1 /******************************************************************************/
2 /* */
3 /* Copyright (c) International Business Machines Corp., 2007 */
4 /* */
5 /* This program is free software; you can redistribute it and/or modify */
6 /* it under the terms of the GNU General Public License as published by */
7 /* the Free Software Foundation; either version 2 of the License, or */
8 /* (at your option) any later version. */
9 /* */
10 /* This program is distributed in the hope that it will be useful, */
11 /* but WITHOUT ANY WARRANTY; without even the implied warranty of */
12 /* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See */
13 /* the GNU General Public License for more details. */
14 /* */
15 /* You should have received a copy of the GNU General Public License */
16 /* along with this program; if not, write to the Free Software */
17 /* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
18 /* */
19 /******************************************************************************/
20
21 /******************************************************************************/
22 /* */
23 /* File: libcontrollers.c */
24 /* */
25 /* Description: This file contains the definitions for the functions/apis */
26 /* for the controllers library. This library is used by the */
27 /* controllers testcases. */
28 /* */
29 /* Author: Sudhir Kumar skumar@linux.vnet.ibm.com */
30 /* */
31 /* History: */
32 /* Created- 15/02/2008 -Sudhir Kumar <skumar@linux.vnet.ibm.com> */
33 /* */
34 /******************************************************************************/
35
36 #include "libcontrollers.h"
37
38 char fullpath[PATH_MAX];
39 int FLAG;
40 volatile int timer_expired = 0;
41 int retval;
42 unsigned int num_line;
43 unsigned int current_shares;
44 unsigned int total_shares;
45 unsigned int *shares_pointer;
46 char target[LINE_MAX];
47 struct dirent *dir_pointer;
48
49 /*
50 * Function: scan_shares_file()
51 * This function scans all the shares files under the mountpoint
52 * of the controller and returns the total added shares of all
53 * the groups (currently excludes default group) ??
54 */
scan_shares_files(unsigned int * shares_pointer)55 int scan_shares_files(unsigned int *shares_pointer)
56 {
57 struct stat statbuffer;
58 DIR *dp;
59 char *path_pointer;
60
61 /*
62 * Check if we can get stat of the file
63 */
64 if (lstat(fullpath, &statbuffer) < 0) {
65 error_function("Can not read stat for file ", fullpath);
66 return -1;
67 }
68
69 if (S_ISDIR(statbuffer.st_mode) == 0) { /* not a directory */
70 /*
71 * We run all user tasks in the created groups and not default groups. So
72 * exclude the shares of default group. FLAG to ensure dir_pointer is non NULL
73 */
74 if ((FLAG == 1)
75 && (strcmp(fullpath, "/dev/cpuctl/cpu.shares") != 0)
76 && (strcmp(dir_pointer->d_name, "cpu.shares") == 0)) {
77 *shares_pointer += read_shares_file(fullpath);
78 }
79 return 0;
80 }
81
82 /*
83 * Now it's a directory. let the path_pointer point to the end
84 * of fullpath to append new files names
85 */
86
87 path_pointer = fullpath + strlen(fullpath);
88 *path_pointer++ = '/';
89 *path_pointer = 0;
90
91 if ((dp = opendir(fullpath)) == NULL) { /* Error in opening directory */
92 error_function("Can't open ", fullpath);
93 return -1;
94 }
95 /*
96 * search all groups recursively and get total shares
97 */
98
99 while ((dir_pointer = readdir(dp)) != NULL) { /* Error in reading directory */
100 if ((strcmp(dir_pointer->d_name, ".") == 0)
101 || (strcmp(dir_pointer->d_name, "..") == 0))
102 continue; /* ignore current and parent directory */
103
104 FLAG = 1;
105 strcpy(path_pointer, dir_pointer->d_name); /* append name to fullpath */
106
107 if ((retval = scan_shares_files(shares_pointer)) != 0)
108 break;
109 }
110
111 /*
112 * This directory is searched fully. let us go back to parent directory again
113 */
114
115 path_pointer[-1] = 0;
116
117 if (closedir(dp) < 0) {
118 error_function("Could not close dir ", fullpath);
119 return -1;
120 }
121 return 0;
122 }
123
124 /*
125 * Function: read_file ()
126 * This function is written keeping in mind the support
127 * to read other files also if required in future.
128 * Each file under a group contains some diff parameter/s
129 */
130
read_file(char * filepath,int action,unsigned int * value)131 int read_file(char *filepath, int action, unsigned int *value)
132 {
133 int num_line = 0;
134 FILE *fp;
135 int tmp;
136 switch (action) {
137 case GET_SHARES:
138 tmp = read_shares_file(filepath);
139 if (tmp == -1)
140 return -1;
141 *value = (unsigned int)tmp;
142 break;
143
144 case GET_TASKS:
145 fp = fopen(filepath, "r");
146 if (fp == NULL) {
147 error_function("Could not open file", filepath);
148 return -1;
149 }
150 while (fgets(target, LINE_MAX, fp) != NULL)
151 num_line++;
152 *value = (unsigned int)num_line;
153 if (fclose(fp)) {
154 error_function("Could not close file", filepath);
155 return -1;
156 }
157 break;
158
159 default:
160 error_function("Wrong action type passed to fun read_file for ",
161 filepath);
162 return -1;
163 }
164 return 0;
165 }
166
167 /*
168 * Function: error_function()
169 * Prints error message and returns -1
170 */
171
error_function(char * msg1,char * msg2)172 static inline void error_function(char *msg1, char *msg2)
173 {
174 fprintf(stdout, "ERROR: %s ", msg1);
175 fprintf(stdout, "%s\n", msg2);
176 }
177
178 /* Function: read_shares_file()
179 * Reads shares value from a given shares file and writes them to
180 * the given pointer location. Returns 0 if success
181 */
182
read_shares_file(char * filepath)183 int read_shares_file(char *filepath)
184 {
185 FILE *fp;
186 unsigned int shares;
187 fp = fopen(filepath, "r");
188 if (fp == NULL) {
189 error_function("Could not open file", filepath);
190 return -1;
191 }
192 fscanf(fp, "%u", &shares);
193 if (fclose(fp)) {
194 error_function("Could not close file", filepath);
195 return -1;
196 }
197 return shares;
198 }
199
200 /* Function: write_to_file()
201 * writes value to shares file or pid to tasks file
202 */
203
write_to_file(char * file,const char * mode,unsigned int value)204 int write_to_file(char *file, const char *mode, unsigned int value)
205 {
206 FILE *fp;
207 fp = fopen(file, mode);
208 if (fp == NULL) {
209 error_function("in opening file for writing:", file);
210 return -1;
211 }
212 fprintf(fp, "%u\n", value);
213 fclose(fp);
214 return 0;
215 }
216
217 /* Function: signal_handler_alarm()
218 * signal handler for the new action
219 */
220
signal_handler_alarm(int signal)221 void signal_handler_alarm(int signal)
222 {
223 timer_expired = 1;
224 }
225