Fixed the issue of creating a surface in a non-main thread on the ios…

… platform.

* Fixed the issue of creating a surface in a non-main thread.

* Fixing the deadlock when setting Sync

* code format

src/platform/ios/PAGView.mm

@@ -20,6 +20,7 @@
 #import "PAGPlayer.h"
 #import "PAGSurface.h"
 #import "platform/cocoa/private/PAGAnimator.h"
+#import "platform/ios/private/GPUDrawable.h"
 
 @implementation PAGView {
   PAGPlayer* pagPlayer;
@@ -53,6 +54,10 @@ - (void)initPAG {
                                            selector:@selector(applicationDidReceiveMemoryWarning:)
                                                name:UIApplicationDidReceiveMemoryWarningNotification
                                              object:nil];
+  [[NSNotificationCenter defaultCenter] addObserver:self
+                                           selector:@selector(AsyncSurfacePrepared:)
+                                               name:pag::kAsyncSurfacePreparedNotification
+                                             object:self.layer];
 }
 
 - (void)dealloc {
@@ -349,4 +354,8 @@ - (CGRect)getBounds:(PAGLayer*)pagLayer {
   }
   return CGRectNull;
 }
+
+- (void)AsyncSurfacePrepared:(NSNotification*)notification {
+  [animator update];
+}
 @end

src/platform/ios/private/GPUDrawable.h

@@ -23,6 +23,8 @@
 
 namespace pag {
 
+extern NSString* const kAsyncSurfacePreparedNotification;
+
 class GPUDrawable : public Drawable {
  public:
   static std::shared_ptr<GPUDrawable> FromLayer(CAEAGLLayer* layer);
@@ -48,6 +50,7 @@ class GPUDrawable : public Drawable {
   int _height = 0;
   CAEAGLLayer* layer = nil;
   std::shared_ptr<tgfx::EAGLWindow> window = nullptr;
+  std::atomic<bool> bufferPreparing = false;
 
   explicit GPUDrawable(CAEAGLLayer* layer);
 

src/platform/ios/private/GPUDrawable.mm

@@ -19,6 +19,8 @@
 #include "GPUDrawable.h"
 
 namespace pag {
+NSString* const kAsyncSurfacePreparedNotification = @"pag.art.AsyncSurfacePrepared";
+
 std::shared_ptr<GPUDrawable> GPUDrawable::FromLayer(CAEAGLLayer* layer) {
   if (layer == nil) {
     return nullptr;
@@ -78,10 +80,40 @@
 }
 
 std::shared_ptr<tgfx::Surface> GPUDrawable::onCreateSurface(tgfx::Context* context) {
-  if (window == nullptr) {
+  if (window == nullptr || bufferPreparing) {
+    return nullptr;
+  }
+  if (surface) {
+    return surface;
+  }
+  // https://github.com/Tencent/libpag/issues/1870
+  // Creating a surface in a non-main thread may lead to a crash.
+  if (NSThread.isMainThread) {
+    surface = window->getSurface(context);
+    return surface;
+  } else {
+    bufferPreparing = true;
+    auto strongThis = weakThis.lock();
+    [layer retain];
+    dispatch_async(dispatch_get_main_queue(), ^{
+      auto context = strongThis->window->getDevice()->lockContext();
+      if (context == nullptr) {
+        strongThis->bufferPreparing = false;
+        [strongThis->layer release];
+        return;
+      }
+      strongThis->surface = strongThis->window->getSurface(context);
+      strongThis->bufferPreparing = false;
+      strongThis->window->getDevice()->unlock();
+      if (strongThis->surface) {
+        [[NSNotificationCenter defaultCenter] postNotificationName:kAsyncSurfacePreparedNotification
+                                                            object:strongThis->layer
+                                                          userInfo:nil];
+      }
+      [strongThis->layer release];
+    });
     return nullptr;
   }
-  return window->getSurface(context);
 }
 
 void GPUDrawable::onFreeSurface() {

src/rendering/PAGAnimator.cpp

@@ -107,13 +107,17 @@ bool PAGAnimator::isSync() {
 }
 
 void PAGAnimator::setSync(bool value) {
-  std::lock_guard<std::mutex> autoLock(locker);
+  locker.lock();
   if (_isSync == value) {
+    locker.unlock();
     return;
   }
   _isSync = value;
-  if (_isSync) {
-    resetTask();
+  auto tempTask = task;
+  task = nullptr;
+  locker.unlock();
+  if (tempTask) {
+    tempTask->wait();
   }
 }
 
@@ -327,10 +331,4 @@ void PAGAnimator::resetStartTime() {
   _startTime = INT64_MIN;
 }
 
-void PAGAnimator::resetTask() {
-  if (task != nullptr) {
-    task->wait();
-    task = nullptr;
-  }
-}
 }  // namespace pag

src/rendering/PAGAnimator.h

@@ -176,7 +176,6 @@ class PAGAnimator {
   void startAnimation();
   void cancelAnimation();
   void resetStartTime();
-  void resetTask();
 
   friend class AnimationTicker;
 };