Add missing support for signal masks to posix_spawn.

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5505 42af7a65-404d-4744-a932-0658087f49c3

TODO

@@ -1,4 +1,4 @@
-NuttX TODO List (Last updated January 8, 2013)
+NuttX TODO List (Last updated January 10, 2013)
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 This file summarizes known NuttX bugs, limitations, inconsistencies with 
@@ -6,7 +6,7 @@ standards, things that could be improved, and ideas for enhancements.
 
 nuttx/
 
- (12)  Task/Scheduler (sched/)
+ (11)  Task/Scheduler (sched/)
   (1)  Memory Managment (mm/)
   (2)  Signals (sched/, arch/)
   (2)  pthreads (sched/)
@@ -189,17 +189,6 @@ o Task/Scheduler (sched/)
   Status:      Open
   Priority:    Medium Low for now
 
-  Title:       INHERITANCE of sigmask
-  Description: New tasks/threads do not inherit the parent's signal mask.
-               This behavior is required under POSIX.
-
-               Also, related: Setting of the initial sigmask was not
-               implemented in posix_spawn (libc/spawn) because of this.
-  Status:      Open
-  Priority:    Low, make medium-low.  These kinds of behaviors are not
-               common in tiny embedded RTOSs.  And it has always been
-               like this and no one has complained so far.
-
 o Memory Managment (mm/)
   ^^^^^^^^^^^^^^^^^^^^^^
 

include/spawn.h

@@ -45,6 +45,7 @@
 #include <sys/types.h>
 
 #include <sched.h>
+#include <signal.h>
 #include <errno.h>
 
 /****************************************************************************
@@ -77,6 +78,9 @@ struct posix_spawnattr_s
   uint8_t  flags;
   uint8_t  priority;
   uint8_t  policy;
+#ifndef CONFIG_DISABLE_SIGNALS
+  sigset_t sigmask;
+#endif
 };
 
 typedef struct posix_spawnattr_s posix_spawnattr_t;
@@ -155,7 +159,12 @@ int posix_spawnattr_getschedparam(FAR const posix_spawnattr_t *attr,
 int posix_spawnattr_getschedpolicy(FAR const posix_spawnattr_t *attr,
       FAR int *policy);
 #define posix_spawnattr_getsigdefault(attr,sigdefault) (ENOSYS)
-#define posix_spawnattr_getsigmask(attr,sigmask) (ENOSYS)
+#ifndef CONFIG_DISABLE_SIGNALS
+int posix_spawnattr_getsigmask(FAR const posix_spawnattr_t *attr,
+                               FAR sigset_t *sigmask);
+#else
+#  define posix_spawnattr_getsigmask(attr,sigmask) (ENOSYS)
+#endif
 
 /* Set spawn attributes interfaces */
 
@@ -165,7 +174,12 @@ int posix_spawnattr_setschedparam(FAR posix_spawnattr_t *attr,
       FAR const struct sched_param *param);
 int posix_spawnattr_setschedpolicy(FAR posix_spawnattr_t *attr, int policy);
 #define posix_spawnattr_setsigdefault(attr,sigdefault) (ENOSYS)
-#define posix_spawnattr_setsigmask(attr,sigmask) (ENOSYS)
+#ifndef CONFIG_DISABLE_SIGNALS
+int posix_spawnattr_setsigmask(FAR posix_spawnattr_t *attr,
+                               FAR const sigset_t *sigmask);
+#else
+#  define posix_spawnattr_setsigmask(attr,sigmask) (ENOSYS)
+#endif
 
 #ifdef __cplusplus
 }

libc/spawn/Make.defs

@@ -46,6 +46,10 @@ CSRCS += lib_psa_getflags.c lib_psa_getschedparam.c lib_psa_getschedpolicy.c
 CSRCS += lib_psa_init.c lib_psa_setflags.c lib_psa_setschedparam.c
 CSRCS += lib_psa_setschedpolicy.c
 
+ifneq ($(CONFIG_DISABLE_SIGNALS),y)
+CSRCS += lib_psa_getsigmask.c lib_psa_setsigmask.c
+endif
+
 # Add the spawn directory to the build
 
