#include <unistd.h>
#include <common/common.h>
+#include <common/readwrite.h>
#include <common/runas.h>
#include <common/compat/getenv.h>
#include <common/compat/string.h>
#include "defaults.h"
#include "time.h"
+#define PROC_MEMINFO_PATH "/proc/meminfo"
+#define PROC_MEMINFO_MEMAVAILABLE_LINE "MemAvailable:"
+#define PROC_MEMINFO_MEMTOTAL_LINE "MemTotal:"
+
+/* The length of the longest field of `/proc/meminfo`. */
+#define PROC_MEMINFO_FIELD_MAX_NAME_LEN 20
+
+#if (PROC_MEMINFO_FIELD_MAX_NAME_LEN == 20)
+#define MAX_NAME_LEN_SCANF_IS_A_BROKEN_API "19"
+#else
+#error MAX_NAME_LEN_SCANF_IS_A_BROKEN_API must be updated to match (PROC_MEMINFO_FIELD_MAX_NAME_LEN - 1)
+#endif
+
/*
* Return a partial realpath(3) of the path even if the full path does not
* exist. For instance, with /tmp/test1/test2/test3, if test2/ does not exist
/**
* Parse a string that represents a time in human readable format. It
- * supports decimal integers suffixed by 's', 'u', 'm', 'us', and 'ms'.
+ * supports decimal integers suffixed by:
+ * "us" for microsecond,
+ * "ms" for millisecond,
+ * "s" for second,
+ * "m" for minute,
+ * "h" for hour
*
* The suffix multiply the integer by:
- * 'u'/'us': 1
- * 'm'/'ms': 1000
- * 's': 1000000
+ * "us" : 1
+ * "ms" : 1000
+ * "s" : 1000000
+ * "m" : 60000000
+ * "h" : 3600000000
*
* Note that unit-less numbers are assumed to be microseconds.
*
{
int ret;
uint64_t base_time;
- long multiplier = 1;
+ uint64_t multiplier = 1;
const char *str_end;
char *num_end;
/* Check if a prefix is present. */
switch (*num_end) {
case 'u':
- multiplier = 1;
- /* Skip another letter in the 'us' case. */
- num_end += (*(num_end + 1) == 's') ? 2 : 1;
+ /*
+ * Microsecond (us)
+ *
+ * Skip the "us" if the string matches the "us" suffix,
+ * otherwise let the check for the end of the string handle
+ * the error reporting.
+ */
+ if (*(num_end + 1) == 's') {
+ num_end += 2;
+ }
break;
case 'm':
- multiplier = 1000;
- /* Skip another letter in the 'ms' case. */
- num_end += (*(num_end + 1) == 's') ? 2 : 1;
+ if (*(num_end + 1) == 's') {
+ /* Millisecond (ms) */
+ multiplier = USEC_PER_MSEC;
+ /* Skip the 's' */
+ num_end++;
+ } else {
+ /* Minute (m) */
+ multiplier = USEC_PER_MINUTE;
+ }
+ num_end++;
break;
case 's':
- multiplier = 1000000;
+ /* Second */
+ multiplier = USEC_PER_SEC;
+ num_end++;
+ break;
+ case 'h':
+ /* Hour */
+ multiplier = USEC_PER_HOURS;
num_end++;
break;
case '\0':
return ret;
}
-LTTNG_HIDDEN
-int timespec_to_ms(struct timespec ts, unsigned long *ms)
+static
+int read_proc_meminfo_field(const char *field, size_t *value)
{
- unsigned long res, remain_ms;
+ int ret;
+ FILE *proc_meminfo;
+ char name[PROC_MEMINFO_FIELD_MAX_NAME_LEN] = {};
- if (ts.tv_sec > ULONG_MAX / MSEC_PER_SEC) {
- errno = EOVERFLOW;
- return -1; /* multiplication overflow */
- }
- res = ts.tv_sec * MSEC_PER_SEC;
- remain_ms = ULONG_MAX - res;
- if (ts.tv_nsec / NSEC_PER_MSEC > remain_ms) {
- errno = EOVERFLOW;
- return -1; /* addition overflow */
+ proc_meminfo = fopen(PROC_MEMINFO_PATH, "r");
+ if (!proc_meminfo) {
+ PERROR("Failed to fopen() " PROC_MEMINFO_PATH);
+ ret = -1;
+ goto fopen_error;
+ }
+
+ /*
+ * Read the contents of /proc/meminfo line by line to find the right
+ * field.
+ */
+ while (!feof(proc_meminfo)) {
+ unsigned long value_kb;
+
+ ret = fscanf(proc_meminfo,
+ "%" MAX_NAME_LEN_SCANF_IS_A_BROKEN_API "s %lu kB\n",
+ name, &value_kb);
+ if (ret == EOF) {
+ /*
+ * fscanf() returning EOF can indicate EOF or an error.
+ */
+ if (ferror(proc_meminfo)) {
+ PERROR("Failed to parse " PROC_MEMINFO_PATH);
+ }
+ break;
+ }
+
+ if (ret == 2 && strcmp(name, field) == 0) {
+ /*
+ * This number is displayed in kilo-bytes. Return the
+ * number of bytes.
+ */
+ *value = ((size_t) value_kb) * 1024;
+ ret = 0;
+ goto found;
+ }
}
- res += ts.tv_nsec / NSEC_PER_MSEC;
- *ms = res;
- return 0;
+ /* Reached the end of the file without finding the right field. */
+ ret = -1;
+
+found:
+ fclose(proc_meminfo);
+fopen_error:
+ return ret;
+}
+
+/*
+ * Returns an estimate of the number of bytes of memory available based on the
+ * the information in `/proc/meminfo`. The number returned by this function is
+ * a best guess.
+ */
+LTTNG_HIDDEN
+int utils_get_memory_available(size_t *value)
+{
+ return read_proc_meminfo_field(PROC_MEMINFO_MEMAVAILABLE_LINE, value);
}
+/*
+ * Returns the total size of the memory on the system in bytes based on the
+ * the information in `/proc/meminfo`.
+ */
LTTNG_HIDDEN
-struct timespec timespec_abs_diff(struct timespec t1, struct timespec t2)
+int utils_get_memory_total(size_t *value)
{
- uint64_t ts1 = (uint64_t) t1.tv_sec * (uint64_t) NSEC_PER_SEC +
- (uint64_t) t1.tv_nsec;
- uint64_t ts2 = (uint64_t) t2.tv_sec * (uint64_t) NSEC_PER_SEC +
- (uint64_t) t2.tv_nsec;
- uint64_t diff = max(ts1, ts2) - min(ts1, ts2);
- struct timespec res;
-
- res.tv_sec = diff / (uint64_t) NSEC_PER_SEC;
- res.tv_nsec = diff % (uint64_t) NSEC_PER_SEC;
- return res;
+ return read_proc_meminfo_field(PROC_MEMINFO_MEMTOTAL_LINE, value);
}
projects / lttng-tools.git / blobdiff