sched/wqueue: replace the notification mech from signal to semaphore

Change-Id: I57596eb661083e914c8718b7c3c1b7190bfa2863
Signed-off-by: chao.an <anchao@xiaomi.com>

Documentation/reference/os/wqueue.rst

@@ -71,10 +71,6 @@ to match the highest priority client.
 **Common Configuration Options**. These options apply to all work
 queues:
 
--  ``CONFIG_SIG_SIGWORK`` The signal number that will be used to
-   wake-up the worker thread. This same signal is used with the
-   Default: 17
-
 Low Priority Kernel Work Queue
 ------------------------------
 

include/nuttx/wqueue.h

@@ -56,8 +56,6 @@
  *   priority worker thread.  Default: 224
  * CONFIG_SCHED_HPWORKSTACKSIZE - The stack size allocated for the worker
  *   thread.  Default: 2048.
- * CONFIG_SIG_SIGWORK - The signal number that will be used to wake-up
- *   the worker thread.  Default: 17
  *
  * CONFIG_SCHED_LPWORK. If CONFIG_SCHED_LPWORK is selected then a lower-
  *   priority work queue will be created.  This lower priority work queue

include/signal.h

@@ -224,16 +224,6 @@
 #  endif
 #endif
 
-/* SIGWORK is used to wake up various internal, NuttX worker thread */
-
-#if defined(CONFIG_SCHED_WORKQUEUE) || defined(CONFIG_PAGING)
-#  ifndef CONFIG_SIG_SIGWORK
-#    define SIGWORK     17  /* Used to wake up the work queue */
-#  else
-#    define SIGWORK     CONFIG_SIG_SIGWORK
-#  endif
-#endif
-
 /* sigprocmask() "how" definitions. Only one of the following can be specified: */
 
 #define SIG_BLOCK       1  /* Block the given signals */

sched/Kconfig

@@ -1556,15 +1556,6 @@ config SIG_SIGCONDTIMEDOUT
 		This non-standard signal number is used the implementation of
 		pthread_cond_timedwait(). Default 16.
 
-config SIG_SIGWORK
-	int "SIGWORK"
-	default 17
-	depends on SCHED_WORKQUEUE || LIB_USRWORK
-	---help---
-		SIGWORK is a non-standard signal used to wake up the internal NuttX
-		worker thread.  This setting specifies the signal number that will be
-		used for SIGWORK.  Default: 17
-
 endmenu # Signal Numbers
 endmenu # Signal Configuration
 

sched/wqueue/Make.defs

@@ -23,21 +23,11 @@
 ifeq ($(CONFIG_SCHED_WORKQUEUE),y)
 
 CSRCS += kwork_queue.c kwork_process.c kwork_cancel.c kwork_signal.c
+CSRCS += kwork_thread.c
 
-# Add high priority work queue files
-
-ifeq ($(CONFIG_SCHED_HPWORK),y)
-CSRCS += kwork_hpthread.c
-endif
-
-# Add low priority work queue files
-
-ifeq ($(CONFIG_SCHED_LPWORK),y)
-CSRCS += kwork_lpthread.c
 ifeq ($(CONFIG_PRIORITY_INHERITANCE),y)
 CSRCS += kwork_inherit.c
 endif # CONFIG_PRIORITY_INHERITANCE
-endif # CONFIG_SCHED_LPWORK
 
 # Add work queue notifier support
 

sched/wqueue/kwork_notifier.c

@@ -33,7 +33,6 @@
 #include <assert.h>
 
 #include <nuttx/kmalloc.h>
-#include <nuttx/semaphore.h>
 #include <nuttx/wqueue.h>
 
 #include "wqueue/wqueue.h"

sched/wqueue/kwork_process.c

@@ -98,14 +98,16 @@
  *   be called from application level logic.
  *
  * Input Parameters:
- *   wqueue - Describes the work queue to be processed
+ *   wqueue  - Describes the work queue to be processed
+ *   kworker - Describes a worker thread
  *
  * Returned Value:
  *   None
  *
  ****************************************************************************/
 
