diff options
Diffstat (limited to 'libstdc++-v3/src')
| -rw-r--r-- | libstdc++-v3/src/c++11/random.cc | 301 |
1 files changed, 244 insertions, 57 deletions
diff --git a/libstdc++-v3/src/c++11/random.cc b/libstdc++-v3/src/c++11/random.cc index 1146d21c3f9..85cb2df4287 100644 --- a/libstdc++-v3/src/c++11/random.cc +++ b/libstdc++-v3/src/c++11/random.cc @@ -23,19 +23,30 @@ // <http://www.gnu.org/licenses/>. #define _GLIBCXX_USE_CXX11_ABI 1 +#define _CRT_RAND_S // define this before including <stdlib.h> to get rand_s + #include <random> #ifdef _GLIBCXX_USE_C99_STDINT_TR1 #if defined __i386__ || defined __x86_64__ # include <cpuid.h> +# ifdef _GLIBCXX_X86_RDRAND +# define USE_RDRAND 1 +# endif +# ifdef _GLIBCXX_X86_RDSEED +# define USE_RDSEED 1 +# endif #endif #include <cerrno> #include <cstdio> -#ifdef _GLIBCXX_HAVE_UNISTD_H +#if defined _GLIBCXX_HAVE_UNISTD_H && defined _GLIBCXX_HAVE_FCNTL_H # include <unistd.h> +# include <fcntl.h> +// Use POSIX open, close, read etc. instead of ISO fopen, fclose, fread +# define USE_POSIX_FILE_IO #endif #ifdef _GLIBCXX_HAVE_SYS_IOCTL_H @@ -50,105 +61,273 @@ # include <linux/random.h> #endif +#ifdef _GLIBCXX_USE_CRT_RAND_S +# include <stdlib.h> +#endif + +#if defined USE_RDRAND || defined USE_RDSEED \ + || defined _GLIBCXX_USE_CRT_RAND_S || defined _GLIBCXX_USE_DEV_RANDOM +# pragma GCC poison _M_mt +#else +// Use the mt19937 member of the union, as in previous GCC releases. +# define USE_MT19937 1 +#endif + namespace std _GLIBCXX_VISIBILITY(default) { namespace { - static unsigned long - _M_strtoul(const std::string& __str) - { - unsigned long __ret = 5489UL; - if (__str != "mt19937") - { - const char* __nptr = __str.c_str(); - char* __endptr; - __ret = std::strtoul(__nptr, &__endptr, 0); - if (*__nptr == '\0' || *__endptr != '\0') - std::__throw_runtime_error(__N("random_device::_M_strtoul" - "(const std::string&)")); - } - return __ret; - } - -#if (defined __i386__ || defined __x86_64__) && defined _GLIBCXX_X86_RDRAND +#if USE_RDRAND unsigned int __attribute__ ((target("rdrnd"))) - __x86_rdrand(void) + __x86_rdrand(void*) { unsigned int retries = 100; unsigned int val; while (__builtin_ia32_rdrand32_step(&val) == 0) if (--retries == 0) - std::__throw_runtime_error(__N("random_device::__x86_rdrand(void)")); + std::__throw_runtime_error(__N("random_device: rdrand failed")); return val; } #endif + +#if USE_RDSEED + unsigned int + __attribute__ ((target("rdseed"))) + __x86_rdseed(void*) + { + unsigned int retries = 100; + unsigned int val; + + while (__builtin_ia32_rdseed_si_step(&val) == 0) + { + if (--retries == 0) + std::__throw_runtime_error(__N("random_device: rdseed failed")); + __builtin_ia32_pause(); + } + + return val; + } +#endif + +#ifdef _GLIBCXX_USE_CRT_RAND_S + unsigned int + __winxp_rand_s(void*) + { + unsigned int val; + if (::rand_s(&val) != 0) + std::__throw_runtime_error(__N("random_device: rand_s failed")); + return val; + } +#endif } void random_device::_M_init(const std::string& token) { - const char *fname = token.c_str(); +#ifdef USE_MT19937 + // If no real random device is supported then use the mt19937 engine. + _M_init_pretr1(token); + return; +#else + + _M_file = nullptr; + _M_func = nullptr; + _M_fd = -1; + + const char* fname [[gnu::unused]] = nullptr; + bool default_token [[gnu::unused]] = false; + + enum { rand_s, rdseed, rdrand, device_file } which; if (token == "default") { -#if (defined __i386__ || defined __x86_64__) && defined _GLIBCXX_X86_RDRAND + default_token = true; + fname = "/dev/urandom"; +#if defined _GLIBCXX_USE_CRT_RAND_S + which = rand_s; +#elif defined USE_RDSEED + which = rdseed; +#elif defined USE_RDRAND + which = rdrand; +#elif defined _GLIBCXX_USE_DEV_RANDOM + which = device_file; +#else +# error "either define USE_MT19937 above or set the default device here" +#endif + } +#ifdef USE_RDSEED + else if (token == "rdseed") + which = rdseed; +#endif // USE_RDSEED +#ifdef USE_RDRAND + else if (token == "rdrand" || token == "rdrnd") + which = rdrand; +#endif // USE_RDRAND +#ifdef _GLIBCXX_USE_CRT_RAND_S + else if (token == "rand_s") + which = rand_s; +#endif // _GLIBCXX_USE_CRT_RAND_S +#ifdef _GLIBCXX_USE_DEV_RANDOM + else if (token == "/dev/urandom" || token == "/dev/random") + { + fname = token.c_str(); + which = device_file; + } +#endif // _GLIBCXX_USE_DEV_RANDOM + else + std::__throw_runtime_error( + __N("random_device::random_device(const std::string&):" + " unsupported token")); + + switch (which) + { +#ifdef _GLIBCXX_USE_CRT_RAND_S + case rand_s: + { + _M_func = &__winxp_rand_s; + return; + } +#endif // _GLIBCXX_USE_CRT_RAND_S +#ifdef USE_RDSEED + case rdseed: + { + unsigned int eax, ebx, ecx, edx; + // Check availability of cpuid and, for now at least, also the + // CPU signature for Intel and AMD. + if (__get_cpuid_max(0, &ebx) > 0 + && (ebx == signature_INTEL_ebx || ebx == signature_AMD_ebx)) + { + // CPUID.(EAX=07H, ECX=0H):EBX.RDSEED[bit 18] + __cpuid_count(7, 0, eax, ebx, ecx, edx); + if (ebx & bit_RDSEED) + { + _M_func = &__x86_rdseed; + return; + } + } + // If rdseed was explicitly requested then we're done here. + if (!default_token) + break; + // Otherwise fall through to try the next available option. + [[gnu::fallthrough]]; + } +#endif // USE_RDSEED +#ifdef USE_RDRAND + case rdrand: + { unsigned int eax, ebx, ecx, edx; // Check availability of cpuid and, for now at least, also the - // CPU signature for Intel's - if (__get_cpuid_max(0, &ebx) > 0 && ebx == signature_INTEL_ebx) + // CPU signature for Intel and AMD. + if (__get_cpuid_max(0, &ebx) > 0 + && (ebx == signature_INTEL_ebx || ebx == signature_AMD_ebx)) { + // CPUID.01H:ECX.RDRAND[bit 30] __cpuid(1, eax, ebx, ecx, edx); if (ecx & bit_RDRND) { - _M_file = nullptr; + _M_func = &__x86_rdrand; return; } } -#endif - - fname = "/dev/urandom"; + // If rdrand was explicitly requested then we're done here. + if (!default_token) + break; + // Otherwise fall through to try the next available option. + [[gnu::fallthrough]]; } - else if (token != "/dev/urandom" && token != "/dev/random") - fail: - std::__throw_runtime_error(__N("random_device::" - "random_device(const std::string&)")); - - _M_file = static_cast<void*>(std::fopen(fname, "rb")); - if (!_M_file) - goto fail; +#endif // USE_RDRAND +#ifdef _GLIBCXX_USE_DEV_RANDOM + case device_file: + { +#ifdef USE_POSIX_FILE_IO + _M_fd = ::open(fname, O_RDONLY); + if (_M_fd != -1) + { + // Set _M_file to non-null so that _M_fini() will do clean up. + _M_file = &_M_fd; + return; + } +#else // USE_POSIX_FILE_IO + _M_file = static_cast<void*>(std::fopen(fname, "rb")); + if (_M_file) + return; +#endif // USE_POSIX_FILE_IO + [[gnu::fallthrough]]; + } +#endif // _GLIBCXX_USE_DEV_RANDOM + default: + { } + } + std::__throw_runtime_error( + __N("random_device::random_device(const std::string&):" + " device not available")); +#endif // USE_MT19937 } + // This function is called by _M_init