+/*
+ |C|Bk|De|Tn|Pu|Rn|
+ \----/
+ Dt
+
+ Group Dt: whether this process is terminated.
+
+ Rn: Running
+ Tn: Terminated
+ De: Destoryed
+ Pu: Paused
+ Bk: Blocked
+ C : Created
+*/
+
+#define PS_READY 0
+#define PS_RUNNING 1
+#define PS_TERMNAT 2
+#define PS_DESTROY 4
+#define PS_PAUSED 8
+#define PS_BLOCKED 16
+#define PS_CREATED 32
+
+#define PS_GrBP (PS_PAUSED | PS_BLOCKED)
+#define PS_GrDT (PS_TERMNAT | PS_DESTROY)
+
+#define proc_terminated(proc) (((proc)->state) & PS_GrDT)
+#define proc_hanged(proc) (((proc)->state) & PS_BLOCKED)
+#define proc_runnable(proc) (((proc)->state) & PS_PAUSED)
+
+struct sigact
+{
+ struct sigact* prev;
+ sigset_t sa_mask;
+ void* sa_actor;
+ void* sa_handler;
+ pid_t sender;
+};