graphics_view: also clear semaphor on fx reset

JoepVanlier · Jul 14, 2024 · 784ed02 · 784ed02
1 parent d550dbb
commit 784ed02
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Showing 3 changed files with 44 additions and 4 deletions.
diff --git a/plugin/components/graphics_view.cpp b/plugin/components/graphics_view.cpp
@@ -717,6 +717,8 @@ void YsfxGraphicsView::Impl::BackgroundWork::stop()
     std::lock_guard<std::mutex> lock{m_messagesMutex};
     while (!m_messages.empty())
         m_messages.pop();
+
+    m_sema.clear();
 }
 
 void YsfxGraphicsView::Impl::BackgroundWork::postMessage(std::shared_ptr<Message> message)
@@ -737,10 +739,12 @@ void YsfxGraphicsView::Impl::BackgroundWork::run()
         std::shared_ptr<Message> msg = popNextMessage();
         jassert(msg);
 
-        switch (msg->m_type) {
-        case '@gfx':
-            processGfxMessage(static_cast<GfxMessage &>(*msg));
-            break;
+        if (msg) {
+            switch (msg->m_type) {
+            case '@gfx':
+                processGfxMessage(static_cast<GfxMessage &>(*msg));
+                break;
+            }
         }
     }
 }

diff --git a/plugin/utility/rt_semaphore.cpp b/plugin/utility/rt_semaphore.cpp
@@ -60,6 +60,14 @@ void RTSemaphore::wait()
         throw std::system_error(ec);
 }
 
+void RTSemaphore::clear()
+{
+    std::error_code ec;
+    clear(ec);
+    if (ec)
+        throw std::system_error(ec);
+}
+
 bool RTSemaphore::try_wait()
 {
     std::error_code ec;
@@ -120,6 +128,15 @@ void RTSemaphore::wait(std::error_code& ec) noexcept
     } while (1);
 }
 
+void RTSemaphore::clear(std::error_code& ec) noexcept
+{
+    ec.clear();
+    mach_timespec_t timeout;
+    timeout.tv_sec = 0 / 1000;
+    timeout.tv_nsec = (0 % 1000) * (1000L * 1000L);
+    while (semaphore_timedwait(sem_, timeout) == KERN_SUCCESS);
+}
+
 bool RTSemaphore::try_wait(std::error_code& ec) noexcept
 {
     return timed_wait(0, ec);
@@ -189,6 +206,12 @@ void RTSemaphore::post(std::error_code& ec) noexcept
         ec = std::error_code(GetLastError(), std::system_category());
 }
 
+void RTSemaphore::clear(std::error_code& ec) noexcept
+{
+    ec.clear();
+    while (WaitForSingleObject(sem_, 0) == WAIT_OBJECT_0);
+}
+
 void RTSemaphore::wait(std::error_code& ec) noexcept
 {
     ec.clear();
@@ -305,6 +328,17 @@ static bool absolute_timeout(uint32_t milliseconds, timespec &result, std::error
     return true;
 }
 
+void RTSemaphore::clear(std::error_code& ec) noexcept
+{
+    ec.clear();
+    timespec abs;
+    absolute_timeout(0, abs, ec);
+
+    // Note that we don't really need to update the absolute timestep because if there are
+    // still events pending, it will just pop them off the stack.
+    while (sem_timedwait(&sem_, &abs) == 0);
+}
+
 bool RTSemaphore::timed_wait(uint32_t milliseconds, std::error_code& ec) noexcept
 {
     ec.clear();

diff --git a/plugin/utility/rt_semaphore.h b/plugin/utility/rt_semaphore.h
@@ -39,11 +39,13 @@ class RTSemaphore {
 
     void post();
     void wait();
+    void clear();
     bool try_wait();
     bool timed_wait(uint32_t milliseconds);
 
     void post(std::error_code& ec) noexcept;
     void wait(std::error_code& ec) noexcept;
+    void clear(std::error_code& ec) noexcept;
     bool try_wait(std::error_code& ec) noexcept;
     bool timed_wait(uint32_t milliseconds, std::error_code& ec) noexcept;