runtime: copy runtime package time code from Go 1.7
authorIan Lance Taylor <ian@gcc.gnu.org>
Sat, 15 Oct 2016 00:29:06 +0000 (00:29 +0000)
committerIan Lance Taylor <ian@gcc.gnu.org>
Sat, 15 Oct 2016 00:29:06 +0000 (00:29 +0000)
    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

12 files changed:
gcc/go/gofrontend/MERGE
gcc/go/gofrontend/types.cc
libgo/Makefile.am
libgo/Makefile.in
libgo/go/runtime/stubs.go
libgo/go/runtime/time.go [new file with mode: 0644]
libgo/runtime/go-nanotime.c
libgo/runtime/malloc.h
libgo/runtime/mgc0.c
libgo/runtime/netpoll.goc
libgo/runtime/runtime.h
libgo/runtime/time.goc [deleted file]

index 2e09ec1db85a37443e12f0813e54587d86bbd8d9..7d0643c7c4be7d13252e48f4b209019cc56e7e79 100644 (file)
@@ -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.
index 38613bb920ea82c99d149be6553c60e4d9303118..d99c834c6e400113d76f40f30c77bdba63142c15 100644 (file)
@@ -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:
index f90331fc5292b887fe1cab351003f0cf5b644650..9e19ad2d75c79d2f165fb654b4ff459a3be1ead9 100644 (file)
@@ -519,7 +519,6 @@ runtime_files = \
        reflect.c \
        runtime1.c \
        sigqueue.c \
-       time.c \
        $(runtime_getncpu_file)
 
 goc2c.$(OBJEXT): runtime/goc2c.c
index 1955ede5b5dd200226389222d9bba2db0c836fa6..4de7131817f67827ec7058e3a21d84ac51e99a1a 100644 (file)
@@ -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:
index e1c28fac5432d69f76fb47e21db9488a71e33185..477c6be1ab480d93e19d67a7607faf061182b4dd 100644 (file)
@@ -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 {
diff --git a/libgo/go/runtime/time.go b/libgo/go/runtime/time.go
new file mode 100644 (file)
index 0000000..d9a1d59
--- /dev/null
@@ -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()
+}
index 7e5e3e098a99101df3cb5883f4433095402da95f..d221847adac2b6f578e418303ad7d7c29f2a60e7 100644 (file)
@@ -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;
 }
index 011eaa91d0705a99748987d9f6595cdcab9a9d01..e674c885aa274009d1b8136aa11ee4e2b816f87b 100644 (file)
@@ -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));
index 2c8e5a8e643c97bbdb6b7a290329781f3542d325..0b96696ee4211bc4fb481f7b266102d605e46a18 100644 (file)
@@ -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;
 
index ecd426f19cc8e62b104c174cbe3cd407d97b0f61..9467c02bc52caca6ffe84ed8605cf770240146b6 100644 (file)
@@ -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);
index be19e9527ccb2f571c5d2fb2547f7953fa3152e7..f73d7450441e2476b86331cfc05f43bbcae76a46 100644 (file)
@@ -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 (file)
index b77ad33..0000000
+++ /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});
-}