firefox/mozilla-1619882-1.patch

diff --git a/gfx/layers/ipc/LayersSurfaces.ipdlh b/gfx/layers/ipc/LayersSurfaces.ipdlh
--- a/gfx/layers/ipc/LayersSurfaces.ipdlh
+++ b/gfx/layers/ipc/LayersSurfaces.ipdlh
@@ -71,6 +71,8 @@
   uint32_t[] offsets;
   YUVColorSpace yUVColorSpace;
   FileDescriptor[] fence;
+  uint32_t uid;
+  FileDescriptor[] refCount;
 };
 
 struct SurfaceTextureDescriptor {
diff --git a/widget/gtk/WaylandDMABufSurface.h b/widget/gtk/WaylandDMABufSurface.h
--- a/widget/gtk/WaylandDMABufSurface.h
+++ b/widget/gtk/WaylandDMABufSurface.h
@@ -40,6 +40,23 @@
 
 class WaylandDMABufSurfaceRGBA;
 
+class DMABufRefcount {
+ public:
+  DMABufRefcount();
+  DMABufRefcount(int aFd);
+
+  bool Created() { return mFd > 0; };
+  int GetFD() { return mFd; }
+  uint64_t GetRefcount();
+  void RefAdd();
+  void Release();
+
+  ~DMABufRefcount();
+
+ private:
+  int mFd;
+};
+
 class WaylandDMABufSurface {
  public:
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(WaylandDMABufSurface)
@@ -82,6 +99,14 @@
   void FenceWait();
   void FenceDelete();
 
+  void SetUID(uint32_t aUID) { mUID = aUID; };
+  uint32_t GetUID() { return mUID; };
+
+  void GlobalRefCountCreate();
+  bool IsGlobalRefSet();
+  void GlobalRefAdd();
+  void GlobalRefRelease();
+
   WaylandDMABufSurface(SurfaceType aSurfaceType);
 
  protected:
@@ -89,6 +114,8 @@
   virtual void ReleaseSurface() = 0;
   bool FenceCreate(int aFd);
 
+  bool GlobalRefCountImport(int aFd);
+
   virtual ~WaylandDMABufSurface() { FenceDelete(); };
 
   SurfaceType mSurfaceType;
@@ -102,6 +129,9 @@
 
   EGLSyncKHR mSync;
   RefPtr<mozilla::gl::GLContext> mGL;
+
+  mozilla::UniquePtr<DMABufRefcount> mGlobalRefCount;
+  uint32_t mUID;
 };
 
 class WaylandDMABufSurfaceRGBA : public WaylandDMABufSurface {
diff --git a/widget/gtk/WaylandDMABufSurface.cpp b/widget/gtk/WaylandDMABufSurface.cpp
--- a/widget/gtk/WaylandDMABufSurface.cpp
+++ b/widget/gtk/WaylandDMABufSurface.cpp
@@ -17,6 +17,8 @@
 #include <unistd.h>
 #include <sys/time.h>
 #include <dlfcn.h>
+#include <sys/mman.h>
+#include <sys/eventfd.h>
 
 #include "mozilla/widget/gbm.h"
 #include "mozilla/widget/va_drmcommon.h"
@@ -57,6 +59,73 @@
 #  define VA_FOURCC_NV12 0x3231564E
 #endif
 
