runtime: copy runtime package time code from Go 1.7

Fix handling of function values for -fgo-c-header to generate FuncVal*,
    not simply FuncVal.
    
    While we're here change runtime.nanotime to use clock_gettime with
    CLOCK_MONOTONIC, rather than gettimeofday.  This is what the gc library
    does.  It provides nanosecond precision and a monotonic clock.
    
    Reviewed-on: https://go-review.googlesource.com/31232

From-SVN: r241197

gcc/go/gofrontend/MERGE

@@ -1,4 +1,4 @@
-ec3dc927da71d15cac48a13c0fb0c1f94572d0d2
+880cb0a45590d992880fc6aabc7484e54c817eeb
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

gcc/go/gofrontend/types.cc

@@ -5928,7 +5928,7 @@ Struct_type::write_field_to_c_header(std::ostream& os, const std::string& name,
       break;
 
     case TYPE_FUNCTION:
-      os << "FuncVal";
+      os << "FuncVal*";
       break;
 
     case TYPE_POINTER:

libgo/Makefile.am

@@ -519,7 +519,6 @@ runtime_files = \
 	reflect.c \
 	runtime1.c \
 	sigqueue.c \
-	time.c \
 	$(runtime_getncpu_file)
 
 goc2c.$(OBJEXT): runtime/goc2c.c

libgo/Makefile.in

@@ -262,8 +262,7 @@ am__objects_6 = go-append.lo go-assert.lo go-assert-interface.lo \
 	$(am__objects_2) panic.lo parfor.lo print.lo proc.lo \
 	runtime.lo signal_unix.lo thread.lo $(am__objects_3) yield.lo \
 	$(am__objects_4) go-iface.lo lfstack.lo malloc.lo netpoll.lo \
-	rdebug.lo reflect.lo runtime1.lo sigqueue.lo time.lo \
-	$(am__objects_5)
+	rdebug.lo reflect.lo runtime1.lo sigqueue.lo $(am__objects_5)
 am_libgo_llgo_la_OBJECTS = $(am__objects_6)
 libgo_llgo_la_OBJECTS = $(am_libgo_llgo_la_OBJECTS)
 libgo_llgo_la_LINK = $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) \
@@ -918,7 +917,6 @@ runtime_files = \
 	reflect.c \
 	runtime1.c \
 	sigqueue.c \
-	time.c \
 	$(runtime_getncpu_file)
 
 noinst_DATA = zstdpkglist.go
@@ -1636,7 +1634,6 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/thread-linux.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/thread-sema.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/thread.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/time.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/yield.Plo@am__quote@
 
 .c.o:

libgo/go/runtime/stubs.go

@@ -196,15 +196,15 @@ func getcallersp(argp unsafe.Pointer) uintptr
 // argp used in Defer structs when there is no argp.
 const _NoArgs = ^uintptr(0)
 
-// //go:linkname time_now time.now
-// func time_now() (sec int64, nsec int32)
+//go:linkname time_now time.now
+func time_now() (sec int64, nsec int32)
 
-/*
+// For gccgo, expose this for C callers.
+//go:linkname unixnanotime runtime.unixnanotime
 func unixnanotime() int64 {
 	sec, nsec := time_now()
 	return sec*1e9 + int64(nsec)
 }
-*/
 
 // round n up to a multiple of a.  a must be a power of 2.
 func round(n, a uintptr) uintptr {

