syscall_return.hh

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/*
 * Copyright (c) 2003-2005 The Regents of The University of Michigan
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors: Gabe Black
 */

#ifndef __SIM_SYSCALLRETURN_HH__
#define __SIM_SYSCALLRETURN_HH__

#include <inttypes.h>

class SyscallReturn
{
  public:

    SyscallReturn(int64_t v)
        : value(v), retryFlag(false)
    {}

    static SyscallReturn retry()
    {
        SyscallReturn s(0);
        s.retryFlag = true;
        return s;
    }

    ~SyscallReturn() {}

    bool successful() const
    {
        return (value >= 0 || value <= -4096);
    }

    bool needsRetry() const { return retryFlag; }

    int64_t returnValue() const
    {
        assert(successful());
        return value;
    }

    int errnoValue() const
    {
        assert(!successful());
        return -value;
    }

    int64_t encodedValue() const
    {
        return value;
    }

  private:

    int64_t value;

    bool retryFlag;
};

#endif