[ozone/wayland] Wrap wl_shm to WaylandShm

This patch does not bring functionality changes, but
just wraps the wl_shm to WaylandShm for more convinient usage.

This is also a prerequisite to unite the
WaylandShmBufferManager and the WaylandBufferManager.

Bug: 963853
Change-Id: I5ce47dc981caccf3df7f0092cb2095712a63443e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1617501Reviewed-by: Michael Spang <spang@chromium.org>
Commit-Queue: Maksim Sisov <msisov@igalia.com>
Cr-Commit-Position: refs/heads/master@{#661174}

ui/ozone/platform/wayland/BUILD.gn

@@ -66,6 +66,8 @@ source_set("wayland") {
     "host/wayland_screen.h",
     "host/wayland_shared_memory_buffer_manager.cc",
     "host/wayland_shared_memory_buffer_manager.h",
+    "host/wayland_shm.cc",
+    "host/wayland_shm.h",
     "host/wayland_shm_buffer.cc",
     "host/wayland_shm_buffer.h",
     "host/wayland_touch.cc",

ui/ozone/platform/wayland/host/wayland_connection.cc

@@ -25,6 +25,7 @@
 #include "ui/ozone/platform/wayland/host/wayland_input_method_context.h"
 #include "ui/ozone/platform/wayland/host/wayland_output_manager.h"
 #include "ui/ozone/platform/wayland/host/wayland_shared_memory_buffer_manager.h"
+#include "ui/ozone/platform/wayland/host/wayland_shm.h"
 #include "ui/ozone/platform/wayland/host/wayland_window.h"
 #include "ui/ozone/platform/wayland/host/wayland_zwp_linux_dmabuf.h"
 
@@ -403,8 +404,9 @@ void WaylandConnection::Global(void* data,
     if (!connection->subcompositor_)
       LOG(ERROR) << "Failed to bind to wl_subcompositor global";
   } else if (!connection->shm_ && strcmp(interface, "wl_shm") == 0) {
-    connection->shm_ =
+    wl::Object<wl_shm> shm =
         wl::Bind<wl_shm>(registry, name, std::min(version, kMaxShmVersion));
+    connection->shm_ = std::make_unique<WaylandShm>(shm.release(), connection);
     if (!connection->shm_)
       LOG(ERROR) << "Failed to bind to wl_shm global";
     connection->shm_buffer_manager_ =

ui/ozone/platform/wayland/host/wayland_connection.h

@@ -35,6 +35,7 @@ class WaylandShmBufferManager;
 class WaylandOutputManager;
 class WaylandWindow;
 class WaylandZwpLinuxDmabuf;
+class WaylandShm;
 
 class WaylandConnection : public PlatformEventSource,
                           public ozone::mojom::WaylandConnection,
@@ -105,7 +106,6 @@ class WaylandConnection : public PlatformEventSource,
   wl_display* display() const { return display_.get(); }
   wl_compositor* compositor() const { return compositor_.get(); }
   wl_subcompositor* subcompositor() const { return subcompositor_.get(); }
-  wl_shm* shm() const { return shm_.get(); }
   xdg_shell* shell() const { return shell_.get(); }
   zxdg_shell_v6* shell_v6() const { return shell_v6_.get(); }
   wl_seat* seat() const { return seat_.get(); }
@@ -152,6 +152,8 @@ class WaylandConnection : public PlatformEventSource,
 
   WaylandZwpLinuxDmabuf* zwp_dmabuf() const { return zwp_dmabuf_.get(); }
 
+  WaylandShm* shm() const { return shm_.get(); }
+
   // Returns bound pointer to own mojo interface.
   ozone::mojom::WaylandConnectionPtr BindInterface();
 
