sewardj | b411202 | 2007-11-09 22:49:28 +0000 | [diff] [blame^] | 1 | #include <pthread.h> |
| 2 | #include <stdio.h> |
| 3 | #include <stdlib.h> |
| 4 | |
| 5 | /* Simple demonstration of lockset tracking at byte granularity. */ |
| 6 | |
| 7 | char bytes[10]; |
| 8 | |
| 9 | void* child_fn ( void* arg ) |
| 10 | { |
| 11 | int i; |
| 12 | for (i = 0; i < 5; i++) |
| 13 | bytes[2*i + 0] ++; |
| 14 | return NULL; |
| 15 | } |
| 16 | |
| 17 | int main ( void ) |
| 18 | { |
| 19 | int i; |
| 20 | pthread_t child; |
| 21 | |
| 22 | if (pthread_create(&child, NULL, child_fn, NULL)) { |
| 23 | perror("pthread_create"); |
| 24 | exit(1); |
| 25 | } |
| 26 | |
| 27 | /* Unprotected relative to child, but harmless, since different |
| 28 | bytes accessed */ |
| 29 | for (i = 0; i < 5; i++) |
| 30 | bytes[2*i + 1] ++; |
| 31 | |
| 32 | /* Unprotected relative to child, but harmful; same bytes */ |
| 33 | for (i = 0; i < 3; i++) |
| 34 | bytes[3*i + 1] ++; |
| 35 | |
| 36 | if (pthread_join(child, NULL)) { |
| 37 | perror("pthread join"); |
| 38 | exit(1); |
| 39 | } |
| 40 | |
| 41 | return 0; |
| 42 | } |