From 403339f8f470c90dee6f6d94ed58644b2787f66b Mon Sep 17 00:00:00 2001
From: Yuan Hu <yuan2.hu@intel.com>
Date: Wed, 19 Jan 2022 22:13:29 +0800
Subject: [PATCH] [AUTOPLUGIN] not select if only one device (#9730)

* if only one Device, not select

Signed-off-by: Hu, Yuan2 <yuan2.hu@intel.com>

* modify test case to match logic

Signed-off-by: Hu, Yuan2 <yuan2.hu@intel.com>
---
 src/plugins/auto/plugin.cpp                | 34 ++++++++++++----------
 src/tests/unit/auto/select_device_test.cpp | 21 ++++++++-----
 2 files changed, 33 insertions(+), 22 deletions(-)

diff --git a/src/plugins/auto/plugin.cpp b/src/plugins/auto/plugin.cpp
index be02361c1fc..cc82be25d4b 100644
--- a/src/plugins/auto/plugin.cpp
+++ b/src/plugins/auto/plugin.cpp
@@ -455,23 +455,27 @@ DeviceInformation MultiDeviceInferencePlugin::SelectDevice(const std::vector<Dev
 
     std::list<DeviceInformation> validDevices;
 
-    auto selectSupportDev = [this, &devices, &validDevices](const std::string& networkPrecision) {
-        for (auto iter = devices.begin(); iter != devices.end();) {
-            std::vector<std::string> capability = GetCore()->GetMetric(iter->deviceName, METRIC_KEY(OPTIMIZATION_CAPABILITIES));
-            auto supportNetwork = std::find(capability.begin(), capability.end(), (networkPrecision));
-            if (supportNetwork != capability.end()) {
-                validDevices.push_back(std::move(*iter));
-                devices.erase(iter++);
-                continue;
+    if (metaDevices.size() > 1) {
+        auto selectSupportDev = [this, &devices, &validDevices](const std::string& networkPrecision) {
+            for (auto iter = devices.begin(); iter != devices.end();) {
+                std::vector<std::string> capability = GetCore()->GetMetric(iter->deviceName, METRIC_KEY(OPTIMIZATION_CAPABILITIES));
+                auto supportNetwork = std::find(capability.begin(), capability.end(), (networkPrecision));
+                if (supportNetwork != capability.end()) {
+                    validDevices.push_back(std::move(*iter));
+                    devices.erase(iter++);
+                    continue;
+                }
+                iter++;
             }
-            iter++;
+        };
+        selectSupportDev(networkPrecision);
+        // If network is FP32, continue to collect the device support FP16 but not support FP32.
+        if (networkPrecision == "FP32") {
+            const std::string f16 = "FP16";
+            selectSupportDev(f16);
         }
-    };
-    selectSupportDev(networkPrecision);
-    // If network is FP32, continue to collect the device support FP16 but not support FP32.
-    if (networkPrecision == "FP32") {
-       const std::string f16 = "FP16";
-       selectSupportDev(f16);
+    } else {
+        validDevices.push_back(metaDevices[0]);
     }
 
     if (validDevices.empty()) {
diff --git a/src/tests/unit/auto/select_device_test.cpp b/src/tests/unit/auto/select_device_test.cpp
index 89d1f6e0853..c8a94da0f4c 100644
--- a/src/tests/unit/auto/select_device_test.cpp
+++ b/src/tests/unit/auto/select_device_test.cpp
@@ -106,14 +106,21 @@ public:
                 auto& devicesInfo = devicesMap[netPrecision];
                 bool find = false;
                 DeviceInformation expect;
-                for (auto& item : devicesInfo) {
-                    auto device =  std::find_if(metaDevices.begin(), metaDevices.end(),
-                            [&item](const DeviceInformation& d)->bool{return d.uniqueName == item.uniqueName;});
-                    if (device != metaDevices.end()) {
-                        find = true;
-                        expect = item;
-                        break;
+                if (metaDevices.size() > 1) {
+                    for (auto& item : devicesInfo) {
+                        auto device =  std::find_if(metaDevices.begin(), metaDevices.end(),
+                                [&item](const DeviceInformation& d)->bool{return d.uniqueName == item.uniqueName;});
+                        if (device != metaDevices.end()) {
+                            find = true;
+                            expect = item;
+                            break;
+                        }
                     }
+                } else if (metaDevices.size() == 1) {
+                    expect = metaDevices[0];
+                    find = true;
+                } else {
+                    find = false;
                 }
                 testConfigs.push_back(std::make_tuple(netPrecision, metaDevices, expect, !find));
             } else {