From 6f54066c43172fe0197e82fb1034c9ae55d1e1f2 Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Sat, 27 Apr 2019 15:02:52 +0300
Subject: Add partial deadlock detection in debug mode

---
 debug/debug.go | 59 ++++++++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 47 insertions(+), 12 deletions(-)

(limited to 'debug')

diff --git a/debug/debug.go b/debug/debug.go
index 573cff7..741bb7a 100644
--- a/debug/debug.go
+++ b/debug/debug.go
@@ -22,40 +22,75 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"path/filepath"
 	"runtime/debug"
 	"time"
+
+	"github.com/sasha-s/go-deadlock"
 )
 
 var writer io.Writer
 var RecoverPrettyPanic bool
+var DeadlockDetection bool
+var WriteLogs bool
 var OnRecover func()
+var LogDirectory = filepath.Join(os.TempDir(), "gomuks")
 
-func init() {
-	var err error
-	writer, err = os.OpenFile("/tmp/gomuks-debug.log", os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0644)
+func Initialize() {
+	err := os.MkdirAll(LogDirectory, 0750)
 	if err != nil {
-		writer = nil
+		RecoverPrettyPanic = false
+		DeadlockDetection = false
+		WriteLogs = false
+		return
+	}
+
+	if WriteLogs {
+		writer, err = os.OpenFile(filepath.Join(LogDirectory, "debug.log"), os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0640)
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	_, _ = fmt.Fprintf(writer, "======================= Debug init @ %s =======================\n", time.Now().Format("2006-01-02 15:04:05"))
+	if DeadlockDetection {
+		deadlocks, err := os.OpenFile(filepath.Join(LogDirectory, "deadlock.log"), os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0640)
+		if err != nil {
+			panic(err)
+		}
+		deadlock.Opts.LogBuf = deadlocks
+		deadlock.Opts.OnPotentialDeadlock = func() {
+			if OnRecover != nil {
+				OnRecover()
+			}
+			os.Exit(88)
+		}
+		_, err = fmt.Fprintf(deadlocks, "======================= Debug init @ %s =======================\n", time.Now().Format("2006-01-02 15:04:05"))
+		if err != nil {
+			panic(err)
+		}
+	} else {
+		deadlock.Opts.Disable = true
 	}
 }
 
 func Printf(text string, args ...interface{}) {
 	if writer != nil {
-		fmt.Fprintf(writer, time.Now().Format("[2006-01-02 15:04:05] "))
-		fmt.Fprintf(writer, text+"\n", args...)
+		_, _ = fmt.Fprintf(writer, time.Now().Format("[2006-01-02 15:04:05] "))
+		_, _ = fmt.Fprintf(writer, text+"\n", args...)
 	}
 }
 
 func Print(text ...interface{}) {
 	if writer != nil {
-		fmt.Fprintf(writer, time.Now().Format("[2006-01-02 15:04:05] "))
-		fmt.Fprintln(writer, text...)
+		_, _ = fmt.Fprintf(writer, time.Now().Format("[2006-01-02 15:04:05] "))
+		_, _ = fmt.Fprintln(writer, text...)
 	}
 }
 
 func PrintStack() {
 	if writer != nil {
-		data := debug.Stack()
-		writer.Write(data)
+		_, _ = writer.Write(debug.Stack())
 	}
 }
 
@@ -90,10 +125,10 @@ A fatal error has occurred.
 
 func PrettyPanic(panic interface{}) {
 	fmt.Print(Oops)
-	traceFile := fmt.Sprintf("/tmp/gomuks-panic-%s.txt", time.Now().Format("2006-01-02--15-04-05"))
+	traceFile := fmt.Sprintf(filepath.Join(LogDirectory, "panic-%s.txt"), time.Now().Format("2006-01-02--15-04-05"))
 
 	var buf bytes.Buffer
-	fmt.Fprintln(&buf, panic)
+	_, _ = fmt.Fprintln(&buf, panic)
 	buf.Write(debug.Stack())
 	err := ioutil.WriteFile(traceFile, buf.Bytes(), 0640)
 
-- 
cgit v1.2.3