#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 "utils.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
}
static
-char *expand_double_slashes_dot_and_dotdot(char *path)
+int expand_double_slashes_dot_and_dotdot(char *path)
{
size_t expanded_path_len, path_len;
const char *curr_char, *path_last_char, *next_slash, *prev_slash;
path_last_char = &path[path_len];
if (path_len == 0) {
- path = NULL;
goto error;
}
}
path[expanded_path_len] = '\0';
-
+ return 0;
error:
- return path;
+ return -1;
}
/*
int ret;
char *absolute_path = NULL;
char *last_token;
- int is_dot, is_dotdot;
+ bool is_dot, is_dotdot;
/* Safety net */
if (path == NULL) {
absolute_path, LTTNG_PATH_MAX);
}
- absolute_path = expand_double_slashes_dot_and_dotdot(absolute_path);
- if (!absolute_path) {
+ ret = expand_double_slashes_dot_and_dotdot(absolute_path);
+ if (ret) {
goto error;
}
/**
* 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':
end:
return ret;
}
+
+static
+int read_proc_meminfo_field(const char *field, size_t *value)
+{
+ int ret;
+ FILE *proc_meminfo;
+ char name[PROC_MEMINFO_FIELD_MAX_NAME_LEN] = {};
+
+ 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;
+ }
+ }
+ /* 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
+int utils_get_memory_total(size_t *value)
+{
+ return read_proc_meminfo_field(PROC_MEMINFO_MEMTOTAL_LINE, value);
+}