diff options
Diffstat (limited to 'src/runtime/signal_unix.go')
| -rw-r--r-- | src/runtime/signal_unix.go | 36 |
1 files changed, 29 insertions, 7 deletions
diff --git a/src/runtime/signal_unix.go b/src/runtime/signal_unix.go index a3d6f34c88..bf4a319b37 100644 --- a/src/runtime/signal_unix.go +++ b/src/runtime/signal_unix.go @@ -335,6 +335,10 @@ func doSigPreempt(gp *g, ctxt *sigctxt) { // Acknowledge the preemption. atomic.Xadd(&gp.m.preemptGen, 1) atomic.Store(&gp.m.signalPending, 0) + + if GOOS == "darwin" { + atomic.Xadd(&pendingPreemptSignals, -1) + } } const preemptMSupported = true @@ -356,7 +360,18 @@ func preemptM(mp *m) { // required). return } + + // On Darwin, don't try to preempt threads during exec. + // Issue #41702. + if GOOS == "darwin" { + execLock.rlock() + } + if atomic.Cas(&mp.signalPending, 0, 1) { + if GOOS == "darwin" { + atomic.Xadd(&pendingPreemptSignals, 1) + } + // If multiple threads are preempting the same M, it may send many // signals to the same M such that it hardly make progress, causing // live-lock problem. Apparently this could happen on darwin. See @@ -364,6 +379,10 @@ func preemptM(mp *m) { // Only send a signal if there isn't already one pending. signalM(mp, sigPreempt) } + + if GOOS == "darwin" { + execLock.runlock() + } } // sigFetchG fetches the value of G safely when running in a signal handler. @@ -424,6 +443,9 @@ func sigtrampgo(sig uint32, info *siginfo, ctx unsafe.Pointer) { // no non-Go signal handler for sigPreempt. // The default behavior for sigPreempt is to ignore // the signal, so badsignal will be a no-op anyway. + if GOOS == "darwin" { + atomic.Xadd(&pendingPreemptSignals, -1) + } return } c.fixsigcode(sig) @@ -482,14 +504,14 @@ func adjustSignalStack(sig uint32, mp *m, gsigStack *gsignalStack) bool { sigaltstack(nil, &st) if st.ss_flags&_SS_DISABLE != 0 { setg(nil) - needm(0) + needm() noSignalStack(sig) dropm() } stsp := uintptr(unsafe.Pointer(st.ss_sp)) if sp < stsp || sp >= stsp+st.ss_size { setg(nil) - needm(0) + needm() sigNotOnStack(sig) dropm() } @@ -929,7 +951,7 @@ func badsignal(sig uintptr, c *sigctxt) { exit(2) *(*uintptr)(unsafe.Pointer(uintptr(123))) = 2 } - needm(0) + needm() if !sigsend(uint32(sig)) { // A foreign thread received the signal sig, and the // Go code does not want to handle it. @@ -1009,15 +1031,15 @@ func sigfwdgo(sig uint32, info *siginfo, ctx unsafe.Pointer) bool { return true } -// msigsave saves the current thread's signal mask into mp.sigmask. +// sigsave saves the current thread's signal mask into *p. // This is used to preserve the non-Go signal mask when a non-Go // thread calls a Go function. // This is nosplit and nowritebarrierrec because it is called by needm // which may be called on a non-Go thread with no g available. //go:nosplit //go:nowritebarrierrec -func msigsave(mp *m) { - sigprocmask(_SIG_SETMASK, nil, &mp.sigmask) +func sigsave(p *sigset) { + sigprocmask(_SIG_SETMASK, nil, p) } // msigrestore sets the current thread's signal mask to sigmask. @@ -1089,7 +1111,7 @@ func minitSignalStack() { // thread's signal mask. When this is called all signals have been // blocked for the thread. This starts with m.sigmask, which was set // either from initSigmask for a newly created thread or by calling -// msigsave if this is a non-Go thread calling a Go function. It +// sigsave if this is a non-Go thread calling a Go function. It // removes all essential signals from the mask, thus causing those // signals to not be blocked. Then it sets the thread's signal mask. // After this is called the thread can receive signals. |