diff options
Diffstat (limited to 'absl')
-rw-r--r-- | absl/container/inlined_vector.h | 2 | ||||
-rw-r--r-- | absl/flags/reflection.cc | 12 | ||||
-rw-r--r-- | absl/random/internal/BUILD.bazel | 9 | ||||
-rw-r--r-- | absl/random/internal/fast_uniform_bits.h | 202 | ||||
-rw-r--r-- | absl/random/internal/fast_uniform_bits_test.cc | 318 | ||||
-rw-r--r-- | absl/synchronization/mutex.h | 5 | ||||
-rw-r--r-- | absl/time/internal/cctz/src/time_zone_format.cc | 22 | ||||
-rw-r--r-- | absl/time/internal/cctz/src/time_zone_format_test.cc | 5 | ||||
-rw-r--r-- | absl/time/internal/cctz/src/time_zone_libc.cc | 9 | ||||
-rw-r--r-- | absl/time/internal/cctz/src/tzfile.h | 8 | ||||
-rw-r--r-- | absl/types/CMakeLists.txt | 2 |
11 files changed, 335 insertions, 259 deletions
diff --git a/absl/container/inlined_vector.h b/absl/container/inlined_vector.h index f18dd4c7..90bb96e8 100644 --- a/absl/container/inlined_vector.h +++ b/absl/container/inlined_vector.h @@ -64,7 +64,7 @@ ABSL_NAMESPACE_BEGIN // `std::vector` for use cases where the vector's size is sufficiently small // that it can be inlined. If the inlined vector does grow beyond its estimated // capacity, it will trigger an initial allocation on the heap, and will behave -// as a `std:vector`. The API of the `absl::InlinedVector` within this file is +// as a `std::vector`. The API of the `absl::InlinedVector` within this file is // designed to cover the same API footprint as covered by `std::vector`. template <typename T, size_t N, typename A = std::allocator<T>> class InlinedVector { diff --git a/absl/flags/reflection.cc b/absl/flags/reflection.cc index 02b7c06a..1b025835 100644 --- a/absl/flags/reflection.cc +++ b/absl/flags/reflection.cc @@ -58,10 +58,6 @@ class FlagRegistry { // Will emit a warning if a 'retired' flag is specified. CommandLineFlag* FindFlagLocked(absl::string_view name); - // Returns the retired flag object for the specified name, or nullptr if not - // found or not retired. Does not emit a warning. - CommandLineFlag* FindRetiredFlagLocked(absl::string_view name); - static FlagRegistry& GlobalRegistry(); // returns a singleton registry private: @@ -88,14 +84,6 @@ CommandLineFlag* FlagRegistry::FindFlagLocked(absl::string_view name) { if (i == flags_.end()) { return nullptr; } - return i->second; -} - -CommandLineFlag* FlagRegistry::FindRetiredFlagLocked(absl::string_view name) { - FlagConstIterator i = flags_.find(name); - if (i == flags_.end() || !i->second->IsRetired()) { - return nullptr; - } return i->second; } diff --git a/absl/random/internal/BUILD.bazel b/absl/random/internal/BUILD.bazel index d81477ff..a0eba5e8 100644 --- a/absl/random/internal/BUILD.bazel +++ b/absl/random/internal/BUILD.bazel @@ -59,7 +59,10 @@ cc_library( ], copts = ABSL_DEFAULT_COPTS, linkopts = ABSL_DEFAULT_LINKOPTS, - deps = ["//absl/base:config"], + deps = [ + "//absl/base:config", + "//absl/meta:type_traits", + ], ) cc_library( @@ -319,10 +322,6 @@ cc_library( "//absl:windows": [], "//conditions:default": ["-Wno-pass-failed"], }), - # copts in RANDEN_HWAES_COPTS can make this target unusable as a module - # leading to a Clang diagnostic. Furthermore, it only has a private header - # anyway and thus there wouldn't be any gain from using it as a module. - features = ["-header_modules"], linkopts = ABSL_DEFAULT_LINKOPTS, deps = [ ":platform", diff --git a/absl/random/internal/fast_uniform_bits.h b/absl/random/internal/fast_uniform_bits.h index f13c8729..425aaf7d 100644 --- a/absl/random/internal/fast_uniform_bits.h +++ b/absl/random/internal/fast_uniform_bits.h @@ -21,6 +21,7 @@ #include <type_traits> #include "absl/base/config.h" +#include "absl/meta/type_traits.h" namespace absl { ABSL_NAMESPACE_BEGIN @@ -38,28 +39,17 @@ constexpr bool IsPowerOfTwoOrZero(UIntType n) { template <typename URBG> constexpr typename URBG::result_type RangeSize() { using result_type = typename URBG::result_type; + static_assert((URBG::max)() != (URBG::min)(), "URBG range cannot be 0."); return ((URBG::max)() == (std::numeric_limits<result_type>::max)() && (URBG::min)() == std::numeric_limits<result_type>::lowest()) ? result_type{0} - : (URBG::max)() - (URBG::min)() + result_type{1}; -} - -template <typename UIntType> -constexpr UIntType LargestPowerOfTwoLessThanOrEqualTo(UIntType n) { - return n < 2 ? n : 2 * LargestPowerOfTwoLessThanOrEqualTo(n / 2); -} - -// Given a URBG generating values in the closed interval [Lo, Hi], returns the -// largest power of two less than or equal to `Hi - Lo + 1`. -template <typename URBG> -constexpr typename URBG::result_type PowerOfTwoSubRangeSize() { - return LargestPowerOfTwoLessThanOrEqualTo(RangeSize<URBG>()); + : ((URBG::max)() - (URBG::min)() + result_type{1}); } // Computes the floor of the log. (i.e., std::floor(std::log2(N)); template <typename UIntType> constexpr UIntType IntegerLog2(UIntType n) { - return (n <= 1) ? 