Add logic to send SIGCHLD to all members of a task group

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5564 42af7a65-404d-4744-a932-0658087f49c3

ChangeLog

@@ -4025,3 +4025,8 @@
 	  poll_interrupt() must cat call net_lostconnection() when a
 	  loss of connection is reported.  Otherwise, the system will
 	  not know that the connection has been lost.
+	* sched/group_create.c, group_join.c, and group_leave.c:  Add
+	  support for task groups.
+	* sched/group_signal.c and task_exithook.c:  Send signal to all
+	  members for the parent task group.
+

include/nuttx/sched.h

@@ -70,7 +70,7 @@
 
 /* In any event, we don't need group members if support for pthreads is disabled */
 
-#ifdef CONFIG_PTHREADS_DISABLE
+#ifdef CONFIG_DISABLE_PTHREAD
 #  undef HAVE_GROUP_MEMBERS
 #endif
 

sched/Makefile

@@ -87,7 +87,11 @@ SCHED_SRCS += sched_waitid.c sched_wait.c
 endif
 endif
 
-GRP_SRCS = group_create.c group_join.c group_leave.c
+GRP_SRCS  = group_create.c group_join.c group_leave.c
+
+ifneq ($(CONFIG_DISABLE_SIGNALS),y)
+GRP_SRCS += group_signal.c
+endif
 
 ENV_SRCS  = env_getenvironptr.c env_dup.c env_share.c env_release.c
 ENV_SRCS += env_findvar.c env_removevar.c

sched/group_signal.c

@@ -0,0 +1,135 @@
+/*****************************************************************************
+ * sched/group_signal.c
+ *
+ *   Copyright (C) 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 <sched.h>
+#include <assert.h>
+#include <signal.h>
+#include <debug.h>
+
+#include "sig_internal.h"
+
+#if defined(HAVE_TASK_GROUP) && !defined(CONFIG_DISABLE_SIGNALS)
+
+/*****************************************************************************
+ * Pre-processor Definitions
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Private Types
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Private Data
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Private Functions
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Public Functions
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Name: group_signal
+ *
+ * Description:
+ *   Send a signal to every member of the group to which task belongs.
+ *
+ * Parameters:
+ *   tcb - The tcb of one task in the task group that needs to be signalled.
+ *
+ * Return Value:
+ *   0 (OK) on success; a negated errno value on failure.
+ *
+ * Assumptions:
+ *   Called during task terminatino in a safe context.  No special precautions
+ *   are required here.
+ *
+ *****************************************************************************/
+
+int group_signal(FAR _TCB *tcb, FAR siginfo_t *info)
+{
+#ifdef HAVE_GROUP_MEMBERS
+  FAR struct task_group_s *group;
+  FAR _TCB *gtcb;
+  int i;
+
+  DEBUGASSERT(tcb && tcb->group && info);
+  group = tcb->group;
+
+  /* Make sure that pre-emption is disabled to that we signal all of teh
+   * members of the group before any of them actually run.
+   */
+
+  sched_lock();
+
+  /* Send the signal to each member of the group */
+
+  for (i = 0; i < group->tg_nmembers; i++)
+    {
+      gtcb = sched_gettcb(group->tg_members[i]);
+      DEBUGASSERT(gtcb);
+      if (gtcb)
+        {
+          /* Use the sig_received interface so that it does not muck with
+           * the siginfo_t.
+           */
+
+#ifdef CONFIG_DEBUG
+          int ret = sig_received(gtcb, info);
+          DEBUGASSERT(ret == 0);
+#else
+          (void)sig_received(gtcb, info);
+#endif
+        }
+    }
+  
+  /* Re-enable pre-emption an return success */
+
+  sched_unlock();
+  return OK;
+#else
+  return sig_received(tcb, info);
+#endif
+}
+
+#endif /* HAVE_TASK_GROUP && !CONFIG_DISABLE_SIGNALS */

sched/os_internal.h

@@ -275,13 +275,21 @@ int  task_reparent(pid_t ppid, pid_t chpid);
 #ifdef HAVE_TASK_GROUP
 int group_allocate(FAR _TCB *tcb);
 int group_initialize(FAR _TCB *tcb);
+int group_bind(FAR _TCB *tcb);
 int group_join(FAR _TCB *tcb);
 void group_leave(FAR _TCB *tcb);
+#ifndef CONFIG_DISABLE_SIGNALS
+int group_signal(FAR _TCB *tcb, FAR siginfo_t *info);
 #else
-# define group_allocate(tcb)   (0)
+# define group_signal(tcb,info) (0)
-# define group_initialize(tcb) (0)
+#endif
-# define group_join(tcb)       (0)
+#else
+# define group_allocate(tcb)    (0)
+# define group_initialize(tcb)  (0)
+# define group_bind(tcb)        (0)
+# define group_join(tcb)        (0)
 # define group_leave(tcb)
+# define group_signal(tcb,info) (0)
 #endif
 
 #ifdef CONFIG_SCHED_CHILD_STATUS

sched/task_exithook.c

@@ -259,7 +259,11 @@ static inline void task_sigchild(FAR _TCB *ptcb, FAR _TCB *ctcb, int status)
        * can provide the correct si_code value with the signal.
        */
 
+#ifdef HAVE_GROUP_MEMBERS
+      (void)group_signal(ptcb, &info);
+#else
       (void)sig_received(ptcb, &info);
+#endif
     }
 }
 #else