Add logic to retain child task exit status if so configured

git-svn-id: http://svn.code.sf.net/p/nuttx/code/trunk@5553 42af7a65-404d-4744-a932-0658087f49c3

nuttx/include/nuttx/sched.h

@@ -74,6 +74,7 @@
 #define TCB_FLAG_NONCANCELABLE     (1 << 2) /* Bit 2: Pthread is non-cancelable */
 #define TCB_FLAG_CANCEL_PENDING    (1 << 3) /* Bit 3: Pthread cancel is pending */
 #define TCB_FLAG_ROUND_ROBIN       (1 << 4) /* Bit 4: Round robin sched enabled */
+#define TCB_FLAG_NOCLDWAIT         (1 << 5) /* Bit 5: Do not retain child exit status */
 
 /* Values for struct child_status_s ch_flags */
 
@@ -183,7 +184,7 @@ struct child_status_s
   FAR struct child_status_s *flink;
 
   uint8_t ch_flags;           /* Child status:  See CHILD_FLAG_* definitions */
-  pid_y   ch_pid;             /* Child task ID */
+  pid_t   ch_pid;             /* Child task ID */
   int     ch_status;          /* Child exit status */
 };
 #endif

nuttx/include/signal.h

@@ -129,11 +129,13 @@
 
 /* struct sigaction flag values */
 
-#define SA_NOCLDSTOP    1 /* Do not generate SIGCHILD when
-                           * children stop (ignored) */
-#define SA_SIGINFO      2 /* Invoke the signal-catching function
-                           * with 3 args instead of 1
-                           * (always assumed) */
+#define SA_NOCLDSTOP    (1 << 0) /* Do not generate SIGCHILD when
+                                  * children stop (ignored) */
+#define SA_SIGINFO      (1 << 1) /* Invoke the signal-catching function
+                                  * with 3 args instead of 1
+                                  * (always assumed) */
+#define SA_NOCLDWAIT    (1 << 2) /* If signo=SIGCHLD, exit status of child
+                                  * processes will be discarded */
 
 /* These are the possible values of the signfo si_code field */
 

nuttx/include/sys/types.h

@@ -158,13 +158,13 @@ typedef uint16_t     ino_t;
  * negative PID values are used to represent invalid PIDs.
  */
 
-typedef int          pid_t;
+typedef int16_t      pid_t;
 
 /* id_t is a general identifier that can be used to contain at least a pid_t,
  * uid_t, or gid_t.
  */
 
-typedef unsigned int id_t;
+typedef int16_t      id_t;
 
 /* Signed integral type of the result of subtracting two pointers */