chromium/mojo/public/cpp/bindings/sync_call_restrictions.h

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

#ifndef MOJO_PUBLIC_CPP_BINDINGS_SYNC_CALL_RESTRICTIONS_H_
#define MOJO_PUBLIC_CPP_BINDINGS_SYNC_CALL_RESTRICTIONS_H_

#include "base/component_export.h"
#include "base/threading/thread_restrictions.h"
#include "build/build_config.h"

#if (!defined(NDEBUG) || defined(DCHECK_ALWAYS_ON))
#define ENABLE_SYNC_CALL_RESTRICTIONS …
#else
#define ENABLE_SYNC_CALL_RESTRICTIONS …
#endif

namespace chromecast {
class CastCdmOriginProvider;
}  // namespace chromecast

namespace content {
class AndroidOverlaySyncHelper;
class DesktopCapturerLacros;
class StreamTextureFactory;
#if BUILDFLAG(IS_WIN)
class DCOMPTextureFactory;
#endif
}  // namespace content

namespace crosapi {
class ScopedAllowSyncCall;
}  // namespace crosapi

namespace gpu {
class CommandBufferProxyImpl;
class GpuChannelHost;
class SharedImageInterfaceProxy;
}  // namespace gpu

namespace ui {
class Compositor;
}  // namespace ui

namespace viz {
class GpuHostImpl;
class HostFrameSinkManager;
class HostGpuMemoryBufferManager;
}  // namespace viz

namespace mojo {
class ScopedAllowSyncCallForTesting;

// In some processes, sync calls are disallowed. For example, in the browser
// process we don't want any sync calls to child processes for performance,
// security and stability reasons. SyncCallRestrictions helps to enforce such
// rules.
//
// Before processing a sync call, the bindings call
// SyncCallRestrictions::AssertSyncCallAllowed() to check whether sync calls are
// allowed. By default sync calls are allowed but they may be globally
// disallowed within a process by calling DisallowSyncCall().
//
// If globally disallowed but you but you have a very compelling reason to
// disregard that (which should be very very rare), you can override it by
// constructing a ScopedAllowSyncCall object which allows making sync calls on
// the current sequence during its lifetime.
class COMPONENT_EXPORT(MOJO_CPP_BINDINGS) SyncCallRestrictions { … };

class ScopedAllowSyncCallForTesting { … };

}  // namespace mojo

#endif  // MOJO_PUBLIC_CPP_BINDINGS_SYNC_CALL_RESTRICTIONS_H_