plug in race in camera release

We can crash if start/stop pressed fast eventually.

4 files changed, 32 insertions, 0 deletions

diff --git a/ftnoir_tracker_aruco/ftnoir_tracker_aruco.cpp b/ftnoir_tracker_aruco/ftnoir_tracker_aruco.cpp
index 786be62d..8acddc28 100644
--- a/ftnoir_tracker_aruco/ftnoir_tracker_aruco.cpp
+++ b/ftnoir_tracker_aruco/ftnoir_tracker_aruco.cpp
@@ -18,6 +18,7 @@
 #include <opencv2/videoio.hpp>
 #include "opentrack/camera-names.hpp"
 #include "opentrack/opencv-calibration.hpp"
+#include "opentrack/sleep.hpp"
 
 typedef struct {
     int width;
@@ -355,6 +356,9 @@ fail:
         if (frame.rows > 0)
             videoWidget->update_image(frame);
     }
+
+    // give opencv time to exit camera threads, etc.
+    portable::sleep(500);
 }
 
 void Tracker::data(double *data)
diff --git a/ftnoir_tracker_ht/ftnoir_tracker_ht.cpp b/ftnoir_tracker_ht/ftnoir_tracker_ht.cpp
index 2ac614a2..ad13d716 100644
--- a/ftnoir_tracker_ht/ftnoir_tracker_ht.cpp
+++ b/ftnoir_tracker_ht/ftnoir_tracker_ht.cpp
@@ -4,6 +4,7 @@
 #include "opentrack/plugin-api.hpp"
 #include <cmath>
 #include "opentrack/camera-names.hpp"
+#include "opentrack/sleep.hpp"
 
 typedef struct {
 	int width;
@@ -158,6 +159,8 @@ void Tracker::run()
             }
         }
     }
+    // give opencv time to exit camera threads, etc.
+    portable::sleep(500);
 }
 
 void Tracker::data(double* data)
diff --git a/ftnoir_tracker_pt/camera.cpp b/ftnoir_tracker_pt/camera.cpp
index 2e745f2a..7c4af38f 100644
--- a/ftnoir_tracker_pt/camera.cpp
+++ b/ftnoir_tracker_pt/camera.cpp
@@ -8,6 +8,7 @@
 #include "camera.h"
 #include <string>
 #include <QDebug>
+#include "opentrack/sleep.hpp"
 
 using namespace cv;
 
@@ -113,6 +114,8 @@ void CVCamera::stop()
         cap->release();
         delete cap;
         cap = nullptr;
+        // give opencv time to exit camera threads, etc.
+        portable::sleep(500);
     }
     active = false;
 }
diff --git a/opentrack/sleep.hpp b/opentrack/sleep.hpp
new file mode 100644
index 00000000..27920842
--- /dev/null
+++ b/opentrack/sleep.hpp
@@ -0,0 +1,22 @@
+#pragma once
+
+namespace portable
+{
+#ifdef _WIN32
+    #include <windows.h>
+
+    template<typename = void>
+    void sleep(unsigned milliseconds)
+    {
+        Sleep(milliseconds);
+    }
+#else
+    #include <unistd.h>
+
+    template<typename = void>
+    void sleep(unsigned milliseconds)
+    {
+        usleep(milliseconds * 1000U); // takes microseconds
+    }
+#endif
+}