Use dep to vendor things

vendor/github.com/faiface/mainthread/mainthread.go

@@ -0,0 +1,87 @@
+package mainthread
+
+import (
+	"errors"
+	"runtime"
+)
+
+// CallQueueCap is the capacity of the call queue. This means how many calls to CallNonBlock will not
+// block until some call finishes.
+//
+// The default value is 16 and should be good for 99% usecases.
+var CallQueueCap = 16
+
+var (
+	callQueue chan func()
+)
+
+func init() {
+	runtime.LockOSThread()
+}
+
+func checkRun() {
+	if callQueue == nil {
+		panic(errors.New("mainthread: did not call Run"))
+	}
+}
+
+// Run enables mainthread package functionality. To use mainthread package, put your main function
+// code into the run function (the argument to Run) and simply call Run from the real main function.
+//
+// Run returns when run (argument) function finishes.
+func Run(run func()) {
+	callQueue = make(chan func(), CallQueueCap)
+
+	done := make(chan struct{})
+	go func() {
+		run()
+		done <- struct{}{}
+	}()
+
+	for {
+		select {
+		case f := <-callQueue:
+			f()
+		case <-done:
+			return
+		}
+	}
+}
+
+// CallNonBlock queues function f on the main thread and returns immediately. Does not wait until f
+// finishes.
+func CallNonBlock(f func()) {
+	checkRun()
+	callQueue <- f
+}
+
+// Call queues function f on the main thread and blocks until the function f finishes.
+func Call(f func()) {
+	checkRun()
+	done := make(chan struct{})
+	callQueue <- func() {
+		f()
+		done <- struct{}{}
+	}
+	<-done
+}
+
+// CallErr queues function f on the main thread and returns an error returned by f.
+func CallErr(f func() error) error {
+	checkRun()
+	errChan := make(chan error)
+	callQueue <- func() {
+		errChan <- f()
+	}
+	return <-errChan
+}
+
+// CallVal queues function f on the main thread and returns a value returned by f.
+func CallVal(f func() interface{}) interface{} {
+	checkRun()
+	respChan := make(chan interface{})
+	callQueue <- func() {
+		respChan <- f()
+	}
+	return <-respChan
+}