futex_map.hh

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/*
 * Copyright (c) 2017 Advanced Micro Devices, Inc.
 * All rights reserved.
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 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
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 * redistributions in binary form must reproduce the above copyright
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 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
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 * this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 */
 
#ifndef __FUTEX_MAP_HH__
#define __FUTEX_MAP_HH__
 
#include <unordered_map>
#include <unordered_set>
 
#include <cpu/thread_context.hh>
 
namespace gem5
{
 
class FutexKey
{
  public:
    uint64_t addr;
    uint64_t tgid;
 
    FutexKey(uint64_t addr_in, uint64_t tgid_in);
 
    bool operator==(const FutexKey &in) const;
};
 
} // namespace gem5
 
namespace std
{
    template <>
    struct hash<gem5::FutexKey>
    {
        size_t operator()(const gem5::FutexKey& in) const
        {
            size_t hash = 65521;
            for (int i = 0; i < sizeof(uint64_t) / sizeof(size_t); i++) {
                hash ^= (size_t)(in.addr >> sizeof(size_t) * i) ^
                        (size_t)(in.tgid >> sizeof(size_t) * i);
            }
            return hash;
        }
    };
} // namespace std
 
namespace gem5
{
 
class WaiterState
{
  public:
    ThreadContext* tc;
    int bitmask;
 
    WaiterState(ThreadContext* _tc, int _bitmask);
 
    bool checkMask(int wakeup_bitmask) const;
};
 
typedef std::list<WaiterState> WaiterList;
 
class FutexMap : public std::unordered_map<FutexKey, WaiterList>
{
  public:
    void suspend(Addr addr, uint64_t tgid, ThreadContext *tc);
 
    int wakeup(Addr addr, uint64_t tgid, int count);
 
    void suspend_bitset(Addr addr, uint64_t tgid, ThreadContext *tc,
                   int bitmask);
 
    int wakeup_bitset(Addr addr, uint64_t tgid, int bitmask);
 
    int requeue(Addr addr1, uint64_t tgid, int count, int count2, Addr addr2);
 
    bool is_waiting(ThreadContext *tc);
 
  private:
 
    std::unordered_set<ThreadContext *> waitingTcs;
};
 
} // namespace gem5
 
#endif // __FUTEX_MAP_HH__