// -*- C++ -*- //========================================================================== /** * @file Synch_Options.h * * @author Douglas C. Schmidt */ //========================================================================== #ifndef ACE_SYNCH_OPTIONS_H #define ACE_SYNCH_OPTIONS_H #include /**/ "ace/pre.h" #include /**/ "ace/ACE_export.h" #if !defined (ACE_LACKS_PRAGMA_ONCE) # pragma once #endif /* ACE_LACKS_PRAGMA_ONCE */ #include "ace/Time_Value.h" ACE_BEGIN_VERSIONED_NAMESPACE_DECL /** * @class ACE_Synch_Options * * @brief Contains the values of options used to determine the * synchronous and asynchronous behavior. * * The supported set of options is depicted in the following table. * The Reactor column indicates whether or not the USE_REACTOR option is * supplied. * The Timeout column specifies the period of time specified by the object; * Unused implies that USE_TIMEOUT is not included in the options and the * default timeout value, ACE_Time_Value::zero, is specified, either * explicitly or by default. * * * * * * * * * *
ReactorTimeoutBehavior
yesUnusedInfinite timeout (using Reactor); * this is the default.
yestimeTry asynch transaction for the * specified time (using Reactor)
yes0,0Poll; try, if EWOULDBLOCK, return * immediately (using Reactor)
noUnusedBlock until completion (don't use Reactor)
notimeWait up to specified amount of time for * completion (don't use Reactor)
no0,0Poll and return immediately
*/ class ACE_Export ACE_Synch_Options { public: /// Options flags for controlling synchronization. /** * Note that these flags can be bit-wise "or'd" together if both * options are desired. */ enum { /// Use the Reactor. USE_REACTOR = 01, /// Use the supplied timeout value. USE_TIMEOUT = 02 }; /** * Initialize the object to default values unless specified otherwise. * * @param options Specifies the options to use; default is neither option * (no reactor, no timeout). * @param timeout Specifies the period of time to use for the operation's * timeout. The default is ACE_Time_Value::zero, noted as * 0,0 in the behavior options table. If a non-zero timeout * is specified, the USE_TIMEOUT option is added to * @a options. * To use a zero timeout, USE_TIMEOUT must be explicitly * specified in @a options. * @param arg A completion tag that can be passed through the options; * the class using ACE_Synch_Options can access this. * ACE_Synch_Options makes no use of it internally. */ ACE_Synch_Options (unsigned long options = 0, const ACE_Time_Value &timeout = ACE_Time_Value::zero, const void *arg = 0); /// Initialize the object; arguments are the same as for the /// constructor. void set (unsigned long options = 0, const ACE_Time_Value &timeout = ACE_Time_Value::zero, const void *arg = 0); /// Returns true if the specified option(s) are enabled, false otherwise. bool operator[] (unsigned long option) const; /// Adds the specified option(s) to the object; does not replace them. void operator= (unsigned long option); /// Returns the "magic cookie" argument. const void *arg (void) const; /// Set the "magic cookie" argument. void arg (const void *); /// Returns a reference to the ACE_Time_Value. This value only makes /// sense if (*this)[USE_TIMEOUT] is true. const ACE_Time_Value &timeout (void) const; /// Set the timeout value. This method does not alter the options; in /// particular, it doesn't add USE_TIMEOUT to the options when a non-zero /// timeout is specified as the constructor and set() do. void timeout (const ACE_Time_Value &tv); /** * Returns a timeout pointer if (*this)[USE_TIMEOUT] is true, else 0. * This should be used with care, e.g., the timeout pointer should not * be stored in a manner that will lead to dangling pointers. */ const ACE_Time_Value *time_value (void) const; // = Static data members (singletons) /// This is the default setting for options, which will block /// synchronously. static ACE_Synch_Options defaults; /// This is the default synchronous setting. static ACE_Synch_Options synch; /// This is the default asynchronous setting. static ACE_Synch_Options asynch; /// Dump the state of an object. void dump (void) const; /// Declare the dynamic allocation hooks. ACE_ALLOC_HOOK_DECLARE; private: /// Keeps track of the enabled options. unsigned long options_; /// Amount of time to wait for timeouts. ACE_Time_Value timeout_; /** * "Magic cookie" always passed in as an argument to the ACE_Reactor's * schedule_timer() method. Used to communicate values for * asynchronous programming. */ const void *arg_; }; ACE_END_VERSIONED_NAMESPACE_DECL #include /**/ "ace/post.h" #endif /* ACE_SYNCH_OPTIONS_H */