From 53c843d9ddf1e98e819665ca3092db4577fe640e Mon Sep 17 00:00:00 2001
From: matthewjmc <matthew@mcmullin.one>
Date: Mon, 16 May 2022 16:32:45 +0700
Subject: [PATCH] [common] Update framebuffer metadata + references

---
 client/src/main.c                   |  2 +-
 common/include/common/framebuffer.h | 17 +++++++++++------
 common/src/framebuffer.c            | 12 ------------
 host/src/app.c                      |  2 +-
 obs/lg.c                            |  2 +-
 5 files changed, 14 insertions(+), 21 deletions(-)

diff --git a/client/src/main.c b/client/src/main.c
index 1db1d7b1..e4cf5f41 100644
--- a/client/src/main.c
+++ b/client/src/main.c
@@ -742,7 +742,7 @@ int main_frameThread(void * unused)
       if (dma->fd == -1)
       {
         const uintptr_t pos    = (uintptr_t)msg.mem - (uintptr_t)g_state.shm.mem;
-        const uintptr_t offset = (uintptr_t)frame->offset + FrameBufferStructSize;
+        const uintptr_t offset = (uintptr_t)frame->offset + sizeof(FrameBuffer);
 
         dma->dataSize = dataSize;
         dma->fd       = ivshmemGetDMABuf(&g_state.shm, pos + offset, dataSize);
diff --git a/common/include/common/framebuffer.h b/common/include/common/framebuffer.h
index 3ac9032e..0bd76425 100644
--- a/common/include/common/framebuffer.h
+++ b/common/include/common/framebuffer.h
@@ -24,16 +24,21 @@
 #include <stdlib.h>
 #include <stdbool.h>
 #include <stdint.h>
+#include <stdatomic.h>
 
-typedef struct stFrameBuffer FrameBuffer;
+#define FB_CHUNK_SIZE           1048576 // 1MB
+#define FB_SPIN_LIMIT           10000   // 10ms
+#define FB_WP_TYPE              atomic_uint_least32_t
+#define FB_WP_SIZE              sizeof(FB_WP_TYPE)
+
+typedef struct stFrameBuffer
+{
+  FB_WP_TYPE wp;
+  uint8_t    data[0];
+} FrameBuffer;
 
 typedef bool (*FrameBufferReadFn)(void * opaque, const void * src, size_t size);
 
-/**
- * The size of the FrameBuffer struct
- */
-extern const size_t FrameBufferStructSize;
-
 /**
  * Wait for the framebuffer to fill to the specified size
  */
diff --git a/common/src/framebuffer.c b/common/src/framebuffer.c
index 6656c66b..f5641ee7 100644
--- a/common/src/framebuffer.c
+++ b/common/src/framebuffer.c
@@ -27,22 +27,10 @@
 #endif
 
 #include <string.h>
-#include <stdatomic.h>
 #include <emmintrin.h>
 #include <smmintrin.h>
 #include <unistd.h>
 
-#define FB_CHUNK_SIZE 1048576 // 1MB
-#define FB_SPIN_LIMIT 10000   // 10ms
-
-struct stFrameBuffer
-{
-  atomic_uint_least32_t wp;
-  uint8_t               data[0];
-};
-
-const size_t FrameBufferStructSize = sizeof(FrameBuffer);
-
 bool framebuffer_wait(const FrameBuffer * frame, size_t size)
 {
   while(atomic_load_explicit(&frame->wp, memory_order_acquire) < size)
diff --git a/host/src/app.c b/host/src/app.c
index cf9e32d6..cf437525 100644
--- a/host/src/app.c
+++ b/host/src/app.c
@@ -275,7 +275,7 @@ static bool sendFrame(void)
   fi->frameHeight       = frame.frameHeight;
   fi->stride            = frame.stride;
   fi->pitch             = frame.pitch;
-  fi->offset            = app.pageSize - FrameBufferStructSize;
+  fi->offset            = app.pageSize - sizeof(FrameBuffer);
   fi->flags             =
     (os_blockScreensaver() ?
      FRAME_FLAG_BLOCK_SCREENSAVER : 0) |
diff --git a/obs/lg.c b/obs/lg.c
index 5307348d..0131280a 100644
--- a/obs/lg.c
+++ b/obs/lg.c
@@ -458,7 +458,7 @@ static int dmabufGetFd(LGPlugin * this, LGMPMessage * msg, KVMFRFrame * frame, s
   if (dma->fd == -1)
   {
     const uintptr_t pos    = (uintptr_t) msg->mem - (uintptr_t) this->shmDev.mem;
-    const uintptr_t offset = (uintptr_t) frame->offset + FrameBufferStructSize;
+    const uintptr_t offset = (uintptr_t) frame->offset + sizeof(FrameBuffer);
 
     dma->dataSize = dataSize;
     dma->fd       = ivshmemGetDMABuf(&this->shmDev, pos + offset, dataSize);