runtime: change lockedg/lockedm to guintptr/muintptr

This change has no real effect in itself. This is to prepare for a
followup change that will call lockOSThread during a cgo callback when
there is no p assigned, and therefore when lockOSThread can not use a
write barrier.

Change-Id: Ia122d41acf54191864bcb68f393f2ed3b2f87abc
Reviewed-on: https://go-review.googlesource.com/63630
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

diff --git a/src/runtime/proc.go b/src/runtime/proc.go
index 98753551a9b9c3ddc2d75cdd2a9c394253d819e2..0e58838c880a9431d02adf144266198cde650416 100644 (file)
--- a/src/runtime/proc.go
+++ b/src/runtime/proc.go
@@ -429,7 +429,7 @@ func badctxt() {
 
 func lockedOSThread() bool {
        gp := getg()
-       return gp.lockedm != nil && gp.m.lockedg != nil
+       return gp.lockedm != 0 && gp.m.lockedg != 0
 }
 
 var (
@@ -1504,8 +1504,8 @@ func oneNewExtraM() {
        gp.m = mp
        mp.curg = gp
        mp.locked = _LockInternal
-       mp.lockedg = gp
-       gp.lockedm = mp
+       mp.lockedg.set(gp)
+       gp.lockedm.set(mp)
        gp.goid = int64(atomic.Xadd64(&sched.goidgen, 1))
        if raceenabled {
                gp.racectx = racegostart(funcPC(newextram) + sys.PCQuantum)
@@ -1819,7 +1819,7 @@ func wakep() {
 func stoplockedm() {
        _g_ := getg()
 
-       if _g_.m.lockedg == nil || _g_.m.lockedg.lockedm != _g_.m {
+       if _g_.m.lockedg == 0 || _g_.m.lockedg.ptr().lockedm.ptr() != _g_.m {
                throw("stoplockedm: inconsistent locking")
        }
        if _g_.m.p != 0 {
@@ -1831,7 +1831,7 @@ func stoplockedm() {
        // Wait until another thread schedules lockedg again.
        notesleep(&_g_.m.park)
        noteclear(&_g_.m.park)
-       status := readgstatus(_g_.m.lockedg)
+       status := readgstatus(_g_.m.lockedg.ptr())
        if status&^_Gscan != _Grunnable {
                print("runtime:stoplockedm: g is not Grunnable or Gscanrunnable\n")
                dumpgstatus(_g_)
@@ -1847,7 +1847,7 @@ func stoplockedm() {
 func startlockedm(gp *g) {
        _g_ := getg()
 
-       mp := gp.lockedm
+       mp := gp.lockedm.ptr()
        if mp == _g_.m {
                throw("startlockedm: locked to me")
        }
@@ -2214,9 +2214,9 @@ func schedule() {
                throw("schedule: holding locks")
        }
 
-       if _g_.m.lockedg != nil {
+       if _g_.m.lockedg != 0 {
                stoplockedm()
-               execute(_g_.m.lockedg, false) // Never returns.
+               execute(_g_.m.lockedg.ptr(), false) // Never returns.
        }
 
 top:
@@ -2267,7 +2267,7 @@ top:
                resetspinning()
        }
 
-       if gp.lockedm != nil {
+       if gp.lockedm != 0 {
                // Hands off own p to the locked m,
                // then blocks waiting for a new p.
                startlockedm(gp)
@@ -2386,8 +2386,8 @@ func goexit0(gp *g) {
                atomic.Xadd(&sched.ngsys, -1)
        }
        gp.m = nil
-       gp.lockedm = nil
-       _g_.m.lockedg = nil
+       gp.lockedm = 0
+       _g_.m.lockedg = 0
        gp.paniconfault = false
        gp._defer = nil // should be true already but just in case.
        gp._panic = nil // non-nil for Goexit during panic. points at stack-allocated data.
@@ -2815,7 +2815,7 @@ func exitsyscall0(gp *g) {
                acquirep(_p_)
                execute(gp, false) // Never returns.
        }
-       if _g_.m.lockedg != nil {
+       if _g_.m.lockedg != 0 {
                // Wait until another thread schedules gp and so m again.
                stoplockedm()
                execute(gp, false) // Never returns.
@@ -3165,8 +3165,8 @@ func Breakpoint() {
 //go:nosplit
 func dolockOSThread() {
        _g_ := getg()
-       _g_.m.lockedg = _g_
-       _g_.lockedm = _g_.m
+       _g_.m.lockedg.set(_g_)
+       _g_.lockedm.set(_g_.m)
 }
 
