signal: split user and system signals in two distinct intervals

Reorganize the bits of sigmask_t so that signals that can be used by
drivers or user applications and signals reserved for internal system
use are placed in two distinct intervals:

  * * * . . . . .
 |_|_|_|_|_|_|_|_|
  7 6 5 4 3 2 1 0  sigmask_t bits

 (*) bits [5-7] are reserved for internal system usage (SIG_TIMEOUT, etc.)
 (.) bits [0-4] are available for driver and user applications usage

This makes easier to allocate a range of contiguous signals. This can be
used for example to wait the occurrence of multiple events, multiplexing
them with multiple signal bits.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@4756 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/bertos/kern/signal.h b/bertos/kern/signal.h
index 70506fe12f6021339a43443cfdbfac6ed1de969a..a5d5e8d37e7495805e70277ec034f1bd7f5349d8 100644 (file)
--- a/bertos/kern/signal.h
+++ b/bertos/kern/signal.h
@@ -117,10 +117,15 @@ int signal_testTearDown(void);
 #define SIG_USER1    BV(1)  /**< Free for user usage */
 #define SIG_USER2    BV(2)  /**< Free for user usage */
 #define SIG_USER3    BV(3)  /**< Free for user usage */
-#define SIG_TIMEOUT  BV(4)  /**< Reserved for timeout use */
-#define SIG_SYSTEM5  BV(5)  /**< Reserved for system use */
-#define SIG_SYSTEM6  BV(6)  /**< Reserved for system use */
-#define SIG_SINGLE   BV(7)  /**< Used to wait for a single event */
+#define SIG_SINGLE   BV(4)  /**< Used to wait for a single event */
+#define SIG_SYSTEM5  BV(5)  /**< Reserved for internal system use */
+#define SIG_SYSTEM6  BV(6)  /**< Reserved for internal system use */
+#define SIG_TIMEOUT  BV(7)  /**< Reserved for timeout use */
+
+/**
+ * Max number of signals that can be used by drivers or user applications.
+ */
+#define SIG_USER_MAX SIG_SINGLE
 /*\}*/
 
 /* \} */ //defgroup kern_signal