hpthread.c
+endif
+
 # Add low priority work queue files
 
 ifeq ($(CONFIG_SCHED_LPWORK),y)
+CSRCS += work_lpthread.c
 ifeq ($(CONFIG_PRIORITY_INHERITANCE),y)
-
 CSRCS += work_inherit.c
+endif # CONFIG_PRIORITY_INHERITANCE
+endif # CONFIG_SCHED_LPWORK
 
 # Include wqueue build support
 
 DEPPATH += --dep-path wqueue
 VPATH += :wqueue
 
-endif # CONFIG_PRIORITY_INHERITANCE
-endif # CONFIG_SCHED_LPWORK
 endif # CONFIG_SCHED_WORKQUEUE
diff --git a/nuttx/sched/wqueue/work_hpthread.c b/nuttx/sched/wqueue/work_hpthread.c
new file mode 100644
index 000000000..7df4ad5de
--- /dev/null
+++ b/nuttx/sched/wqueue/work_hpthread.c
@@ -0,0 +1,122 @@
+/****************************************************************************
+ * sched/wqueue/work_hothread.c
+ *
+ *   Copyright (C) 2009-2014 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 <nuttx/wqueue.h>
+#include <nuttx/kmalloc.h>
+
+#include "wqueue/wqueue.h"
+
+#if defined(CONFIG_SCHED_WORKQUEUE) && defined(CONFIG_SCHED_HPWORK)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Type Declarations
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: work_hpthread
+ *
+ * Description:
+ *   This is the worker thread that performs the actions placed on the high
+ *   priority work queue.
+ *
+ *   This, along with the lower priority worker thread(s) are the kernel
+ *   mode work queues (also build in the flat build).  One of these threads
+ *   also performs periodic garbage collection (that would otherwise be
+ *   performed by the idle thread if CONFIG_SCHED_WORKQUEUE is not defined).
+ *   That will be the higher priority worker thread only if a lower priority
+ *   worker thread is available.
+ *
+ *   All kernel mode worker threads are started by the OS during normal
+ *   bring up.  This entry point is referenced by OS internally and should
+ *   not be accessed by application logic.
+ *
+ * Input parameters:
+ *   argc, argv (not used)
+ *
+ * Returned Value:
+ *   Does not return
+ *
+ ****************************************************************************/
+
+int work_hpthread(int argc, char *argv[])
+{
+  /* Loop forever */
+
+  for (;;)
+    {
+      /* First, perform garbage collection.  This cleans-up memory de-allocations
+       * that were queued because they could not be freed in that execution
+       * context (for example, if the memory was freed from an interrupt handler).
+       * NOTE: If the work thread is disabled, this clean-up is performed by
+       * the IDLE thread (at a very, very low priority).
+       */
+
+#ifndef CONFIG_SCHED_LPWORK
+      sched_garbagecollection();
+#endif
+
+      /* Then process queued work.  We need to keep interrupts disabled while
+       * we process items in the work list.
+       */
+
+      work_process(&g_work[HPWORK]);
+    }
+
+  return OK; /* To keep some compilers happy */
+}
+
+#endif /* CONFIG_SCHED_WORKQUEUE && CONFIG_SCHED_HPWORK*/
diff --git a/nuttx/sched/wqueue/work_inherit.c b/nuttx/sched/wqueue/work_inherit.c
index 14c012ea5..7e6c1e6f4 100644
--- a/nuttx/sched/wqueue/work_inherit.c
+++ b/nuttx/sched/wqueue/work_inherit.c
@@ -1,7 +1,7 @@
 /****************************************************************************
- * sched/environ/env_putenv.c
+ * sched/work/work_inherit.c
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -44,6 +44,7 @@
 #include <nuttx/wqueue.h>
 
 #include "sched/sched.h"
+#include "wqueue/wqueue.h"
 