 DEPPATH += --dep-path spawn

libc/spawn/lib_ps.c

@@ -40,6 +40,7 @@
 #include <nuttx/config.h>
 
 #include <semaphore.h>
+#include <signal.h>
 #include <sched.h>
 #include <fcntl.h>
 #include <spawn.h>
@@ -137,6 +138,8 @@ static void ps_semtake(FAR sem_t *sem)
  *     - POSIX_SPAWN_SETSCHEDULER: Set the new tasks scheduler priority to
  *       the sched_policy value.
  *
+ *     NOTE: POSIX_SPAWN_SETSIGMASK is handled in ps_proxy().
+ *
  *   argv - argv[] is the argument list for the new task.  argv[] is an
  *     array of pointers to null-terminated strings. The list is terminated
  *     with a null pointer.
@@ -326,38 +329,59 @@ static inline int spawn_open(FAR struct spawn_open_file_action_s *action)
 static int spawn_proxy(int argc, char *argv[])
 {
   FAR struct spawn_general_file_action_s *entry;
+  FAR const posix_spawnattr_t *attr = g_ps_parms.attr;
   int ret;
 
-  /* Perform I/O redirection.  We get here only if the file_actions parameter
+  /* Perform file actions and/or set a custom signal mask.  We get here only
-   * to posix_spawn[p] was non-NULL.
+   * if the file_actions parameter to posix_spawn[p] was non-NULL and/or the
+   * option to change the signal mask was selected.
    */
 
+#ifndef CONFIG_DISABLE_SIGNALS
+  DEBUGASSERT(g_ps_parms.file_actions ||
+              (attr && (attr->flags & POSIX_SPAWN_SETSIGMASK) != 0));
+#else
   DEBUGASSERT(g_ps_parms.file_actions);
+#endif
 
-  /* Execute each file action */
+  /* Check if we need to change the signal mask */
 
-  for (entry = (FAR struct spawn_general_file_action_s *)*g_ps_parms.file_actions;
+#ifndef CONFIG_DISABLE_SIGNALS
-       entry && ret == OK;
+  if (attr && (attr->flags & POSIX_SPAWN_SETSIGMASK) != 0)
-       entry = entry->flink)
     {
-      switch (entry->action)
+      (void)sigprocmask(SIG_SETMASK, &attr->sigmask, NULL);
+    }
+
+  /* Were we also requested to perform file actions? */
+
+  if (g_ps_parms.file_actions)
+#endif
+    {
+      /* Execute each file action */
+
+      for (entry = (FAR struct spawn_general_file_action_s *)*g_ps_parms.file_actions;
+           entry && ret == OK;
+           entry = entry->flink)
         {
-        case SPAWN_FILE_ACTION_CLOSE:
+          switch (entry->action)
-          ret = spawn_close((FAR struct spawn_close_file_action_s *)entry);
+            {
-          break;
+            case SPAWN_FILE_ACTION_CLOSE:
+              ret = spawn_close((FAR struct spawn_close_file_action_s *)entry);
+              break;
 
-        case SPAWN_FILE_ACTION_DUP2:
+            case SPAWN_FILE_ACTION_DUP2:
-          ret = spawn_dup2((FAR struct spawn_dup2_file_action_s *)entry);
+              ret = spawn_dup2((FAR struct spawn_dup2_file_action_s *)entry);
-          break;
+              break;
 
-        case SPAWN_FILE_ACTION_OPEN:
+            case SPAWN_FILE_ACTION_OPEN:
-          ret = spawn_open((FAR struct spawn_open_file_action_s *)entry);
+              ret = spawn_open((FAR struct spawn_open_file_action_s *)entry);
-          break;
+              break;
 
-        case SPAWN_FILE_ACTION_NONE:
+            case SPAWN_FILE_ACTION_NONE:
-        default:
+            default:
-          ret = EINVAL;
+              ret = EINVAL;
-          break;
+              break;
+            }
         }
     }
 
@@ -367,8 +391,7 @@ static int spawn_proxy(int argc, char *argv[])
     {
       /* Start the task */
 
-      ret = ps_exec(g_ps_parms.pid, g_ps_parms.path, g_ps_parms.attr,
+      ret = ps_exec(g_ps_parms.pid, g_ps_parms.path, attr, g_ps_parms.argv);
-                    g_ps_parms.argv);
     }
 
