#ifndef CYGONCE_KERNEL_CLOCK_HXX #define CYGONCE_KERNEL_CLOCK_HXX //========================================================================== // // clock.hxx // // Clock and Alarm class declaration(s) // //========================================================================== // ####ECOSGPLCOPYRIGHTBEGIN#### // ------------------------------------------- // This file is part of eCos, the Embedded Configurable Operating System. // Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc. // // eCos is free software; you can redistribute it and/or modify it under // the terms of the GNU General Public License as published by the Free // Software Foundation; either version 2 or (at your option) any later // version. // // eCos is distributed in the hope that it will be useful, but WITHOUT // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License // for more details. // // You should have received a copy of the GNU General Public License // along with eCos; if not, write to the Free Software Foundation, Inc., // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. // // As a special exception, if other files instantiate templates or use // macros or inline functions from this file, or you compile this file // and link it with other works to produce a work based on this file, // this file does not by itself cause the resulting work to be covered by // the GNU General Public License. However the source code for this file // must still be made available in accordance with section (3) of the GNU // General Public License v2. // // This exception does not invalidate any other reasons why a work based // on this file might be covered by the GNU General Public License. // ------------------------------------------- // ####ECOSGPLCOPYRIGHTEND#### //========================================================================== //#####DESCRIPTIONBEGIN#### // // Author(s): nickg // Contributors: nickg // Date: 1997-09-09 // Purpose: Define Clock and Alarm class interfaces // Description: The classes defined here collectively implement the // internal API used to create, configure and manage Counters, // Clocks and Alarms. // Usage: #include // //####DESCRIPTIONEND#### // //========================================================================== #include #include // assertion macros #include // ------------------------------------------------------------------------- // Forward definitions and typedefs. class Cyg_Alarm; typedef void cyg_alarm_fn(Cyg_Alarm *alarm, CYG_ADDRWORD data); typedef Cyg_CList_T Cyg_Alarm_List; // ------------------------------------------------------------------------- // Counter object. class Cyg_Counter { friend class Cyg_Alarm; #if defined(CYGIMP_KERNEL_COUNTERS_SINGLE_LIST) Cyg_Alarm_List alarm_list; // Linear list of Alarms #elif defined(CYGIMP_KERNEL_COUNTERS_MULTI_LIST) Cyg_Alarm_List alarm_list[CYGNUM_KERNEL_COUNTERS_MULTI_LIST_SIZE]; #endif volatile cyg_tick_count counter; // counter value cyg_uint32 increment; // increment per tick // Add an alarm to this counter void add_alarm( Cyg_Alarm *alarm ); // Remove an alarm from this counter void rem_alarm( Cyg_Alarm *alarm ); public: CYGDBG_DEFINE_CHECK_THIS Cyg_Counter( cyg_uint32 increment = 1 ); ~Cyg_Counter(); // Return current value of counter cyg_tick_count current_value(); // Return low and high halves of the // counter value. cyg_uint32 current_value_lo(); cyg_uint32 current_value_hi(); // Set the counter's current value void set_value( cyg_tick_count new_value); // Advance counter by some number of ticks void tick( cyg_uint32 ticks = 1); }; // ------------------------------------------------------------------------- // Clock class. This is derived from a Counter and defines extra // features to support clock-like behaviour. class Cyg_Clock : public Cyg_Counter { public: CYGDBG_DEFINE_CHECK_THIS // This structure allows a more accurate representation // of the resolution than a single integer would allow. // The resolution is defined as dividend/divisor nanoseconds // per tick. struct cyg_resolution { cyg_uint32 dividend; cyg_uint32 divisor; }; private: cyg_resolution resolution; // Current clock resolution public: Cyg_Clock( // Create clock with given resolution cyg_resolution resolution ); ~Cyg_Clock(); // Destructor cyg_resolution get_resolution(); // Return current resolution void set_resolution( // Set new resolution cyg_resolution resolution ); // There is a need for converting from "other" ticks to clock ticks. // We will construct 4 numbers to do the conversion as: // clock_ticks = (((otherticks*mul1)/div1)*mul2/div2) // with the values chosen to minimize the possibility of overflow. // Do the arithmetic in cyg_uint64s throughout. struct converter { cyg_uint64 mul1, div1, mul2, div2; }; // There are two of these because the 4 numbers are different depending // on the direction of the conversion, to prevent loss of significance. // NB these relate to the resolution of the clock object they are // called against, not necessarily "the" system real time clock. void get_other_to_clock_converter( cyg_uint64 ns_per_other_tick, struct converter *pcc ); void get_clock_to_other_converter( cyg_uint64 ns_per_other_tick, struct converter *pcc ); // A utility to perform the conversion in the obvious way, with // rounding to nearest at each stage. Static because it uses a // previously acquired converter. static cyg_tick_count convert( cyg_tick_count value, struct converter *pcc ); #ifdef CYGVAR_KERNEL_COUNTERS_CLOCK // There is a system supplied real time clock... static Cyg_Clock *real_time_clock; #endif }; // ------------------------------------------------------------------------- // Alarm class. An alarm may be attached to a counter (or a clock) to be // called when the trigger value is reached. class Cyg_Alarm #if defined(CYGIMP_KERNEL_COUNTERS_SINGLE_LIST) || defined(CYGIMP_KERNEL_COUNTERS_MULTI_LIST) : public Cyg_DNode_T #endif { friend class Cyg_Counter; protected: Cyg_Counter *counter; // Attached to this counter/clock cyg_alarm_fn *alarm; // Call-back function CYG_ADDRWORD data; // Call-back data cyg_tick_count trigger; // Absolute trigger time cyg_tick_count interval; // Retrigger interval cyg_bool enabled; // True if enabled Cyg_Alarm(); void synchronize( void ); // deal with times in the past, // make next alarm in synch. public: CYGDBG_DEFINE_CHECK_THIS Cyg_Alarm // Constructor ( Cyg_Counter *counter, // Attached to this counter cyg_alarm_fn *alarm, // Call-back function CYG_ADDRWORD data // Call-back data ); ~Cyg_Alarm(); // Destructor void initialize( // Initialize Alarm cyg_tick_count trigger, // Absolute trigger time cyg_tick_count interval = 0 // Relative retrigger interval ); void enable(); // Ensure alarm enabled void disable(); // Ensure alarm disabled void get_times( cyg_tick_count *trigger, // Next trigger time cyg_tick_count *interval // Current interval ); }; // ------------------------------------------------------------------------- #endif // ifndef CYGONCE_KERNEL_CLOCK_HXX // EOF clock.hxx