Fix a *critical* bug in the task exit logic. Implements SIGCHILD

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5513 42af7a65-404d-4744-a932-0658087f49c3

include/nuttx/sched.h

@@ -202,6 +202,9 @@ struct _TCB
   /* Task Management Fields *****************************************************/
 
   pid_t    pid;                          /* This is the ID of the thread        */
+#ifdef CONFIG_SCHED_HAVE_PARENT
+  pid_t    parent;                       /* This is the ID of the parent thread */
+#endif
   start_t  start;                        /* Thread start function               */
   entry_t  entry;                        /* Entry Point into the thread         */
 

include/nuttx/wqueue.h

@@ -68,7 +68,7 @@
  * CONFIG_SCHED_WORKSTACKSIZE - The stack size allocated for the worker
  *   thread.  Default: CONFIG_IDLETHREAD_STACKSIZE.
  * CONFIG_SIG_SIGWORK - The signal number that will be used to wake-up
- *   the worker thread.  Default: 4
+ *   the worker thread.  Default: 17
  *
  * CONFIG_SCHED_LPWORK. If CONFIG_SCHED_WORKQUEUE is defined, then a single
  *   work queue is created by default.  If CONFIG_SCHED_LPWORK is also defined

include/signal.h

@@ -66,44 +66,56 @@
 
 /* A few of the real time signals are used within the OS.  They have
  * default values that can be overridden from the configuration file. The
- * rest are all user signals:
+ * rest are all user signals.
+ *
+ * These are semi-standard signal definitions:
  */
 
 #ifndef CONFIG_SIG_SIGUSR1
-#define SIGUSR1         0  /* User signal 1 */
+#  define SIGUSR1       1  /* User signal 1 */
 #else
-#define SIGUSR1         CONFIG_SIG_SIGUSR1
+#  define SIGUSR1       CONFIG_SIG_SIGUSR1
 #endif
 
 #ifndef CONFIG_SIG_SIGUSR2
-#define SIGUSR2         1  /* User signal 2 */
+#  define SIGUSR2       2  /* User signal 2 */
 #else
-#define SIGUSR2         CONFIG_SIG_SIGUSR2
+#  define SIGUSR2       CONFIG_SIG_SIGUSR2
 #endif
 
 #ifndef CONFIG_SIG_SIGALARM
-#define SIGALRM         2  /* Default signal used with POSIX timers (used only */
+#  define SIGALRM       3  /* Default signal used with POSIX timers (used only */
                            /* no other signal is provided) */
 #else
-#define SIGALRM         CONFIG_SIG_SIGALARM
+#  define SIGALRM       CONFIG_SIG_SIGALARM
 #endif
 
-#ifndef CONFIG_DISABLE_PTHREAD
-#ifndef CONFIG_SIG_SIGCONDTIMEDOUT
-#define SIGCONDTIMEDOUT 3  /* Used in the implementation of pthread_cond_timedwait */
-#else
-#define SIGCONDTIMEDOUT CONFIG_SIG_SIGCONDTIMEDOUT
+#ifdef CONFIG_SCHED_HAVE_PARENT
+#  ifndef CONFIG_SIG_SIGCHLD
+#    define SIGCHLD     4  /* Used by child threads to signal parent thread */
+#  else
+#    define SIGCHLD     CONFIG_SIG_SIGCHLD
+#  endif
 #endif
+
+/* The following are non-standard signal definitions */
+
+#ifndef CONFIG_DISABLE_PTHREAD
+#  ifndef CONFIG_SIG_SIGCONDTIMEDOUT
+#    define SIGCONDTIMEDOUT 16  /* Used in the implementation of pthread_cond_timedwait */
+#  else
+#    define SIGCONDTIMEDOUT CONFIG_SIG_SIGCONDTIMEDOUT
+#  endif
 #endif
 
 /* SIGWORK is used to wake up various internal, NuttX worker thread */
 
 #if defined(CONFIG_SCHED_WORKQUEUE) || defined(CONFIG_PAGING)
-#ifndef CONFIG_SIG_SIGWORK
-#define SIGWORK         4  /* Used to wake up the work queue */
-#else
-#define SIGWORK         CONFIG_SIG_SIGWORK
-#endif
+#  ifndef CONFIG_SIG_SIGWORK
+#    define SIGWORK     17  /* Used to wake up the work queue */
+#  else
+#    define SIGWORK     CONFIG_SIG_SIGWORK
+#  endif
 #endif
 
 /* sigprocmask() "how" definitions. Only one of the following can be specified: */
@@ -122,12 +134,18 @@
 
 /* These are the possible values of the signfo si_code field */
 
-#define SI_USER         0 /* Signal sent from kill, raise, or abort */
-#define SI_QUEUE        1 /* Signal sent from sigqueue */
-#define SI_TIMER        2 /* Signal is result of timer expiration */
-#define SI_ASYNCIO      3 /* Signal is the result of asynch IO completion */
-#define SI_MESGQ        4 /* Signal generated by arrival of a message on an */
-                          /* empty message queue */
+#define SI_USER         0  /* Signal sent from kill, raise, or abort */
+#define SI_QUEUE        1  /* Signal sent from sigqueue */
+#define SI_TIMER        2  /* Signal is result of timer expiration */
+#define SI_ASYNCIO      3  /* Signal is the result of asynch IO completion */
+#define SI_MESGQ        4  /* Signal generated by arrival of a message on an */
+                           /* empty message queue */
+#define CLD_EXITED      5  /* Child has exited (SIGCHLD only) */
+#define CLD_KILLED      6  /* Child was killed (SIGCHLD only) */
+#define CLD_DUMPED      7  /* Child terminated abnormally (SIGCHLD only) */
+#define CLD_TRAPPED     8  /* Traced child has trapped (SIGCHLD only) */
+#define CLD_STOPPED     9  /* Child has stopped (SIGCHLD only) */
+#define CLD_CONTINUED   10 /* Stopped child had continued (SIGCHLD only) */
 
 /* Values for the sigev_notify field of struct sigevent */
 
@@ -175,6 +193,10 @@ struct siginfo
   uint8_t      si_signo;     /* Identifies signal */
   uint8_t      si_code;      /* Source: SI_USER, SI_QUEUE, SI_TIMER, SI_ASYNCIO, or SI_MESGQ */
   union sigval si_value;     /* Data passed with signal */
+#ifdef CONFIG_SCHED_HAVE_PARENT
+  pid_t        si_pid;       /* Sending task ID */
+  int          si_status;    /* Exit value or signal (SIGCHLD only). */
+#endif
 };
 
 typedef struct siginfo siginfo_t;