| 1 | /* Hacky parallelism; Ian Jackson */ |
| 2 | |
| 3 | #define _GNU_SOURCE |
| 4 | |
| 5 | #include "secnet.h" |
| 6 | #include "util.h" |
| 7 | #include "hackypar.h" |
| 8 | |
| 9 | #ifdef HACKY_PARALLEL |
| 10 | |
| 11 | #include <stdio.h> |
| 12 | #include <unistd.h> |
| 13 | #include <errno.h> |
| 14 | #include <string.h> |
| 15 | #include <signal.h> |
| 16 | #include <assert.h> |
| 17 | #include <sys/wait.h> |
| 18 | |
| 19 | #define HASHSIZE 16 |
| 20 | #define CACHESIZE 16 |
| 21 | |
| 22 | typedef enum { hp_idle, hp_compute, hp_deferring, hp_fail } HPState; |
| 23 | |
| 24 | static HPState state; |
| 25 | static pid_t child; |
| 26 | |
| 27 | static void checkchild(void) { |
| 28 | int r, status; |
| 29 | |
| 30 | if (!child) return; |
| 31 | |
| 32 | r= waitpid(child,&status,WNOHANG); if (!r) return; |
| 33 | if (r==-1) { |
| 34 | Message(M_ERR,"hacky_par: waitpid: %s\n",strerror(errno)); |
| 35 | return; |
| 36 | } |
| 37 | child= 0; |
| 38 | |
| 39 | if (WIFSIGNALED(status)) { |
| 40 | Message(M_ERR,"hacky_par: signaled! %s\n",strsignal(WTERMSIG(status))); |
| 41 | } else if (!WIFEXITED(status)) { |
| 42 | Message(M_ERR,"hacky_par: unexpected status! %d\n", r); |
| 43 | } |
| 44 | } |
| 45 | |
| 46 | static HPState start(void) { |
| 47 | assert(!child); |
| 48 | |
| 49 | child= fork(); |
| 50 | if (child == -1) { |
| 51 | Message(M_ERR,"hacky_par: fork failed: %s\n",strerror(errno)); |
| 52 | return hp_fail; |
| 53 | } |
| 54 | |
| 55 | if (!child) { /* we are the child */ |
| 56 | return hp_compute; |
| 57 | } |
| 58 | |
| 59 | Message(M_INFO,"hacky_par: started, punting\n"); |
| 60 | return hp_deferring; |
| 61 | } |
| 62 | |
| 63 | int hacky_par_start_failnow(void) { |
| 64 | state= hp_idle; |
| 65 | checkchild(); |
| 66 | if (child) { |
| 67 | state= hp_deferring; |
| 68 | Message(M_INFO,"hacky_par: busy, punting\n"); |
| 69 | return 1; |
| 70 | } |
| 71 | return 0; |
| 72 | } |
| 73 | |
| 74 | int hacky_par_mid_failnow(void) { |
| 75 | state= start(); |
| 76 | return state != hp_compute; |
| 77 | } |
| 78 | |
| 79 | bool_t (*packy_par_gen)(struct site *st); |
| 80 | |
| 81 | void hacky_par_end(int *ok, |
| 82 | uint32_t retries, uint32_t timeout, |
| 83 | bool_t (*send_msg)(struct site *st), struct site *st) { |
| 84 | int i; |
| 85 | |
| 86 | switch (state) { |
| 87 | case hp_deferring: |
| 88 | assert(!*ok); |
| 89 | *ok= 1; |
| 90 | return; |
| 91 | case hp_fail: |
| 92 | assert(!*ok); |
| 93 | return; |
| 94 | case hp_idle: |
| 95 | return; |
| 96 | case hp_compute: |
| 97 | if (!ok) { |
| 98 | Message(M_ERR,"hacky_par: compute failed\n"); |
| 99 | _exit(2); |
| 100 | } |
| 101 | Message(M_INFO,"hacky_par: got result, sending\n"); |
| 102 | for (i=1; i<retries; i++) { |
| 103 | sleep((timeout + 999)/1000); |
| 104 | if (!send_msg(st)) { |
| 105 | Message(M_ERR,"hacky_par: retry failed\n"); |
| 106 | _exit(1); |
| 107 | } |
| 108 | } |
| 109 | _exit(0); |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | #else /*!HACKY_PARALLEL*/ |
| 114 | |
| 115 | int hacky_par_start_failnow(void) { return 0; } |
| 116 | int hacky_par_mid_failnow(void) { return 0; } |
| 117 | void hacky_par_end(int *ok, |
| 118 | uint32_t retries, uint32_t timeout, |
| 119 | bool_t (*send_msg)(struct site *st), struct site *st) { } |
| 120 | |
| 121 | #endif /*HACKY_PARALLEL...else*/ |