wait.h

#ifndef CRYPTOPP_WAIT_H
#define CRYPTOPP_WAIT_H

#include "config.h"

#ifdef SOCKETS_AVAILABLE

#include "misc.h"
#include "cryptlib.h"
#include <vector>

#ifdef USE_WINDOWS_STYLE_SOCKETS
#include <winsock2.h>
#else
#include <sys/types.h>
#endif

#include "hrtimer.h"

NAMESPACE_BEGIN(CryptoPP)

class Tracer
{
public:
        Tracer(unsigned int level) : m_level(level) {}
        virtual ~Tracer() {}

protected:
        //! Override this in your most-derived tracer to do the actual tracing.
        virtual void Trace(unsigned int n, std::string const& s) = 0;

        /*! By default, tracers will decide which trace messages to trace according to a trace level
                mechanism. If your most-derived tracer uses a different mechanism, override this to
                return false. If this method returns false, the default TraceXxxx(void) methods will all
                return 0 and must be overridden explicitly by your tracer for trace messages you want. */
        virtual bool UsingDefaults() const { return true; }

protected:
        unsigned int m_level;

        void TraceIf(unsigned int n, std::string const&s)
                { if (n) Trace(n, s); }

        /*! Returns nr if, according to the default log settings mechanism (using log levels),
            the message should be traced. Returns 0 if the default trace level mechanism is not
                in use, or if it is in use but the event should not be traced. Provided as a utility
                method for easier and shorter coding of default TraceXxxx(void) implementations. */
        unsigned int Tracing(unsigned int nr, unsigned int minLevel) const
                { return (UsingDefaults() && m_level >= minLevel) ? nr : 0; }
};

// Your Tracer-derived class should inherit as virtual public from Tracer or another
// Tracer-derived class, and should pass the log level in its constructor. You can use the
// following methods to begin and end your Tracer definition.

// This constructor macro initializes Tracer directly even if not derived directly from it;
// this is intended, virtual base classes are always initialized by the most derived class.
#define CRYPTOPP_TRACER_CONSTRUCTOR(DERIVED) \
        public: DERIVED(unsigned int level = 0) : Tracer(level) {}

#define CRYPTOPP_BEGIN_TRACER_CLASS_1(DERIVED, BASE1) \
        class DERIVED : virtual public BASE1 { CRYPTOPP_TRACER_CONSTRUCTOR(DERIVED)

#define CRYPTOPP_BEGIN_TRACER_CLASS_2(DERIVED, BASE1, BASE2) \
        class DERIVED : virtual public BASE1, virtual public BASE2 { CRYPTOPP_TRACER_CONSTRUCTOR(DERIVED)

#define CRYPTOPP_END_TRACER_CLASS };

// In your Tracer-derived class, you should define a globally unique event number for each
// new event defined. This can be done using the following macros.

#define CRYPTOPP_BEGIN_TRACER_EVENTS(UNIQUENR)  enum { EVENTBASE = UNIQUENR,
#define CRYPTOPP_TRACER_EVENT(EVENTNAME)                                EventNr_##EVENTNAME,
#define CRYPTOPP_END_TRACER_EVENTS                              };

// In your own Tracer-derived class, you must define two methods per new trace event type:
// - unsigned int TraceXxxx() const
//   Your default implementation of this method should return the event number if according
//   to the default trace level system the event should be traced, or 0 if it should not.
// - void TraceXxxx(string const& s)
//   This method should call TraceIf(TraceXxxx(), s); to do the tracing.
// For your convenience, a macro to define these two types of methods are defined below.
// If you use this macro, you should also use the TRACER_EVENTS macros above to associate
// event names with numbers.

