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60de5df9 | 1 | /* |
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2 | * Copyright (c) 1983 Regents of the University of California. |
3 | * All rights reserved. | |
4 | * | |
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5 | * This code is derived from software contributed to Berkeley by |
6 | * Edward Wang at The University of California, Berkeley. | |
7 | * | |
87f529ec | 8 | * %sccs.include.redist.c% |
60de5df9 EW |
9 | */ |
10 | ||
46e9ea25 | 11 | #ifndef lint |
419d8eab | 12 | static char sccsid[] = "@(#)wwrint.c 3.11 (Berkeley) %G%"; |
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13 | #endif /* not lint */ |
14 | ||
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15 | #include "ww.h" |
16 | #include <fcntl.h> | |
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17 | |
18 | /* | |
19 | * Tty input interrupt handler. | |
20 | * (1) Read input into buffer (wwib*). | |
16078900 | 21 | * (2) Set the interrupt flag if anything is read. |
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22 | * Currently, the last is used to get out of the blocking |
23 | * select() in wwiomux(). | |
24 | * To avoid race conditions, we only modify wwibq in here, except | |
25 | * when the buffer is empty; and everywhere else, we only change wwibp. | |
26 | * It should be completely safe. | |
27 | */ | |
419d8eab | 28 | void |
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29 | wwrint() |
30 | { | |
31 | register n; | |
32 | ||
33 | if (wwibp == wwibq) | |
34 | wwibp = wwibq = wwib; | |
35 | wwnread++; | |
36 | (void) fcntl(0, F_SETFL, FNDELAY|wwnewtty.ww_fflags); | |
37 | n = read(0, wwibq, wwibe - wwibq); | |
38 | (void) fcntl(0, F_SETFL, wwnewtty.ww_fflags); | |
39 | if (n > 0) { | |
40 | wwibq += n; | |
41 | wwnreadc += n; | |
16078900 | 42 | wwsetintr(); |
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43 | } else if (n == 0) |
44 | wwnreadz++; | |
45 | else | |
46 | wwnreade++; | |
78b88f48 | 47 | } |