libgo/go/runtime/time.go

@@ -0,0 +1,307 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Time-related runtime and pieces of package time.
+
+package runtime
+
+import "unsafe"
+
+// Export temporarily for gccgo's C code to call:
+//go:linkname addtimer runtime.addtimer
+//go:linkname deltimer runtime.deltimer
+
+// Package time knows the layout of this structure.
+// If this struct changes, adjust ../time/sleep.go:/runtimeTimer.
+// For GOOS=nacl, package syscall knows the layout of this structure.
+// If this struct changes, adjust ../syscall/net_nacl.go:/runtimeTimer.
+type timer struct {
+	i int // heap index
+
+	// Timer wakes up at when, and then at when+period, ... (period > 0 only)
+	// each time calling f(arg, now) in the timer goroutine, so f must be
+	// a well-behaved function and not block.
+	when   int64
+	period int64
+	f      func(interface{}, uintptr)
+	arg    interface{}
+	seq    uintptr
+}
+
+var timers struct {
+	lock         mutex
+	gp           *g
+	created      bool
+	sleeping     bool
+	rescheduling bool
+	waitnote     note
+	t            []*timer
+}
+
+// nacl fake time support - time in nanoseconds since 1970
+var faketime int64
+
+// Package time APIs.
+// Godoc uses the comments in package time, not these.
+
+// time.now is implemented in assembly.
+
+// timeSleep puts the current goroutine to sleep for at least ns nanoseconds.
+//go:linkname timeSleep time.Sleep
+func timeSleep(ns int64) {
+	if ns <= 0 {
+		return
+	}
+
+	t := new(timer)
+	t.when = nanotime() + ns
+	t.f = goroutineReady
+	t.arg = getg()
+	lock(&timers.lock)
+	addtimerLocked(t)
+	goparkunlock(&timers.lock, "sleep", traceEvGoSleep, 2)
+}
+
+// startTimer adds t to the timer heap.
+//go:linkname startTimer time.startTimer
+func startTimer(t *timer) {
+	if raceenabled {
+		racerelease(unsafe.Pointer(t))
+	}
+	addtimer(t)
+}
+
+// stopTimer removes t from the timer heap if it is there.
+// It returns true if t was removed, false if t wasn't even there.
+//go:linkname stopTimer time.stopTimer
+func stopTimer(t *timer) bool {
+	return deltimer(t)
+}
+
+// Go runtime.
+
+// Ready the goroutine arg.
+func goroutineReady(arg interface{}, seq uintptr) {
+	goready(arg.(*g), 0)
+}
+
+func addtimer(t *timer) {
+	lock(&timers.lock)
+	addtimerLocked(t)
+	unlock(&timers.lock)
+}
+
+// Add a timer to the heap and start or kick the timer proc.
+// If the new timer is earlier than any of the others.
+// Timers are locked.
+func addtimerLocked(t *timer) {
+	// when must never be negative; otherwise timerproc will overflow
+	// during its delta calculation and never expire other runtime·timers.
+	if t.when < 0 {
+		t.when = 1<<63 - 1
+	}
+	t.i = len(timers.t)
+	timers.t = append(timers.t, t)
+	siftupTimer(t.i)
+	if t.i == 0 {
+		// siftup moved to top: new earliest deadline.
+		if timers.sleeping {
+			timers.sleeping = false
+			notewakeup(&timers.waitnote)
+		}
+		if timers.rescheduling {
+			timers.rescheduling = false
+			goready(timers.gp, 0)
+		}
+	}
+	if !timers.created {
+		timers.created = true
+		go timerproc()
+	}
+}
+
+// Delete timer t from the heap.
+// Do not need to update the timerproc: if it wakes up early, no big deal.
+func deltimer(t *timer) bool {
+	// Dereference t so that any panic happens before the lock is held.
+	// Discard result, because t might be moving in the heap.
+	_ = t.i
+
+	lock(&timers.lock)
+	// t may not be registered anymore and may have
