More files related to user-level file servers.

Also add acme!

src/cmd/acme/time.c

@@ -0,0 +1,121 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <thread.h>
+#include <cursor.h>
+#include <mouse.h>
+#include <keyboard.h>
+#include <frame.h>
+#include <fcall.h>
+#include <plumb.h>
+#include "dat.h"
+#include "fns.h"
+
+static Channel*	ctimer;	/* chan(Timer*)[100] */
+static Timer *timer;
+
+static
+uint
+msec(void)
+{
+	return nsec()/1000000;
+}
+
+void
+timerstop(Timer *t)
+{
+	t->next = timer;
+	timer = t;
+}
+
+void
+timercancel(Timer *t)
+{
+	t->cancel = TRUE;
+}
+
+static
+void
+timerproc(void *v)
+{
+	int i, nt, na, dt, del;
+	Timer **t, *x;
+	uint old, new;
+
+	USED(v);
+	threadsetname("timerproc");
+	rfork(RFFDG);
+	t = nil;
+	na = 0;
+	nt = 0;
+	old = msec();
+	for(;;){
+		sleep(1);	/* will sleep minimum incr */
+		new = msec();
+		dt = new-old;
+		old = new;
+		if(dt < 0)	/* timer wrapped; go around, losing a tick */
+			continue;
+		for(i=0; i<nt; i++){
+			x = t[i];
+			x->dt -= dt;
+			del = FALSE;
+			if(x->cancel){
+				timerstop(x);
+				del = TRUE;
+			}else if(x->dt <= 0){
+				/*
+				 * avoid possible deadlock if client is
+				 * now sending on ctimer
+				 */
+				if(nbsendul(x->c, 0) > 0)
+					del = TRUE;
+			}
+			if(del){
+				memmove(&t[i], &t[i+1], (nt-i-1)*sizeof t[0]);
+				--nt;
+				--i;
+			}
+		}
+		if(nt == 0){
+			x = recvp(ctimer);
+	gotit:
+			if(nt == na){
+				na += 10;
+				t = realloc(t, na*sizeof(Timer*));
+				if(t == nil)
+					error("timer realloc failed");
+			}
+			t[nt++] = x;
+			old = msec();
+		}
+		if(nbrecv(ctimer, &x) > 0)
+			goto gotit;
+	}
+}
+
+void
+timerinit(void)
+{
+	ctimer = chancreate(sizeof(Timer*), 100);
+	proccreate(timerproc, nil, STACK);
+}
+
+Timer*
+timerstart(int dt)
+{
+	Timer *t;
+
+	t = timer;
+	if(t)
+		timer = timer->next;
+	else{
+		t = emalloc(sizeof(Timer));
+		t->c = chancreate(sizeof(int), 0);
+	}
+	t->next = nil;
+	t->dt = dt;
+	t->cancel = FALSE;
+	sendp(ctimer, t);
+	return t;
+}