From 4417728955026eb9cf1bbdb6139e962496a370a9 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Wed, 13 May 2015 14:43:43 -0600
Subject: [PATCH] Re-implemened pthread_kill().  It as just a simple wrapper
 around kill() but since the correct dispatching of singles for multi-threaded
 task groups has been implemented, calling kill() does no work.  The corrected
 implementation of pthread_kill() will direct the signal specifically to the
 specific pthread and no other.

---
 TODO                         | 12 +------
 sched/pthread/pthread_kill.c | 64 +++++++++++++++++++++++++++++++-----
 sched/signal/sig_dispatch.c  |  1 -
 sched/signal/sig_kill.c      |  2 --
 4 files changed, 56 insertions(+), 23 deletions(-)

diff --git a/TODO b/TODO
index bf600e1f1b..4751de5883 100644
--- a/TODO
+++ b/TODO
@@ -11,7 +11,7 @@ nuttx/
 
  (11)  Task/Scheduler (sched/)
   (1)  Memory Management (mm/)
-  (4)  Signals (sched/signal, arch/)
+  (3)  Signals (sched/signal, arch/)
   (2)  pthreads (sched/pthread)
   (0)  Message Queues (sched/mqueue)
   (4)  C++ Support
@@ -307,16 +307,6 @@ o Signals (sched/signal, arch/)
   Status:      Open
   Priority:    Low. Even if there are only 31 usable signals, that is still a lot.
 
-  Title:       PTHREAD_KILL
-  Description: Currently pthread_kill() is a simple wrapper around kill().  This is
-               not correct.  kill() will deliver signals to a task group with
-               incompatible rules.
-
-              "The pthread_kill() function shall request that a signal be delivered
-               to the specified thread." Reference http://pubs.opengroup.org/onlinepubs/009695399/functions/pthread_kill.html
-  Status:      Open
-  Priority:    Medium-Low unless you need this functionality.
-
 o pthreads (sched/pthreads)
   ^^^^^^^^^^^^^^^^^
 
diff --git a/sched/pthread/pthread_kill.c b/sched/pthread/pthread_kill.c
index 1759f75c8d..cf5d068459 100644
--- a/sched/pthread/pthread_kill.c
+++ b/sched/pthread/pthread_kill.c
@@ -1,7 +1,7 @@
 /************************************************************************
  * sched/pthread/pthread_kill.c
  *
- *   Copyright (C) 2007, 2009, 2011 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2009, 2011, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -45,8 +45,10 @@
 #include <errno.h>
 #include <debug.h>
 
+#include "signal/signal.h"
+
 /************************************************************************
- * Global Functions
+ * Public Functions
  ************************************************************************/
 
 /************************************************************************
@@ -80,16 +82,60 @@
 
 int pthread_kill(pthread_t thread, int signo)
 {
+#ifdef CONFIG_SCHED_HAVE_PARENT
+  FAR struct tcb_s *rtcb = (FAR struct tcb_s *)g_readytorun.head;
+#endif
+  FAR struct tcb_s *stcb;
+  siginfo_t info;
   int ret;
 
-  set_errno(EINVAL);
-  ret = kill((pid_t)thread, signo);
-  if (ret != OK)
+  /* Make sure that the signal is valid */
+
+  if (!GOOD_SIGNO(signo))
     {
-       ret = get_errno();
+      ret = -EINVAL;
+      goto errout;
     }
 
-  return ret;
+  /* Keep things stationary through the following */
+
+  sched_lock();
+
+  /* Create the siginfo structure */
+
+  info.si_signo           = signo;
+  info.si_code            = SI_USER;
+  info.si_value.sival_ptr = NULL;
+#ifdef CONFIG_SCHED_HAVE_PARENT
+  info.si_pid             = rtcb->pid;
+  info.si_status          = OK;
+#endif
+
+  /* Get the TCB associated with the thread */
+
+  stcb = sched_gettcb((pid_t)thread);
+  if (!stcb)
+    {
+      ret = -ESRCH;
+      goto errout_with_lock;
+    }
+
+  /* Dispatch the signal to thread, bypassing normal task group thread
+   * dispatch rules.
+   */
+
+  ret = sig_tcbdispatch(stcb, &info);
+  sched_unlock();
+
+  if (ret < 0)
+    {
+      goto errout;
+    }
+
+  return OK;
+
+errout_with_lock:
+  sched_unlock();
+errout:
+  return -ret;
 }
-
-
diff --git a/sched/signal/sig_dispatch.c b/sched/signal/sig_dispatch.c
index 954b4d2cd2..1985fc7f27 100644
--- a/sched/signal/sig_dispatch.c
+++ b/sched/signal/sig_dispatch.c
@@ -501,4 +501,3 @@ int sig_dispatch(pid_t pid, FAR siginfo_t *info)
 
 #endif
 }
-
diff --git a/sched/signal/sig_kill.c b/sched/signal/sig_kill.c
index 3a65535e74..956029a693 100644
--- a/sched/signal/sig_kill.c
+++ b/sched/signal/sig_kill.c
@@ -136,5 +136,3 @@ errout:
   set_errno(-ret);
   return ERROR;
 }
-
-