1 | #include <errno.h> |
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2 | #include <error.h> |
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3 | #include <pthread.h> |
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4 | #include <stdio.h> |
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5 | #include <stdlib.h> |
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6 | #include <ucontext.h> |
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7 | |
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8 | #include "pt-machine.h" |
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9 | |
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10 | |
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11 | #define N 4 |
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12 | |
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13 | #ifdef FLOATING_STACKS |
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14 | static char stacks[N][8192]; |
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15 | static ucontext_t ctx[N][2]; |
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16 | static volatile int failures; |
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17 | |
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18 | static void |
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19 | fct (long int n) |
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20 | { |
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21 | /* Just to use the thread local descriptor. */ |
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22 | printf ("%ld: in %s now\n", n, __FUNCTION__); |
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23 | errno = 0; |
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24 | } |
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25 | |
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26 | static void * |
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27 | threadfct (void *arg) |
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28 | { |
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29 | int n = (int) (long int) arg; |
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30 | |
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31 | if (getcontext (&ctx[n][1]) != 0) |
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32 | { |
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33 | printf ("%d: cannot get context: %m\n", n); |
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34 | exit (1); |
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35 | } |
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36 | |
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37 | printf ("%d: %s: before makecontext\n", n, __FUNCTION__); |
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38 | |
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39 | ctx[n][1].uc_stack.ss_sp = stacks[n]; |
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40 | ctx[n][1].uc_stack.ss_size = 8192; |
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41 | ctx[n][1].uc_link = &ctx[n][0]; |
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42 | makecontext (&ctx[n][1], (void (*) (void)) fct, 1, (long int) n); |
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43 | |
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44 | printf ("%d: %s: before swapcontext\n", n, __FUNCTION__); |
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45 | |
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46 | if (swapcontext (&ctx[n][0], &ctx[n][1]) != 0) |
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47 | { |
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48 | ++failures; |
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49 | printf ("%d: %s: swapcontext failed\n", n, __FUNCTION__); |
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50 | } |
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51 | else |
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52 | printf ("%d: back in %s\n", n, __FUNCTION__); |
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53 | |
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54 | return NULL; |
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55 | } |
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56 | #endif |
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57 | |
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58 | |
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59 | #ifdef FLOATING_STACKS |
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60 | static volatile int global; |
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61 | #endif |
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62 | |
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63 | int |
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64 | main (void) |
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65 | { |
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66 | #ifndef FLOATING_STACKS |
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67 | puts ("not supported"); |
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68 | return 0; |
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69 | #else |
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70 | int n; |
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71 | pthread_t th[N]; |
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72 | ucontext_t mctx; |
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73 | |
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74 | puts ("making contexts"); |
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75 | if (getcontext (&mctx) != 0) |
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76 | { |
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77 | if (errno == ENOSYS) |
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78 | { |
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79 | puts ("context handling not supported"); |
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80 | exit (0); |
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81 | } |
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82 | |
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83 | printf ("%s: getcontext: %m\n", __FUNCTION__); |
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84 | exit (1); |
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85 | } |
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86 | |
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87 | /* Play some tricks with this context. */ |
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88 | if (++global == 1) |
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89 | if (setcontext (&mctx) != 0) |
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90 | { |
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91 | printf ("%s: setcontext: %m\n", __FUNCTION__); |
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92 | exit (1); |
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93 | } |
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94 | if (global != 2) |
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95 | { |
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96 | printf ("%s: 'global' not incremented twice\n", __FUNCTION__); |
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97 | exit (1); |
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98 | } |
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99 | |
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100 | for (n = 0; n < N; ++n) |
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101 | if (pthread_create (&th[n], NULL, threadfct, (void *) n) != 0) |
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102 | error (EXIT_FAILURE, errno, "cannot create all threads"); |
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103 | |
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104 | for (n = 0; n < N; ++n) |
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105 | pthread_join (th[n], NULL); |
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106 | |
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107 | return failures; |
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108 | #endif |
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109 | } |
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