#define CRYPTOPP_TRACER_EVENT_METHODS(EVENTNAME, LOGLEVEL) \
        virtual unsigned int Trace##EVENTNAME() const { return Tracing(EventNr_##EVENTNAME, LOGLEVEL); } \
        virtual void Trace##EVENTNAME(std::string const& s) { TraceIf(Trace##EVENTNAME(), s); }


/*! A simple unidirectional linked list with m_prev == 0 to indicate the final entry.
    The aim of this implementation is to provide a very lightweight and practical
        tracing mechanism with a low performance impact. Functions and methods supporting
        this call-stack mechanism would take a parameter of the form "CallStack const& callStack",
        and would pass this parameter to subsequent functions they call using the construct:

        SubFunc(arg1, arg2, CallStack("my func at place such and such", &callStack));
        
        The advantage of this approach is that it is easy to use and should be very efficient,
        involving no allocation from the heap, just a linked list of stack objects containing
        pointers to static ASCIIZ strings (or possibly additional but simple data if derived). */
class CallStack
{
public:
        CallStack(char const* i, CallStack const* p) : m_info(i), m_prev(p) {}
        CallStack const* Prev() const { return m_prev; }
        virtual std::string Format() const;

protected:
        char const* m_info;
        CallStack const* m_prev;
};

/*! An extended CallStack entry type with an additional numeric parameter. */
class CallStackWithNr : public CallStack
{
public:
        CallStackWithNr(char const* i, word32 n, CallStack const* p) : CallStack(i, p), m_nr(n) {}
        std::string Format() const;

protected:
        word32 m_nr;
};

/*! An extended CallStack entry type with an additional string parameter. */
class CallStackWithStr : public CallStack
{
public:
        CallStackWithStr(char const* i, char const* z, CallStack const* p) : CallStack(i, p), m_z(z) {}
        std::string Format() const;

protected:
        char const* m_z;
};

CRYPTOPP_BEGIN_TRACER_CLASS_1(WaitObjectsTracer, Tracer)
        CRYPTOPP_BEGIN_TRACER_EVENTS(0x48752841)
                CRYPTOPP_TRACER_EVENT(NoWaitLoop)
        CRYPTOPP_END_TRACER_EVENTS
        CRYPTOPP_TRACER_EVENT_METHODS(NoWaitLoop, 1)
CRYPTOPP_END_TRACER_CLASS

struct WaitingThreadData;

//! container of wait objects
class WaitObjectContainer : public NotCopyable
{
public:
        //! exception thrown by WaitObjectContainer
        class Err : public Exception
        {
        public:
                Err(const std::string& s) : Exception(IO_ERROR, s) {}
        };

        static unsigned int MaxWaitObjects();

        WaitObjectContainer(WaitObjectsTracer* tracer = 0);

        void Clear();
        void SetNoWait(CallStack const& callStack);
        void ScheduleEvent(double milliseconds, CallStack const& callStack);
        // returns false if timed out
        bool Wait(unsigned long milliseconds);

#ifdef USE_WINDOWS_STYLE_SOCKETS
        ~WaitObjectContainer();
        void AddHandle(HANDLE handle, CallStack const& callStack);
#else
        void AddReadFd(int fd, CallStack const& callStack);
        void AddWriteFd(int fd, CallStack const& callStack);
#endif

private:
        WaitObjectsTracer* m_tracer;

#ifdef USE_WINDOWS_STYLE_SOCKETS
        void CreateThreads(unsigned int count);
        std::vector<HANDLE> m_handles;
        std::vector<WaitingThreadData *> m_threads;
        HANDLE m_startWaiting;
        HANDLE m_stopWaiting;
#else
        fd_set m_readfds, m_writefds;
        int m_maxFd;
#endif
        bool m_noWait;
        double m_firstEventTime;
        Timer m_eventTimer;

#ifdef USE_WINDOWS_STYLE_SOCKETS
        typedef size_t LastResultType;
#else
        typedef int LastResultType;
#endif
        enum { LASTRESULT_NOWAIT = -1, LASTRESULT_SCHEDULED = -2, LASTRESULT_TIMEOUT = -3 };
        LastResultType m_lastResult;
        unsigned int m_sameResultCount;
        Timer m_noWaitTimer;
        void SetLastResult(LastResultType result);
        void DetectNoWait(LastResultType result, CallStack const& callStack);
};

NAMESPACE_END

#endif

#endif

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