 //go:nosplit
@@ -3194,8 +3194,8 @@ func dounlockOSThread() {
        if _g_.m.locked != 0 {
                return
        }
-       _g_.m.lockedg = nil
-       _g_.lockedm = nil
+       _g_.m.lockedg = 0
+       _g_.lockedm = 0
 }
 
 //go:nosplit
@@ -4102,7 +4102,7 @@ func schedtrace(detailed bool) {
        for mp := allm; mp != nil; mp = mp.alllink {
                _p_ := mp.p.ptr()
                gp := mp.curg
-               lockedg := mp.lockedg
+               lockedg := mp.lockedg.ptr()
                id1 := int32(-1)
                if _p_ != nil {
                        id1 = _p_.id
@@ -4122,7 +4122,7 @@ func schedtrace(detailed bool) {
        for gi := 0; gi < len(allgs); gi++ {
                gp := allgs[gi]
                mp := gp.m
-               lockedm := gp.lockedm
+               lockedm := gp.lockedm.ptr()
                id1 := int32(-1)
                if mp != nil {
                        id1 = mp.id

diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go
index b439a3197600edd539172efa79594a248864ac90..15adfc74ec709556970b2553fe9a097a20f5564a 100644 (file)
--- a/src/runtime/runtime2.go
+++ b/src/runtime/runtime2.go
@@ -357,7 +357,7 @@ type g struct {
        sysexitticks   int64    // cputicks when syscall has returned (for tracing)
        traceseq       uint64   // trace event sequencer
        tracelastp     puintptr // last P emitted an event for this goroutine
-       lockedm        *m
+       lockedm        muintptr
        sig            uint32
        writebuf       []byte
        sigcode0       uintptr
@@ -423,7 +423,7 @@ type m struct {
        alllink       *m // on allm
        schedlink     muintptr
        mcache        *mcache
-       lockedg       *g
+       lockedg       guintptr
        createstack   [32]uintptr // stack that created this thread.
        freglo        [16]uint32  // d[i] lsb and f[i]
        freghi        [16]uint32  // d[i] msb and f[i+16]

diff --git a/src/runtime/signal_sighandler.go b/src/runtime/signal_sighandler.go
index b2e15a653924980879ec2c505bf06256a9c05510..672d7828ff677f76750d9b161f84366dc317e0ed 100644 (file)
--- a/src/runtime/signal_sighandler.go
+++ b/src/runtime/signal_sighandler.go
@@ -88,9 +88,9 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
        }
 
        print("PC=", hex(c.sigpc()), " m=", _g_.m.id, " sigcode=", c.sigcode(), "\n")
-       if _g_.m.lockedg != nil && _g_.m.ncgo > 0 && gp == _g_.m.g0 {
+       if _g_.m.lockedg != 0 && _g_.m.ncgo > 0 && gp == _g_.m.g0 {
                print("signal arrived during cgo execution\n")
-               gp = _g_.m.lockedg
+               gp = _g_.m.lockedg.ptr()
        }
        print("\n")
 

diff --git a/src/runtime/signal_windows.go b/src/runtime/signal_windows.go
index 73bd5b5cfcedc5e306ef14fd213e3a35e2ed3a1b..b26be5f30b3b6f0fded8e4808b95a7e9c34fd2db 100644 (file)
--- a/src/runtime/signal_windows.go
+++ b/src/runtime/signal_windows.go
@@ -126,11 +126,11 @@ func lastcontinuehandler(info *exceptionrecord, r *context, gp *g) int32 {
        print("Exception ", hex(info.exceptioncode), " ", hex(info.exceptioninformation[0]), " ", hex(info.exceptioninformation[1]), " ", hex(r.ip()), "\n")
 
        print("PC=", hex(r.ip()), "\n")
-       if _g_.m.lockedg != nil && _g_.m.ncgo > 0 && gp == _g_.m.g0 {
+       if _g_.m.lockedg != 0 && _g_.m.ncgo > 0 && gp == _g_.m.g0 {
                if iscgo {
                        print("signal arrived during external code execution\n")
                }
-               gp = _g_.m.lockedg
+               gp = _g_.m.lockedg.ptr()
        }
        print("\n")
 

diff --git a/src/runtime/traceback.go b/src/runtime/traceback.go
index c74d4387576281c57dd8e743b66ba24da97ea303..c43ed9c732b6a7e6ec1693f229a47529d4e6ff78 100644 (file)
--- a/src/runtime/traceback.go
+++ b/src/runtime/traceback.go
@@ -795,7 +795,7 @@ func goroutineheader(gp *g) {
        if waitfor >= 1 {
                print(", ", waitfor, " minutes")
        }
-       if gp.lockedm != nil {
+       if gp.lockedm != 0 {
                print(", locked to thread")
        }
        print("]:\n")