signals: Adds a very limited, minimal implementation for SIGEV_THREAD

include/nuttx/signal.h

@@ -45,7 +45,7 @@
 #include <sys/types.h>
 #include <signal.h>
 
-#if defined(CONFIG_SIG_EVTHREAD) && defined(__KERNEL__)
+#if defined(CONFIG_SIG_EVTHREAD) && defined(CONFIG_BUILD_FLAT)
 
 /****************************************************************************
  * Public Function Prototypes
@@ -72,5 +72,5 @@
 
 int sig_notification(pid_t pid, FAR struct sigevent *event);
 
-#endif /* CONFIG_SIG_EVTHREAD && __KERNEL__ */
+#endif /* CONFIG_SIG_EVTHREAD && CONFIG_BUILD_FLAT */
 #endif /* __INCLUDE_NUTTX_SIGNAL_H */

include/pthread.h

@@ -432,6 +432,10 @@ int pthread_sigmask(int how, FAR const sigset_t *set, FAR sigset_t *oset);
 }
 #endif
 
+/********************************************************************************
+ * Minimal Type Definitions
+ ********************************************************************************/
+
 #else /* __INCLUDE_PTHREAD_H */
 
 #include <sys/types.h>

include/signal.h

@@ -210,6 +210,12 @@ union sigval
  * available on a queue
  */
 
+#ifdef CONFIG_CAN_PASS_STRUCTS
+typedef CODE void (*sigev_notify_function_t)(union sigval value);
+#else
+typedef CODE void (*sigev_notify_function_t)(FAR void *sival_ptr);
+#endif
+
 struct sigevent
 {
   uint8_t      sigev_notify; /* Notification method: SIGEV_SIGNAL, SIGEV_NONE, or SIGEV_THREAD */
@@ -217,8 +223,8 @@ struct sigevent
   union sigval sigev_value;  /* Data passed with notification */
 
 #ifdef CONFIG_SIG_EVTHREAD
-  CODE void         (*sigev_notify_function)(union sigval); /* Notification function */
+  sigev_notify_function_t sigev_notify_function; /* Notification function */
-  FAR pthread_attr_t *sigev_notify_attributes;              /* Notification attributes (not used) */
+  FAR pthread_attr_t *sigev_notify_attributes;   /* Notification attributes (not used) */
 #endif
 };
 
@@ -264,10 +270,6 @@ struct sigaction
 #define sa_handler   sa_u._sa_handler
 #define sa_sigaction sa_u._sa_sigaction
 
-/********************************************************************************
- * Public Data
- ********************************************************************************/
-
 /********************************************************************************
  * Public Function Prototypes
  ********************************************************************************/
@@ -310,6 +312,10 @@ int sigqueue(int pid, int signo, FAR void *sival_ptr);
 }
 #endif
 
+/********************************************************************************
+ * Minimal Type Definitions
+ ********************************************************************************/
+
 #else /* __INCLUDE_SIGNAL_H */
 
 #include <stdint.h>

libc/aio/lio_listio.c

@@ -45,16 +45,13 @@
 #include <assert.h>
 #include <errno.h>
 
+#include <nuttx/signal.h>
+
 #include "libc.h"
 #include "aio/aio.h"
 
 #ifdef CONFIG_FS_AIO
 
-/****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
-/* Configuration ************************************************************/
-
 /****************************************************************************
  * Private Types
  ****************************************************************************/
@@ -69,14 +66,6 @@ struct lio_sighand_s
   struct sigaction oact;           /* Signal handler to restore */
 };
 
-/****************************************************************************
- * Private Variables
- ****************************************************************************/
-
-/****************************************************************************
- * Public Data
- ****************************************************************************/
-
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
@@ -205,11 +194,11 @@ static void lio_sighandler(int signo, siginfo_t *info, void *ucontext)
       if (sighand->sig->sigev_notify == SIGEV_SIGNAL)
         {
 #ifdef CONFIG_CAN_PASS_STRUCTS
-          (void)sigqueue(sighand->pid, sighand->sig->sigev_signo,
+          DEBUGASSERT(sigqueue(sighand->pid, sighand->sig->sigev_signo,
-                         sighand->sig->sigev_value);
+                               sighand->sig->sigev_value));
 #else
-          (void)sigqueue(sighand->pid, sighand->sig->sigev_signo,
+          DEBUGASSERT(sigqueue(sighand->pid, sighand->sig->sigev_signo,
-                         sighand->sig->sigev_value.sival_ptr);
+                               sighand->sig->sigev_value.sival_ptr));
 #endif
         }
 
@@ -218,7 +207,7 @@ static void lio_sighandler(int signo, siginfo_t *info, void *ucontext)
 
       else if (ighand->sig->sigev_notify == SIGEV_THREAD)
         {
-#warning Missing SIGEV_THREAD logic
+          DEBUGASSERT(sig_notification(sighand->pid, &sighand->sig));
         }
 #endif
 
