From c061675001713aca12661e255ea2f1afd3c95a91 Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Sat, 11 Apr 2020 19:33:48 +0100
Subject: [PATCH] Allow modal progress sleep to finish early on completion

---
 src/gfx.cpp      |  2 +-
 src/progress.cpp | 20 ++++++++++++++++++++
 src/progress.h   |  1 +
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/gfx.cpp b/src/gfx.cpp
index 364fca20a2..8409e7a86a 100644
--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -1495,7 +1495,7 @@ void DrawDirtyBlocks()
 		_modal_progress_work_mutex.unlock();
 
 		/* Wait a while and update _realtime_tick so we are given the rights */
-		if (!is_first_modal_progress_loop) CSleep(MODAL_PROGRESS_REDRAW_TIMEOUT);
+		if (!is_first_modal_progress_loop) SleepWhileModalProgress(MODAL_PROGRESS_REDRAW_TIMEOUT);
 #if defined(__GNUC__) || defined(__clang__)
 		__atomic_add_fetch(&_realtime_tick, MODAL_PROGRESS_REDRAW_TIMEOUT, __ATOMIC_RELAXED);
 #else
diff --git a/src/progress.cpp b/src/progress.cpp
index e45e5db078..57d96c3538 100644
--- a/src/progress.cpp
+++ b/src/progress.cpp
@@ -10,6 +10,14 @@
 #include "stdafx.h"
 #include "progress.h"
 
+#include <chrono>
+#include <mutex>
+#include <condition_variable>
+#if defined(__MINGW32__)
+#include "3rdparty/mingw-std-threads/mingw.mutex.h"
+#include "3rdparty/mingw-std-threads/mingw.condition_variable.h"
+#endif
+
 #include "safeguards.h"
 
 /** Are we in a modal progress or not? */
@@ -22,6 +30,9 @@ std::mutex _modal_progress_work_mutex;
 /** Rights for the painting. */
 std::mutex _modal_progress_paint_mutex;
 
+static std::mutex _modal_progress_cv_mutex;
+static std::condition_variable _modal_progress_cv;
+
 /**
  * Set the modal progress state.
  * @note Makes IsFirstModalProgressLoop return true for the next call.
@@ -29,8 +40,11 @@ std::mutex _modal_progress_paint_mutex;
  */
 void SetModalProgress(bool state)
 {
+	_modal_progress_cv_mutex.lock();
 	_in_modal_progress = state;
 	_first_in_modal_loop = true;
+	_modal_progress_cv_mutex.unlock();
+	if (!state) _modal_progress_cv.notify_all();
 }
 
 /**
@@ -44,3 +58,9 @@ bool IsFirstModalProgressLoop()
 	_first_in_modal_loop = false;
 	return ret;
 }
+
+void SleepWhileModalProgress(int milliseconds)
+{
+	std::unique_lock<std::mutex> lk(_modal_progress_cv_mutex);
+	_modal_progress_cv.wait_for(lk, std::chrono::milliseconds(milliseconds), []{ return !_in_modal_progress; });
+}
diff --git a/src/progress.h b/src/progress.h
index e0fa977a44..92f6c89037 100644
--- a/src/progress.h
+++ b/src/progress.h
@@ -39,6 +39,7 @@ static inline bool UseThreadedModelProgress()
 
 bool IsFirstModalProgressLoop();
 void SetModalProgress(bool state);
+void SleepWhileModalProgress(int milliseconds);
 
 extern std::mutex _modal_progress_work_mutex;
 extern std::mutex _modal_progress_paint_mutex;