1 files changed, 119 insertions, 0 deletions
diff --git a/vendor/github.com/modern-go/concurrent/unbounded_executor.go b/vendor/github.com/modern-go/concurrent/unbounded_executor.go
new file mode 100644
index 00000000..05a77dce
--- /dev/null
+++ b/vendor/github.com/modern-go/concurrent/unbounded_executor.go
@@ -0,0 +1,119 @@
+package concurrent
+
+import (
+	"context"
+	"fmt"
+	"runtime"
+	"runtime/debug"
+	"sync"
+	"time"
+	"reflect"
+)
+
+// HandlePanic logs goroutine panic by default
+var HandlePanic = func(recovered interface{}, funcName string) {
+	ErrorLogger.Println(fmt.Sprintf("%s panic: %v", funcName, recovered))
+	ErrorLogger.Println(string(debug.Stack()))
+}
+
+// UnboundedExecutor is a executor without limits on counts of alive goroutines
+// it tracks the goroutine started by it, and can cancel them when shutdown
+type UnboundedExecutor struct {
+	ctx                   context.Context
+	cancel                context.CancelFunc
+	activeGoroutinesMutex *sync.Mutex
+	activeGoroutines      map[string]int
+	HandlePanic           func(recovered interface{}, funcName string)
+}
+
+// GlobalUnboundedExecutor has the life cycle of the program itself
+// any goroutine want to be shutdown before main exit can be started from this executor
+// GlobalUnboundedExecutor expects the main function to call stop
+// it does not magically knows the main function exits
+var GlobalUnboundedExecutor = NewUnboundedExecutor()
+
+// NewUnboundedExecutor creates a new UnboundedExecutor,
+// UnboundedExecutor can not be created by &UnboundedExecutor{}
+// HandlePanic can be set with a callback to override global HandlePanic
+func NewUnboundedExecutor() *UnboundedExecutor {
+	ctx, cancel := context.WithCancel(context.TODO())
+	return &UnboundedExecutor{
+		ctx:                   ctx,
+		cancel:                cancel,
+		activeGoroutinesMutex: &sync.Mutex{},
+		activeGoroutines:      map[string]int{},
+	}
+}
+
+// Go starts a new goroutine and tracks its lifecycle.
+// Panic will be recovered and logged automatically, except for StopSignal
+func (executor *UnboundedExecutor) Go(handler func(ctx context.Context)) {
+	pc := reflect.ValueOf(handler).Pointer()
+	f := runtime.FuncForPC(pc)
+	funcName := f.Name()
+	file, line := f.FileLine(pc)
+	executor.activeGoroutinesMutex.Lock()
+	defer executor.activeGoroutinesMutex.Unlock()
+	startFrom := fmt.Sprintf("%s:%d", file, line)
+	executor.activeGoroutines[startFrom] += 1
+	go func() {
+		defer func() {
+			recovered := recover()
+			// if you want to quit a goroutine without trigger HandlePanic
+			// use runtime.Goexit() to quit
+			if recovered != nil {
+				if executor.HandlePanic == nil {
+					HandlePanic(recovered, funcName)
+				} else {
+					executor.HandlePanic(recovered, funcName)
+				}
+			}
+			executor.activeGoroutinesMutex.Lock()
+			executor.activeGoroutines[startFrom] -= 1
+			executor.activeGoroutinesMutex.Unlock()
+		}()
+		handler(executor.ctx)
+	}()
+}
+
+// Stop cancel all goroutines started by this executor without wait
+func (executor *UnboundedExecutor) Stop() {
+	executor.cancel()
+}
+
+// StopAndWaitForever cancel all goroutines started by this executor and
+// wait until all goroutines exited
+func (executor *UnboundedExecutor) StopAndWaitForever() {
+	executor.StopAndWait(context.Background())
+}
+
+// StopAndWait cancel all goroutines started by this executor and wait.
+// Wait can be cancelled by the context passed in.
+func (executor *UnboundedExecutor) StopAndWait(ctx context.Context) {
+	executor.cancel()
+	for {
+		oneHundredMilliseconds := time.NewTimer(time.Millisecond * 100)
+		select {
+		case <-oneHundredMilliseconds.C:
+			if executor.checkNoActiveGoroutines() {
+				return
+			}
+		case <-ctx.Done():
+			return
+		}
+	}
+}
+
+func (executor *UnboundedExecutor) checkNoActiveGoroutines() bool {
+	executor.activeGoroutinesMutex.Lock()
+	defer executor.activeGoroutinesMutex.Unlock()
+	for startFrom, count := range executor.activeGoroutines {
+		if count > 0 {
+			InfoLogger.Println("UnboundedExecutor is still waiting goroutines to quit",
+				"startFrom", startFrom,
+				"count", count)
+			return false
+		}
+	}
+	return true
+}