@@ -237,7 +239,6 @@ class WaylandConnection : public PlatformEventSource,
   wl::Object<wl_compositor> compositor_;
   wl::Object<wl_subcompositor> subcompositor_;
   wl::Object<wl_seat> seat_;
-  wl::Object<wl_shm> shm_;
   wl::Object<xdg_shell> shell_;
   wl::Object<zxdg_shell_v6> shell_v6_;
   wl::Object<wp_presentation> presentation_;
@@ -254,6 +255,7 @@ class WaylandConnection : public PlatformEventSource,
   std::unique_ptr<WaylandCursorPosition> wayland_cursor_position_;
   std::unique_ptr<WaylandShmBufferManager> shm_buffer_manager_;
   std::unique_ptr<WaylandZwpLinuxDmabuf> zwp_dmabuf_;
+  std::unique_ptr<WaylandShm> shm_;
 
   // Objects that are using when GPU runs in own process.
   std::unique_ptr<WaylandBufferManager> buffer_manager_;

ui/ozone/platform/wayland/host/wayland_cursor.cc

@@ -11,6 +11,7 @@
 #include "ui/gfx/skia_util.h"
 #include "ui/ozone/platform/wayland/common/wayland_util.h"
 #include "ui/ozone/platform/wayland/host/wayland_connection.h"
+#include "ui/ozone/platform/wayland/host/wayland_shm.h"
 
 namespace ui {
 

ui/ozone/platform/wayland/host/wayland_cursor.h

@@ -26,6 +26,7 @@ class Point;
 namespace ui {
 
 class WaylandConnection;
+class WaylandShm;
 
 // Manages the actual visual representation (what users see drawn) of the
 // 'pointer' (which is the Wayland term for mouse/mice).
@@ -54,7 +55,7 @@ class WaylandCursor {
 
   void HideCursor(uint32_t serial);
 
-  wl_shm* shm_ = nullptr;                // Owned by WaylandConnection.
+  WaylandShm* shm_ = nullptr;            // Owned by WaylandConnection.
   wl_pointer* input_pointer_ = nullptr;  // Owned by WaylandPointer.
 
   // Holds the buffers and their memory until the compositor releases them.

ui/ozone/platform/wayland/host/wayland_shared_memory_buffer_manager.cc

@@ -8,19 +8,11 @@
 
 #include "base/trace_event/trace_event.h"
 #include "ui/ozone/platform/wayland/host/wayland_connection.h"
+#include "ui/ozone/platform/wayland/host/wayland_shm.h"
 #include "ui/ozone/platform/wayland/host/wayland_window.h"
 
 namespace ui {
 
-WaylandShmBufferManager::ShmBuffer::ShmBuffer() = default;
-
-WaylandShmBufferManager::ShmBuffer::ShmBuffer(
-    wl::Object<struct wl_buffer> buffer,
-    wl::Object<struct wl_shm_pool> pool)
-    : shm_buffer(std::move(buffer)), shm_pool(std::move(pool)) {}
-
-WaylandShmBufferManager::ShmBuffer::~ShmBuffer() = default;
-
 WaylandShmBufferManager::WaylandShmBufferManager(WaylandConnection* connection)
     : connection_(connection) {}
 
@@ -43,20 +35,11 @@ bool WaylandShmBufferManager::CreateBufferForWidget(
   if (it != shm_buffers_.end())
     return false;
 
-  wl::Object<wl_shm_pool> pool(
-      wl_shm_create_pool(connection_->shm(), fd.get(), length));
-  if (!pool)
-    return false;
-
-  wl::Object<wl_buffer> shm_buffer(
-      wl_shm_pool_create_buffer(pool.get(), 0, size.width(), size.height(),
-                                size.width() * 4, WL_SHM_FORMAT_ARGB8888));
-  if (!shm_buffer)
+  auto buffer = connection_->shm()->CreateBuffer(std::move(fd), length, size);
+  if (!buffer)
     return false;
 