0 : 1 + IntegerLog2(n / 2); + return (n <= 1) ? 0 : 1 + IntegerLog2(n >> 1); } // Returns the number of bits of randomness returned through @@ -68,18 +58,23 @@ template <typename URBG> constexpr size_t NumBits() { return RangeSize<URBG>() == 0 ? std::numeric_limits<typename URBG::result_type>::digits - : IntegerLog2(PowerOfTwoSubRangeSize<URBG>()); + : IntegerLog2(RangeSize<URBG>()); } // Given a shift value `n`, constructs a mask with exactly the low `n` bits set. // If `n == 0`, all bits are set. template <typename UIntType> -constexpr UIntType MaskFromShift(UIntType n) { +constexpr UIntType MaskFromShift(size_t n) { return ((n % std::numeric_limits<UIntType>::digits) == 0) ? ~UIntType{0} : (UIntType{1} << n) - UIntType{1}; } +// Tags used to dispatch FastUniformBits::generate to the simple or more complex +// entropy extraction algorithm. +struct SimplifiedLoopTag {}; +struct RejectionLoopTag {}; + // FastUniformBits implements a fast path to acquire uniform independent bits // from a type which conforms to the [rand.req.urbg] concept. // Parameterized by: @@ -107,50 +102,16 @@ class FastUniformBits { "Class-template FastUniformBits<> must be parameterized using " "an unsigned type."); - // PowerOfTwoVariate() generates a single random variate, always returning a - // value in the half-open interval `[0, PowerOfTwoSubRangeSize<URBG>())`. If - // the URBG already generates values in a power-of-two range, the generator - // itself is used. Otherwise, we use rejection sampling on the largest - // possible power-of-two-sized subrange. - struct PowerOfTwoTag {}; - struct RejectionSamplingTag {}; - template <typename URBG> - static typename URBG::result_type PowerOfTwoVariate( - URBG& g) { // NOLINT(runtime/references) - using tag = - typename std::conditional<IsPowerOfTwoOrZero(RangeSize<URBG>()), - PowerOfTwoTag, RejectionSamplingTag>::type; - return PowerOfTwoVariate(g, tag{}); - } - - template <typename URBG> - static typename URBG::result_type PowerOfTwoVariate( - URBG& g, // NOLINT(runtime/references) - PowerOfTwoTag) { - return g() - (URBG::min)(); - } - - template <typename URBG> - static typename URBG::result_type PowerOfTwoVariate( - URBG& g, // NOLINT(runtime/references) - RejectionSamplingTag) { - // Use rejection sampling to ensure uniformity across the range. - typename URBG::result_type u; - do { - u = g() - (URBG::min)(); - } while (u >= PowerOfTwoSubRangeSize<URBG>()); - return u; - } - // Generate() generates a random value, dispatched on whether - // the underlying URBG must loop over multiple calls or not. + // the underlying URBG must use rejection sampling to generate a value, + // or whether a simplified loop will suffice. template <typename URBG> result_type Generate(URBG& g, // NOLINT(runtime/references) - std::true_type /* avoid_looping */); + SimplifiedLoopTag); template <typename URBG> result_type Generate(URBG& g, // NOLINT(runtime/references) - std::false_type /* avoid_looping */); + RejectionLoopTag); }; template <typename UIntType> @@ -162,31 +123,47 @@ FastUniformBits<UIntType>::operator()(URBG& g) { // NOLINT(runtime/references) // Y = (2 ^ kRange) - 1 static_assert((URBG::max)() > (URBG::min)(), "URBG::max and URBG::min may not be equal."); - using urbg_result_type = typename URBG::result_type; - constexpr urbg_result_type kRangeMask = - RangeSize<URBG>() == 0 - ? (std::numeric_limits<urbg_result_type>::max)() - : static_cast<urbg_result_type>(PowerOfTwoSubRangeSize<URBG>() - 1); - return Generate(g, std::integral_constant<bool, (kRangeMask >= (max)())>{}); + + using tag = absl::conditional_t<IsPowerOfTwoOrZero(RangeSize<URBG>()), + SimplifiedLoopTag, RejectionLoopTag>; + return Generate(g, tag{}); } template <typename UIntType> template <typename URBG> typename FastUniformBits<UIntType>::result_type FastUniformBits<UIntType>::Generate(URBG& g, // NOLINT(runtime/references) - std::true_type /* avoid_looping */) { - // The width of the result_type is less than than the width of the random bits - // provided by URBG. Thus, generate a single value and then simply mask off - // the required bits. + SimplifiedLoopTag) { + // The simplified version of FastUniformBits works only on URBGs that have + // a range that is a power of 2. In this case we simply loop and shift without + // attempting to balance the bits across calls. + static_assert(IsPowerOfTwoOrZero(RangeSize<URBG>()), + "incorrect Generate tag for URBG instance"); + + static constexpr size_t kResultBits = + std::numeric_limits<result_type>::digits; + static constexpr size_t kUrbgBits = NumBits<URBG>(); + static constexpr size_t kIters = + (kResultBits / kUrbgBits) + (kResultBits % kUrbgBits != 0); + static constexpr size_t kShift = (kIters == 1) ? 0 : kUrbgBits; + static constexpr auto kMin = (URBG::min)(); - return PowerOfTwoVariate(g) & (max)(); + result_type r = static_cast<result_type>(g() - kMin); + for (size_t n = 1; n < kIters; ++n) { + r = (r << kShift) + static_cast<result_type>(g() - kMin); + } + return r; } template <typename UIntType> template <typename URBG> typename FastUniformBits<UIntType>::result_type FastUniformBits<UIntType>::Generate(URBG& g, // NOLINT(runtime/references) - std::false_type /* avoid_looping */) { + RejectionLoopTag) { + static_assert(!IsPowerOfTwoOrZero(RangeSize<URBG>()), + "incorrect Generate tag for URBG instance"); + using urbg_result_type = typename URBG::result_type; + // See [rand.adapt.ibits] for more details on the constants calculated below. // // It is preferable to use roughly the same number of bits from each generator @@ -199,21 +176,44 @@ FastUniformBits<UIntType>::Generate(URBG& g, // NOLINT(runtime/references) // `kSmallIters` and `kLargeIters` times respectively such // that // - // `kTotalWidth == kSmallIters * kSmallWidth - // + kLargeIters * kLargeWidth` + // `kResultBits == kSmallIters * kSmallBits + // + kLargeIters * kLargeBits` // - // where `kTotalWidth` is the total number of bits in `result_type`. + // where `kResultBits` is the total number of bits in `result_type`. // - constexpr size_t kTotalWidth = std::numeric_limits<result_type>::digits; - constexpr size_t kUrbgWidth = NumBits<URBG>(); - constexpr size_t kTotalIters = - kTotalWidth / kUrbgWidth + (kTotalWidth % kUrbgWidth != 0); - constexpr size_t kSmallWidth = kTotalWidth / kTotalIters; - constexpr size_t kLargeWidth = kSmallWidth + 1; + static constexpr size_t kResultBits = + std::numeric_limits<result_type>::digits; // w + static constexpr urbg_result_type kUrbgRange = RangeSize<URBG>(); // R + static constexpr size_t kUrbgBits = NumBits<URBG>(); // m + + // compute the initial estimate of the bits used. + // [rand.adapt.ibits] 2 (c) + static constexpr size_t kA = // ceil(w/m) + (kResultBits / kUrbgBits) + ((kResultBits % kUrbgBits) != 0); // n' + + static constexpr size_t kABits = kResultBits / kA; // w0' + static constexpr urbg_result_type kARejection = + ((kUrbgRange >> kABits) << kABits); // y0' + + // refine the selection to reduce the rejection frequency. + static constexpr size_t kTotalIters = + ((kUrbgRange - kARejection) <= (kARejection / kA)) ? kA : (kA + 1); // n + + // [rand.adapt.ibits] 2 (b) + static constexpr size_t kSmallIters = + kTotalIters - (kResultBits % kTotalIters); // n0 + static constexpr size_t kSmallBits = kResultBits / kTotalIters; // w0 + static constexpr urbg_result_type kSmallRejection = + ((kUrbgRange >> kSmallBits) << kSmallBits); // y0 + + static constexpr size_t kLargeBits = kSmallBits + 1; // w0+1 + static constexpr urbg_result_type kLargeRejection = + ((kUrbgRange >> kLargeBits) << kLargeBits); // y1 + // - // Because `kLargeWidth == kSmallWidth + 1`, it follows that + // Because `kLargeBits == kSmallBits + 1`, it follows that // - // `kTotalWidth == kTotalIters * kSmallWidth + kLargeIters` + // `kResultBits == kSmallIters * kSmallBits + kLargeIters` // // and therefore // @@ -224,36 +224,40 @@ FastUniformBits<UIntType>::Generate(URBG& g, // NOLINT(runtime/references) // mentioned above, if the URBG width is a divisor of `kTotalWidth`, then // there would be no need for any large iterations (i.e., one loop would // suffice), and indeed, in this case, `kLargeIters` would be zero. - constexpr size_t kLargeIters = kTotalWidth % kSmallWidth; - constexpr size_t kSmallIters = - (kTotalWidth - (kLargeWidth * kLargeIters)) / kSmallWidth; + static_assert(kResultBits == kSmallIters * kSmallBits + + (kTotalIters - kSmallIters) * kLargeBits, + "Error in looping constant calculations."); - static_assert( - kTotalWidth == kSmallIters * kSmallWidth + kLargeIters * kLargeWidth, - "Error in looping constant calculations."); + // The small shift is essentially small bits, but due to the potential + // of generating a smaller result_type from a larger urbg type, the actual + // shift might be 0. + static constexpr size_t kSmallShift = kSmallBits % kResultBits; + static constexpr auto kSmallMask = + MaskFromShift<urbg_result_type>(kSmallShift); + static constexpr size_t kLargeShift = kLargeBits % kResultBits; + static constexpr auto kLargeMask = + MaskFromShift<urbg_result_type>(kLargeShift); - result_type s = 0; + static constexpr auto kMin = (URBG::min)(); - constexpr size_t kSmallShift = kSmallWidth % kTotalWidth; - constexpr result_type kSmallMask = MaskFromShift(result_type{kSmallShift}); + result_type s = 0; for (size_t n = 0; n < kSmallIters; ++n) { - s = (s << kSmallShift) + - (static_cast<result_type>(PowerOfTwoVariate(g)) & kSmallMask); - } + urbg_result_type v; + do { + v = g() - kMin; + } while (v >= kSmallRejection); - constexpr size_t kLargeShift = kLargeWidth % kTotalWidth; - constexpr result_type kLargeMask = MaskFromShift(result_type{kLargeShift}); - for (size_t n = 0; n < kLargeIters; ++n) { - s = (s << kLargeShift) + - (static_cast<result_type>(PowerOfTwoVariate(g)) & kLargeMask); + s = (s << kSmallShift) + static_cast<result_type>(v & kSmallMask); } - static_assert( - kLargeShift == kSmallShift + 1 || - (kLargeShift == 0 && - kSmallShift == std::numeric_limits<result_type>::digits - 1), - "Error in looping constant calculations"); + for (size_t n = kSmallIters; n < kTotalIters; ++n) { + urbg_result_type v; + do { + v = g() - kMin; + } while (v >= kLargeRejection); + s = (s << kLargeShift) + static_cast<result_type>(v & kLargeMask); + } return s; } diff --git a/absl/random/internal/fast_uniform_bits_test.cc b/absl/random/internal/fast_uniform_bits_test.cc index f5b837e5..cee702df 100644 --- a/absl/random/internal/fast_uniform_bits_test.cc +++ b/absl/random/internal/fast_uniform_bits_test.cc @@ -34,8 +34,8 @@ TYPED_TEST(FastUniformBitsTypedTest, BasicTest) { using Limits = std::numeric_limits<TypeParam>; using FastBits = FastUniformBits<TypeParam>; - EXPECT_EQ(0, FastBits::min()); - EXPECT_EQ(Limits::max(), FastBits::max()); + EXPECT_EQ(0, (FastBits::min)()); + EXPECT_EQ((Limits::max)(), (FastBits::max)()); constexpr int kIters = 10000; std::random_device rd; @@ -43,8 +43,8 @@ TYPED_TEST(FastUniformBitsTypedTest, BasicTest) { FastBits fast; for (int i = 0; i < kIters; i++) { const auto v = fast(gen); - EXPECT_LE(v, FastBits::max()); - EXPECT_GE(v, FastBits::min()); + EXPECT_LE(v, (FastBits::max)()); + EXPECT_GE(v, (FastBits::min)()); } } @@ -52,21 +52,26 @@ template <typename UIntType, UIntType Lo, UIntType Hi, UIntType Val = Lo> struct FakeUrbg { using result_type = UIntType; + FakeUrbg() = default; + explicit FakeUrbg(bool r) : reject(r) {} + static constexpr result_type(max)() { return Hi; } static constexpr result_type(min)() { return Lo; } - result_type operator()() { return Val; } -}; + result_type operator()() { + // when reject is set, return Hi half the time. + return ((++calls % 2) == 1 && reject) ? Hi : Val; + } -using UrngOddbits = FakeUrbg<uint8_t, 1, 0xfe, 0x73>; -using Urng4bits = FakeUrbg<uint8_t, 1, 0x10, 2>; -using Urng31bits = FakeUrbg<uint32_t, 1, 0xfffffffe, 0x60070f03>; -using Urng32bits = FakeUrbg<uint32_t, 0, 0xffffffff, 0x74010f01>; + bool reject = false; + size_t calls = 0; +}; TEST(FastUniformBitsTest, IsPowerOfTwoOrZero) { EXPECT_TRUE(IsPowerOfTwoOrZero(uint8_t{0})); EXPECT_TRUE(IsPowerOfTwoOrZero(uint8_t{1})); EXPECT_TRUE(IsPowerOfTwoOrZero(uint8_t{2})); EXPECT_FALSE(IsPowerOfTwoOrZero(uint8_t{3})); + EXPECT_TRUE(IsPowerOfTwoOrZero(uint8_t{4})); EXPECT_TRUE(IsPowerOfTwoOrZero(uint8_t{16})); EXPECT_FALSE(IsPowerOfTwoOrZero(uint8_t{17})); EXPECT_FALSE(IsPowerOfTwoOrZero((std::numeric_limits<uint8_t>::max)())); @@ -75,6 +80,7 @@ TEST(FastUniformBitsTest, IsPowerOfTwoOrZero) { EXPECT_TRUE(IsPowerOfTwoOrZero(uint16_t{1})); EXPECT_TRUE(IsPowerOfTwoOrZero(uint16_t{2})); EXPECT_FALSE(IsPowerOfTwoOrZero(uint16_t{3})); + EXPECT_TRUE(IsPowerOfTwoOrZero(uint16_t{4})); EXPECT_TRUE(IsPowerOfTwoOrZero(uint16_t{16})); EXPECT_FALSE(IsPowerOfTwoOrZero(uint16_t{17})); EXPECT_FALSE(IsPowerOfTwoOrZero((std::numeric_limits<uint16_t>::max)())); @@ -91,181 +97,237 @@ TEST(FastUniformBitsTest, IsPowerOfTwoOrZero) { EXPECT_TRUE(IsPowerOfTwoOrZero(uint64_t{1})); EXPECT_TRUE(IsPowerOfTwoOrZero(uint64_t{2})); EXPECT_FALSE(IsPowerOfTwoOrZero(uint64_t{3})); + EXPECT_TRUE(IsPowerOfTwoOrZero(uint64_t{4})); EXPECT_TRUE(IsPowerOfTwoOrZero(uint64_t{64})); EXPECT_FALSE(IsPowerOfTwoOrZero(uint64_t{17})); EXPECT_FALSE(IsPowerOfTwoOrZero((std::numeric_limits<uint64_t>::max)())); } TEST(FastUniformBitsTest, IntegerLog2) { - EXPECT_EQ(IntegerLog2(uint16_t{0}), 0); - EXPECT_EQ(IntegerLog2(uint16_t{1}), 0); - EXPECT_EQ(IntegerLog2(uint16_t{2}), 1); - EXPECT_EQ(IntegerLog2(uint16_t{3}), 1); - EXPECT_EQ(IntegerLog2(uint16_t{4}), 2); - EXPECT_EQ(IntegerLog2(uint16_t{5}), 2); - EXPECT_EQ(IntegerLog2(std::numeric_limits<uint64_t>::max()), 63); + EXPECT_EQ(0, IntegerLog2(uint16_t{0})); + EXPECT_EQ(0, IntegerLog2(uint16_t{1})); + EXPECT_EQ(1, IntegerLog2(uint16_t{2})); + EXPECT_EQ(1, IntegerLog2(uint16_t{3})); + EXPECT_EQ(2, IntegerLog2(uint16_t{4})); + EXPECT_EQ(2, IntegerLog2(uint16_t{5})); + EXPECT_EQ(2, IntegerLog2(uint16_t{7})); + EXPECT_EQ(3, IntegerLog2(uint16_t{8})); + EXPECT_EQ(63, IntegerLog2((std::numeric_limits<uint64_t>::max)())); } TEST(FastUniformBitsTest, RangeSize) { - EXPECT_EQ((RangeSize<FakeUrbg<uint8_t, 0, 3>>()), 4); - EXPECT_EQ((RangeSize<FakeUrbg<uint8_t, 2, 2>>()), 1); - EXPECT_EQ((RangeSize<FakeUrbg<uint8_t, 2, 5>>()), 4); - EXPECT_EQ((RangeSize<FakeUrbg<uint8_t, 2, 6>>()), 5); - EXPECT_EQ((RangeSize<FakeUrbg<uint8_t, 2, 10>>()), 9); + EXPECT_EQ(2, (RangeSize<FakeUrbg<uint8_t, 0, 1>>())); + EXPECT_EQ(3, (RangeSize<FakeUrbg<uint8_t, 0, 2>>())); + EXPECT_EQ(4, (RangeSize<FakeUrbg<uint8_t, 0, 3>>())); + // EXPECT_EQ(0, (RangeSize<FakeUrbg<uint8_t, 2, 2>>())); + EXPECT_EQ(4, (RangeSize<FakeUrbg<uint8_t, 2, 5>>())); + EXPECT_EQ(5, (RangeSize<FakeUrbg<uint8_t, 2, 6>>())); + EXPECT_EQ(9, (RangeSize<FakeUrbg<uint8_t, 2, 10>>())); EXPECT_EQ( - (RangeSize<FakeUrbg<uint8_t, 0, std::numeric_limits<uint8_t>::max()>>()), - 0); - - EXPECT_EQ((RangeSize<FakeUrbg<uint16_t, 0, 3>>()), 4); - EXPECT_EQ((RangeSize<FakeUrbg<uint16_t, 2, 2>>()), 1); - EXPECT_EQ((RangeSize<FakeUrbg<uint16_t, 2, 5>>()), 4); - EXPECT_EQ((RangeSize<FakeUrbg<uint16_t, 2, 6>>()), 5); - EXPECT_EQ((RangeSize<FakeUrbg<uint16_t, 1000, 1017>>()), 18); - EXPECT_EQ((RangeSize< - FakeUrbg<uint16_t, 0, std::numeric_limits<uint16_t>::max()>>()), - 0); - - EXPECT_EQ((RangeSize<FakeUrbg<uint32_t, 0, 3>>()), 4); - EXPECT_EQ((RangeSize<FakeUrbg<uint32_t, 2, 2>>()), 1); - EXPECT_EQ((RangeSize<FakeUrbg<uint32_t, 2, 5>>()), 4); - EXPECT_EQ((RangeSize<FakeUrbg<uint32_t, 2, 6>>()), 5); - EXPECT_EQ((RangeSize<FakeUrbg<uint32_t, 1000, 1017>>()), 18); - EXPECT_EQ((RangeSize<FakeUrbg<uint32_t, 0, 0xffffffff>>()), 0); - EXPECT_EQ((RangeSize<FakeUrbg<uint32_t, 1, 0xffffffff>>()), 0xffffffff); - EXPECT_EQ((RangeSize<FakeUrbg<uint32_t, 1, 0xfffffffe>>()), 0xfffffffe); - EXPECT_EQ((RangeSize<FakeUrbg<uint32_t, 2, 0xfffffffe>>()), 0xfffffffd); - EXPECT_EQ((RangeSize< - FakeUrbg<uint32_t, 0, std::numeric_limits<uint32_t>::max()>>()), - 0); - - EXPECT_EQ((RangeSize<FakeUrbg<uint64_t, 0, 3>>()), 4); - EXPECT_EQ((RangeSize<FakeUrbg<uint64_t, 2, 2>>()), 1); - EXPECT_EQ((RangeSize<FakeUrbg<uint64_t, 2, 5>>()), 4); - EXPECT_EQ((RangeSize<FakeUrbg<uint64_t, 2, 6>>()), 5); - EXPECT_EQ((RangeSize<FakeUrbg<uint64_t, 1000, 1017>>()), 18); - EXPECT_EQ((RangeSize<FakeUrbg<uint64_t, 0, 0xffffffff>>()), 0x100000000ull); - EXPECT_EQ((RangeSize<FakeUrbg<uint64_t, 1, 0xffffffff>>()), 0xffffffffull); - EXPECT_EQ((RangeSize<FakeUrbg<uint64_t, 1, 0xfffffffe>>()), 0xfffffffeull); - EXPECT_EQ((RangeSize<FakeUrbg<uint64_t, 2, 0xfffffffe>>()), 0xfffffffdull); - EXPECT_EQ((RangeSize<FakeUrbg<uint64_t, 0, 0xffffffffffffffffull>>()), 0ull); - EXPECT_EQ((RangeSize<FakeUrbg<uint64_t, 1, 0xffffffffffffffffull>>()), - 0xffffffffffffffffull); - EXPECT_EQ((RangeSize<FakeUrbg<uint64_t, 1, 0xfffffffffffffffeull>>()), - 0xfffffffffffffffeull); - EXPECT_EQ((RangeSize<FakeUrbg<uint64_t, 2, 0xfffffffffffffffeull>>()), - 0xfffffffffffffffdull); - EXPECT_EQ((RangeSize< - FakeUrbg<uint64_t, 0, std::numeric_limits<uint64_t>::max()>>()), - 