+	// a bogus i (typically 0, if generated by Go).
+	// Verify it before proceeding.
+	i := t.i
+	last := len(timers.t) - 1
+	if i < 0 || i > last || timers.t[i] != t {
+		unlock(&timers.lock)
+		return false
+	}
+	if i != last {
+		timers.t[i] = timers.t[last]
+		timers.t[i].i = i
+	}
+	timers.t[last] = nil
+	timers.t = timers.t[:last]
+	if i != last {
+		siftupTimer(i)
+		siftdownTimer(i)
+	}
+	unlock(&timers.lock)
+	return true
+}
+
+// Timerproc runs the time-driven events.
+// It sleeps until the next event in the timers heap.
+// If addtimer inserts a new earlier event, addtimer1 wakes timerproc early.
+func timerproc() {
+	timers.gp = getg()
+	for {
+		lock(&timers.lock)
+		timers.sleeping = false
+		now := nanotime()
+		delta := int64(-1)
+		for {
+			if len(timers.t) == 0 {
+				delta = -1
+				break
+			}
+			t := timers.t[0]
+			delta = t.when - now
+			if delta > 0 {
+				break
+			}
+			if t.period > 0 {
+				// leave in heap but adjust next time to fire
+				t.when += t.period * (1 + -delta/t.period)
+				siftdownTimer(0)
+			} else {
+				// remove from heap
+				last := len(timers.t) - 1
+				if last > 0 {
+					timers.t[0] = timers.t[last]
+					timers.t[0].i = 0
+				}
+				timers.t[last] = nil
+				timers.t = timers.t[:last]
+				if last > 0 {
+					siftdownTimer(0)
+				}
+				t.i = -1 // mark as removed
+			}
+			f := t.f
+			arg := t.arg
+			seq := t.seq
+			unlock(&timers.lock)
+			if raceenabled {
+				raceacquire(unsafe.Pointer(t))
+			}
+			f(arg, seq)
+			lock(&timers.lock)
+		}
+		if delta < 0 || faketime > 0 {
+			// No timers left - put goroutine to sleep.
+			timers.rescheduling = true
+			goparkunlock(&timers.lock, "timer goroutine (idle)", traceEvGoBlock, 1)
+			continue
+		}
+		// At least one timer pending. Sleep until then.
+		timers.sleeping = true
+		noteclear(&timers.waitnote)
+		unlock(&timers.lock)
+		notetsleepg(&timers.waitnote, delta)
+	}
+}
+
+func timejump() *g {
+	if faketime == 0 {
+		return nil
+	}
+
+	lock(&timers.lock)
+	if !timers.created || len(timers.t) == 0 {
+		unlock(&timers.lock)
+		return nil
+	}
+
+	var gp *g
+	if faketime < timers.t[0].when {
+		faketime = timers.t[0].when
+		if timers.rescheduling {
+			timers.rescheduling = false
+			gp = timers.gp
+		}
+	}
+	unlock(&timers.lock)
+	return gp
+}
+
+// Heap maintenance algorithms.
+
+func siftupTimer(i int) {
+	t := timers.t
+	when := t[i].when
+	tmp := t[i]
+	for i > 0 {
+		p := (i - 1) / 4 // parent
+		if when >= t[p].when {
+			break
+		}
+		t[i] = t[p]
+		t[i].i = i
+		t[p] = tmp
+		t[p].i = p
+		i = p
+	}
+}
+
+func siftdownTimer(i int) {
+	t := timers.t
+	n := len(t)
+	when := t[i].when
+	tmp := t[i]
+	for {
+		c := i*4 + 1 // left child
+		c3 := c + 2  // mid child
+		if c >= n {
+			break
+		}
+		w := t[c].when
+		if c+1 < n && t[c+1].when < w {
+			w = t[c+1].when
+			c++
+		}
+		if c3 < n {
+			w3 := t[c3].when
+			if c3+1 < n && t[c3+1].when < w3 {
+				w3 = t[c3+1].when
+				c3++
+			}
+			if w3 < w {
+				w = w3
+				c = c3
+			}
+		}
+		if w >= when {
+			break
+		}
+		t[i] = t[c]
+		t[i].i = i
+		t[c] = tmp
+		t[c].i = c
+		i = c
+	}
+}
+
+// Entry points for net, time to call nanotime.
+
+//go:linkname net_runtimeNano net.runtimeNano
+func net_runtimeNano() int64 {
+	return nanotime()
+}
+
+//go:linkname time_runtimeNano time.runtimeNano
+func time_runtimeNano() int64 {
+	return nanotime()
+}

