Commit aca05fc5 authored by Nick Mathewson's avatar Nick Mathewson 🥄
Browse files

get_total_system_memory(): see how much RAM we have

parent 17d5734d
......@@ -353,6 +353,7 @@ AC_CHECK_FUNCS(
strtok_r \
strtoull \
sysconf \
sysctl \
uname \
vasprintf \
_vscprintf
......@@ -877,6 +878,7 @@ AC_CHECK_HEADERS(
sys/prctl.h \
sys/resource.h \
sys/socket.h \
sys/sysctl.h \
sys/syslimits.h \
sys/time.h \
sys/types.h \
......
......@@ -38,6 +38,9 @@
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SYSCTL_H
#include <sys/sysctl.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
......@@ -3311,3 +3314,119 @@ format_win32_error(DWORD err)
}
#endif
#if defined(HW_PHYSMEM64)
/* This appears to be an OpenBSD thing */
#define INT64_HW_MEM HW_PHYSMEM64
#elif defined(HW_MEMSIZE)
/* OSX defines this one */
#define INT64_HW_MEM HW_MEMSIZE
#endif
/**
* Helper: try to detect the total system memory, and return it. On failure,
* return 0.
*/
static uint64_t
get_total_system_memory_impl(void)
{
#if defined(__linux__)
/* On linux, sysctl is deprecated. Because proc is so awesome that you
* shouldn't _want_ to write portable code, I guess? */
unsigned long long result=0;
int fd = -1;
char *s = NULL;
const char *cp;
size_t file_size=0;
if (-1 == (fd = tor_open_cloexec("/proc/meminfo",O_RDONLY,0)))
return 0;
s = read_file_to_str_until_eof(fd, 65536, &file_size);
if (!s)
goto err;
cp = strstr(s, "MemTotal:");
if (!cp)
goto err;
/* Use the system sscanf so that space will match a wider number of space */
if (sscanf(cp, "MemTotal: %llu kB\n", &result) != 1)
goto err;
close(fd);
tor_free(s);
return result * 1024;
err:
tor_free(s);
close(fd);
return 0;
#elif defined (_WIN32)
/* Windows has MEMORYSTATUSEX; pretty straightforward. */
MEMORYSTATUSEX ms;
memset(&ms, 0, sizeof(ms));
ms.dwLength = sizeof(ms);
if (! GlobalMemoryStatusEx(&ms))
return 0;
return ms.ullTotalPhys;
#elif defined(HAVE_SYSCTL) && defined(INT64_HW_MEM)
/* On many systems, HW_PYHSMEM is clipped to 32 bits; let's use a better
* variant if we know about it. */
uint64_t memsize = 0;
size_t len = sizeof(memsize);
int mib[2] = {CTL_HW, INT64_HW_MEM};
if (sysctl(mib,2,&memsize,&len,NULL,0))
return 0;
return memsize;
#elif defined(HAVE_SYSCTL) && defined(HW_PHYSMEM)
/* On some systems (like FreeBSD I hope) you can use a size_t with
* HW_PHYSMEM. */
size_t memsize=0;
size_t len = sizeof(memsize);
int mib[2] = {CTL_HW, HW_USERMEM};
if (sysctl(mib,2,&memsize,&len,NULL,0))
return -1;
return memsize;
#else
/* I have no clue. */
return 0;
#endif
}
/**
* Try to find out how much physical memory the system has. On success,
* return 0 and set *<b>mem_out</b> to that value. On failure, return -1.
*/
int
get_total_system_memory(size_t *mem_out)
{
static size_t mem_cached=0;
uint64_t m = get_total_system_memory_impl();
if (0 == m) {
/* We couldn't find our memory total */
if (0 == mem_cached) {
/* We have no cached value either */
*mem_out = 0;
return -1;
}
*mem_out = mem_cached;
return 0;
}
#if SIZE_T_MAX != UINT64_MAX
if (m > SIZE_T_MAX) {
/* I think this could happen if we're a 32-bit Tor running on a 64-bit
* system: we could have more system memory than would fit in a
* size_t. */
m = SIZE_T_MAX;
}
#endif
*mem_out = mem_cached = (size_t) m;
return -1;
}
......@@ -637,6 +637,8 @@ char *make_path_absolute(char *fname);
char **get_environment(void);
int get_total_system_memory(size_t *mem_out);
int spawn_func(void (*func)(void *), void *data);
void spawn_exit(void) ATTR_NORETURN;
......
......@@ -2751,6 +2751,7 @@ sandbox_init_filter(void)
"/dev/srandom", 0,
"/dev/urandom", 0,
"/dev/random", 0,
"/proc/meminfo", 0,
NULL, 0
);
......
......@@ -3606,6 +3606,34 @@ test_util_socketpair(void *arg)
tor_close_socket(fds[1]);
}
static void
test_util_max_mem(void *arg)
{
size_t memory1, memory2;
int r, r2;
(void) arg;
r = get_total_system_memory(&memory1);
r2 = get_total_system_memory(&memory2);
tt_int_op(r, ==, r2);
tt_int_op(memory2, ==, memory1);
TT_BLATHER(("System memory: "U64_FORMAT, U64_PRINTF_ARG(memory1)));
if (r==0) {
/* You have at least a megabyte. */
tt_int_op(memory1, >, (1<<20));
} else {
/* You do not have a petabyte. */
#if SIZEOF_SIZE_T == SIZEOF_UINT64_T
tt_int_op(memory1, <, (U64_LITERAL(1)<<50));
#endif
}
done:
;
}
struct testcase_t util_tests[] = {
UTIL_LEGACY(time),
UTIL_TEST(parse_http_time, 0),
......@@ -3669,6 +3697,7 @@ struct testcase_t util_tests[] = {
(void*)"0" },
{ "socketpair_ersatz", test_util_socketpair, TT_FORK,
&socketpair_setup, (void*)"1" },
UTIL_TEST(max_mem, 0),
END_OF_TESTCASES
};
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