clap

commit c19a570e95d065a54da2923defc215743ca536fa
parent 9c6fcf93e4843da792d0c56fe1cddd1c29391098
Author: Alexandre BIQUE <bique.alexandre@gmail.com>
Date:   Wed, 20 Oct 2021 21:26:18 +0200

Make that code more robust

Diffstat:
M
examples/common/param-queue.hh
 | 
20
+++++++++++---------
M
examples/plugins/core-plugin.cc
 | 
14
+++++++++++++-

2 files changed, 24 insertions(+), 10 deletions(-)
diff --git a/examples/common/param-queue.hh b/examples/common/param-queue.hh
@@ -14,19 +14,22 @@ public:
    ParamQueue() = default;
 
    void push(const T &value) {
-      int w;  // write element
-      int wn; // next write element
+      while (!tryPush(value))
+         ;
+   }
+
+   bool tryPush(const T &value) {
+      int w = _writeOffset.load(); // write element
+      int wn = (w + 1) % CAPACITY; // next write element
 
-      do {
-         w = _writeOffset.load();
-         wn = (w + 1) % CAPACITY;
-      } while (wn == _readOffset); // wait until there is space
+      if (wn == _readOffset)
+         return false;
 
       _data[w] = value;
       _writeOffset = wn;
    }
 
-   bool tryPop(T& value) {
+   bool tryPop(T &value) {
       int r = _readOffset;
 
       if (r == _writeOffset)
@@ -38,8 +41,7 @@ public:
       return true;
    }
 
-   void reset()
-   {
+   void reset() {
       _writeOffset = 0;
       _readOffset = 0;
    }
diff --git a/examples/plugins/core-plugin.cc b/examples/plugins/core-plugin.cc
@@ -2,6 +2,8 @@
 #include <boost/archive/text_oarchive.hpp>
 
 #include <sstream>
+#include <chrono>
+#include <thread>
 
 #include "core-plugin.hh"
 #include "stream-helper.hh"
@@ -171,7 +173,17 @@ namespace clap {
    }
 
    void CorePlugin::guiAdjust(clap_id paramId, double value, clap_event_param_flags flags) {
-      _guiToPluginQueue.push({paramId, value, flags});
+      GuiToPluginValue item{paramId, value, flags};
+      while (true) {
+         // very highly likely to succeed
+         if (_guiToPluginQueue.tryPush(item))
+            return;
+
+         if (canUseParams())
+            _hostParams->request_flush(_host);
+
+         std::this_thread::sleep_for(std::chrono::milliseconds(1));
+      }
    }
 
    void CorePlugin::processGuiEvents(const clap_process *process) {