libgo/runtime/go-nanotime.c

@@ -14,8 +14,8 @@ int64 runtime_nanotime (void)
 int64
 runtime_nanotime (void)
 {
-  struct timeval tv;
+  struct timespec ts;
 
-  gettimeofday (&tv, NULL);
-  return (int64) tv.tv_sec * 1000000000 + (int64) tv.tv_usec * 1000;
+  clock_gettime (CLOCK_MONOTONIC, &ts);
+  return (int64) ts.tv_sec * 1000000000 + (int64) ts.tv_nsec;
 }

libgo/runtime/malloc.h

@@ -543,5 +543,4 @@ int32	runtime_setgcpercent(int32);
 
 struct Workbuf;
 void	runtime_proc_scan(struct Workbuf**, void (*)(struct Workbuf**, Obj));
-void	runtime_time_scan(struct Workbuf**, void (*)(struct Workbuf**, Obj));
 void	runtime_netpoll_scan(struct Workbuf**, void (*)(struct Workbuf**, Obj));

libgo/runtime/mgc0.c

@@ -1277,7 +1277,6 @@ markroot(ParFor *desc, uint32 i)
 		enqueue1(&wbuf, (Obj){(byte*)&runtime_allp, sizeof runtime_allp, 0});
 		enqueue1(&wbuf, (Obj){(byte*)&work, sizeof work, 0});
 		runtime_proc_scan(&wbuf, enqueue1);
-		runtime_time_scan(&wbuf, enqueue1);
 		runtime_netpoll_scan(&wbuf, enqueue1);
 		break;
 

libgo/runtime/netpoll.goc

@@ -89,11 +89,6 @@ static FuncVal deadlineFn	= {(void(*)(void))deadline};
 static FuncVal readDeadlineFn	= {(void(*)(void))readDeadline};
 static FuncVal writeDeadlineFn	= {(void(*)(void))writeDeadline};
 
