From 57fda7f2a8d8f3c047b08f00c45b218d1bd6be31 Mon Sep 17 00:00:00 2001
From: Maxim Shevtsov <maxim.y.shevtsov@intel.com>
Date: Mon, 7 Dec 2020 16:58:26 +0300
Subject: [PATCH] fixed data race introduced in the
 https://github.com/openvinotoolkit/openvino/pull/3300 (#3490)

it is easy to capture when there are 2 app-level inference requests, but only single worker (MULTI) request

main thread                                        |       callback thread
___________________________________________________________________________
                                                   | <in the callback, the worker request>
                                                   |   <the request returns itself to the "idle" queue>
                                                   | 1) idleGuard.Release()->try_push(workerRequestPtr)
2)<notified on vacant worker arrived via callback> |
3) starts another request with StartAsync          | ...
4) <in the ThisRequestExecutor::run()>             |
workerInferRequest->_task = std::move(task);       | if (_inferPipelineTasks.try_pop(workerRequestPtr->task))

the last line introduces DATA RACE (sporadically manifested in the bad_function_call exception), the fix is in this commit
---
 .../src/multi_device/multi_device_exec_network.cpp           | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/inference-engine/src/multi_device/multi_device_exec_network.cpp b/inference-engine/src/multi_device/multi_device_exec_network.cpp
index 10b9a280963..d9c1bf0a9b3 100644
--- a/inference-engine/src/multi_device/multi_device_exec_network.cpp
+++ b/inference-engine/src/multi_device/multi_device_exec_network.cpp
@@ -95,10 +95,11 @@ MultiDeviceExecutableNetwork::MultiDeviceExecutableNetwork(const DeviceMap<Infer
                     }
                     // try to return the request to the idle list (fails if the overall object destruction has began)
                     if (idleGuard.Release()->try_push(workerRequestPtr)) {
+                        Task t;
                         // try pop the task, as we know there is at least one idle request
-                        if (_inferPipelineTasks.try_pop(workerRequestPtr->_task)) {
+                        if (_inferPipelineTasks.try_pop(t)) {
                             // if succeeded, let's schedule that
-                            ScheduleToWorkerInferRequest(std::move(workerRequestPtr->_task));
+                            ScheduleToWorkerInferRequest(std::move(t));
                         }
                     }
                 });