-void work_process(FAR struct kwork_wqueue_s *wqueue, int wndx)
+void work_process(FAR struct kwork_wqueue_s *wqueue,
+                  FAR struct kworker_s *kworker)
 {
   volatile FAR struct work_s *work;
   worker_t  worker;
@@ -229,16 +231,9 @@ void work_process(FAR struct kwork_wqueue_s *wqueue, int wndx)
 
   if (next == WORK_DELAY_MAX)
     {
-      sigset_t set;
-
-      /* Wait indefinitely until signalled with SIGWORK */
-
-      sigemptyset(&set);
-      nxsig_addset(&set, SIGWORK);
-
-      wqueue->worker[wndx].busy = false;
-      DEBUGVERIFY(nxsig_waitinfo(&set, NULL));
-      wqueue->worker[wndx].busy = true;
+      kworker->busy = false;
+      nxsem_wait_uninterruptible(&kworker->sem);
+      kworker->busy = true;
     }
   else
     {
@@ -247,9 +242,11 @@ void work_process(FAR struct kwork_wqueue_s *wqueue, int wndx)
        * Interrupts will be re-enabled while we wait.
        */
 
-      wqueue->worker[wndx].busy = false;
-      nxsig_usleep(next * USEC_PER_TICK);
-      wqueue->worker[wndx].busy = true;
+      kworker->busy = false;
+      nxsem_tickwait_uninterruptible(&kworker->sem,
+                                     clock_systime_ticks(),
+                                     next * USEC_PER_TICK);
+      kworker->busy = true;
     }
 
   leave_critical_section(flags);

sched/wqueue/kwork_signal.c

@@ -57,6 +57,7 @@
 int work_signal(int qid)
 {
   FAR struct kwork_wqueue_s *work;
+  int semcount;
   int threads;
   int i;
 
@@ -105,7 +106,13 @@ int work_signal(int qid)
 
   /* Otherwise, signal the first IDLE thread found */
 
-  return nxsig_kill(work->worker[i].pid, SIGWORK);
+  nxsem_get_value(&work->worker[i].sem, &semcount);
+  if (semcount < 1)
+    {
+      nxsem_post(&work->worker[i].sem);
+    }
+
+  return OK;
 }
 
 #endif /* CONFIG_SCHED_WORKQUEUE */

sched/wqueue/kwork_thread.c

@@ -1,5 +1,5 @@
 /****************************************************************************
- * sched/wqueue/kwork_hpthread.c
+ * sched/wqueue/kwork_thread.c
  *
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
@@ -26,34 +26,42 @@
 
 #include <unistd.h>
 #include <sched.h>
+#include <stdio.h>
 #include <string.h>
+#include <stdlib.h>
 #include <errno.h>
 #include <queue.h>
 #include <debug.h>
 
 #include <nuttx/wqueue.h>
 #include <nuttx/kthread.h>
-#include <nuttx/kmalloc.h>
-#include <nuttx/clock.h>
 
 #include "wqueue/wqueue.h"
 
-#ifdef CONFIG_SCHED_HPWORK
+#if defined(CONFIG_SCHED_WORKQUEUE)
 
 /****************************************************************************
  * Public Data
  ****************************************************************************/
 
+#if defined(CONFIG_SCHED_HPWORK)
 /* The state of the kernel mode, high priority work queue(s). */
 
 struct hp_wqueue_s g_hpwork;
+#endif /* CONFIG_SCHED_HPWORK */
+
+#if defined(CONFIG_SCHED_LPWORK)
+/* The state of the kernel mode, low priority work queue(s). */
+
+struct lp_wqueue_s g_lpwork;
+#endif /* CONFIG_SCHED_LPWORK */
 