-// runtimeNano returns the current value of the runtime clock in nanoseconds.
-func runtimeNano() (ns int64) {
-	ns = runtime_nanotime();
-}
-
 func runtime_pollServerInit() {
 	runtime_netpollinit();
 }
@@ -176,13 +171,13 @@ func runtime_pollSetDeadline(pd *PollDesc, d int64, mode int) {
 	}
 	pd->seq++;  // invalidate current timers
 	// Reset current timers.
-	if(pd->rt.fv) {
+	if(pd->rt.f) {
 		runtime_deltimer(&pd->rt);
-		pd->rt.fv = nil;
+		pd->rt.f = nil;
 	}
-	if(pd->wt.fv) {
+	if(pd->wt.f) {
 		runtime_deltimer(&pd->wt);
-		pd->wt.fv = nil;
+		pd->wt.f = nil;
 	}
 	// Setup new timers.
 	if(d != 0 && d <= runtime_nanotime())
@@ -192,7 +187,7 @@ func runtime_pollSetDeadline(pd *PollDesc, d int64, mode int) {
 	if(mode == 'w' || mode == 'r'+'w')
 		pd->wd = d;
 	if(pd->rd > 0 && pd->rd == pd->wd) {
-		pd->rt.fv = &deadlineFn;
+		pd->rt.f = &deadlineFn;
 		pd->rt.when = pd->rd;
 		// Copy current seq into the timer arg.
 		// Timer func will check the seq against current descriptor seq,
@@ -203,7 +198,7 @@ func runtime_pollSetDeadline(pd *PollDesc, d int64, mode int) {
 		runtime_addtimer(&pd->rt);
 	} else {
 		if(pd->rd > 0) {
-			pd->rt.fv = &readDeadlineFn;
+			pd->rt.f = &readDeadlineFn;
 			pd->rt.when = pd->rd;
 			pd->rt.arg.type = nil; // should be *pollDesc type descriptor.
 			pd->rt.arg.data = pd;
@@ -211,7 +206,7 @@ func runtime_pollSetDeadline(pd *PollDesc, d int64, mode int) {
 			runtime_addtimer(&pd->rt);
 		}
 		if(pd->wd > 0) {
-			pd->wt.fv = &writeDeadlineFn;
+			pd->wt.f = &writeDeadlineFn;
 			pd->wt.when = pd->wd;
 			pd->wt.arg.type = nil; // should be *pollDesc type descriptor.
 			pd->wt.arg.data = pd;
@@ -244,13 +239,13 @@ func runtime_pollUnblock(pd *PollDesc) {
 	runtime_atomicstorep(&rg, nil);  // full memory barrier between store to closing and read of rg/wg in netpollunblock
 	rg = netpollunblock(pd, 'r', false);
 	wg = netpollunblock(pd, 'w', false);
-	if(pd->rt.fv) {
+	if(pd->rt.f) {
 		runtime_deltimer(&pd->rt);
-		pd->rt.fv = nil;
+		pd->rt.f = nil;
 	}
-	if(pd->wt.fv) {
+	if(pd->wt.f) {
 		runtime_deltimer(&pd->wt);
-		pd->wt.fv = nil;
+		pd->wt.f = nil;
 	}
 	runtime_unlock(pd);
 	if(rg)
@@ -408,17 +403,17 @@ deadlineimpl(Eface arg, uintptr seq, bool read, bool write)
 		return;
 	}
 	if(read) {
-		if(pd->rd <= 0 || pd->rt.fv == nil)
+		if(pd->rd <= 0 || pd->rt.f == nil)
 			runtime_throw("deadlineimpl: inconsistent read deadline");
 		pd->rd = -1;
-		runtime_atomicstorep(&pd->rt.fv, nil);  // full memory barrier between store to rd and load of rg in netpollunblock
+		runtime_atomicstorep(&pd->rt.f, nil);  // full memory barrier between store to rd and load of rg in netpollunblock
 		rg = netpollunblock(pd, 'r', false);
 	}
 	if(write) {
-		if(pd->wd <= 0 || (pd->wt.fv == nil && !read))
+		if(pd->wd <= 0 || (pd->wt.f == nil && !read))
 			runtime_throw("deadlineimpl: inconsistent write deadline");
 		pd->wd = -1;
-		runtime_atomicstorep(&pd->wt.fv, nil);  // full memory barrier between store to wd and load of wg in netpollunblock
+		runtime_atomicstorep(&pd->wt.f, nil);  // full memory barrier between store to wd and load of wg in netpollunblock
 		wg = netpollunblock(pd, 'w', false);
 	}
 	runtime_unlock(pd);

libgo/runtime/runtime.h

@@ -66,8 +66,7 @@ typedef	struct	SigTab		SigTab;
 typedef	struct	mcache		MCache;
 typedef struct	FixAlloc	FixAlloc;
 typedef	struct	hchan		Hchan;
-typedef	struct	Timers		Timers;
-typedef	struct	Timer		Timer;
+typedef	struct	timer		Timer;
 typedef	struct	gcstats		GCStats;
 typedef	struct	LFNode		LFNode;
 typedef	struct	ParFor		ParFor;
@@ -181,36 +180,6 @@ enum {
 };
 #endif
 
