Thread.cpp

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Hash : f1345d1c
Author :
Date : 2023-08-02T14:23:59

Call ReleaseThread() entry point from ThreadCleanupCallback

Change relevant only for the Android platform.

Fixes problems:
1. Current code calls `thread->setCurrent(nullptr)` in
   `Display::threadCleanup()` method, while not executing other code
   that will actually unmake Context from current. This will affect
   following EGL calls from the application's side in its own thread
   cleanup callback. For example, calls to `eglMakeCurrent()` (to unmake
   from current) or `eglReleaseThread()` will be no-op. This may lead to
   memory leak if context was previously marked for destruction.

2. The `Display::threadCleanup()` did not also clears
   the `CurrentValidContext`. This may cause crashes or other UB if an
   application will call some GLES API in its thread termination
   callback (for example `glFinish()`), if ANGLE already destroyed the
   context in its ThreadCleanupCallback (use after delete).

3. Context will remain current to a thread that terminated. Current
   implementation of GLES drivers on Mali/Adreno GPUs automatically
   unmade context from current, so the application may make this context
   current to some other thread. ANGLE should mimic this behavior to
   avoid possible bugs.

All of the above problems may be fixed by simply calling from the
ThreadCleanupCallback either:
- MakeCurrent(t, d, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT)
- ReleaseThread(t)

This CL choose to call `ReleaseThread()` because this is the API that
the application may call in its own thread cleanup callback. And if
application's callback will be called later than ANGLE's callback, then
application's `eglReleaseThread()` call we be a no-op.

Even if the application does not have its own thread cleanup callback
(like most of the applications), there is no harm to call
`ReleaseThread()` anyway. The only difference with `MakeCurrent()` is
that it will also cleanup invalid objects and some other memory
depending on the backend.

This CL naturally replaces existing logic with Display termination when
there is no active threads thanks to the previous CL:
    "Perform Display terminate(InternalCleanup) from makeCurrent()".

Bug: angleproject:6723
Bug: angleproject:8283
Test: angle_end2end_tests --gtest_filter=EGLContextSharingTest.ThreadCleanupCallback*
Test: angle_end2end_tests --gtest_filter=EGLContextSharingTest.UnmakeFromCurrentOnThreadExit*
Change-Id: I8c5b31f34f91c4bfdac165ac30c213ff5fef992e
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4742383
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Igor Nazarov <i.nazarov@samsung.com>

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src/libANGLE/Thread.cpp

//
// Copyright 2016 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//

// Thread.cpp : Defines the Thread class which represents a global EGL thread.

#include "libANGLE/Thread.h"

#include "libANGLE/Context.h"
#include "libANGLE/Debug.h"
#include "libANGLE/Display.h"
#include "libANGLE/Error.h"

namespace angle
{
#if defined(ANGLE_USE_ANDROID_TLS_SLOT)
bool gUseAndroidOpenGLTlsSlot = false;
#endif
}  // namespace angle

namespace egl
{
namespace
{
Debug *sDebug = nullptr;
}  // namespace

Thread::Thread()
    : mLabel(nullptr),
      mError(EGL_SUCCESS),
      mAPI(EGL_OPENGL_ES_API),
      mContext(static_cast<gl::Context *>(EGL_NO_CONTEXT))
{}

void Thread::setLabel(EGLLabelKHR label)
{
    mLabel = label;
}

EGLLabelKHR Thread::getLabel() const
{
    return mLabel;
}

void Thread::setSuccess()
{
    mError = EGL_SUCCESS;
}

void Thread::setError(EGLint error,
                      const char *command,
                      const LabeledObject *object,
                      const char *message)
{
    mError = error;
    if (error != EGL_SUCCESS && message)
    {
        EnsureDebugAllocated();
        sDebug->insertMessage(error, command, ErrorCodeToMessageType(error), getLabel(),
                              object ? object->getLabel() : nullptr, message);
    }
}

void Thread::setError(const Error &error, const char *command, const LabeledObject *object)
{
    mError = error.getCode();
    if (error.isError() && !error.getMessage().empty())
    {
        EnsureDebugAllocated();
        sDebug->insertMessage(error.getCode(), command, ErrorCodeToMessageType(error.getCode()),
                              getLabel(), object ? object->getLabel() : nullptr,
                              error.getMessage());
    }
}

EGLint Thread::getError() const
{
    return mError;
}

void Thread::setAPI(EGLenum api)
{
    mAPI = api;
}

EGLenum Thread::getAPI() const
{
    return mAPI;
}

void Thread::setCurrent(gl::Context *context)
{
    mContext = context;
    if (mContext)
    {
        ASSERT(mContext->getDisplay());
    }
}

Surface *Thread::getCurrentDrawSurface() const
{
    if (mContext)
    {
        return mContext->getCurrentDrawSurface();
    }
    return nullptr;
}

Surface *Thread::getCurrentReadSurface() const
{
    if (mContext)
    {
        return mContext->getCurrentReadSurface();
    }
    return nullptr;
}

gl::Context *Thread::getContext() const
{
    return mContext;
}

Display *Thread::getDisplay() const
{
    if (mContext)
    {
        return mContext->getDisplay();
    }
    return nullptr;
}

void EnsureDebugAllocated()
{
    // All EGL calls use a global lock, this is thread safe
    if (sDebug == nullptr)
    {
        sDebug = new Debug();
    }
}

void DeallocateDebug()
{
    SafeDelete(sDebug);
}

Debug *GetDebug()
{
    EnsureDebugAllocated();
    return sDebug;
}
}  // namespace egl

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