Move work queue logic from sched/ to libc/wqueue. It is not core logic and will be extended to support user-space work queues

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5711 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 254 insertions, 0 deletions

diff --git a/nuttx/libc/wqueue/work_thread.c b/nuttx/libc/wqueue/work_thread.c
new file mode 100644
index 000000000..32dff9c8c
--- /dev/null
+++ b/nuttx/libc/wqueue/work_thread.c
@@ -0,0 +1,254 @@
+/****************************************************************************
+ * libc/wqueue/work_thread.c
+ *
+ *   Copyright (C) 2009-2013 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 <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>
+
+#ifdef CONFIG_SCHED_WORKQUEUE
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Type Declarations
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Variables
+ ****************************************************************************/
+
+/* The state of each work queue */
+
+struct wqueue_s g_work[NWORKERS];
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: work_process
+ *
+ * Description:
+ *   This is the logic that performs actions placed on any work list.
+ *
+ * Input parameters:
+ *   wqueue - Describes the work queue to be processed
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+static void work_process(FAR struct wqueue_s *wqueue)
+{
+  volatile FAR struct work_s *work;
+  worker_t  worker;
+  irqstate_t flags;
+  FAR void *arg;
+  uint32_t elapsed;
+  uint32_t remaining;
+  uint32_t next;
+
+  /* Then process queued work.  We need to keep interrupts disabled while
+   * we process items in the work list.
+   */
+
+  next  = CONFIG_SCHED_WORKPERIOD / USEC_PER_TICK;
+  flags = irqsave();
+  work  = (FAR struct work_s *)wqueue->q.head;
+  while (work)
+    {
+      /* Is this work ready?  It is ready if there is no delay or if
+       * the delay has elapsed. qtime is the time that the work was added
+       * to the work queue.  It will always be greater than or equal to
+       * zero.  Therefore a delay of zero will always execute immediately.
+       */
+
+      elapsed = clock_systimer() - work->qtime;
+      if (elapsed >= work->delay)
+        {
+          /* Remove the ready-to-execute work from the list */
+
+          (void)dq_rem((struct dq_entry_s *)work, &wqueue->q);
+
+          /* Extract the work description from the entry (in case the work
+           * instance by the re-used after it has been de-queued).
+           */
+
+          worker = work->worker;
+          arg    = work->arg;
+
+          /* Mark the work as no longer being queued */
+
+          work->worker = NULL;
+
+          /* Do the work.  Re-enable interrupts while the work is being
+           * performed... we don't have any idea how long that will take!
+           */
+
+          irqrestore(flags);
+          worker(arg);
+
+          /* Now, unfortunately, since we re-enabled interrupts we don't
+           * know the state of the work list and we will have to start
+           * back at the head of the list.
+           */
+
+          flags = irqsave();
+          work  = (FAR struct work_s *)wqueue->q.head;
+        }
+      else
+        {
+          /* This one is not ready.. will it be ready before the next
+           * scheduled wakeup interval?
+           */
+
+          remaining = elapsed - work->delay;
+          if (remaining < next)
+            {
+              /* Yes.. Then schedule to wake up when the work is ready */
+
+              next = remaining;
+            }
+              
+          /* Then try the next in the list. */
+
+          work = (FAR struct work_s *)work->dq.flink;
+        }
+    }
+
+  /* Wait awhile to check the work list.  We will wait here until either
+   * the time elapses or until we are awakened by a signal.
+   */
+
+  usleep(next * USEC_PER_TICK);
+  irqrestore(flags);
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+/****************************************************************************
+ * Name: work_hpthread and work_lpthread
+ *
+ * Description:
+ *   These are the main worker threads that performs actions placed on the
+ *   work lists.  One thread also performs periodic garbage collection (that
+ *   is performed by the idle thread if CONFIG_SCHED_WORKQUEUE is not defined).
+ *
+ * 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 */
+}
+
+#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_WORKQUEUE */