-struct	Timers
-{
-	Lock;
-	G	*timerproc;
-	bool		sleeping;
-	bool		rescheduling;
-	Note	waitnote;
-	Timer	**t;
-	int32	len;
-	int32	cap;
-};
-
-// Package time knows the layout of this structure.
-// If this struct changes, adjust ../time/sleep.go:/runtimeTimer.
-// For GOOS=nacl, package syscall knows the layout of this structure.
-// If this struct changes, adjust ../syscall/net_nacl.go:/runtimeTimer.
-struct	Timer
-{
-	intgo	i;	// heap index
-
-	// Timer wakes up at when, and then at when+period, ... (period > 0 only)
-	// each time calling f(now, arg) in the timer goroutine, so f must be
-	// a well-behaved function and not block.
-	int64	when;
-	int64	period;
-	FuncVal	*fv;
-	Eface	arg;
-	uintptr	seq;
-};
-
 // Lock-free stack node.
 struct LFNode
 {
@@ -403,7 +372,8 @@ bool	__go_sigsend(int32 sig);
 int32	runtime_callers(int32, Location*, int32, bool keep_callers);
 int64	runtime_nanotime(void)	// monotonic time
   __asm__(GOSYM_PREFIX "runtime.nanotime");
-int64	runtime_unixnanotime(void); // real time, can skip
+int64	runtime_unixnanotime(void) // real time, can skip
+  __asm__ (GOSYM_PREFIX "runtime.unixnanotime");
 void	runtime_dopanic(int32) __attribute__ ((noreturn));
 void	runtime_startpanic(void);
 void	runtime_freezetheworld(void);
@@ -422,8 +392,10 @@ int64	runtime_tickspersecond(void)
      __asm__ (GOSYM_PREFIX "runtime.tickspersecond");
 void	runtime_blockevent(int64, int32);
 extern int64 runtime_blockprofilerate;
-void	runtime_addtimer(Timer*);
-bool	runtime_deltimer(Timer*);
+void	runtime_addtimer(Timer*)
+  __asm__ (GOSYM_PREFIX "runtime.addtimer");
+bool	runtime_deltimer(Timer*)
+  __asm__ (GOSYM_PREFIX "runtime.deltimer");
 G*	runtime_netpoll(bool);
 void	runtime_netpollinit(void);
 int32	runtime_netpollopen(uintptr, PollDesc*);

