| 1 | // | 
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| 2 | // Cforall Version 1.0.0 Copyright (C) 2017 University of Waterloo | 
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| 3 | // | 
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| 4 | // The contents of this file are covered under the licence agreement in the | 
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| 5 | // file "LICENCE" distributed with Cforall. | 
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| 6 | // | 
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| 7 | // devicedriver.cfa -- | 
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| 8 | // | 
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| 9 | // Author           : Peter A. Buhr | 
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| 10 | // Created On       : Sat Mar 16 15:30:34 2019 | 
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| 11 | // Last Modified By : Peter A. Buhr | 
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| 12 | // Last Modified On : Sat Apr 20 09:07:19 2019 | 
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| 13 | // Update Count     : 90 | 
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| 14 | // | 
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| 15 |  | 
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| 16 | #include <fstream.hfa> | 
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| 17 | #include <coroutine.hfa> | 
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| 18 |  | 
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| 19 | enum Status { CONT, MSG, ESTX, ELNTH, ECRC }; | 
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| 20 | coroutine Driver { | 
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| 21 | Status status; | 
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| 22 | char * msg, byte; | 
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| 23 | }; // Driver | 
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| 24 |  | 
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| 25 | void ?{}( Driver & d, char * m ) { d.msg = m; } | 
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| 26 | Status next( Driver & d, char b ) with( d ) { | 
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| 27 | byte = b; resume( d ); return status; | 
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| 28 | } // next | 
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| 29 |  | 
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| 30 | void checkCRC( Driver & d, unsigned int sum ) with( d ) { | 
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| 31 | suspend; | 
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| 32 | unsigned short int crc = byte << 8;                                     // sign extension over written | 
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| 33 | suspend; | 
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| 34 | // prevent sign extension for signed char | 
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| 35 | status = (crc | (unsigned char)byte) == sum ? MSG : ECRC; | 
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| 36 | } // checkCRC | 
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| 37 |  | 
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| 38 | void main( Driver & d ) with( d ) { | 
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| 39 | enum { STX = '\002', ESC = '\033', ETX = '\003', MaxMsg = 64 }; | 
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| 40 | msg: for () {                                                                                 // parse message | 
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| 41 | status = CONT; | 
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| 42 | unsigned int lnth = 0, sum = 0; | 
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| 43 | while ( byte != STX ) suspend; | 
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| 44 | emsg: for () { | 
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| 45 | suspend; | 
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| 46 | choose ( byte ) {                                                       // process byte | 
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| 47 | case STX: | 
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| 48 | status = ESTX; suspend; continue msg; | 
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| 49 | case ETX: | 
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| 50 | break emsg; | 
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| 51 | case ESC: | 
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| 52 | suspend; | 
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| 53 | } // choose | 
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| 54 | if ( lnth >= MaxMsg ) {                                         // buffer full ? | 
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| 55 | status = ELNTH; suspend; continue msg; | 
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| 56 | } // if | 
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| 57 | msg[lnth++] = byte; | 
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| 58 | sum += byte; | 
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| 59 | } // for | 
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| 60 | msg[lnth] = '\0';                                                               // terminate string | 
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| 61 | checkCRC( d, sum );                                                             // refactor CRC check | 
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| 62 | suspend; | 
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| 63 | } // for | 
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| 64 | } // main | 
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| 65 |  | 
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| 66 | int main() { | 
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| 67 | char msg[65], byte; | 
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| 68 | Driver driver = { msg }; | 
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| 69 |  | 
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| 70 | sin | nlOn;                                                                                     // read newline (all) characters | 
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| 71 | eof: for () {                                                                                 // read until end of file | 
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| 72 | sin | byte;                                                                             // read one character | 
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| 73 | if ( eof( sin ) ) break eof;                                          // eof ? | 
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| 74 | choose( next( driver, byte ) ) {                                // analyse character | 
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| 75 | case MSG: | 
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| 76 | sout | "msg:" | msg; | 
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| 77 | case ESTX: | 
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| 78 | sout | "STX in message"; | 
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| 79 | case ELNTH: | 
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| 80 | sout | "message too long"; | 
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| 81 | case ECRC: | 
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| 82 | sout | "CRC failure"; | 
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| 83 | default: ; | 
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| 84 | } // choose | 
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| 85 | } // for | 
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| 86 | } // main | 
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| 87 |  | 
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| 88 | // Local Variables: // | 
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| 89 | // tab-width: 4 // | 
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| 90 | // compile-command: "cfa -g -Wall -Wextra devicedriver.cfa" // | 
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| 91 | // End: // | 
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