Cut the multiproduct_kati -> soong-ui-build dep.
This is done by moving SetupSignals() to its own little package.
There are a number of tiny little utility packages for soong_ui we might
be better of merging, but that's for another change (maybe)
Test: Presubmits.
Change-Id: I07b0ca98bfb8884ef4223d665e632183b9896a0d
diff --git a/ui/signal/signal.go b/ui/signal/signal.go
new file mode 100644
index 0000000..4929a7b
--- /dev/null
+++ b/ui/signal/signal.go
@@ -0,0 +1,94 @@
+// Copyright 2017 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package signal
+
+import (
+ "os"
+ "os/signal"
+ "runtime/debug"
+ "syscall"
+
+ "android/soong/ui/logger"
+ "time"
+)
+
+// SetupSignals sets up signal handling to ensure all of our subprocesses are killed and that
+// our log/trace buffers are flushed to disk.
+//
+// All of our subprocesses are in the same process group, so they'll receive a SIGINT at the
+// same time we do. Most of the time this means we just need to ignore the signal and we'll
+// just see errors from all of our subprocesses. But in case that fails, when we get a signal:
+//
+// 1. Wait two seconds to exit normally.
+// 2. Call cancel() which is normally the cancellation of a Context. This will send a SIGKILL
+// to any subprocesses attached to that context.
+// 3. Wait two seconds to exit normally.
+// 4. Call cleanup() to close the log/trace buffers, then panic.
+// 5. If another two seconds passes (if cleanup got stuck, etc), then panic.
+//
+func SetupSignals(log logger.Logger, cancel, cleanup func()) {
+ signals := make(chan os.Signal, 5)
+ signal.Notify(signals, os.Interrupt, syscall.SIGHUP, syscall.SIGQUIT, syscall.SIGTERM)
+ go handleSignals(signals, log, cancel, cleanup)
+}
+
+func handleSignals(signals chan os.Signal, log logger.Logger, cancel, cleanup func()) {
+ var timeouts int
+ var timeout <-chan time.Time
+
+ handleTimeout := func() {
+ timeouts += 1
+ switch timeouts {
+ case 1:
+ // Things didn't exit cleanly, cancel our ctx (SIGKILL to subprocesses)
+ // Do this asynchronously to ensure it won't block and prevent us from
+ // taking more drastic measures.
+ log.Println("Still alive, killing subprocesses...")
+ go cancel()
+ case 2:
+ // Cancel didn't work. Try to run cleanup manually, then we'll panic
+ // at the next timer whether it finished or not.
+ log.Println("Still alive, cleaning up...")
+
+ // Get all stacktraces to see what was stuck
+ debug.SetTraceback("all")
+
+ go func() {
+ defer log.Panicln("Timed out exiting...")
+ cleanup()
+ }()
+ default:
+ // In case cleanup() deadlocks, the next tick will panic.
+ log.Panicln("Got signal, but timed out exiting...")
+ }
+ }
+
+ for {
+ select {
+ case s := <-signals:
+ log.Println("Got signal:", s)
+
+ // Another signal triggers our next timeout handler early
+ if timeout != nil {
+ handleTimeout()
+ }
+
+ // Wait 2 seconds for everything to exit cleanly.
+ timeout = time.Tick(time.Second * 2)
+ case <-timeout:
+ handleTimeout()
+ }
+ }
+}