libgo/runtime/time.goc

@@ -1,353 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Time-related runtime and pieces of package time.
-
-package time
-
-#include <sys/time.h>
-
-#include "runtime.h"
-#include "defs.h"
-#include "arch.h"
-#include "malloc.h"
-
-enum {
-	debug = 0,
-};
-
-static Timers timers;
-static void addtimer(Timer*);
-static void dumptimers(const char*);
-
-// nacl fake time support. 
-int64 runtime_timens;
-
-// Package time APIs.
-// Godoc uses the comments in package time, not these.
-
-// time.now is implemented in assembly.
-
-// runtimeNano returns the current value of the runtime clock in nanoseconds.
-func runtimeNano() (ns int64) {
-	ns = runtime_nanotime();
-}
-
-// Sleep puts the current goroutine to sleep for at least ns nanoseconds.
-func Sleep(ns int64) {
-	runtime_tsleep(ns, "sleep");
-}
-
-// startTimer adds t to the timer heap.
-func startTimer(t *Timer) {
-	runtime_addtimer(t);
-}
-
-// stopTimer removes t from the timer heap if it is there.
-// It returns true if t was removed, false if t wasn't even there.
-func stopTimer(t *Timer) (stopped bool) {
-	stopped = runtime_deltimer(t);
-}
-
-// C runtime.
-
-int64 runtime_unixnanotime(void)
-{
-	struct time_now_ret r;
-
-	r = now();
-	return r.sec*1000000000 + r.nsec;
-}
-
-static void timerproc(void*);
-static void siftup(int32);
-static void siftdown(int32);
-
-// Ready the goroutine e.data.
-static void
-ready(Eface e, uintptr seq)
-{
-	USED(seq);
-
-	runtime_ready(e.__object);
-}
-
-static FuncVal readyv = {(void(*)(void))ready};
-
-// Put the current goroutine to sleep for ns nanoseconds.
-void
-runtime_tsleep(int64 ns, const char *reason)
-{
-	G* g;
-	Timer t;
-
-	g = runtime_g();
-
-	if(ns <= 0)
-		return;
-
-	t.when = runtime_nanotime() + ns;
-	t.period = 0;
-	t.fv = &readyv;
-	t.arg.__object = g;
-	t.seq = 0;
-	runtime_lock(&timers);
-	addtimer(&t);
-	runtime_parkunlock(&timers, reason);
-}
-
-void
-runtime_addtimer(Timer *t)
-{
-	runtime_lock(&timers);
-	addtimer(t);
-	runtime_unlock(&timers);
-}
-
-// Add a timer to the heap and start or kick the timer proc
-// if the new timer is earlier than any of the others.
-static void
-addtimer(Timer *t)
-{
-	int32 n;
-	Timer **nt;
-
-	// when must never be negative; otherwise timerproc will overflow
-	// during its delta calculation and never expire other timers.
-	if(t->when < 0)
-		t->when = (int64)((1ULL<<63)-1);
-
-	if(timers.len >= timers.cap) {
-		// Grow slice.
-		n = 16;
-		if(n <= timers.cap)
-			n = timers.cap*3 / 2;
-		nt = runtime_malloc(n*sizeof nt[0]);
-		runtime_memmove(nt, timers.t, timers.len*sizeof nt[0]);
-		runtime_free(timers.t);
-		timers.t = nt;
-		timers.cap = n;
-	}
-	t->i = timers.len++;
-	timers.t[t->i] = t;
-	siftup(t->i);
-	if(t->i == 0) {
-		// siftup moved to top: new earliest deadline.
-		if(timers.sleeping) {
-			timers.sleeping = false;
-			runtime_notewakeup(&timers.waitnote);
-		}
-		if(timers.rescheduling) {
-			timers.rescheduling = false;
-			runtime_ready(timers.timerproc);
-		}
-	}
-	if(timers.timerproc == nil) {
-		timers.timerproc = __go_go(timerproc, nil);
-		timers.timerproc->issystem = true;
-	}
-	if(debug)
-		dumptimers("addtimer");
-}
-
-// Used to force a dereference before the lock is acquired.
-static int32 gi;
-
-// Delete timer t from the heap.
-// Do not need to update the timerproc:
-// if it wakes up early, no big deal.
-bool
-runtime_deltimer(Timer *t)
-{
-	int32 i;
-
-	// Dereference t so that any panic happens before the lock is held.
-	// Discard result, because t might be moving in the heap.
-	i = t->i;
-	gi = i;
-
-	runtime_lock(&timers);
-
-	// t may not be registered anymore and may have
