token_port.hh

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#ifndef __MEM_TOKEN_PORT_HH__
#define __MEM_TOKEN_PORT_HH__
 
#include "mem/port.hh"
#include "sim/clocked_object.hh"
 
namespace gem5
{
 
class TokenManager;
class TokenResponsePort;
 
class TokenRequestPort : public RequestPort
{
  private:
    /* Manager to track tokens between this token port pair. */
    TokenManager *tokenManager;
 
  public:
    TokenRequestPort(const std::string& name, SimObject* owner,
                    PortID id = InvalidPortID) :
        RequestPort(name, owner, id), tokenManager(nullptr)
    { }
 
    void bind(Port &peer) override;
 
    void unbind() override {}
 
    void recvTokens(int num_tokens);
 
    bool haveTokens(int num_tokens);
 
    void acquireTokens(int num_tokens);
 
    void setTokenManager(TokenManager *_tokenManager);
};
 
class TokenResponsePort : public ResponsePort
{
  private:
    TokenRequestPort *tokenRequestPort;
 
    std::deque<PacketPtr> respQueue;
 
    void recvRespRetry() override;
 
  public:
    TokenResponsePort(const std::string& name, ClockedObject *owner,
                   PortID id = InvalidPortID) :
        ResponsePort(name, owner, id), tokenRequestPort(nullptr)
    { }
    ~TokenResponsePort() { }
 
    void bind(Port &peer) override;
 
    void unbind() override;
 
    void sendTokens(int num_tokens);
 
    bool sendTimingResp(PacketPtr pkt);
 
    /* There is no storage here so the packet will not be found. */
    bool trySatisfyFunctional(PacketPtr) { return false; }
};
 
class TokenManager
{
  protected:
    /* Maximum tokens possible */
    int maxTokens;
 
    /* Number of currently available tokens */
    int availableTokens;
 
  public:
    TokenManager(int init_tokens);
    ~TokenManager() { }
 
    int getMaxTokenCount() const;
 
    void recvTokens(int num_tokens);
 
    bool haveTokens(int num_tokens);
 
    void acquireTokens(int num_tokens);
};
 
} // namespace gem5
 
#endif