From aca05fc5c08d6296c4f93850a0256bfd96890b18 Mon Sep 17 00:00:00 2001 From: Nick Mathewson Date: Thu, 3 Apr 2014 11:46:01 -0400 Subject: [PATCH] get_total_system_memory(): see how much RAM we have --- configure.ac | 2 + src/common/compat.c | 119 +++++++++++++++++++++++++++++++++++++++++++ src/common/compat.h | 2 + src/or/main.c | 1 + src/test/test_util.c | 29 +++++++++++ 5 files changed, 153 insertions(+) diff --git a/configure.ac b/configure.ac index 6e41041961..d8543b0d2e 100644 --- a/configure.ac +++ b/configure.ac @@ -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 \ diff --git a/src/common/compat.c b/src/common/compat.c index 135f2c9af6..58dd7f5da6 100644 --- a/src/common/compat.c +++ b/src/common/compat.c @@ -38,6 +38,9 @@ #ifdef HAVE_SYS_TYPES_H #include #endif +#ifdef HAVE_SYS_SYSCTL_H +#include +#endif #ifdef HAVE_SYS_STAT_H #include #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 *mem_out 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; +} + diff --git a/src/common/compat.h b/src/common/compat.h index bb88818d82..01faf14ae4 100644 --- a/src/common/compat.h +++ b/src/common/compat.h @@ -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; diff --git a/src/or/main.c b/src/or/main.c index feca35c440..8c75a3b5e6 100644 --- a/src/or/main.c +++ b/src/or/main.c @@ -2751,6 +2751,7 @@ sandbox_init_filter(void) "/dev/srandom", 0, "/dev/urandom", 0, "/dev/random", 0, + "/proc/meminfo", 0, NULL, 0 ); diff --git a/src/test/test_util.c b/src/test/test_util.c index a471b8eb19..20e65853d4 100644 --- a/src/test/test_util.c +++ b/src/test/test_util.c @@ -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 };