commit 2370109af70b31937b44c663ab4882d2c74fbc53
author Roman Stratiienko <r.stratiienko@gmail.com> Sat Sep 26 02:08:41 2020 +0300
committer Roman Stratiienko <r.stratiienko@gmail.com> Mon Sep 28 15:21:29 2020 +0300
tree ba84eeffc4bd094f9cddb5179a039c331691aece
parent 25ddbc44acfbe6d53439deb68e0f92b5809b5738

drm_hwcomposer: Fix RegisterCallback() function

- Fixes segfault during client switch.
- Allows to run VTS on Android-11.

VTS Results:
============================================
    arm64-v8a VtsHalGraphicsComposerV2_1TargetTest: [53 tests / 42808 msec]
    armeabi-v7a VtsHalGraphicsComposerV2_1TargetTest: [53 tests / 33353 msec]
=============== Summary ===============
2/2 modules completed
Total Tests       : 106
PASSED            : 106
FAILED            : 0
============================================

Signed-off-by: Roman Stratiienko <r.stratiienko@gmail.com>

compositor/DrmDisplayCompositor.cpp

diff --git a/compositor/DrmDisplayCompositor.cpp b/compositor/DrmDisplayCompositor.cpp
index 467f8ba..ba0d56b 100644
--- a/compositor/DrmDisplayCompositor.cpp
+++ b/compositor/DrmDisplayCompositor.cpp
@@ -813,7 +813,9 @@
 }
 
 int DrmDisplayCompositor::FlattenOnClient() {
-  if (refresh_display_cb_) {
+  const std::lock_guard<std::mutex> lock(refresh_callback_lock);
+
+  if (refresh_callback_hook_ && refresh_callback_data_) {
     {
       AutoLock lock(&lock_, __func__);
       if (!IsFlatteningNeeded()) {
@@ -829,7 +831,7 @@
         "No writeback connector available, "
         "falling back to client composition");
     SetFlattening(FlatteningState::kClientRequested);
-    refresh_display_cb_(display_);
+    refresh_callback_hook_(refresh_callback_data_, display_);
     return 0;
   } else {
     ALOGV("No writeback connector available");

compositor/DrmDisplayCompositor.h

diff --git a/compositor/DrmDisplayCompositor.h b/compositor/DrmDisplayCompositor.h
index e500c9e..29afc66 100644
--- a/compositor/DrmDisplayCompositor.h
+++ b/compositor/DrmDisplayCompositor.h
@@ -59,9 +59,15 @@
 
   int Init(ResourceManager *resource_manager, int display);
 
-  template <typename Fn>
-  void SetRefreshCallback(Fn &&refresh_cb) {
-    refresh_display_cb_ = std::forward<Fn>(refresh_cb);
+  hwc2_callback_data_t refresh_callback_data_ = NULL;
+  HWC2_PFN_REFRESH refresh_callback_hook_ = NULL;
+  std::mutex refresh_callback_lock;
+
+  void SetRefreshCallback(hwc2_callback_data_t data,
+                          hwc2_function_pointer_t hook) {
+    const std::lock_guard<std::mutex> lock(refresh_callback_lock);
+    refresh_callback_data_ = data;
+    refresh_callback_hook_ = reinterpret_cast<HWC2_PFN_REFRESH>(hook);
   }
 
   std::unique_ptr<DrmDisplayComposition> CreateComposition() const;