| 1 | /* Hacky parallelism */ |
| 2 | /* |
| 3 | * This file is part of secnet. |
| 4 | * See README for full list of copyright holders. |
| 5 | * |
| 6 | * secnet is free software; you can redistribute it and/or modify it |
| 7 | * under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 3 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * secnet is distributed in the hope that it will be useful, but |
| 12 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * version 3 along with secnet; if not, see |
| 18 | * https://www.gnu.org/licenses/gpl.html. |
| 19 | */ |
| 20 | |
| 21 | #define _GNU_SOURCE |
| 22 | |
| 23 | #include "secnet.h" |
| 24 | #include "util.h" |
| 25 | #include "hackypar.h" |
| 26 | |
| 27 | #ifdef HACKY_PARALLEL |
| 28 | |
| 29 | #include <stdio.h> |
| 30 | #include <unistd.h> |
| 31 | #include <errno.h> |
| 32 | #include <string.h> |
| 33 | #include <signal.h> |
| 34 | #include <assert.h> |
| 35 | #include <sys/wait.h> |
| 36 | |
| 37 | #define HASHSIZE 16 |
| 38 | #define CACHESIZE 16 |
| 39 | |
| 40 | typedef enum { hp_idle, hp_compute, hp_deferring, hp_fail } HPState; |
| 41 | |
| 42 | static HPState state; |
| 43 | static pid_t child; |
| 44 | |
| 45 | static void checkchild(void) |
| 46 | { |
| 47 | int r, status; |
| 48 | |
| 49 | if (!child) return; |
| 50 | |
| 51 | r= waitpid(child,&status,WNOHANG); if (!r) return; |
| 52 | if (r==-1) { |
| 53 | Message(M_ERR,"hacky_par: waitpid: %s\n",strerror(errno)); |
| 54 | return; |
| 55 | } |
| 56 | child= 0; |
| 57 | |
| 58 | if (WIFSIGNALED(status)) { |
| 59 | Message(M_ERR,"hacky_par: signaled! %s\n",strsignal(WTERMSIG(status))); |
| 60 | } else if (!WIFEXITED(status)) { |
| 61 | Message(M_ERR,"hacky_par: unexpected status! %d\n", r); |
| 62 | } |
| 63 | } |
| 64 | |
| 65 | static HPState start(void) |
| 66 | { |
| 67 | assert(!child); |
| 68 | |
| 69 | child= fork(); |
| 70 | if (child == -1) { |
| 71 | Message(M_ERR,"hacky_par: fork failed: %s\n",strerror(errno)); |
| 72 | return hp_fail; |
| 73 | } |
| 74 | |
| 75 | if (!child) { /* we are the child */ |
| 76 | afterfork(); |
| 77 | return hp_compute; |
| 78 | } |
| 79 | |
| 80 | Message(M_INFO,"hacky_par: started, punting\n"); |
| 81 | return hp_deferring; |
| 82 | } |
| 83 | |
| 84 | int hacky_par_start_failnow(void) |
| 85 | { |
| 86 | state= hp_idle; |
| 87 | checkchild(); |
| 88 | if (child) { |
| 89 | state= hp_deferring; |
| 90 | Message(M_INFO,"hacky_par: busy, punting\n"); |
| 91 | return 1; |
| 92 | } |
| 93 | return 0; |
| 94 | } |
| 95 | |
| 96 | int hacky_par_mid_failnow(void) |
| 97 | { |
| 98 | state= start(); |
| 99 | return state != hp_compute; |
| 100 | } |
| 101 | |
| 102 | bool_t (*packy_par_gen)(struct site *st); |
| 103 | |
| 104 | void hacky_par_end(int *ok, |
| 105 | int32_t retries, int32_t timeout, |
| 106 | bool_t (*send_msg)(struct site *st), struct site *st) |
| 107 | { |
| 108 | int i; |
| 109 | |
| 110 | switch (state) { |
| 111 | case hp_deferring: |
| 112 | assert(!*ok); |
| 113 | *ok= 1; |
| 114 | return; |
| 115 | case hp_fail: |
| 116 | assert(!*ok); |
| 117 | return; |
| 118 | case hp_idle: |
| 119 | return; |
| 120 | case hp_compute: |
| 121 | if (!ok) { |
| 122 | Message(M_ERR,"hacky_par: compute failed\n"); |
| 123 | _exit(2); |
| 124 | } |
| 125 | Message(M_INFO,"hacky_par: got result, sending\n"); |
| 126 | for (i=1; i<retries; i++) { |
| 127 | sleep((timeout + 999)/1000); |
| 128 | if (!send_msg(st)) { |
| 129 | Message(M_ERR,"hacky_par: retry failed\n"); |
| 130 | _exit(1); |
| 131 | } |
| 132 | } |
| 133 | _exit(0); |
| 134 | } |
| 135 | } |
| 136 | |
| 137 | #else /*!HACKY_PARALLEL*/ |
| 138 | |
| 139 | int hacky_par_start_failnow(void) { return 0; } |
| 140 | int hacky_par_mid_failnow(void) { return 0; } |
| 141 | void hacky_par_end(int *ok, |
| 142 | int32_t retries, int32_t timeout, |
| 143 | bool_t (*send_msg)(struct site *st), struct site *st) { } |
| 144 | |
| 145 | #endif /*HACKY_PARALLEL...else*/ |