From 21cfadf0dc1e93c339e319c502f14ee42973c44d Mon Sep 17 00:00:00 2001 From: Cherry Zhang Date: Thu, 3 Dec 2020 16:53:30 -0500 Subject: [PATCH] runtime: avoid receiving preemotion signal while exec'ing The iOS kernel has the same problem as the macOS kernel. Extend the workaround of #41702 (CL 262438 and CL 262817) to iOS. Updates #35851. Change-Id: I7ccec00dc96643c08c5be8b385394856d0fa0f64 Reviewed-on: https://go-review.googlesource.com/c/go/+/275293 Trust: Cherry Zhang Reviewed-by: Ian Lance Taylor --- src/runtime/proc.go | 4 ++-- src/runtime/signal_unix.go | 10 +++++----- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/src/runtime/proc.go b/src/runtime/proc.go index 0319de5fde..64e102fb0a 100644 --- a/src/runtime/proc.go +++ b/src/runtime/proc.go @@ -1363,7 +1363,7 @@ found: checkdead() unlock(&sched.lock) - if GOOS == "darwin" { + if GOOS == "darwin" || GOOS == "ios" { // Make sure pendingPreemptSignals is correct when an M exits. // For #41702. if atomic.Load(&m.signalPending) != 0 { @@ -3852,7 +3852,7 @@ func syscall_runtime_BeforeExec() { // On Darwin, wait for all pending preemption signals to // be received. See issue #41702. - if GOOS == "darwin" { + if GOOS == "darwin" || GOOS == "ios" { for int32(atomic.Load(&pendingPreemptSignals)) > 0 { osyield() } diff --git a/src/runtime/signal_unix.go b/src/runtime/signal_unix.go index 6aad079f03..e8f39c3321 100644 --- a/src/runtime/signal_unix.go +++ b/src/runtime/signal_unix.go @@ -336,7 +336,7 @@ func doSigPreempt(gp *g, ctxt *sigctxt) { atomic.Xadd(&gp.m.preemptGen, 1) atomic.Store(&gp.m.signalPending, 0) - if GOOS == "darwin" { + if GOOS == "darwin" || GOOS == "ios" { atomic.Xadd(&pendingPreemptSignals, -1) } } @@ -352,12 +352,12 @@ const preemptMSupported = true func preemptM(mp *m) { // On Darwin, don't try to preempt threads during exec. // Issue #41702. - if GOOS == "darwin" { + if GOOS == "darwin" || GOOS == "ios" { execLock.rlock() } if atomic.Cas(&mp.signalPending, 0, 1) { - if GOOS == "darwin" { + if GOOS == "darwin" || GOOS == "ios" { atomic.Xadd(&pendingPreemptSignals, 1) } @@ -369,7 +369,7 @@ func preemptM(mp *m) { signalM(mp, sigPreempt) } - if GOOS == "darwin" { + if GOOS == "darwin" || GOOS == "ios" { execLock.runlock() } } @@ -432,7 +432,7 @@ 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" { + if GOOS == "darwin" || GOOS == "ios" { atomic.Xadd(&pendingPreemptSignals, -1) } return -- 2.48.1