add LCC - a better C-Compiler for WEGA

WEGA/contrib/lcc/lib/libc/port/gen/sleep.c

@@ -0,0 +1,65 @@
+/*
+ * Suspend the process for `sleep_tm' seconds - using alarm/pause
+ * system calls.  If caller had an alarm already set to go off `n'
+ * seconds from now, then Case 1: (sleep_tm >= n) sleep for n, and
+ * cause the callers previously specified alarm interrupt routine
+ * to be executed, then return the value (sleep_tm - n) to the caller
+ * as the unslept amount of time, Case 2: (sleep_tm < n) sleep for
+ * sleep_tm, after which, reset alarm to go off when it would have
+ * anyway.  In case process is aroused during sleep by any caught
+ * signal, then reset any prior alarm, as above, and return to the
+ * caller the (unsigned) quantity of (requested) seconds unslept.
+ */
+#include <signal.h>
+
+extern int pause();
+extern unsigned alarm();
+
+typedef	int	(*pfri)();
+unsigned
+sleep(sleep_tm)
+unsigned sleep_tm;
+{
+/*
+	int	alrm_flg, (*alrm_sig)(), awake();
+ */
+	int	alrm_flg, awake();
+	pfri	alrm_sig;
+	unsigned unslept, alrm_tm, left_ovr;
+
+	if(sleep_tm == 0)
+		return(0);
+
+	alrm_tm = alarm(0);			/* prev. alarm time */
+	alrm_sig = signal(SIGALRM, awake);	/* prev. alarm prog */
+
+	alrm_flg = 0;
+	left_ovr = 0;
+
+	if(alrm_tm != 0) {	/* skip all this if no prev. alarm */
+		if(alrm_tm > sleep_tm) {	/* alarm set way-out */
+			alrm_tm -= sleep_tm;
+			++alrm_flg;
+		} else {	/* alarm will shorten sleep time */
+			left_ovr = sleep_tm - alrm_tm;
+			sleep_tm = alrm_tm;
+			alrm_tm = 0;
+			--alrm_flg;
+			(void) signal(SIGALRM, alrm_sig);
+		}
+	}
+
+	(void) alarm(sleep_tm);
+	pause();		/* Some other signal may be caught,
+				   returning here, in which case we
+				   set-up to return to our caller */
+	unslept = alarm(0);
+	if(alrm_flg >= 0)
+		(void) signal(SIGALRM, alrm_sig);
+	if(alrm_flg > 0 || (alrm_flg < 0 && unslept != 0))
+		(void) alarm(alrm_tm + unslept);
+	return(left_ovr + unslept);
+}
+
+static
+awake() {}