Add a start hook that can be setup to call a function in the context of a new thread before the new threads main() has been called.

git-svn-id: http://svn.code.sf.net/p/nuttx/code/trunk@5571 42af7a65-404d-4744-a932-0658087f49c3

nuttx/sched/Kconfig

@@ -296,6 +296,16 @@ config SCHED_WAITPID
 		compliant) and will enable the waitid() and wait() interfaces as
 		well.
 
+config SCHED_STARTHOOK
+	bool "Enable startup hook"
+	default n
+	---help---
+		Enable a non-standard, internal OS API call task_starthook().
+		task_starthook() registers a function that will be called on task
+		startup before that actual task entry point is called.  The
+		starthook is useful, for example, for setting up automatic
+		configuration of C++ constructors.
+
 config SCHED_ATEXIT
 	bool "Enable atexit() API"
 	default n

nuttx/sched/Makefile

@@ -54,6 +54,10 @@ TSK_SRCS += task_posixspawn.c
 endif
 endif
 
+ifeq ($(CONFIG_SCHED_STARTHOOK),y)
+TSK_SRCS += task_starthook.c
+endif
+
 SCHED_SRCS = sched_setparam.c sched_setpriority.c sched_getparam.c
 SCHED_SRCS += sched_setscheduler.c sched_getscheduler.c
 SCHED_SRCS += sched_yield.c sched_rrgetinterval.c sched_foreach.c

nuttx/sched/group_setupidlefiles.c

@@ -50,6 +50,7 @@
 #include <nuttx/net/net.h>
 
 #include "os_internal.h"
+#include "group_internal.h"
 
 #if CONFIG_NFILE_DESCRIPTORS > 0 || CONFIG_NSOCKET_DESCRIPTORS > 0
 

nuttx/sched/group_setupstreams.c

@@ -46,6 +46,8 @@
 #include <nuttx/net/net.h>
 #include <nuttx/lib.h>
 
+#include "group_internal.h"
+
 /* Make sure that there are file or socket descriptors in the system and
  * that some number of streams have been configured.
  */

nuttx/sched/group_setuptaskfiles.c

@@ -46,6 +46,7 @@
 #include <nuttx/net/net.h>
 
 #include "os_internal.h"
+#include "group_internal.h"
 
 #if CONFIG_NFILE_DESCRIPTORS > 0 || CONFIG_NSOCKET_DESCRIPTORS > 0
 
@@ -159,8 +160,8 @@ static inline void sched_dupsockets(FAR _TCB *tcb)
 
   /* Get pointers to the parent and child task socket lists */
 
-  parent = rtcb->group->tg_sockets->sl_sockets;
-  child  = tcb->group->tg_sockets->sl_sockets;
+  parent = rtcb->group->tg_socketlist.sl_sockets;
+  child  = tcb->group->tg_socketlist.sl_sockets;
 
   /* Check each socket in the parent socket list */
 

nuttx/sched/task_start.c

@@ -94,6 +94,15 @@ void task_start(void)
   FAR _TCB *tcb = (FAR _TCB*)g_readytorun.head;
   int argc;
 
+  /* Execute the start hook if one has been registered */
+
+#ifdef CONFIG_SCHED_STARTHOOK
+  if (tcb->starthook)
+    {
+      tcb->starthook(tcb->starthookarg);
+    }
+#endif
+
   /* Count how many non-null arguments we are passing */
 
   for (argc = 1; argc <= CONFIG_MAX_TASK_ARGS; argc++)

nuttx/sched/task_starthook.c

@@ -0,0 +1,100 @@
+/****************************************************************************
+ * sched/task_start.c
+ *
+ *   Copyright (C) 2007-2010 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/sched.h>
+
+#ifdef CONFIG_SCHED_STARTHOOK
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Type Declarations
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: task_starthook
+ *
+ * Description:
+ *   Configure a start hook... a function that will be called on the thread
+ *   of the new task before the new task's main entry point is called.
+ *   The start hook is useful, for example, for setting up automatic
+ *   configuration of C++ constructors.
+ *
+ * Inputs:
+ *   tcb - The new, unstarted task task that needs the start hook
+ *   starthook - The pointer to the start hook function
+ *   arg - The argument to pass to the start hook function.
+ *
+ * Return:
+ *   None
+ *
+ ****************************************************************************/
+
+void task_starthook(FAR _TCB *tcb, starthook_t starthook, FAR void *arg)
+{
+  DEBUGASSERT(tcb);
+  tcb->starthook    = starthook;
+  tcb->starthookarg = arg;
+}
+
+#endif /* CONFIG_SCHED_STARTHOOK */