0); -} + 0, (RangeSize< + FakeUrbg<uint8_t, 0, (std::numeric_limits<uint8_t>::max)()>>())); -TEST(FastUniformBitsTest, PowerOfTwoSubRangeSize) { - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint8_t, 0, 3>>()), 4); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint8_t, 2, 2>>()), 1); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint8_t, 2, 5>>()), 4); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint8_t, 2, 6>>()), 4); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint8_t, 2, 10>>()), 8); - EXPECT_EQ((PowerOfTwoSubRangeSize< - FakeUrbg<uint8_t, 0, std::numeric_limits<uint8_t>::max()>>()), - 0); - - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint16_t, 0, 3>>()), 4); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint16_t, 2, 2>>()), 1); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint16_t, 2, 5>>()), 4); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint16_t, 2, 6>>()), 4); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint16_t, 1000, 1017>>()), 16); - EXPECT_EQ((PowerOfTwoSubRangeSize< - FakeUrbg<uint16_t, 0, std::numeric_limits<uint16_t>::max()>>()), - 0); - - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint32_t, 0, 3>>()), 4); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint32_t, 2, 2>>()), 1); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint32_t, 2, 5>>()), 4); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint32_t, 2, 6>>()), 4); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint32_t, 1000, 1017>>()), 16); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint32_t, 0, 0xffffffff>>()), 0); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint32_t, 1, 0xffffffff>>()), - 0x80000000); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint32_t, 1, 0xfffffffe>>()), - 0x80000000); - EXPECT_EQ((PowerOfTwoSubRangeSize< - FakeUrbg<uint32_t, 0, std::numeric_limits<uint32_t>::max()>>()), - 0); - - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint64_t, 0, 3>>()), 4); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint64_t, 2, 2>>()), 1); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint64_t, 2, 5>>()), 4); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint64_t, 2, 6>>()), 4); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint64_t, 1000, 1017>>()), 16); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint64_t, 0, 0xffffffff>>()), - 0x100000000ull); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint64_t, 1, 0xffffffff>>()), - 0x80000000ull); - EXPECT_EQ((PowerOfTwoSubRangeSize<FakeUrbg<uint64_t, 1, 0xfffffffe>>()), - 0x80000000ull); + EXPECT_EQ(4, (RangeSize<FakeUrbg<uint16_t, 0, 3>>())); + EXPECT_EQ(4, (RangeSize<FakeUrbg<uint16_t, 2, 5>>())); + EXPECT_EQ(5, (RangeSize<FakeUrbg<uint16_t, 2, 6>>())); + EXPECT_EQ(18, (RangeSize<FakeUrbg<uint16_t, 1000, 1017>>())); EXPECT_EQ( - (PowerOfTwoSubRangeSize<FakeUrbg<uint64_t, 0, 0xffffffffffffffffull>>()), - 0); + 0, (RangeSize< + FakeUrbg<uint16_t, 0, (std::numeric_limits<uint16_t>::max)()>>())); + + EXPECT_EQ(4, (RangeSize<FakeUrbg<uint32_t, 0, 3>>())); + EXPECT_EQ(4, (RangeSize<FakeUrbg<uint32_t, 2, 5>>())); + EXPECT_EQ(5, (RangeSize<FakeUrbg<uint32_t, 2, 6>>())); + EXPECT_EQ(18, (RangeSize<FakeUrbg<uint32_t, 1000, 1017>>())); + EXPECT_EQ(0, (RangeSize<FakeUrbg<uint32_t, 0, 0xffffffff>>())); + EXPECT_EQ(0xffffffff, (RangeSize<FakeUrbg<uint32_t, 1, 0xffffffff>>())); + EXPECT_EQ(0xfffffffe, (RangeSize<FakeUrbg<uint32_t, 1, 0xfffffffe>>())); + EXPECT_EQ(0xfffffffd, (RangeSize<FakeUrbg<uint32_t, 2, 0xfffffffe>>())); EXPECT_EQ( - (PowerOfTwoSubRangeSize<FakeUrbg<uint64_t, 1, 0xffffffffffffffffull>>()), - 0x8000000000000000ull); + 0, (RangeSize< + FakeUrbg<uint32_t, 0, (std::numeric_limits<uint32_t>::max)()>>())); + + EXPECT_EQ(4, (RangeSize<FakeUrbg<uint64_t, 0, 3>>())); + EXPECT_EQ(4, (RangeSize<FakeUrbg<uint64_t, 2, 5>>())); + EXPECT_EQ(5, (RangeSize<FakeUrbg<uint64_t, 2, 6>>())); + EXPECT_EQ(18, (RangeSize<FakeUrbg<uint64_t, 1000, 1017>>())); + EXPECT_EQ(0x100000000, (RangeSize<FakeUrbg<uint64_t, 0, 0xffffffff>>())); + EXPECT_EQ(0xffffffff, (RangeSize<FakeUrbg<uint64_t, 1, 0xffffffff>>())); + EXPECT_EQ(0xfffffffe, (RangeSize<FakeUrbg<uint64_t, 1, 0xfffffffe>>())); + EXPECT_EQ(0xfffffffd, (RangeSize<FakeUrbg<uint64_t, 2, 0xfffffffe>>())); + EXPECT_EQ(0, (RangeSize<FakeUrbg<uint64_t, 0, 