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
 
 /****************************************************************************
- * Name: work_hpthread
+ * Name: work_thread
  *
  * Description:
  *   These are the worker threads that performs the actions placed on the
@@ -74,26 +82,14 @@ struct hp_wqueue_s g_hpwork;
  *
  ****************************************************************************/
 
-static int work_hpthread(int argc, char *argv[])
+static int work_thread(int argc, char *argv[])
 {
-  int wndx = 0;
-#if CONFIG_SCHED_HPNTHREADS > 1
-  pid_t me = getpid();
-  int i;
+  FAR struct kwork_wqueue_s *queue;
+  FAR struct kworker_s      *worker;
 
-  /* Find out thread index by search the workers in g_hpwork */
-
-  for (wndx = 0, i = 0; i < CONFIG_SCHED_HPNTHREADS; i++)
-    {
-      if (g_hpwork.worker[i].pid == me)
-        {
-          wndx = i;
-          break;
-        }
-    }
-
-  DEBUGASSERT(i < CONFIG_SCHED_HPNTHREADS);
-#endif
+  queue  = (FAR struct kwork_wqueue_s *)
+           ((uintptr_t)strtoul(argv[1], NULL, 0));
+  worker = (FAR struct kworker_s *)((uintptr_t)strtoul(argv[2], NULL, 0));
 
   /* Loop forever */
 
@@ -104,12 +100,73 @@ static int work_hpthread(int argc, char *argv[])
        * triggered, or delayed work expires.
        */
 
-      work_process((FAR struct kwork_wqueue_s *)&g_hpwork, wndx);
+      work_process(queue, worker);
     }
 
   return OK; /* To keep some compilers happy */
 }
 
+/****************************************************************************
+ * Name: work_thread_create
+ *
+ * Description:
+ *   This function creates and activates a work thread task with kernel-
+ *   mode privileges.
+ *
+ * Input Parameters:
+ *   name       - Name of the new task
+ *   priority   - Priority of the new task
+ *   stack_size - size (in bytes) of the stack needed
+ *   nthread    - Number of work thread should be created
+ *   wqueue     - Work queue instance
+ *
+ * Returned Value:
+ *   A negated errno value is returned on failure.
+ *
+ ****************************************************************************/
+
+static int work_thread_create(FAR const char *name, int priority,
+                              int stack_size, int nthread,
+                              FAR struct kwork_wqueue_s *wqueue)
+{
+  FAR char *argv[3];
+  char args[2][16];
+  int wndx;
+  int pid;
+
+  snprintf(args[0], 16, "0x%" PRIxPTR, (uintptr_t)wqueue);
+  argv[0] = args[0];
+  argv[2] = NULL;
+
+  for (wndx = 0; wndx < nthread; wndx++)
+    {
+      nxsem_init(&wqueue->worker[wndx].sem, 0, 0);
+      nxsem_set_protocol(&wqueue->worker[wndx].sem, SEM_PRIO_NONE);
+
+      wqueue->worker[wndx].busy = true;
+
+      snprintf(args[1], 16, "0x%" PRIxPTR, (uintptr_t)&wqueue->worker[wndx]);
+      argv[1] = args[1];
+
+      pid = kthread_create(name, priority, stack_size,
+                           (main_t)work_thread, argv);
+
+      DEBUGASSERT(pid > 0);
+      if (pid < 0)
+        {
+          serr("ERROR: work_thread_create %d failed: %d\n", wndx, pid);
+          sched_unlock();
+          return pid;
+        }
+
+#ifdef CONFIG_PRIORITY_INHERITANCE
+      wqueue->worker[wndx].pid  = pid;
+#endif
+    }
+
+  return OK;
+}
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -124,47 +181,50 @@ static int work_hpthread(int argc, char *argv[])
  *   None
  *
  * Returned Value:
- *   The task ID of the worker thread is returned on success.  A negated
- *   errno value is returned on failure.
+ *   A negated errno value is returned on failure.
  *
  ****************************************************************************/
 
