From e921b13e40ef3bbfe29baa530ae741dad9d74d56 Mon Sep 17 00:00:00 2001
From: Emerson Knapp <eknapp@amazon.com>
Date: Wed, 31 Mar 2021 14:53:38 -0700
Subject: [PATCH] pause() and resume() instead of set_paused(bool)

Signed-off-by: Emerson Knapp <eknapp@amazon.com>
---
 .../include/rosbag2_cpp/player_clock.hpp      | 16 ++++++++----
 rosbag2_cpp/src/rosbag2_cpp/player_clock.cpp  | 25 +++++++++++++------
 2 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/rosbag2_cpp/include/rosbag2_cpp/player_clock.hpp b/rosbag2_cpp/include/rosbag2_cpp/player_clock.hpp
index 992d047707..985c09d495 100644
--- a/rosbag2_cpp/include/rosbag2_cpp/player_clock.hpp
+++ b/rosbag2_cpp/include/rosbag2_cpp/player_clock.hpp
@@ -88,18 +88,24 @@ class PlayerClock
   double get_rate() const;
 
   /**
-   * Set the paused state of the clock.
-   * If currently in a `sleep_until`, this will wake the sleep to return false,
-   * so that the caller is not hanging forever.
+   * Stop the flow of time of the clock.
+   * If this changes the pause state, this will wake any waiting `sleep_until`
    */
   ROSBAG2_CPP_PUBLIC
-  void set_paused(bool paused);
+  void pause();
+
+  /**
+   * Start the flow of time of the clock
+   * If this changes the pause state, this will wake any waiting `sleep_until`
+   */
+  ROSBAG2_CPP_PUBLIC
+  void resume();
 
   /**
    * Return whether the clock is currently paused.
    */
   ROSBAG2_CPP_PUBLIC
-  bool get_paused() const;
+  bool is_paused() const;
 
 private:
   std::unique_ptr<PlayerClockImpl> impl_;
diff --git a/rosbag2_cpp/src/rosbag2_cpp/player_clock.cpp b/rosbag2_cpp/src/rosbag2_cpp/player_clock.cpp
index 50f41a690f..70b92c15b1 100644
--- a/rosbag2_cpp/src/rosbag2_cpp/player_clock.cpp
+++ b/rosbag2_cpp/src/rosbag2_cpp/player_clock.cpp
@@ -115,26 +115,35 @@ double PlayerClock::get_rate() const
   return impl_->rate;
 }
 
-void PlayerClock::set_paused(bool paused)
+void PlayerClock::pause()
 {
   {
     std::lock_guard<std::mutex> lock(impl_->mutex);
-    if (paused == impl_->paused) {
+    if (impl_->paused) {
       return;
     }
     // Note: needs to not be paused when taking snapshot, otherwise it will use last ros ref
-    if (!paused) {
-      impl_->paused = paused;
-    }
     impl_->snapshot(now());
-    if (paused) {
-      impl_->paused = paused;
+    impl_->paused = true;
+  }
+  impl_->cv.notify_all();
+}
+
+void PlayerClock::resume()
+{
+  {
+    std::lock_guard<std::mutex> lock(impl_->mutex);
+    if (!impl_->paused) {
+      return;
     }
+    // Note: needs to not be paused when taking snapshot, otherwise it will use last ros ref
+    impl_->paused = false;
+    impl_->snapshot(now());
   }
   impl_->cv.notify_all();
 }
 
-bool PlayerClock::get_paused() const
+bool PlayerClock::is_paused() const
 {
   std::lock_guard<std::mutex> lock(impl_->mutex);
   return impl_->paused;