1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
|
/* $Id: passive_memory.c,v 1.18 2004/08/26 01:07:47 graziano Exp $ */
#include "config_nws.h"
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "diagnostic.h"
#include "memory.h"
#include "osutil.h"
/* returns the free memory. 0 on error */
static double
getFreeMem() {
double bytesBuffer;
double bytesCache;
double bytesFree;
double ret;
FILE *file;
char line[511 + 1];
ret = 0;
bytesFree = bytesBuffer = bytesCache = -1;
/* we try to read /proc/meminfo first: it's more accurate and
* faster */
file = fopen("/proc/meminfo", "r");
if (file != NULL) {
/* we are on business: we need to look for few tags:
* MemFree, Buffers and Cached */
while(fgets(line, sizeof(line), file) != NULL) {
if (line[0] == ' ') {
/* skip empty lines */
continue;
}
if (!strncmp(line, "MemFree", strlen("MemFree"))) {
/* we got the free mem */
if (!sscanf(line, "%*s %lf", &bytesFree)) {
bytesFree = -1;
}
}
if (!strncmp(line, "Buffers", strlen("Buffers"))) {
/* we got the buffers */
if (!sscanf(line, "%*s %lf", &bytesBuffer)) {
bytesBuffer = -1;
}
}
if (!strncmp(line, "Cached", strlen("Cached"))) {
/* we got the fs caches */
if (!sscanf(line, "%*s %lf", &bytesCache)) {
bytesCache = -1;
}
}
}
/* let's check if we got something useful */
if (bytesFree == -1 || bytesBuffer == -1 || bytesCache == -1) {
DDEBUG("PassiveMemoryGetFree: unknown /proc/meminfo format\n");
} else {
/* let's compute the free memory */
ret = (bytesFree + bytesBuffer + bytesCache)/1024;
}
fclose(file);
}
/* if we fail to read /proc we use the NWS standard call (uses
* sysconf) */
if (ret <= 0) {
ret = AvailableMemory();
}
if (ret >= 0)
DDEBUG1("getFreeMem: %f MBytes free memory\n", ret);
return ret;
}
int
PassiveMemoryGetFree(double *measure) {
double ret;
ret = getFreeMem();
if (ret <= 0) {
return 0;
}
*measure = ret;
LOG1("PassiveMemoryGetFree: %f MBytes free memory\n", ret);
return 1;
}
int
PassiveMemoryMonitorAvailable(void) {
/* the easy way to test if we can get some data, is to run
* getFreeMem and see if we got anything back */
return (getFreeMem() > 0);
}
|