-	// a bogus i (typically 0, if generated by Go).
-	// Verify it before proceeding.
-	i = t->i;
-	if(i < 0 || i >= timers.len || timers.t[i] != t) {
-		runtime_unlock(&timers);
-		return false;
-	}
-
-	timers.len--;
-	if(i == timers.len) {
-		timers.t[i] = nil;
-	} else {
-		timers.t[i] = timers.t[timers.len];
-		timers.t[timers.len] = nil;
-		timers.t[i]->i = i;
-		siftup(i);
-		siftdown(i);
-	}
-	if(debug)
-		dumptimers("deltimer");
-	runtime_unlock(&timers);
-	return true;
-}
-
-// Timerproc runs the time-driven events.
-// It sleeps until the next event in the timers heap.
-// If addtimer inserts a new earlier event, addtimer
-// wakes timerproc early.
-static void
-timerproc(void* dummy __attribute__ ((unused)))
-{
-	int64 delta, now;
-	Timer *t;
-	FuncVal *fv;
-	void (*f)(Eface, uintptr);
-	Eface arg;
-	uintptr seq;
-
-	for(;;) {
-		runtime_lock(&timers);
-		timers.sleeping = false;
-		now = runtime_nanotime();
-		for(;;) {
-			if(timers.len == 0) {
-				delta = -1;
-				break;
-			}
-			t = timers.t[0];
-			delta = t->when - now;
-			if(delta > 0)
-				break;
-			if(t->period > 0) {
-				// leave in heap but adjust next time to fire
-				t->when += t->period * (1 + -delta/t->period);
-				siftdown(0);
-			} else {
-				// remove from heap
-				timers.t[0] = timers.t[--timers.len];
-				timers.t[0]->i = 0;
-				siftdown(0);
-				t->i = -1;  // mark as removed
-			}
-			fv = t->fv;
-			f = (void*)t->fv->fn;
-			arg = t->arg;
-			seq = t->seq;
-			runtime_unlock(&timers);
-			__builtin_call_with_static_chain(f(arg, seq), fv);
-
-			// clear f and arg to avoid leak while sleeping for next timer
-			f = nil;
-			USED(f);
-			arg.__type_descriptor = nil;
-			arg.__object = nil;
-			USED(&arg);
-
-			runtime_lock(&timers);
-		}
-		if(delta < 0) {
-			// No timers left - put goroutine to sleep.
-			timers.rescheduling = true;
-			runtime_g()->isbackground = true;
-			runtime_parkunlock(&timers, "timer goroutine (idle)");
-			runtime_g()->isbackground = false;
-			continue;
-		}
-		// At least one timer pending.  Sleep until then.
-		timers.sleeping = true;
-		runtime_noteclear(&timers.waitnote);
-		runtime_unlock(&timers);
-		runtime_notetsleepg(&timers.waitnote, delta);
-	}
-}
-
-// heap maintenance algorithms.
-
-static void
-siftup(int32 i)
-{
-	int32 p;
-	int64 when;
-	Timer **t, *tmp;
-
-	t = timers.t;
-	when = t[i]->when;
-	tmp = t[i];
-	while(i > 0) {
-		p = (i-1)/4;  // parent
-		if(when >= t[p]->when)
-			break;
-		t[i] = t[p];
-		t[i]->i = i;
-		t[p] = tmp;
-		tmp->i = p;
-		i = p;
-	}
-}
-
-static void
-siftdown(int32 i)
-{
-	int32 c, c3, len;
-	int64 when, w, w3;
-	Timer **t, *tmp;
-
-	t = timers.t;
-	len = timers.len;
-	when = t[i]->when;
-	tmp = t[i];
-	for(;;) {
-		c = i*4 + 1;  // left child
-		c3 = c + 2;  // mid child
-		if(c >= len) {
-			break;
-		}
-		w = t[c]->when;
-		if(c+1 < len && t[c+1]->when < w) {
-			w = t[c+1]->when;
-			c++;
-		}
-		if(c3 < len) {
-			w3 = t[c3]->when;
-			if(c3+1 < len && t[c3+1]->when < w3) {
-				w3 = t[c3+1]->when;
-				c3++;
-			}
-			if(w3 < w) {
-				w = w3;
-				c = c3;
-			}
-		}
-		if(w >= when)
-			break;
-		t[i] = t[c];
-		t[i]->i = i;
-		t[c] = tmp;
-		tmp->i = c;
-		i = c;
-	}
-}
-
-static void
-dumptimers(const char *msg)
-{
-	Timer *t;
-	int32 i;
-
-	runtime_printf("timers: %s\n", msg);
-	for(i = 0; i < timers.len; i++) {
-		t = timers.t[i];
-		runtime_printf("\t%d\t%p:\ti %d when %D period %D fn %p\n",
-				i, t, t->i, t->when, t->period, t->fv->fn);
-	}
-	runtime_printf("\n");
-}
-
-void
-runtime_time_scan(struct Workbuf** wbufp, void (*enqueue1)(struct Workbuf**, Obj))
-{
-	enqueue1(wbufp, (Obj){(byte*)&timers, sizeof timers, 0});
-}