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1 /***************************************************************************** |
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2 * Copyright (C) 2017 |
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3 * |
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4 * Michiel Broek <mbroek at mbse dot eu> |
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5 * |
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6 * This file is part of the bms (Brewery Management System) |
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7 * |
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8 * This is free software; you can redistribute it and/or modify it |
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9 * under the terms of the GNU General Public License as published by the |
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10 * Free Software Foundation; either version 2, or (at your option) any |
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11 * later version. |
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12 * |
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13 * bms is distributed in the hope that it will be useful, but |
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14 * WITHOUT ANY WARRANTY; without even the implied warranty of |
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15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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16 * General Public License for more details. |
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17 * |
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18 * You should have received a copy of the GNU General Public License |
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19 * along with ThermFerm; see the file COPYING. If not, write to the Free |
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20 * Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. |
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21 *****************************************************************************/ |
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22 |
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23 #include "lock.h" |
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24 #include "bms.h" |
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25 #include "futil.h" |
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26 |
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27 |
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28 extern char *Private_Path; |
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29 |
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30 |
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31 /* |
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32 * Put a lock on this program. |
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33 */ |
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34 int lockprog(char *name) |
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35 { |
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36 char *tempfile, *lockfile; |
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37 FILE *fp; |
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38 pid_t oldpid; |
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39 |
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40 tempfile = calloc(PATH_MAX, sizeof(char)); |
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41 lockfile = calloc(PATH_MAX, sizeof(char)); |
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42 |
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43 snprintf(tempfile, PATH_MAX, "%s/run/%s.tmp", Private_Path, name); |
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44 snprintf(lockfile, PATH_MAX, "%s/run/%s.pid", Private_Path, name); |
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45 |
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46 if (mkdirs(tempfile, 0755) == FALSE) { |
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47 printf("Can't create path \"%s\"\n", tempfile); |
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48 free(tempfile); |
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49 free(lockfile); |
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50 return 1; |
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51 } |
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52 |
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53 if ((fp = fopen(tempfile, "w")) == NULL) { |
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54 perror(name); |
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55 printf("Can't create lockfile \"%s\"\n", tempfile); |
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56 free(tempfile); |
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57 free(lockfile); |
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58 return 1; |
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59 } |
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60 fprintf(fp, "%10u\n", getpid()); |
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61 fclose(fp); |
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62 |
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63 while (TRUE) { |
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64 if (link(tempfile, lockfile) == 0) { |
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65 unlink(tempfile); |
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66 free(tempfile); |
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67 free(lockfile); |
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68 return 0; |
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69 } |
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70 if ((fp = fopen(lockfile, "r")) == NULL) { |
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71 perror(name); |
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72 printf("Can't open lockfile \"%s\"\n", tempfile); |
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73 unlink(tempfile); |
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74 free(tempfile); |
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75 free(lockfile); |
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76 return 1; |
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77 } |
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78 if (fscanf(fp, "%u", &oldpid) != 1) { |
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79 perror(name); |
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80 printf("Can't read old pid from \"%s\"\n", tempfile); |
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81 fclose(fp); |
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82 unlink(tempfile); |
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83 free(tempfile); |
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84 free(lockfile); |
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85 return 1; |
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86 } |
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87 fclose(fp); |
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88 if (kill(oldpid,0) == -1) { |
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89 if (errno == ESRCH) { |
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90 printf("Stale lock found for pid %u\n", oldpid); |
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91 unlink(lockfile); |
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92 /* no return, try lock again */ |
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93 } else { |
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94 perror(name); |
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95 printf("Kill for %u failed\n",oldpid); |
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96 unlink(tempfile); |
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97 free(tempfile); |
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98 free(lockfile); |
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99 return 1; |
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100 } |
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101 } else { |
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102 printf("Another %s is already running, pid=%u\n", name, oldpid); |
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103 unlink(tempfile); |
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104 free(tempfile); |
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105 free(lockfile); |
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106 return 1; |
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107 } |
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108 } |
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109 } |
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110 |
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111 |
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112 |
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113 void ulockprog(char *name) |
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114 { |
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115 char *lockfile; |
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116 pid_t oldpid; |
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117 FILE *fp; |
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118 |
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119 lockfile = calloc(PATH_MAX, sizeof(char)); |
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120 snprintf(lockfile, PATH_MAX, "%s/run/%s.pid", Private_Path, name); |
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121 |
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122 if ((fp = fopen(lockfile, "r")) == NULL) { |
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123 syslog(LOG_NOTICE, "Can't open lockfile \"%s\"", lockfile); |
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124 free(lockfile); |
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125 return; |
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126 } |
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127 |
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128 if (fscanf(fp, "%u", &oldpid) != 1) { |
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129 syslog(LOG_NOTICE, "Can't read old pid from \"%s\"", lockfile); |
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130 fclose(fp); |
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131 unlink(lockfile); |
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132 free(lockfile); |
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133 return; |
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134 } |
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135 |
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136 fclose(fp); |
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137 |
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138 if (oldpid == getpid()) { |
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139 (void)unlink(lockfile); |
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140 } |
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141 |
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142 free(lockfile); |
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143 } |
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144 |
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145 |