@@ -660,7 +649,7 @@ int lio_listio(int mode, FAR struct aiocb *const list[], int nent,
            */
 
           status = lio_waitall(list, nent);
-          if (status < 0 && ret != OK)
+          if (status < 0 && ret == OK)
             {
               /* Something bad happened while waiting and this is the first
                * error to be reported.
@@ -688,7 +677,7 @@ int lio_listio(int mode, FAR struct aiocb *const list[], int nent,
           /* Setup a signal handler to detect when until all I/O completes. */
 
           status = lio_sigsetup(list, nent, sig);
-          if (status < 0 && ret != OK)
+          if (status < 0 && ret == OK)
             {
               /* Something bad happened while setting up the signal and this
                * is the first error to be reported.
@@ -707,8 +696,7 @@ int lio_listio(int mode, FAR struct aiocb *const list[], int nent,
           status = sigqueue(getpid(), sig->sigev_signo,
                             sig->sigev_value.sival_ptr);
 #endif
-
+          if (status < 0 && ret == OK)
-          if (status < 0 && ret != OK)
             {
               /* Something bad happened while signalling ourself and this is
                * the first error to be reported.
@@ -725,7 +713,16 @@ int lio_listio(int mode, FAR struct aiocb *const list[], int nent,
 
   else if (sig && sig->sigev_notify == SIGEV_THREAD)
     {
-#warning Missing SIGEV_THREAD logic
+      status = sig_notification(sighand->pid, &sighand->sig);
+      if (status < 0 && ret == OK)
+        {
+         /* Something bad happened while performing the notification
+          * and this is the first error to be reported.
+          */
+
+          retcode = -status;
+          ret     = ERROR;
+        }
     }
 #endif
 

sched/Kconfig

@@ -778,11 +778,14 @@ endmenu # RTOS hooks
 config SIG_EVTHREAD
 	bool "Support SIGEV_THHREAD"
 	default n
-	depends on EXPERIMENTAL
+	depends on BUILD_FLAT && SCHED_WORKQUEUE
 	---help---
 		Built in support for the SIGEV_THREAD signal deliver method.
 
-		NOTE: Only partially implemented as of this writing.
+		NOTE: The current implementation uses a work queue to notify the
+		client.  This, however, would only work in the FLAT build.  A
+		different mechanism would need to be development to support this
+		feature on the PROTECTED or KERNEL build.
 
 menu "Signal Numbers"
 	depends on !DISABLE_SIGNALS

sched/signal/Make.defs

@@ -44,6 +44,10 @@ CSRCS += sig_removependingsignal.c sig_releasependingsignal.c sig_lowest.c
 CSRCS += sig_mqnotempty.c sig_cleanup.c sig_dispatch.c sig_deliver.c
 CSRCS += sig_pause.c sig_nanosleep.c
 
+ifeq ($(CONFIG_SIG_EVTHREAD),y)
+CSRCS += sig_notification.c
+endif
+
 # Include signal build support
 
 DEPPATH += --dep-path signal

sched/signal/sig_notification.c

@@ -0,0 +1,172 @@
+/****************************************************************************
+ * sched/signal/sig_notification.c
+ *
+ *   Copyright (C) 2015 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 <sys/types.h>
+#include <signal.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <nuttx/kmalloc.h>
+#include <nuttx/wqueue.h>
+
+#ifdef CONFIG_SIG_EVTHREAD
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+/* Use the low-prioriry work queue is it is available */
+
+#if defined(CONFIG_SCHED_LPWORK)
+#  define NTWORK LPWORK
+#elif defined(CONFIG_SCHED_HPWORK)
+#  define NTWORK HPWORK
+#else
+#  error Work queue is not enabled
+#endif
+
+/****************************************************************************
+ * Private Type Definitions
+ ****************************************************************************/
+
+/* This structure retains all that is necessary to perform the notification */
+
+struct sig_notify_s
+{
+  struct work_s nt_work;           /* Work queue structure */
+  union sigval nt_value;           /* Data passed with notification */
+  sigev_notify_function_t nt_func; /* Notification function */
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: sig_ntworker
+ *
+ * Description:
+ *   Perform the callback from the context of the worker thread.
+ *
+ * Input Parameters:
+ *   arg - Work argument.
+ *
+ * Returned Value:
+ *   None.
+ *
+ ****************************************************************************/
+
+static void sig_ntworker(FAR void *arg)
+{
+  FAR struct sig_notify_s *notify = (FAR struct sig_notify_s *)arg;
+
+  DEBUGASSERT(notify != NULL);
+
+  /* Perform the callback */
+
+#ifdef CONFIG_CAN_PASS_STRUCTS
+  notify->nt_func(notify->nt_value);
+#else
+  notify->nt_func(notify->nt_value.sival_ptr);
+#endif
+
+  /* Free the alloated notification parameters */
+
+  kmm_free(notify);
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: sig_notification
+ *
+ * Description:
+ *   Notify a client a signal event via a function call.  This function is
+ *   an internal OS interface that implements the common logic for signal
+ *   event notification for the case of SIGEV_THREAD.
+ *
+ * Input Parameters:
+ *   pid - The task/thread ID a the client thread to be signaled.
+ *   event - The instance of struct sigevent that describes how to signal
+ *     the client.
+ *
+ * Returned Value:
+ *   Zero (OK) is returned on success; A negated errno value is returned
+ *   on failure.
+ *
+ ****************************************************************************/
+
+int sig_notification(pid_t pid, FAR struct sigevent *event)
+{
+  FAR struct sig_notify_s *notify;
+  DEBUGASSERT(event != NULL && event->sigev_notify_function != NULL);
+  int ret;
+
+  /* Allocate a structure to hold the notification information */
+
+  notify = kmm_zalloc(sizeof(struct sig_notify_s));
+  if (notify == NULL)
+    {
+      return -ENOMEM;
+    }
+
+  /* Initialize the notification information */
+
+#ifdef CONFIG_CAN_PASS_STRUCTS
+  notify->nt_value = event->sigev_value;
+#else
+  notify->nt_value.sival_ptr = event->sigev_value.sival_ptr;
+#endif
+  notify->nt_func = event->sigev_notify_function;
+
+  /* Then queue the work */
+
+  ret = work_queue(NTWORK, &notify->nt_work, sig_ntworker, notify, 0);
+  if (ret < 0)
+    {
+      kmm_free(notify);
+    }
+
+  return ret;
+}
+
+#endif /* CONFIG_SIG_EVTHREAD */