+void DMABufRefcount::RefAdd() {
+  uint64_t counter;
+  read(mFd, &counter, sizeof(counter));
+  counter++;
+  write(mFd, &counter, sizeof(counter));
+}
+
+void DMABufRefcount::Release() {
+  uint64_t counter;
+  read(mFd, &counter, sizeof(counter));
+  counter--;
+  write(mFd, &counter, sizeof(counter));
+}
+
+uint64_t DMABufRefcount::GetRefcount() {
+  uint64_t counter;
+  read(mFd, &counter, sizeof(counter));
+  write(mFd, &counter, sizeof(counter));
+  return counter;
+}
+
+DMABufRefcount::DMABufRefcount()
+    : mFd(eventfd(1, EFD_CLOEXEC | EFD_NONBLOCK)) {}
+
+DMABufRefcount::DMABufRefcount(int aFd) : mFd(aFd) {}
+
+DMABufRefcount::~DMABufRefcount() {
+  if (mFd > 0) {
+    close(mFd);
+  }
+}
+
+void WaylandDMABufSurface::GlobalRefCountCreate() {
+  MOZ_ASSERT(!mGlobalRefCount);
+  mGlobalRefCount = MakeUnique<DMABufRefcount>();
+  if (!mGlobalRefCount->Created()) {
+    NS_WARNING("Failed to create dmabuf global ref count!");
+    mGlobalRefCount = nullptr;
+  }
+}
+
+bool WaylandDMABufSurface::GlobalRefCountImport(int aFd) {
+  MOZ_ASSERT(!mGlobalRefCount);
+  mGlobalRefCount = MakeUnique<DMABufRefcount>(aFd);
+  if (!mGlobalRefCount->Created()) {
+    NS_WARNING("Failed to import dmabuf global ref count!");
+    mGlobalRefCount = nullptr;
+    return false;
+  }
+  return true;
+}
+
+bool WaylandDMABufSurface::IsGlobalRefSet() {
+  MOZ_ASSERT(mGlobalRefCount);
+  return mGlobalRefCount->GetRefcount() > 1;
+}
+
+void WaylandDMABufSurface::GlobalRefAdd() {
+  MOZ_ASSERT(mGlobalRefCount);
+  mGlobalRefCount->RefAdd();
+}
+
+void WaylandDMABufSurface::GlobalRefRelease() {
+  MOZ_ASSERT(mGlobalRefCount);
+  mGlobalRefCount->Release();
+}
+
 WaylandDMABufSurface::WaylandDMABufSurface(SurfaceType aSurfaceType)
     : mSurfaceType(aSurfaceType),
       mBufferModifier(DRM_FORMAT_MOD_INVALID),
@@ -64,7 +133,9 @@
       mDrmFormats(),
       mStrides(),
       mOffsets(),
-      mSync(0) {
+      mSync(0),
+      mGlobalRefCount(nullptr),
+      mUID(0) {
   for (auto& slot : mDmabufFds) {
     slot = -1;
   }
@@ -316,6 +387,7 @@
   mBufferPlaneCount = desc.fds().Length();
   mGbmBufferFlags = desc.flags();
   MOZ_RELEASE_ASSERT(mBufferPlaneCount <= DMABUF_BUFFER_PLANES);
+  mUID = desc.uid();
 
   for (int i = 0; i < mBufferPlaneCount; i++) {
     mDmabufFds[i] = desc.fds()[i].ClonePlatformHandle().release();
@@ -329,6 +401,13 @@
       close(fd);
     }
   }
+
+  if (desc.refCount().Length() > 0) {
+    int fd = desc.refCount()[0].ClonePlatformHandle().release();
+    if (!GlobalRefCountImport(fd)) {
+      close(fd);
+    }
+  }
 }
 
 bool WaylandDMABufSurfaceRGBA::Create(const SurfaceDescriptor& aDesc) {
@@ -346,6 +425,7 @@
   AutoTArray<uint32_t, DMABUF_BUFFER_PLANES> offsets;
   AutoTArray<uintptr_t, DMABUF_BUFFER_PLANES> images;
   AutoTArray<ipc::FileDescriptor, 1> fenceFDs;
+  AutoTArray<ipc::FileDescriptor, 1> refCountFDs;
 
   width.AppendElement(mWidth);
   height.AppendElement(mHeight);
@@ -362,9 +442,14 @@
         egl->fDupNativeFenceFDANDROID(egl->Display(), mSync)));
   }
 
-  aOutDescriptor = SurfaceDescriptorDMABuf(
-      mSurfaceType, mBufferModifier, mGbmBufferFlags, fds, width, height,
-      format, strides, offsets, GetYUVColorSpace(), fenceFDs);
+  if (mGlobalRefCount) {
+    refCountFDs.AppendElement(ipc::FileDescriptor(mGlobalRefCount->GetFD()));
+  }
+
+  aOutDescriptor =
+      SurfaceDescriptorDMABuf(mSurfaceType, mBufferModifier, mGbmBufferFlags,
+                              fds, width, height, format, strides, offsets,
+                              GetYUVColorSpace(), fenceFDs, mUID, refCountFDs);
 
   return true;
 }
@@ -693,6 +778,7 @@
   mBufferPlaneCount = aDesc.fds().Length();
   mBufferModifier = aDesc.modifier();
   mColorSpace = aDesc.yUVColorSpace();
+  mUID = aDesc.uid();
 
   MOZ_RELEASE_ASSERT(mBufferPlaneCount <= DMABUF_BUFFER_PLANES);
   for (int i = 0; i < mBufferPlaneCount; i++) {
@@ -710,6 +796,13 @@
       close(fd);
     }
   }
+
+  if (aDesc.refCount().Length() > 0) {
+    int fd = aDesc.refCount()[0].ClonePlatformHandle().release();
+    if (!GlobalRefCountImport(fd)) {
+      close(fd);
+    }
+  }
 }
 
 bool WaylandDMABufSurfaceNV12::Serialize(
@@ -721,6 +814,7 @@
   AutoTArray<uint32_t, DMABUF_BUFFER_PLANES> strides;
   AutoTArray<uint32_t, DMABUF_BUFFER_PLANES> offsets;
   AutoTArray<ipc::FileDescriptor, 1> fenceFDs;
+  AutoTArray<ipc::FileDescriptor, 1> refCountFDs;
 
   for (int i = 0; i < mBufferPlaneCount; i++) {
     width.AppendElement(mWidth[i]);
@@ -737,9 +831,13 @@
         egl->fDupNativeFenceFDANDROID(egl->Display(), mSync)));
   }
 
