From 2f6b7e08f8f143385fc1508b8175919a81fc9565 Mon Sep 17 00:00:00 2001
From: Geoffrey McRae <geoff@hostfission.com>
Date: Thu, 21 Dec 2017 00:57:27 +1100
Subject: [PATCH] [client] define locking types and semantics to allow for alt
 methods

---
 client/renderers/opengl.c | 26 +++++++++++++++-----------
 client/utils.h            |  7 ++++++-
 2 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/client/renderers/opengl.c b/client/renderers/opengl.c
index b86157d6..2f2d1dd5 100644
--- a/client/renderers/opengl.c
+++ b/client/renderers/opengl.c
@@ -71,7 +71,7 @@ struct Inst
   bool              resizeWindow;
   bool              frameUpdate;
 
-  volatile int      formatLock;
+  LG_Lock           formatLock;
   LG_RendererFormat format;
   GLuint            intFormat;
   GLuint            vboFormat;
@@ -81,7 +81,7 @@ struct Inst
   bool              hasBuffers;
   GLuint            vboID[1];
   uint8_t         * texPixels[BUFFER_COUNT];
-  volatile int      syncLock;
+  LG_Lock           syncLock;
   int               texIndex, wTexIndex;
   int               texList;
   int               fpsList;
@@ -99,7 +99,7 @@ struct Inst
   uint64_t          renderCount;
   SDL_Rect          fpsRect;
 
-  volatile int      mouseLock;
+  LG_Lock           mouseLock;
   LG_RendererCursor mouseCursor;
   int               mouseWidth;
   int               mouseHeight;
@@ -144,6 +144,10 @@ bool opengl_create(void ** opaque, const LG_RendererParams params)
   memcpy(&this->params, &params        , sizeof(LG_RendererParams));
   memcpy(&this->opt   , &defaultOptions, sizeof(struct Options   ));
 
+  LG_LOCK_INIT(this->formatLock);
+  LG_LOCK_INIT(this->syncLock  );
+  LG_LOCK_INIT(this->mouseLock );
+
   return true;
 }
 
@@ -203,7 +207,7 @@ bool opengl_on_mouse_shape(void * opaque, const LG_RendererCursor cursor, const
   if (!this)
     return false;
 
-  while(__sync_lock_test_and_set(&this->mouseLock, 1));
+  LG_LOCK(this->mouseLock);
   this->mouseCursor = cursor;
   this->mouseWidth  = width;
   this->mouseHeight = height;
@@ -220,7 +224,7 @@ bool opengl_on_mouse_shape(void * opaque, const LG_RendererCursor cursor, const
 
   memcpy(this->mouseData, data, size);
   this->newShape = true;
-  __sync_lock_release(&this->mouseLock);
+  LG_UNLOCK(this->mouseLock);
 
   return true;
 }
@@ -250,7 +254,7 @@ bool opengl_on_frame_event(void * opaque, const LG_RendererFormat format, const
     return false;
   }
 
-  while(__sync_lock_test_and_set(&this->formatLock, 1));
+  LG_LOCK(this->formatLock);
   if (this->reconfigure)
   {
     __sync_lock_release(&this->formatLock);
@@ -270,7 +274,7 @@ bool opengl_on_frame_event(void * opaque, const LG_RendererFormat format, const
   while(__sync_lock_test_and_set(&this->syncLock, 1));
   memcpySSE(this->texPixels[this->wTexIndex], data, this->texSize);
   this->frameUpdate = true;
-  __sync_lock_release(&this->syncLock);
+  LG_UNLOCK(this->syncLock);
 
   ++this->frameCount;
   return true;
@@ -430,7 +434,7 @@ static bool _check_gl_error(unsigned int line, const char * name)
 
 static bool configure(struct Inst * this, SDL_Window *window)
 {
-  while(__sync_lock_test_and_set(&this->formatLock, 1));
+  LG_LOCK(this->formatLock);
   if (!this->reconfigure)
   {
     __sync_lock_release(&this->formatLock);
@@ -787,7 +791,7 @@ static bool draw_frame(struct Inst * this, bool * frameUpdate)
   *frameUpdate = this->frameUpdate;
   if (!this->frameUpdate)
   {
-    __sync_lock_release(&this->syncLock);
+    LG_UNLOCK(this->syncLock);
     return true;
   }
 
@@ -795,9 +799,9 @@ static bool draw_frame(struct Inst * this, bool * frameUpdate)
   if (++this->wTexIndex == BUFFER_COUNT)
     this->wTexIndex = 0;
   this->frameUpdate = false;
-  __sync_lock_release(&this->syncLock);
+  LG_UNLOCK(this->syncLock);
 
-  while(__sync_lock_test_and_set(&this->formatLock, 1));
+  LG_LOCK(this->formatLock);
   if (this->params.showFPS && this->renderTime > 1e9)
   {
     char str[128];
diff --git a/client/utils.h b/client/utils.h
index 5b637bf7..1a68f82b 100644
--- a/client/utils.h
+++ b/client/utils.h
@@ -44,4 +44,9 @@ static inline void nsleep(uint64_t ns)
     .tv_nsec = ns - ((ns / 1e9) * 1e9)
   };
   nanosleep(&ts, NULL);
-}
\ No newline at end of file
+}
+
+typedef volatile int LG_Lock;
+#define LG_LOCK_INIT(x) (x) = 0
+#define LG_LOCK(x)      while(__sync_lock_test_and_set(&(x), 1))
+#define LG_UNLOCK(x)    __sync_lock_release(&this->mouseLock)
\ No newline at end of file