1 files changed, 122 insertions, 0 deletions
diff --git a/internal/state.go b/internal/state.go
new file mode 100755
index 00000000..8f7d939b
--- /dev/null
+++ b/internal/state.go
@@ -0,0 +1,122 @@
+package internal
+
+import (
+	"fmt"
+	"sync/atomic"
+)
+
+// State represents WorkerProcess status and updated time.
+type State interface {
+	fmt.Stringer
+	// Value returns WorkerState value
+	Value() int64
+	// Set sets the WorkerState
+	Set(value int64)
+	// NumJobs shows how many times WorkerProcess was invoked
+	NumExecs() int64
+	// IsActive returns true if WorkerProcess not Inactive or Stopped
+	IsActive() bool
+	// RegisterExec using to registering php executions
+	RegisterExec()
+	// SetLastUsed sets worker last used time
+	SetLastUsed(lu uint64)
+	// LastUsed return worker last used time
+	LastUsed() uint64
+}
+
+const (
+	// StateInactive - no associated process
+	StateInactive int64 = iota
+
+	// StateReady - ready for job.
+	StateReady
+
+	// StateWorking - working on given payload.
+	StateWorking
+
+	// StateInvalid - indicates that WorkerProcess is being disabled and will be removed.
+	StateInvalid
+
+	// StateStopping - process is being softly stopped.
+	StateStopping
+
+	StateKilling
+
+	// State of worker, when no need to allocate new one
+	StateDestroyed
+
+	// StateStopped - process has been terminated.
+	StateStopped
+
+	// StateErrored - error WorkerState (can't be used).
+	StateErrored
+
+	StateRemove
+)
+
+type WorkerState struct {
+	value    int64
+	numExecs int64
+	// to be lightweight, use UnixNano
+	lastUsed uint64
+}
+
+// Thread safe
+func NewWorkerState(value int64) *WorkerState {
+	return &WorkerState{value: value}
+}
+
+// String returns current WorkerState as string.
+func (s *WorkerState) String() string {
+	switch s.Value() {
+	case StateInactive:
+		return "inactive"
+	case StateReady:
+		return "ready"
+	case StateWorking:
+		return "working"
+	case StateInvalid:
+		return "invalid"
+	case StateStopped:
+		return "stopped"
+	case StateErrored:
+		return "errored"
+	}
+
+	return "undefined"
+}
+
+// NumExecs returns number of registered WorkerProcess execs.
+func (s *WorkerState) NumExecs() int64 {
+	return atomic.LoadInt64(&s.numExecs)
+}
+
+// Value WorkerState returns WorkerState value
+func (s *WorkerState) Value() int64 {
+	return atomic.LoadInt64(&s.value)
+}
+
+// IsActive returns true if WorkerProcess not Inactive or Stopped
+func (s *WorkerState) IsActive() bool {
+	val := s.Value()
+	return val == StateWorking || val == StateReady
+}
+
+// change WorkerState value (status)
+func (s *WorkerState) Set(value int64) {
+	atomic.StoreInt64(&s.value, value)
+}
+
+// register new execution atomically
+func (s *WorkerState) RegisterExec() {
+	atomic.AddInt64(&s.numExecs, 1)
+}
+
+// Update last used time
+func (s *WorkerState) SetLastUsed(lu uint64) {
+	atomic.StoreUint64(&s.lastUsed, lu)
+}
+
+func (s *WorkerState) LastUsed() uint64 {
+	return atomic.LoadUint64(&s.lastUsed)
+}