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

6 files changed, 25 insertions, 413 deletions

diff --git a/libgo/runtime/go-nanotime.c b/libgo/runtime/go-nanotime.c
index 7e5e3e0..d221847 100644
--- a/libgo/runtime/go-nanotime.c
+++ b/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;
 }
diff --git a/libgo/runtime/malloc.h b/libgo/runtime/malloc.h
index 011eaa9..e674c88 100644
--- a/libgo/runtime/malloc.h
+++ b/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));
diff --git a/libgo/runtime/mgc0.c b/libgo/runtime/mgc0.c
index 2c8e5a8..0b96696 100644
--- a/libgo/runtime/mgc0.c
+++ b/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;
 
diff --git a/libgo/runtime/netpoll.goc b/libgo/runtime/netpoll.goc
index ecd426f..9467c02 100644
--- a/libgo/runtime/netpoll.goc
+++ b/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);
diff --git a/libgo/runtime/runtime.h b/libgo/runtime/runtime.h
index be19e95..f73d745 100644
--- a/libgo/runtime/runtime.h
+++ b/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*);
diff --git a/libgo/runtime/time.goc b/libgo/runtime/time.goc
deleted file mode 100644
index b77ad33..0000000
--- a/libgo/runtime/time.goc
+++ /dev/null
@@ -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});
-}