75 lines
1.8 KiB
C++
75 lines
1.8 KiB
C++
/*
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* \brief A guard for RAM session clients to limit memory exhaustion
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* \author Christian Prochaska
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* \date 2012-04-25
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*/
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/*
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* Copyright (C) 2012-2017 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU Affero General Public License version 3.
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*/
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#ifndef _RAM_SESSION_CLIENT_GUARD_H_
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#define _RAM_SESSION_CLIENT_GUARD_H_
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#include <base/lock.h>
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#include <base/log.h>
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#include <base/ram_allocator.h>
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#include <pd_session/client.h>
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#include <dataspace/client.h>
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namespace Genode {
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class Ram_session_client_guard : public Ram_allocator
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{
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private:
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Pd_session_client _pd;
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size_t const _amount; /* total amount */
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size_t _consumed; /* already consumed bytes */
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Lock mutable _consumed_lock { };
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public:
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Ram_session_client_guard(Pd_session_capability session, Ram_quota amount)
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: _pd(session), _amount(amount.value), _consumed(0) { }
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Ram_dataspace_capability alloc(size_t size, Cache_attribute cached) override
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{
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Lock::Guard _consumed_lock_guard(_consumed_lock);
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if ((_amount - _consumed) < size) {
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warning("quota exceeded! amount=", _amount, ", "
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"size=", size, ", consumed=", _consumed);
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return Ram_dataspace_capability();
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}
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Ram_dataspace_capability cap = _pd.alloc(size, cached);
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_consumed += size;
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return cap;
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}
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void free(Ram_dataspace_capability ds) override
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{
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Lock::Guard _consumed_lock_guard(_consumed_lock);
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_consumed -= Dataspace_client(ds).size();
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_pd.free(ds);
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}
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size_t dataspace_size(Ram_dataspace_capability ds) const override
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{
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Lock::Guard _consumed_lock_guard(_consumed_lock);
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return _pd.dataspace_size(ds);
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}
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};
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}
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#endif /* _RAM_SESSION_CLIENT_GUARD_H_ */
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