| 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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