Fix a multithreading bug in libagl's EGL.

The bug caused libagl to return 0 from eglGetError if an EGL error value
(including EGL_SUCCESS) was set on a different thread but not yet on the
current thread.

Bug: 3403756
Change-Id: Ifd965091d116745c2e22c121151ade9e78eb14c6

1 files changed, 5 insertions, 0 deletions

diff --git a/opengl/libagl/egl.cpp b/opengl/libagl/egl.cpp
index 7ac6f92776..a1cb23a250 100644
--- a/opengl/libagl/egl.cpp
+++ b/opengl/libagl/egl.cpp
@@ -82,6 +82,11 @@ static GLint getError() {
     if (ggl_unlikely(gEGLErrorKey == -1))
         return EGL_SUCCESS;
     GLint error = (GLint)pthread_getspecific(gEGLErrorKey);
+    if (error == 0) {
+        // The TLS key has been created by another thread, but the value for
+        // this thread has not been initialized.
+        return EGL_SUCCESS;
+    }
     pthread_setspecific(gEGLErrorKey, (void*)EGL_SUCCESS);
     return error;
 }