X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Futils.c;h=4c000e9b400864591a5bbd7715c2db7e3a1aef26;hp=3f74e1fae3c21487e71e8a6aeec3be1a38558677;hb=09b72f7aa737f46196db18bcdf3bc947a08c27a2;hpb=857f0d94259cbe44649a16a8c098658352b97fa9 diff --git a/src/common/utils.c b/src/common/utils.c index 3f74e1fae..4c000e9b4 100644 --- a/src/common/utils.c +++ b/src/common/utils.c @@ -33,6 +33,7 @@ #include #include +#include #include #include #include @@ -41,6 +42,20 @@ #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 @@ -197,7 +212,7 @@ error: } 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; @@ -206,7 +221,6 @@ char *expand_double_slashes_dot_and_dotdot(char *path) path_last_char = &path[path_len]; if (path_len == 0) { - path = NULL; goto error; } @@ -292,9 +306,9 @@ char *expand_double_slashes_dot_and_dotdot(char *path) } path[expanded_path_len] = '\0'; - + return 0; error: - return path; + return -1; } /* @@ -313,7 +327,7 @@ char *_utils_expand_path(const char *path, bool keep_symlink) int ret; char *absolute_path = NULL; char *last_token; - int is_dot, is_dotdot; + bool is_dot, is_dotdot; /* Safety net */ if (path == NULL) { @@ -364,8 +378,8 @@ char *_utils_expand_path(const char *path, bool keep_symlink) 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; } @@ -1104,12 +1118,19 @@ end: /** * 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. * @@ -1124,7 +1145,7 @@ int utils_parse_time_suffix(char const * const str, uint64_t * const time_us) { int ret; uint64_t base_time; - long multiplier = 1; + uint64_t multiplier = 1; const char *str_end; char *num_end; @@ -1161,17 +1182,37 @@ int utils_parse_time_suffix(char const * const str, uint64_t * const time_us) /* 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': @@ -1646,3 +1687,77 @@ int utils_show_help(int section, const char *page_name, 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); +}