fix: drop racy code, refactor and group API schema (#931)

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

pkg/grpc/base/singlethread.go

@@ -0,0 +1,52 @@
+package base
+
+import (
+	"sync"
+
+	pb "github.com/go-skynet/LocalAI/pkg/grpc/proto"
+)
+
+// SingleThread are backends that does not support multiple requests.
+// There will be only one request being served at the time.
+// This is useful for models that are not thread safe and cannot run
+// multiple requests at the same time.
+type SingleThread struct {
+	Base
+	backendBusy sync.Mutex
+}
+
+// Locking returns true if the backend needs to lock resources
+func (llm *SingleThread) Locking() bool {
+	return true
+}
+
+func (llm *SingleThread) Lock() {
+	llm.backendBusy.Lock()
+}
+
+func (llm *SingleThread) Unlock() {
+	llm.backendBusy.Unlock()
+}
+
+func (llm *SingleThread) Busy() bool {
+	r := llm.backendBusy.TryLock()
+	if r {
+		llm.backendBusy.Unlock()
+	}
+	return r
+}
+
+// backends may wish to call this to capture the gopsutil info, then enhance with additional memory usage details?
+func (llm *SingleThread) Status() (pb.StatusResponse, error) {
+	mud := memoryUsage()
+
+	state := pb.StatusResponse_READY
+	if llm.Busy() {
+		state = pb.StatusResponse_BUSY
+	}
+
+	return pb.StatusResponse{
+		State:  state,
+		Memory: mud,
+	}, nil
+}