   /* Post the semaphore to inform the parent task that we have completed
@@ -424,18 +447,16 @@ static int spawn_proxy(int argc, char *argv[])
  *     It will contains these attributes, not all of which are supported by
  *     NuttX:
  *
- *     - POSIX_SPAWN_SETPGROUP:  Setting of the new tasks process group is
+ *     - POSIX_SPAWN_SETPGROUP:  Setting of the new task's process group is
  *       not supported.  NuttX does not support process groups.
  *     - POSIX_SPAWN_SETSCHEDPARAM: Set new tasks priority to the sched_param
  *       value.
- *     - POSIX_SPAWN_SETSCHEDULER: Set the new tasks scheduler priority to
+ *     - POSIX_SPAWN_SETSCHEDULER: Set the new task's scheduler priority to
  *       the sched_policy value.
  *     - POSIX_SPAWN_RESETIDS: Resetting of effective user ID of the child
  *       process is not supported.  NuttX does not support effective user
  *       IDs.
- *     - POSIX_SPAWN_SETSIGMASK: Setting the initial signal mask of the new
+ *     - POSIX_SPAWN_SETSIGMASK: Set the new task's signal mask.
- *       task is not supported.  NuttX does support signal masks, but there
- *       is no mechanism in place now to do this.
  *     - POSIX_SPAWN_SETSIGDEF:  Resetting signal default actions is not
  *       supported.  NuttX does not support default signal actions.
  *
@@ -496,11 +517,15 @@ int posix_spawn(FAR pid_t *pid, FAR const char *path,
 
   DEBUGASSERT(path);
 
-  /* If there are no file actions to be performed, then start the new child
+  /* If there are no file actions to be performed and there is no change to
-   * task directory form the parent task.
+   * the signal mask, then start the new child task directly from the parent task.
    */
 
+#ifndef CONFIG_DISABLE_SIGNALS
+  if (!file_actions && (attr->flags & POSIX_SPAWN_SETSIGMASK) == 0)
+#else
   if (!file_actions)
+#endif
     {
       return ps_exec(pid, path, attr, argv);
     }

libc/spawn/lib_psa_getsigmask.c

@@ -0,0 +1,78 @@
+/****************************************************************************
+ * libc/string/lib_psa_getsigmask.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 <signal.h>
+#include <spawn.h>
+#include <assert.h>
+
+#ifndef CONFIG_DISABLE_SIGNALS
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: posix_spawnattr_getsigmask
+ *
+ * Description:
+ *   The posix_spawnattr_getsigdefault() function will obtain the value of
+ *   the spawn-sigmask  attribute from the attributes object referenced
+ *   by attr.
+ *
+ * Input Parameters:
+ *   attr - The address spawn attributes to be queried.
+ *   sigmask  - The location to return the spawn flags
+ *
+ * Returned Value:
+ *   On success, these functions return 0; on failure they return an error
+ *   number from <errno.h>.
+ *
+ ****************************************************************************/
+
+int posix_spawnattr_getsigmask(FAR const posix_spawnattr_t *attr,
+                               FAR sigset_t *sigmask)
+{
+  DEBUGASSERT(attr && sigmask);
+  *sigmask = attr->sigmask;
+  return OK;
+}
+
+#endif /* !CONFIG_DISABLE_SIGNALS */

libc/spawn/lib_psa_setsigmask.c

@@ -0,0 +1,79 @@
+/****************************************************************************
+ * libc/string/lib_psa_setsigmask.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 <signal.h>
+#include <spawn.h>
+#include <assert.h>
+
+#ifndef CONFIG_DISABLE_SIGNALS
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: posix_spawnattr_setsigmask
+ *
+ * Description:
+ *   The posix_spawnattr_setsigmask() function will set the spawn-
+ *   sigmask attribute in an initialized attributes object referenced
+ *   by attr.
+ *
+ * Input Parameters:
+ *   attr - The address spawn attributes to be used.
+ *   flags - The new value of the default signal set
+ *
+ * Returned Value:
+ *   On success, these functions return 0; on failure they return an error
+ *   number from <errno.h>.
+ *
+ ****************************************************************************/
+
+int posix_spawnattr_setsigmask(FAR posix_spawnattr_t *attr,
+                                  FAR const sigset_t *sigmask)
+{
+  DEBUGASSERT(attr && sigmask);
+  attr->sigmask = *sigmask;
+  return OK;
+}
+
+#endif /* !CONFIG_DISABLE_SIGNALS */
+

sched/task_setup.c

@@ -231,8 +231,8 @@ int task_schedsetup(FAR _TCB *tcb, int priority, start_t start, main_t main)
       tcb->start          = start;
       tcb->entry.main     = main;
 
-      /* exec() and pthread_create() inherit the signal mask of the
+      /* exec(), pthread_create(), task_create(), and vfork() all
-       * parent thread.  I suppose that task_create() should as well.
+       * inherit the signal mask of the parent thread.
        */
 
 #ifndef CONFIG_DISABLE_SIGNALS