-  shm_buffers_.insert(std::make_pair(
-      widget,
-      std::make_unique<ShmBuffer>(std::move(shm_buffer), std::move(pool))));
+  shm_buffers_.insert(std::make_pair(widget, std::move(buffer)));
 
   connection_->ScheduleFlush();
   return true;
@@ -77,7 +60,7 @@ bool WaylandShmBufferManager::PresentBufferForWidget(
   wl_surface* surface = connection_->GetWindow(widget)->surface();
   wl_surface_damage(surface, damage.x(), damage.y(), damage.width(),
                     damage.height());
-  wl_surface_attach(surface, it->second->shm_buffer.get(), 0, 0);
+  wl_surface_attach(surface, it->second.get(), 0, 0);
   wl_surface_commit(surface);
   connection_->ScheduleFlush();
   return true;

ui/ozone/platform/wayland/host/wayland_shared_memory_buffer_manager.h

@@ -45,25 +45,8 @@ class WaylandShmBufferManager {
   bool DestroyBuffer(gfx::AcceleratedWidget widget);
 
  private:
-  // Internal representation of a shared memory buffer.
-  struct ShmBuffer {
-    ShmBuffer();
-    ShmBuffer(wl::Object<struct wl_buffer> buffer,
-              wl::Object<struct wl_shm_pool> pool);
-    ~ShmBuffer();
-
-    // A wl_buffer backed by a shared memory handle passed from the gpu process.
-    wl::Object<struct wl_buffer> shm_buffer;
-
-    // Is used to create shared memory based buffer objects.
-    wl::Object<struct wl_shm_pool> shm_pool;
-
-    DISALLOW_COPY_AND_ASSIGN(ShmBuffer);
-  };
-
   // A container of created buffers.
-  base::flat_map<gfx::AcceleratedWidget, std::unique_ptr<ShmBuffer>>
-      shm_buffers_;
+  base::flat_map<gfx::AcceleratedWidget, wl::Object<wl_buffer>> shm_buffers_;
 
   // Non-owned pointer to the main connection.
   WaylandConnection* connection_ = nullptr;

ui/ozone/platform/wayland/host/wayland_shm.cc

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/ozone/platform/wayland/host/wayland_shm.h"
+
+#include "ui/ozone/platform/wayland/host/wayland_connection.h"
+
+namespace ui {
+
+namespace {
+
+constexpr uint32_t kShmFormat = WL_SHM_FORMAT_ARGB8888;
+
+}  // namespace
+
+WaylandShm::WaylandShm(wl_shm* shm, WaylandConnection* connection)
+    : shm_(shm), connection_(connection) {}
+
+WaylandShm::~WaylandShm() = default;
+
+wl::Object<wl_buffer> WaylandShm::CreateBuffer(base::ScopedFD fd,
+                                               size_t length,
+                                               const gfx::Size& size) {
+  if (!fd.is_valid() || length == 0 || size.IsEmpty())
+    return wl::Object<wl_buffer>(nullptr);
+
+  wl::Object<wl_shm_pool> pool(
+      wl_shm_create_pool(shm_.get(), fd.get(), length));
+  if (!pool)
+    return wl::Object<wl_buffer>(nullptr);
+
+  wl::Object<wl_buffer> shm_buffer(
+      wl_shm_pool_create_buffer(pool.get(), 0, size.width(), size.height(),
+                                size.width() * 4, kShmFormat));
+
+  connection_->ScheduleFlush();
+  return shm_buffer;
+}
+
+}  // namespace ui

ui/ozone/platform/wayland/host/wayland_shm.h

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_OZONE_PLATFORM_WAYLAND_HOST_WAYLAND_SHM_H_
+#define UI_OZONE_PLATFORM_WAYLAND_HOST_WAYLAND_SHM_H_
+
+#include <memory>
+
+#include "base/files/scoped_file.h"
+#include "base/macros.h"
+#include "ui/gfx/geometry/rect.h"
+#include "ui/ozone/platform/wayland/common/wayland_object.h"
+#include "ui/ozone/platform/wayland/common/wayland_util.h"
+
+namespace ui {
+
+class WaylandConnection;
+
+// Wrapper around |wl_shm| Wayland factory, which creates
+// |wl_buffer|s backed by a fd to a shared memory.
+class WaylandShm {
+ public:
+  WaylandShm(wl_shm* shm, WaylandConnection* connection);
+  ~WaylandShm();
+
+  // Creates a wl_buffer based on shared memory handle for the specified
+  // |widget|.
+  wl::Object<struct wl_buffer> CreateBuffer(base::ScopedFD fd,
+                                            size_t length,
+                                            const gfx::Size& size);
+
+ private:
+  wl::Object<wl_shm> const shm_;
+
+  // Non-owned pointer to the main connection.
+  WaylandConnection* const connection_;
+
+  DISALLOW_COPY_AND_ASSIGN(WaylandShm);
+};
+
+}  // namespace ui
+
+#endif  // UI_OZONE_PLATFORM_WAYLAND_HOST_WAYLAND_SHM_H_

