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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#ifndef GFX_TRANSACTION_ID_ALLOCATOR_H
#define GFX_TRANSACTION_ID_ALLOCATOR_H
#include "nsISupportsImpl.h"
#include "mozilla/layers/LayersTypes.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/VsyncDispatcher.h"
namespace mozilla {
namespace layers {
class TransactionIdAllocator {
protected:
virtual ~TransactionIdAllocator() = default;
public:
NS_INLINE_DECL_REFCOUNTING(TransactionIdAllocator)
/**
* Allocate a unique id number for the current refresh tick, can
* only be called while IsInRefresh().
*
* If too many id's are allocated without being returned then
* the refresh driver will suspend until they catch up. This
* "throttling" behaviour can be skipped by passing aThrottle=false.
* Otherwise call sites should generally be passing aThrottle=true.
*/
virtual TransactionId GetTransactionId(bool aThrottle) = 0;
/**
* Return the transaction id that for the last non-revoked transaction.
* This allows the caller to tell whether a composite was triggered by
* a paint that occurred after a call to TransactionId().
*/
virtual TransactionId LastTransactionId() const = 0;
/**
* Notify that all work (including asynchronous composites)
* for a given transaction id has been completed.
*
* If the refresh driver has been suspended because
* of having too many outstanding id's, then this may
* resume it.
*/
virtual void NotifyTransactionCompleted(TransactionId aTransactionId) = 0;
/**
* Revoke a transaction id that isn't needed to track
* completion of asynchronous work. This is similar
* to NotifyTransactionCompleted except avoids
* return ordering issues.
*/
virtual void RevokeTransactionId(TransactionId aTransactionId) = 0;
/**
* Stop waiting for pending transactions, if any.
*
* This is used when ClientLayerManager is assigning to another refresh
* driver, and the current refresh driver may never receive transaction
* completed notifications.
*/
virtual void ClearPendingTransactions() = 0;
/**
* Transaction id is usually initialized as 0, however when ClientLayerManager
* switches to another refresh driver, completed transactions of the previous
* refresh driver could be delivered and confuse the newly adopted refresh
* driver. To prevent this situation, use this function to reset transaction
* id to the last transaction id from previous refresh driver, so that all
* completed transactions of previous refresh driver will be ignored.
*/
virtual void ResetInitialTransactionId(TransactionId aTransactionId) = 0;
/**
* Get the start time of the current refresh tick.
*/
virtual mozilla::TimeStamp GetTransactionStart() = 0;
virtual VsyncId GetVsyncId() = 0;
virtual mozilla::TimeStamp GetVsyncStart() = 0;
};
} // namespace layers
} // namespace mozilla
#endif /* GFX_TRANSACTION_ID_ALLOCATOR_H */