0xffffffffffffffff>>())); + EXPECT_EQ(0xffffffffffffffff, + (RangeSize<FakeUrbg<uint64_t, 1, 0xffffffffffffffff>>())); + EXPECT_EQ(0xfffffffffffffffe, + (RangeSize<FakeUrbg<uint64_t, 1, 0xfffffffffffffffe>>())); + EXPECT_EQ(0xfffffffffffffffd, + (RangeSize<FakeUrbg<uint64_t, 2, 0xfffffffffffffffe>>())); EXPECT_EQ( - (PowerOfTwoSubRangeSize<FakeUrbg<uint64_t, 1, 0xfffffffffffffffeull>>()), - 0x8000000000000000ull); - EXPECT_EQ((PowerOfTwoSubRangeSize< - FakeUrbg<uint64_t, 0, std::numeric_limits<uint64_t>::max()>>()), - 0); + 0, (RangeSize< + FakeUrbg<uint64_t, 0, (std::numeric_limits<uint64_t>::max)()>>())); } -TEST(FastUniformBitsTest, Urng4_VariousOutputs) { +// The constants need to be choosen so that an infinite rejection loop doesn't +// happen... +using Urng1_5bit = FakeUrbg<uint8_t, 0, 2, 0>; // ~1.5 bits (range 3) +using Urng4bits = FakeUrbg<uint8_t, 1, 0x10, 2>; +using Urng22bits = FakeUrbg<uint32_t, 0, 0x3fffff, 0x301020>; +using Urng31bits = FakeUrbg<uint32_t, 1, 0xfffffffe, 0x60070f03>; // ~31.9 bits +using Urng32bits = FakeUrbg<uint32_t, 0, 0xffffffff, 0x74010f01>; +using Urng33bits = + FakeUrbg<uint64_t, 1, 0x1ffffffff, 0x013301033>; // ~32.9 bits +using Urng63bits = FakeUrbg<uint64_t, 1, 0xfffffffffffffffe, + 0xfedcba9012345678>; // ~63.9 bits +using Urng64bits = + FakeUrbg<uint64_t, 0, 0xffffffffffffffff, 0x123456780fedcba9>; + +TEST(FastUniformBitsTest, OutputsUpTo32Bits) { // Tests that how values are composed; the single-bit deltas should be spread // across each invocation. + Urng1_5bit urng1_5; Urng4bits urng4; + Urng22bits urng22; Urng31bits urng31; Urng32bits urng32; + Urng33bits urng33; + Urng63bits urng63; + Urng64bits urng64; // 8-bit types { FastUniformBits<uint8_t> fast8; + EXPECT_EQ(0x0, fast8(urng1_5)); EXPECT_EQ(0x11, fast8(urng4)); + EXPECT_EQ(0x20, fast8(urng22)); EXPECT_EQ(0x2, fast8(urng31)); EXPECT_EQ(0x1, fast8(urng32)); + EXPECT_EQ(0x32, fast8(urng33)); + EXPECT_EQ(0x77, fast8(urng63)); + EXPECT_EQ(0xa9, fast8(urng64)); } // 16-bit types { FastUniformBits<uint16_t> fast16; + EXPECT_EQ(0x0, fast16(urng1_5)); EXPECT_EQ(0x1111, fast16(urng4)); - EXPECT_EQ(0xf02, fast16(urng31)); - EXPECT_EQ(0xf01, fast16(urng32)); + EXPECT_EQ(0x1020, fast16(urng22)); + EXPECT_EQ(0x0f02, fast16(urng31)); + EXPECT_EQ(0x0f01, fast16(urng32)); + EXPECT_EQ(0x1032, fast16(urng33)); + EXPECT_EQ(0x5677, fast16(urng63)); + EXPECT_EQ(0xcba9, fast16(urng64)); } // 32-bit types { FastUniformBits<uint32_t> fast32; + EXPECT_EQ(0x0, fast32(urng1_5)); EXPECT_EQ(0x11111111, fast32(urng4)); + EXPECT_EQ(0x08301020, fast32(urng22)); EXPECT_EQ(0x0f020f02, fast32(urng31)); EXPECT_EQ(0x74010f01, fast32(urng32)); + EXPECT_EQ(0x13301032, fast32(urng33)); + EXPECT_EQ(0x12345677, fast32(urng63)); + EXPECT_EQ(0x0fedcba9, fast32(urng64)); } +} + +TEST(FastUniformBitsTest, Outputs64Bits) { + // Tests that how values are composed; the single-bit deltas should be spread + // across each invocation. + FastUniformBits<uint64_t> fast64; - // 64-bit types { - FastUniformBits<uint64_t> fast64; + FakeUrbg<uint8_t, 0, 1, 0> urng0; + FakeUrbg<uint8_t, 0, 1, 1> urng1; + Urng4bits urng4; + Urng22bits urng22; + Urng31bits urng31; + Urng32bits urng32; + Urng33bits urng33; + Urng63bits urng63; + Urng64bits urng64; + + // somewhat degenerate cases only create a single bit. + EXPECT_EQ(0x0, fast64(urng0)); + EXPECT_EQ(64, urng0.calls); + EXPECT_EQ(0xffffffffffffffff, fast64(urng1)); + EXPECT_EQ(64, urng1.calls); + + // less degenerate cases. EXPECT_EQ(0x1111111111111111, fast64(urng4)); + EXPECT_EQ(16, urng4.calls); + EXPECT_EQ(0x01020c0408301020, fast64(urng22)); + EXPECT_EQ(3, urng22.calls); EXPECT_EQ(0x387811c3c0870f02, fast64(urng31)); + EXPECT_EQ(3, urng31.calls); EXPECT_EQ(0x74010f0174010f01, fast64(urng32)); + EXPECT_EQ(2, urng32.calls); + EXPECT_EQ(0x808194040cb01032, fast64(urng33)); + EXPECT_EQ(3, urng33.calls); + EXPECT_EQ(0x1234567712345677, fast64(urng63)); + EXPECT_EQ(2, urng63.calls); + EXPECT_EQ(0x123456780fedcba9, fast64(urng64)); + EXPECT_EQ(1, urng64.calls); + } + + // The 1.5 bit case is somewhat interesting in that the algorithm refinement + // causes one extra small sample. Comments here reference the names used in + // [rand.adapt.ibits] that correspond to this case. + { + Urng1_5bit urng1_5; + + // w = 64 + // R = 3 + // m = 1 + // n' = 64 + // w0' = 1 + // y0' = 2 + // n = (1 <= 0) > 64 : 65 = 65 + // n0 = 65 - (64%65) = 