+#if defined(CONFIG_SCHED_HPWORK)
 int work_start_highpri(void)
 {
-  pid_t pid;
-  int wndx;
-
-  /* Don't permit any of the threads to run until we have fully initialized
-   * g_hpwork.
-   */
-
-  sched_lock();
-
   /* Start the high-priority, kernel mode worker thread(s) */
 
   sinfo("Starting high-priority kernel worker thread(s)\n");
 
-  for (wndx = 0; wndx < CONFIG_SCHED_HPNTHREADS; wndx++)
-    {
-      pid = kthread_create(HPWORKNAME, CONFIG_SCHED_HPWORKPRIORITY,
-                           CONFIG_SCHED_HPWORKSTACKSIZE,
-                           (main_t)work_hpthread,
-                           (FAR char * const *)NULL);
-
-      DEBUGASSERT(pid > 0);
-      if (pid < 0)
-        {
-          serr("ERROR: kthread_create %d failed: %d\n", wndx, (int)pid);
-          sched_unlock();
-          return (int)pid;
-        }
-
-      g_hpwork.worker[wndx].pid  = pid;
-      g_hpwork.worker[wndx].busy = true;
-    }
-
-  sched_unlock();
-  return g_hpwork.worker[0].pid;
+  return work_thread_create(HPWORKNAME, CONFIG_SCHED_HPWORKPRIORITY,
+                            CONFIG_SCHED_HPWORKSTACKSIZE,
+                            CONFIG_SCHED_HPNTHREADS,
+                            (FAR struct kwork_wqueue_s *)&g_hpwork);
 }
-
 #endif /* CONFIG_SCHED_HPWORK */
+
+/****************************************************************************
+ * Name: work_start_lowpri
+ *
+ * Description:
+ *   Start the low-priority, kernel-mode worker thread(s)
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   A negated errno value is returned on failure.
+ *
+ ****************************************************************************/
+
+#if defined(CONFIG_SCHED_LPWORK)
+int work_start_lowpri(void)
+{
+  /* Start the low-priority, kernel mode worker thread(s) */
+
+  sinfo("Starting low-priority kernel worker thread(s)\n");
+
+  return work_thread_create(LPWORKNAME, CONFIG_SCHED_LPWORKPRIORITY,
+                            CONFIG_SCHED_LPWORKSTACKSIZE,
+                            CONFIG_SCHED_LPNTHREADS,
+                            (FAR struct kwork_wqueue_s *)&g_lpwork);
+}
+#endif /* CONFIG_SCHED_LPWORK */
+
+#endif /* CONFIG_SCHED_WORKQUEUE */

sched/wqueue/wqueue.h

@@ -31,6 +31,7 @@
 #include <queue.h>
 
 #include <nuttx/clock.h>
+#include <nuttx/semaphore.h>
 
 #ifdef CONFIG_SCHED_WORKQUEUE
 
@@ -51,7 +52,10 @@
 
 struct kworker_s
 {
+#ifdef CONFIG_PRIORITY_INHERITANCE
   pid_t             pid;    /* The task ID of the worker thread */
+#endif
+  sem_t             sem;    /* The counting semaphore of the worker thread */
   volatile bool     busy;   /* True: Worker is not available */
 };
 
@@ -161,15 +165,16 @@ int work_start_lowpri(void);
  *   be called from application level logic.
  *
  * Input Parameters:
- *   wqueue - Describes the work queue to be processed
- *   wndx   - The worker thread index
+ *   wqueue  - Describes the work queue to be processed
+ *   kworker - Describes a worker thread
  *
  * Returned Value:
  *   None
  *
  ****************************************************************************/
 
-void work_process(FAR struct kwork_wqueue_s *wqueue, int wndx);
+void work_process(FAR struct kwork_wqueue_s *wqueue,
+                  FAR struct kworker_s *kworker);
 
 /****************************************************************************
  * Name: work_initialize_notifier