diff options
Diffstat (limited to 'libgo/go/runtime/proc.go')
| -rw-r--r-- | libgo/go/runtime/proc.go | 51 |
1 files changed, 50 insertions, 1 deletions
diff --git a/libgo/go/runtime/proc.go b/libgo/go/runtime/proc.go index bb16924e01c..ef166cb9d28 100644 --- a/libgo/go/runtime/proc.go +++ b/libgo/go/runtime/proc.go @@ -528,6 +528,8 @@ func schedinit() { sched.maxmcount = 10000 + usestackmaps = probestackmaps() + mallocinit() mcommoninit(_g_.m) cpuinit() // must run before alginit @@ -891,7 +893,49 @@ loop: case _Gcopystack: // Stack being switched. Go around again. - case _Grunnable, _Gsyscall, _Gwaiting: + case _Gsyscall: + if usestackmaps { + // Claim goroutine by setting scan bit. + // Racing with execution or readying of gp. + // The scan bit keeps them from running + // the goroutine until we're done. + if castogscanstatus(gp, s, s|_Gscan) { + if gp.scanningself { + // Don't try to scan the stack + // if the goroutine is going to do + // it itself. + // FIXME: can this happen? + restartg(gp) + break + } + if !gp.gcscandone { + // Send a signal to let the goroutine scan + // itself. This races with enter/exitsyscall. + // If the goroutine is not stopped at a safepoint, + // it will not scan the stack and we'll try again. + mp := gp.m + noteclear(&mp.scannote) + gp.scangcw = uintptr(unsafe.Pointer(gcw)) + tgkill(getpid(), _pid_t(mp.procid), _SIGURG) + + // Wait for gp to scan its own stack. + notesleep(&mp.scannote) + + if !gp.gcscandone { + // The signal delivered at a bad time. + // Try again. + restartg(gp) + break + } + } + restartg(gp) + break loop + } + break + } + fallthrough + + case _Grunnable, _Gwaiting: // Claim goroutine by setting scan bit. // Racing with execution or readying of gp. // The scan bit keeps them from running @@ -954,6 +998,11 @@ loop: // The GC requests that this routine be moved from a scanmumble state to a mumble state. func restartg(gp *g) { + if gp.scang != 0 || gp.scangcw != 0 { + print("g ", gp.goid, "is being scanned scang=", gp.scang, " scangcw=", gp.scangcw, "\n") + throw("restartg: being scanned") + } + s := readgstatus(gp) switch s { default: |