+  if (mGlobalRefCount) {
+    refCountFDs.AppendElement(ipc::FileDescriptor(mGlobalRefCount->GetFD()));
+  }
+
   aOutDescriptor = SurfaceDescriptorDMABuf(
       mSurfaceType, mBufferModifier, 0, fds, width, height, format, strides,
-      offsets, GetYUVColorSpace(), fenceFDs);
+      offsets, GetYUVColorSpace(), fenceFDs, mUID, refCountFDs);
   return true;
 }
 
diff --git a/widget/gtk/WindowSurfaceWayland.h b/widget/gtk/WindowSurfaceWayland.h
--- a/widget/gtk/WindowSurfaceWayland.h
+++ b/widget/gtk/WindowSurfaceWayland.h
@@ -36,8 +36,6 @@
                             int aImageDataSize);
 
  private:
-  int CreateTemporaryFile(int aSize);
-
   wl_shm_pool* mShmPool;
   int mShmPoolFd;
   int mAllocatedSize;
diff --git a/widget/gtk/WindowSurfaceWayland.cpp b/widget/gtk/WindowSurfaceWayland.cpp
--- a/widget/gtk/WindowSurfaceWayland.cpp
+++ b/widget/gtk/WindowSurfaceWayland.cpp
@@ -206,42 +206,25 @@
   return mWindowSurfaceWayland->GetWaylandDisplay();
 }
 
-int WaylandShmPool::CreateTemporaryFile(int aSize) {
-  const char* tmppath = getenv("XDG_RUNTIME_DIR");
-  MOZ_RELEASE_ASSERT(tmppath, "Missing XDG_RUNTIME_DIR env variable.");
-
-  nsPrintfCString tmpname("%s/mozilla-shared-XXXXXX", tmppath);
-
-  char* filename;
-  int fd = -1;
-  int ret = 0;
-
-  if (tmpname.GetMutableData(&filename)) {
-    fd = mkstemp(filename);
-    if (fd >= 0) {
-      int flags = fcntl(fd, F_GETFD);
-      if (flags >= 0) {
-        fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
-      }
-    }
-  }
-
+static int WaylandAllocateShmMemory(int aSize) {
+  static int counter = 0;
+  nsPrintfCString shmName("/wayland.mozilla.ipc.%d", counter++);
+  int fd = shm_open(shmName.get(), O_CREAT | O_RDWR | O_EXCL, 0600);
   if (fd >= 0) {
-    unlink(tmpname.get());
+    shm_unlink(shmName.get());
   } else {
-    printf_stderr("Unable to create mapping file %s\n", filename);
+    printf_stderr("Unable to SHM memory segment\n");
     MOZ_CRASH();
   }
 
+  int ret = 0;
 #ifdef HAVE_POSIX_FALLOCATE
   do {
     ret = posix_fallocate(fd, 0, aSize);
   } while (ret == EINTR);
   if (ret != 0) {
     close(fd);
-    MOZ_CRASH_UNSAFE_PRINTF(
-        "posix_fallocate() fails on %s size %d error code %d\n", filename,
-        aSize, ret);
+    MOZ_CRASH("posix_fallocate() fails to allocate shm memory");
   }
 #else
   do {
@@ -249,8 +232,7 @@
   } while (ret < 0 && errno == EINTR);
   if (ret < 0) {
     close(fd);
-    MOZ_CRASH_UNSAFE_PRINTF("ftruncate() fails on %s size %d error code %d\n",
-                            filename, aSize, ret);
+    MOZ_CRASH("ftruncate() fails to allocate shm memory");
   }
 #endif
 
@@ -259,7 +241,7 @@
 
 WaylandShmPool::WaylandShmPool(nsWaylandDisplay* aWaylandDisplay, int aSize)
     : mAllocatedSize(aSize) {
-  mShmPoolFd = CreateTemporaryFile(mAllocatedSize);
+  mShmPoolFd = WaylandAllocateShmMemory(mAllocatedSize);
   mImageData = mmap(nullptr, mAllocatedSize, PROT_READ | PROT_WRITE, MAP_SHARED,
                     mShmPoolFd, 0);
   MOZ_RELEASE_ASSERT(mImageData != MAP_FAILED,