From 05b21d80e8f1062ce43932a15ae27a3908f48491 Mon Sep 17 00:00:00 2001
From: Lia Stratopoulos <167905060+lia-viam@users.noreply.github.com>
Date: Thu, 1 May 2025 15:26:08 -0400
Subject: [PATCH 1/4] condition var refresh thread

---
 src/viam/sdk/robot/client.cpp | 23 ++++++++++++++++-------
 src/viam/sdk/robot/client.hpp |  4 +++-
 2 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/src/viam/sdk/robot/client.cpp b/src/viam/sdk/robot/client.cpp
index 740c50fff..6a353bfd1 100644
--- a/src/viam/sdk/robot/client.cpp
+++ b/src/viam/sdk/robot/client.cpp
@@ -143,7 +143,11 @@ RobotClient::~RobotClient() {
 }
 
 void RobotClient::close() {
-    should_refresh_.store(false);
+    if (should_refresh_) {
+        std::unique_lock<std::mutex> lk{refresh_lock_};
+        should_refresh_ = false;
+        refresh_cv_.notify_one();
+    }
 
     if (refresh_thread_.joinable()) {
         refresh_thread_.join();
@@ -220,16 +224,21 @@ void RobotClient::refresh() {
 }
 
 void RobotClient::refresh_every() {
-    while (should_refresh_.load()) {
-        try {
-            std::this_thread::sleep_for(refresh_interval_);
-            refresh();
+    std::unique_lock<std::mutex> lk{refresh_lock_};
 
-        } catch (std::exception&) {
+    while (true) {
+        if (refresh_cv_.wait_for(lk, refresh_interval_) == std::cv_status::timeout) {
+            try {
+                refresh();
+            } catch (const std::exception& e) {
+                VIAM_SDK_LOG(warn) << "Refresh thread terminated with exception: " << e.what();
+                break;
+            }
+        } else if (should_refresh_ == false) {
             break;
         }
     }
-};
+}
 
 RobotClient::RobotClient(ViamChannel channel)
     : viam_channel_(std::move(channel)),
diff --git a/src/viam/sdk/robot/client.hpp b/src/viam/sdk/robot/client.hpp
index 3c19a9edc..be10c248e 100644
--- a/src/viam/sdk/robot/client.hpp
+++ b/src/viam/sdk/robot/client.hpp
@@ -186,7 +186,9 @@ class RobotClient {
     void refresh_every();
 
     std::thread refresh_thread_;
-    std::atomic<bool> should_refresh_;
+    std::mutex refresh_lock_;
+    std::condition_variable refresh_cv_;
+    bool should_refresh_;
     std::chrono::seconds refresh_interval_;
 
     ViamChannel viam_channel_;

From a2c8bf2ef0c33269566a4975c7eef5af9139f37f Mon Sep 17 00:00:00 2001
From: Lia Stratopoulos <167905060+lia-viam@users.noreply.github.com>
Date: Thu, 1 May 2025 15:45:04 -0400
Subject: [PATCH 2/4] include cond var

---
 src/viam/sdk/robot/client.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/viam/sdk/robot/client.hpp b/src/viam/sdk/robot/client.hpp
index be10c248e..6e6a36112 100644
--- a/src/viam/sdk/robot/client.hpp
+++ b/src/viam/sdk/robot/client.hpp
@@ -3,7 +3,7 @@
 /// @brief gRPC client implementation for a `robot`.
 #pragma once
 
-#include <atomic>
+#include <condition_variable>
 #include <string>
 #include <thread>
 

From a78291f58bf507c9a767d222f263269bd4c06e85 Mon Sep 17 00:00:00 2001
From: Lia Stratopoulos <167905060+lia-viam@users.noreply.github.com>
Date: Thu, 1 May 2025 17:11:21 -0400
Subject: [PATCH 3/4] concise refresh

---
 src/viam/sdk/robot/client.cpp | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/viam/sdk/robot/client.cpp b/src/viam/sdk/robot/client.cpp
index 6a353bfd1..5f8a8332b 100644
--- a/src/viam/sdk/robot/client.cpp
+++ b/src/viam/sdk/robot/client.cpp
@@ -226,18 +226,19 @@ void RobotClient::refresh() {
 void RobotClient::refresh_every() {
     std::unique_lock<std::mutex> lk{refresh_lock_};
 
-    while (true) {
-        if (refresh_cv_.wait_for(lk, refresh_interval_) == std::cv_status::timeout) {
+    refresh_cv_.wait_for(lk, refresh_interval_, [this] {
+        if (should_refresh_) {
             try {
                 refresh();
             } catch (const std::exception& e) {
-                VIAM_SDK_LOG(warn) << "Refresh thread terminated with exception: " << e.what();
-                break;
+                VIAM_SDK_LOG(warn) << "Refresh thread got exception " << e.what();
+                // TODO: maybe recoverable
+                return true;
             }
-        } else if (should_refresh_ == false) {
-            break;
         }
-    }
+
+        return !should_refresh_;
+    });
 }
 
 RobotClient::RobotClient(ViamChannel channel)

From 7198e15e28b5ffdf9751b4f29b898f3040c18652 Mon Sep 17 00:00:00 2001
From: lia <167905060+lia-viam@users.noreply.github.com>
Date: Fri, 2 May 2025 10:05:35 -0400
Subject: [PATCH 4/4] const lock guard

---
 src/viam/sdk/robot/client.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/viam/sdk/robot/client.cpp b/src/viam/sdk/robot/client.cpp
index 5f8a8332b..c4ad0c37f 100644
--- a/src/viam/sdk/robot/client.cpp
+++ b/src/viam/sdk/robot/client.cpp
@@ -144,7 +144,7 @@ RobotClient::~RobotClient() {
 
 void RobotClient::close() {
     if (should_refresh_) {
-        std::unique_lock<std::mutex> lk{refresh_lock_};
+        const std::unique_lock<std::mutex> lk{refresh_lock_};
         should_refresh_ = false;
         refresh_cv_.notify_one();
     }