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29 
30 /**
31  * @file datatop_cpu_stats_poll.c
32  * @brief Calls dtop_value_only_init for necessary cpu datapoints.
33  *
34  * File contains methods for determing number of cpu's online and calling
35  * correct initialization function to gather scaling_cur_freq data point
36  * for each cpu along with each cpu's online status.
37  */
38 
39 #include <unistd.h>
40 #include <stdio.h>
41 #include <dirent.h>
42 #include <string.h>
43 #include <stdlib.h>
44 #include <errno.h>
45 #include <sys/stat.h>
46 #include <sys/types.h>
47 #include <ctype.h>
48 #include "datatop_interface.h"
49 #include "datatop_fileops.h"
50 #include "datatop_str.h"
51 #include "datatop_polling.h"
52 
53 #define DTOP_GEN_SIZE 8192
54 #define DTOP_GEN_LINE (DTOP_GEN_SIZE>>2)
55 #define NO_CPUS_ONLINE -1
56 
57 /**
58  * @brief Searches /sys/devices/system/cpu/ directory to get find number of CPUs.
59  *
60  * @return Number of CPUs found in directory.
61  */
dtop_cpu_search(void)62 static int dtop_cpu_search(void)
63 {
64 	DIR *dp;
65 	struct dirent *entry;
66 	struct stat s;
67 	int cpu_amt;
68 	char cwd[1024];
69 
70 	if (!getcwd(cwd, sizeof(cwd))) {
71 		fprintf(stderr, "Failed to get current working dir\n");
72 		return -1;
73 	}
74 
75 	dp = opendir("/sys/devices/system/cpu/");
76 	if (dp == NULL) {
77 		fprintf(stderr, "err=%d: %s\n", errno, strerror(errno));
78 		fprintf(stderr, "Cannot open directory: %s\n",
79 					"/sys/devices/system/cpu/");
80 		return NO_CPUS_ONLINE;
81 	}
82 
83 	chdir("/sys/devices/system/cpu/");
84 	cpu_amt = 0;
85 	while ((entry = readdir(dp))) {
86 		if (stat(entry->d_name, &s)) {
87 			printf("stat err=%d: %s\n", errno, strerror(errno));
88 			return NO_CPUS_ONLINE;
89 		}
90 
91 		if (entry->d_name[0] == 'c' &&
92 			entry->d_name[1] == 'p' &&
93 			entry->d_name[2] == 'u' &&
94 			(isdigit(entry->d_name[3]))) {
95 
96 			cpu_amt++;
97 		}
98 	}
99 
100 	closedir(dp);
101 	chdir(cwd);
102 	return cpu_amt;
103 }
104 
105 /**
106  * @brief Creates a dpg designed for CPU online and CPU scaling_cur_freq stats.
107  *
108  * @param name Name of file dpg represents.
109  */
construct_cpu_stat_dpg(char * name)110 static void construct_cpu_stat_dpg(char *name)
111 {
112 	char *file = malloc(strlen(name) + 1);
113 	struct dtop_data_point *dp =
114 			malloc(sizeof(struct dtop_data_point));
115 	struct dtop_data_point_gatherer *dpg = malloc
116 		(sizeof(struct dtop_data_point_gatherer));
117 
118 	strlcpy(file, name, strlen(name) + 1);
119 
120 	dp[0].type = DTOP_ULONG;
121 	dp[0].name = malloc(5);
122 	strlcpy(dp[0].name, "", 5);
123 	dp[0].prefix = NULL;
124 	dp[0].data.d_ulong = 0;
125 	dp[0].initial_data.d_ulong = 0;
126 	dp[0].skip = DO_NOT_SKIP;
127 	dp[0].initial_data_populated = NOT_POPULATED;
128 
129 	dpg->prefix = file;
130 	dpg->file = file;
131 	dpg->poll = dtop_value_only_poll;
132 	dpg->data_points = dp;
133 	dpg->data_points_len = 1;
134 	dpg->deconstruct = dtop_value_only_dpg_deconstructor;
135 
136 	dtop_register(dpg);
137 }
138 
139 /**
140  * @brief Calls dpg constructor for necessary CPU stat files.
141  *
142  * Creates file names based on number of CPUs found and calls the
143  * dpg constructor for them.
144  *
145  * @param file Directory where the CPUs are found.
146  * @param add String which is concatenated onto file and represents
147  * the path after a CPU directory is entered.
148  * @param cpu_amt Amount of CPUs found on device.
149  */
cpu_poll_helper(char * file,char * add,int cpu_amt)150 static void cpu_poll_helper(char *file, char *add, int cpu_amt)
151 {
152 	int i;
153 	for (i = 0; i < cpu_amt; i++) {
154 		char *cpu_num = malloc(5);
155 		char *newfile;
156 		int nf_len;
157 		snprintf(cpu_num, 5, "%d", i);
158 		nf_len = strlen(file) + strlen(add) + strlen(cpu_num) + 2;
159 		newfile = malloc(nf_len);
160 		strlcpy(newfile, file, nf_len);
161 		strlcat(newfile, cpu_num, nf_len);
162 		strlcat(newfile, add, nf_len);
163 		free(cpu_num);
164 		construct_cpu_stat_dpg(newfile);
165 		free(newfile);
166 	}
167 }
168 
169 /**
170  * @brief Calls necessary functions for CPU stat dpgs.
171  */
dtop_cpu_stats_init(void)172 void dtop_cpu_stats_init(void)
173 {
174 	int cpu_amt;
175 	char *file = "/sys/devices/system/cpu/cpu";
176 	char *add = "/cpufreq/scaling_cur_freq";
177 
178 	cpu_amt = dtop_cpu_search();
179 	cpu_poll_helper(file, add, cpu_amt);
180 	add = "/online";
181 	cpu_poll_helper(file, add, cpu_amt);
182 }
183