add deadlock mutex package

write to deadlock stderr after closing gocui

more deadlock checking

vendor/github.com/sasha-s/go-deadlock/stacktraces.go

@@ -0,0 +1,107 @@
+package deadlock
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/user"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"sync"
+)
+
+func callers(skip int) []uintptr {
+	s := make([]uintptr, 50) // Most relevant context seem to appear near the top of the stack.
+	return s[:runtime.Callers(2+skip, s)]
+}
+
+func printStack(w io.Writer, stack []uintptr) {
+	home := os.Getenv("HOME")
+	usr, err := user.Current()
+	if err == nil {
+		home = usr.HomeDir
+	}
+	cwd, _ := os.Getwd()
+
+	for i, pc := range stack {
+		f := runtime.FuncForPC(pc)
+		name := f.Name()
+		pkg := ""
+		if pos := strings.LastIndex(name, "/"); pos >= 0 {
+			name = name[pos+1:]
+		}
+		if pos := strings.Index(name, "."); pos >= 0 {
+			pkg = name[:pos]
+			name = name[pos+1:]
+		}
+		file, line := f.FileLine(pc)
+		if (pkg == "runtime" && name == "goexit") || (pkg == "testing" && name == "tRunner") {
+			fmt.Fprintln(w)
+			return
+		}
+		tail := ""
+		if i == 0 {
+			tail = " <<<<<" // Make the line performing a lock prominent.
+		}
+		// Shorten the file name.
+		clean := file
+		if cwd != "" {
+			cl, err := filepath.Rel(cwd, file)
+			if err == nil {
+				clean = cl
+			}
+		}
+		if home != "" {
+			s2 := strings.Replace(file, home, "~", 1)
+			if len(clean) > len(s2) {
+				clean = s2
+			}
+		}
+		fmt.Fprintf(w, "%s:%d %s.%s %s%s\n", clean, line-1, pkg, name, code(file, line), tail)
+	}
+	fmt.Fprintln(w)
+}
+
+var fileSources struct {
+	sync.Mutex
+	lines map[string][][]byte
+}
+
+// Reads souce file lines from disk if not cached already.
+func getSourceLines(file string) [][]byte {
+	fileSources.Lock()
+	defer fileSources.Unlock()
+	if fileSources.lines == nil {
+		fileSources.lines = map[string][][]byte{}
+	}
+	if lines, ok := fileSources.lines[file]; ok {
+		return lines
+	}
+	text, _ := ioutil.ReadFile(file)
+	fileSources.lines[file] = bytes.Split(text, []byte{'\n'})
+	return fileSources.lines[file]
+}
+
+func code(file string, line int) string {
+	lines := getSourceLines(file)
+	line -= 2
+	if line >= len(lines) || line < 0 {
+		return "???"
+	}
+	return "{ " + string(bytes.TrimSpace(lines[line])) + " }"
+}
+
+// Stacktraces for all goroutines.
+func stacks() []byte {
+	buf := make([]byte, 1024*16)
+	for {
+		n := runtime.Stack(buf, true)
+		if n < len(buf) {
+			return buf[:n]
+		}
+		buf = make([]byte, 2*len(buf))
+	}
+}