for targets that use mt19937 for + // randomness, and by code compiled against old releases of libstdc++. void random_device::_M_init_pretr1(const std::string& token) { - _M_mt.seed(_M_strtoul(token)); +#ifdef USE_MT19937 + unsigned long seed = 5489UL; + if (token != "default" && token != "mt19937") + { + const char* nptr = token.c_str(); + char* endptr; + seed = std::strtoul(nptr, &endptr, 0); + if (*nptr == '\0' || *endptr != '\0') + std::__throw_runtime_error(__N("random_device::_M_init_pretr1" + "(const std::string&)")); + } + _M_mt.seed(seed); +#else + // Convert old default token "mt19937" or numeric seed tokens to "default". + if (token == "mt19937" || isdigit((unsigned char)token[0])) + _M_init("default"); + else + _M_init(token); +#endif } void random_device::_M_fini() { - if (_M_file) - std::fclose(static_cast<FILE*>(_M_file)); + // _M_file == nullptr means no resources to free. + if (!_M_file) + return; + +#ifdef USE_POSIX_FILE_IO + ::close(_M_fd); + _M_fd = -1; +#else + std::fclose(static_cast<FILE*>(_M_file)); +#endif + _M_file = nullptr; } random_device::result_type random_device::_M_getval() { -#if (defined __i386__ || defined __x86_64__) && defined _GLIBCXX_X86_RDRAND - if (!_M_file) - return __x86_rdrand(); +#ifdef USE_MT19937 + return _M_mt(); +#else + +#if defined USE_RDRAND || defined USE_RDSEED || defined _GLIBCXX_USE_CRT_RAND_S + if (_M_func) + return _M_func(nullptr); #endif - result_type __ret; - void* p = &__ret; + result_type ret; + void* p = &ret; size_t n = sizeof(result_type); -#ifdef _GLIBCXX_HAVE_UNISTD_H +#ifdef USE_POSIX_FILE_IO do { - const int e = read(fileno(static_cast<FILE*>(_M_file)), p, n); + const int e = ::read(_M_fd, p, n); if (e > 0) { n -= e; @@ -158,34 +337,40 @@ namespace std _GLIBCXX_VISIBILITY(default) __throw_runtime_error(__N("random_device could not be read")); } while (n > 0); -#else +#else // USE_POSIX_FILE_IO const size_t e = std::fread(p, n, 1, static_cast<FILE*>(_M_file)); if (e != 1) __throw_runtime_error(__N("random_device could not be read")); -#endif +#endif // USE_POSIX_FILE_IO - return __ret; + return ret; +#endif // USE_MT19937 } + // Only called by code compiled against old releases of libstdc++. + // Forward the call to _M_getval() and let it decide what to do. random_device::result_type random_device::_M_getval_pretr1() - { - return _M_mt(); - } + { return _M_getval(); } double random_device::_M_getentropy() const noexcept { -#if defined _GLIBCXX_HAVE_SYS_IOCTL_H && defined RNDGETENTCNT +#if defined _GLIBCXX_USE_DEV_RANDOM \ + && defined _GLIBCXX_HAVE_SYS_IOCTL_H && defined RNDGETENTCNT if (!_M_file) return 0.0; - const int fd = fileno(static_cast<FILE*>(_M_file)); +#ifdef USE_POSIX_FILE_IO + const int fd = _M_fd; +#else + const int fd = ::fileno(static_cast<FILE*>(_M_file)); +#endif if (fd < 0) return 0.0; int ent; - if (ioctl(fd, RNDGETENTCNT, &ent) < 0) + if (::ioctl(fd, RNDGETENTCNT, &ent) < 0) return 0.0; if (ent < 0) @@ -198,9 +383,10 @@ namespace std _GLIBCXX_VISIBILITY(default) return static_cast<double>(ent); #else return 0.0; -#endif +#endif // _GLIBCXX_USE_DEV_RANDOM && _GLIBCXX_HAVE_SYS_IOCTL_H && RNDGETENTCNT } +#ifdef USE_MT19937 template class mersenne_twister_engine< uint_fast32_t, 32, 624, 397, 31, @@ -208,5 +394,6 @@ namespace std _GLIBCXX_VISIBILITY(default) 0xffffffffUL, 7, 0x9d2c5680UL, 15, 0xefc60000UL, 18, 1812433253UL>; +#endif // USE_MT19937 } -#endif +#endif // _GLIBCXX_USE_C99_STDINT_TR1 |