ui/ozone/platform/wayland/host/wayland_shm_buffer.cc

@@ -8,16 +8,11 @@
 #include "base/memory/unsafe_shared_memory_region.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/ozone/platform/wayland/host/wayland_connection.h"
-
-namespace {
-
-const uint32_t kShmFormat = WL_SHM_FORMAT_ARGB8888;
-
-}  // namespace
+#include "ui/ozone/platform/wayland/host/wayland_shm.h"
 
 namespace ui {
 
-WaylandShmBuffer::WaylandShmBuffer(wl_shm* shm, const gfx::Size& size)
+WaylandShmBuffer::WaylandShmBuffer(WaylandShm* shm, const gfx::Size& size)
     : size_(size) {
   Initialize(shm);
 }
@@ -27,7 +22,7 @@ WaylandShmBuffer::WaylandShmBuffer(WaylandShmBuffer&& buffer) = default;
 WaylandShmBuffer& WaylandShmBuffer::operator=(WaylandShmBuffer&& buffer) =
     default;
 
-void WaylandShmBuffer::Initialize(wl_shm* shm) {
+void WaylandShmBuffer::Initialize(WaylandShm* shm) {
   DCHECK(shm);
 
   SkImageInfo info = SkImageInfo::MakeN32Premul(size_.width(), size_.height());
@@ -48,18 +43,15 @@ void WaylandShmBuffer::Initialize(wl_shm* shm) {
       base::UnsafeSharedMemoryRegion::TakeHandleForSerialization(
           std::move(shared_memory_region));
 
-  wl::Object<wl_shm_pool> pool(wl_shm_create_pool(
-      shm, platform_shared_memory.GetPlatformHandle().fd, buffer_size));
-
-  auto* new_buffer = wl_shm_pool_create_buffer(
-      pool.get(), 0, size_.width(), size_.height(), stride, kShmFormat);
-  if (!new_buffer) {
+  base::subtle::ScopedFDPair fd_pair =
+      platform_shared_memory.PassPlatformHandle();
+  buffer_ = shm->CreateBuffer(std::move(fd_pair.fd), buffer_size, size_);
+  if (!buffer_) {
     shared_memory_mapping_ = base::WritableSharedMemoryMapping();
     return;
   }
 
   stride_ = stride;
-  buffer_.reset(new_buffer);
 }
 
 uint8_t* WaylandShmBuffer::GetMemory() const {

ui/ozone/platform/wayland/host/wayland_shm_buffer.h

@@ -18,6 +18,8 @@
 
 namespace ui {
 
+class WaylandShm;
+
 // Encapsulates a Wayland SHM buffer, covering basically 2 use cases:
 // (1) Buffers created and mmap'ed locally to draw skia bitmap(s) into; and
 // (2) Buffers created using file descriptor (e.g: sent by gpu process/thread,
@@ -26,7 +28,7 @@ namespace ui {
 // wl_buffer and WritableSharedMemoryMapping (if any) instance.
 class WaylandShmBuffer {
  public:
-  WaylandShmBuffer(wl_shm* shm, const gfx::Size& size);
+  WaylandShmBuffer(WaylandShm* shm, const gfx::Size& size);
   ~WaylandShmBuffer();
 
   WaylandShmBuffer(WaylandShmBuffer&& buffer);
@@ -49,7 +51,7 @@ class WaylandShmBuffer {
   int stride() const { return stride_; }
 
  private:
-  void Initialize(wl_shm* shm);
+  void Initialize(WaylandShm* shm);
 
   gfx::Size size_;
   int stride_;