 #if defined(CONFIG_SCHED_WORKQUEUE) && defined(CONFIG_SCHED_LPWORK) && \
     defined(CONFIG_PRIORITY_INHERITANCE)
diff --git a/nuttx/sched/wqueue/work_lpthread.c b/nuttx/sched/wqueue/work_lpthread.c
new file mode 100644
index 000000000..70dcc7e7a
--- /dev/null
+++ b/nuttx/sched/wqueue/work_lpthread.c
@@ -0,0 +1,119 @@
+/****************************************************************************
+ * sched/wqueue/work_lpthread.c
+ *
+ *   Copyright (C) 2009-2014 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 <nuttx/wqueue.h>
+#include <nuttx/kmalloc.h>
+
+#include "wqueue/wqueue.h"
+
+#if defined(CONFIG_SCHED_WORKQUEUE) && defined(CONFIG_SCHED_LPWORK)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Type Declarations
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: work_lpthread
+ *
+ * Description:
+ *   These are the worker thread(s) that performs the actions placed on the
+ *   low priority work queue.
+ *
+ *   These, along with the higher priority worker thread are the kernel mode
+ *   work queues (also build in the flat build).  One of these threads also
+ *   performs periodic garbage collection (that would otherwise be performed
+ *   by the idle thread if CONFIG_SCHED_WORKQUEUE is not defined).  That will
+ *   be the lower priority worker thread if it is available.
+ *
+ *   All kernel mode worker threads are started by the OS during normal
+ *   bring up.  This entry point is referenced by OS internally and should
+ *   not be accessed by application logic.
+ *
+ * Input parameters:
+ *   argc, argv (not used)
+ *
+ * Returned Value:
+ *   Does not return
+ *
+ ****************************************************************************/
+
+int work_lpthread(int argc, char *argv[])
+{
+  /* Loop forever */
+
+  for (;;)
+    {
+      /* First, perform garbage collection.  This cleans-up memory de-allocations
+       * that were queued because they could not be freed in that execution
+       * context (for example, if the memory was freed from an interrupt handler).
+       * NOTE: If the work thread is disabled, this clean-up is performed by
+       * the IDLE thread (at a very, very low priority).
+       */
+
+      sched_garbagecollection();
+
+      /* Then process queued work.  We need to keep interrupts disabled while
+       * we process items in the work list.
+       */
+
+      work_process(&g_work[LPWORK]);
+    }
+
+  return OK; /* To keep some compilers happy */
+}
+
+#endif /* CONFIG_SCHED_WORKQUEUE && CONFIG_SCHED_LPWORK */
diff --git a/nuttx/sched/wqueue/wqueue.h b/nuttx/sched/wqueue/wqueue.h
new file mode 100644
index 000000000..acd03409c
--- /dev/null
+++ b/nuttx/sched/wqueue/wqueue.h
@@ -0,0 +1,123 @@
+/****************************************************************************
+ * sched/wqueue/wqueue.h
+ *
+ *   Copyright (C) 2014 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.
+ *
+ ****************************************************************************/
+
+#ifndef __SCHED_WQUEUE_WQUEUE_H
+#define __SCHED_WQUEUE_WQUEUE_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#ifdef CONFIG_SCHED_WORKQUEUE
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Type Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: work_hpthread
+ *
+ * Description:
+ *   This is the worker thread that performs the actions placed on the high
+ *   priority work queue.
+ *
+ *   This, along with the lower priority worker thread(s) are the kernel
+ *   mode work queues (also build in the flat build).  One of these threads
+ *   also performs periodic garbage collection (that would otherwise be
+ *   performed by the idle thread if CONFIG_SCHED_WORKQUEUE is not defined).
+ *   That will be the higher priority worker thread only if a lower priority
+ *   worker thread is available.
+ *
+ *   All kernel mode worker threads are started by the OS during normal
+ *   bring up.  This entry point is referenced by OS internally and should
+ *   not be accessed by application logic.
+ *
+ * Input parameters:
+ *   argc, argv (not used)
+ *
+ * Returned Value:
+ *   Does not return
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_SCHED_HPWORK
+int work_hpthread(int argc, char *argv[]);
+#endif
+
+/****************************************************************************
+ * Name: work_lpthread
+ *
+ * Description:
+ *   These are the worker thread(s) that performs the actions placed on the
+ *   low priority work queue.
+ *
+ *   These, along with the higher priority worker thread are the kernel mode
+ *   work queues (also build in the flat build).  One of these threads also
+ *   performs periodic garbage collection (that would otherwise be performed
+ *   by the idle thread if CONFIG_SCHED_WORKQUEUE is not defined).  That will
+ *   be the lower priority worker thread if it is available.
+ *
+ *   All kernel mode worker threads are started by the OS during normal
+ *   bring up.  This entry point is referenced by OS internally and should
+ *   not be accessed by application logic.
+ *
+ * Input parameters:
+ *   argc, argv (not used)
+ *
+ * Returned Value:
+ *   Does not return
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_SCHED_LPWORK
+int work_lpthread(int argc, char *argv[]);
+#endif
+
+#endif /* CONFIG_SCHED_WORKQUEUE */
+#endif /* __SCHED_WQUEUE_WQUEUE_H */