src/cpu/inorder/thread_state.hh

/*
 * Copyright (c) 2006 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
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors: Kevin Lim
 */

#ifndef __CPU_INORDER_THREAD_STATE_HH__
#define __CPU_INORDER_THREAD_STATE_HH__

#include "arch/isa_traits.hh"
#include "base/callback.hh"
#include "base/output.hh"
#include "cpu/thread_context.hh"
#include "cpu/thread_state.hh"
#include "sim/sim_exit.hh"

class EndQuiesceEvent;
class Event;
class FunctionalMemory;
class FunctionProfile;
class InOrderCPU;
class Process;
class ProfileNode;

/**
 * Class that has various thread state, such as the status, the
 * current instruction being processed, whether or not the thread has
 * a trap pending or is being externally updated, the ThreadContext
 * pointer, etc.  It also handles anything related to a specific
 * thread's process, such as syscalls and checking valid addresses.
 */
class InOrderThreadState : public ThreadState {
    typedef ThreadContext::Status Status;

  private:
    /** Pointer to the CPU. */
    InOrderCPU *cpu;

  public:
    /* This variable controls if writes to a thread context should cause a all
     * dynamic/speculative state to be thrown away. Nominally this is the
     * desired behavior because the external thread context write has updated
     * some state that could be used by an inflight instruction, however there
     * are some cases like in a fault/trap handler where this behavior would
     * lead to successive restarts and forward progress couldn't be made. This
     * variable controls if the squashing will occur.
     */
    bool noSquashFromTC;

    /** Whether or not the thread is currently waiting on a trap, and
     * thus able to be externally updated without squashing.
     */
    bool trapPending;

    InOrderThreadState(InOrderCPU *_cpu, ThreadID _thread_num,
                       Process *_process)
        : ThreadState(reinterpret_cast<BaseCPU*>(_cpu), _thread_num,
                      _process),
          cpu(_cpu), noSquashFromTC(false), trapPending(false),
          lastGradIsBranch(false)
    { }

    /** Handles the syscall. */
    void syscall(int64_t callnum) { process->syscall(callnum, tc); }

    void dumpFuncProfile();    

    /** Pointer to the ThreadContext of this thread. */
    ThreadContext *tc;

    /** Returns a pointer to the TC of this thread. */
    ThreadContext *getTC() { return tc; }
    
    /** Is last instruction graduated a branch? */
    bool lastGradIsBranch;
    TheISA::PCState lastBranchPC;
};

#endif // __CPU_INORDER_THREAD_STATE_HH__