1 + // n1 = 64 + // w0 = 0 + // y0 = 3 + // w1 = 1 + // y1 = 2 + EXPECT_EQ(0x0, fast64(urng1_5)); + EXPECT_EQ(65, urng1_5.calls); + } + + // Validate rejections for non-power-of-2 cases. + { + Urng1_5bit urng1_5(true); + Urng31bits urng31(true); + Urng33bits urng33(true); + Urng63bits urng63(true); + + // For 1.5 bits, there would be 1+2*64, except the first + // value was accepted and shifted off the end. + EXPECT_EQ(0, fast64(urng1_5)); + EXPECT_EQ(128, urng1_5.calls); + EXPECT_EQ(0x387811c3c0870f02, fast64(urng31)); + EXPECT_EQ(6, urng31.calls); + EXPECT_EQ(0x808194040cb01032, fast64(urng33)); + EXPECT_EQ(6, urng33.calls); + EXPECT_EQ(0x1234567712345677, fast64(urng63)); + EXPECT_EQ(4, urng63.calls); } } TEST(FastUniformBitsTest, URBG32bitRegression) { // Validate with deterministic 32-bit std::minstd_rand // to ensure that operator() performs as expected. + + EXPECT_EQ(2147483646, RangeSize<std::minstd_rand>()); + EXPECT_EQ(30, IntegerLog2(RangeSize<std::minstd_rand>())); + std::minstd_rand gen(1); FastUniformBits<uint64_t> fast64; - EXPECT_EQ(0x05e47095f847c122ull, fast64(gen)); - EXPECT_EQ(0x8f82c1ba30b64d22ull, fast64(gen)); - EXPECT_EQ(0x3b971a3558155039ull, fast64(gen)); + EXPECT_EQ(0x05e47095f8791f45, fast64(gen)); + EXPECT_EQ(0x028be17e3c07c122, fast64(gen)); + EXPECT_EQ(0x55d2847c1626e8c2, fast64(gen)); } } // namespace diff --git a/absl/synchronization/mutex.h b/absl/synchronization/mutex.h index 876698ca..52401fe3 100644 --- a/absl/synchronization/mutex.h +++ b/absl/synchronization/mutex.h @@ -685,6 +685,11 @@ class Condition { // return processed_ >= current; // }; // mu_.Await(Condition(&reached)); + // + // NOTE: never use "mu_.AssertHeld()" instead of "mu_.AssertReadHeld()" in the + // lambda as it may be called when the mutex is being unlocked from a scope + // holding only a reader lock, which will make the assertion not fulfilled and + // crash the binary. // See class comment for performance advice. In particular, if there // might be more than one waiter for the same condition, make sure diff --git a/absl/time/internal/cctz/src/time_zone_format.cc b/absl/time/internal/cctz/src/time_zone_format.cc index 2e02233c..d8cb0474 100644 --- a/absl/time/internal/cctz/src/time_zone_format.cc +++ b/absl/time/internal/cctz/src/time_zone_format.cc @@ -654,14 +654,23 @@ const char* ParseTM(const char* dp, const char* fmt, std::tm* tm) { } // Sets year, tm_mon and tm_mday given the year, week_num, and tm_wday, -// and the day on which weeks are defined to start. -void FromWeek(int week_num, weekday week_start, year_t* year, std::tm* tm) { +// and the day on which weeks are defined to start. Returns false if year +// would need to move outside its bounds. +bool FromWeek(int week_num, weekday week_start, year_t* year, std::tm* tm) { const civil_year y(*year % 400); civil_day cd = prev_weekday(y, week_start); // week 0 cd = next_weekday(cd - 1, FromTmWday(tm->tm_wday)) + (week_num * 7); - *year += cd.year() - y.year(); + if (const year_t shift = cd.year() - y.year()) { + if (shift > 0) { + if (*year > std::numeric_limits<year_t>::max() - shift) return false; + } else { + if (*year < std::numeric_limits<year_t>::min() - shift) return false; + } + *year += shift; + } tm->tm_mon = cd.month() - 1; tm->tm_mday = cd.day(); + return true; } } // namespace @@ -965,7 +974,12 @@ bool parse(const std::string& format, const std::string& input, } // Compute year, tm.tm_mon and tm.tm_mday if we parsed a week number. - if (week_num != -1) FromWeek(week_num, week_start, &year, &tm); + if (week_num != -1) { + if (!FromWeek(week_num, week_start, &year, &tm)) { + if (err != nullptr) *err = "Out-of-range field"; + return false; + } + } const int month = tm.tm_mon + 1; civil_second cs(year, month, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec); diff --git a/absl/time/internal/cctz/src/time_zone_format_test.cc b/absl/time/internal/cctz/src/time_zone_format_test.cc index e625a839..a11f93e2 100644 --- a/absl/time/internal/cctz/src/time_zone_format_test.cc +++ b/absl/time/internal/cctz/src/time_zone_format_test.cc @@ -1481,6 +1481,11 @@ TEST(Parse, WeekYearShift) { EXPECT_EQ(exp, tp); EXPECT_TRUE(parse("%Y-%W-%w", "2020-52-5", utc, &tp)); EXPECT_EQ(exp, tp); + + // Slipping into the previous/following calendar years should fail when + // we're already at the extremes. + EXPECT_FALSE(parse("%Y-%U-%u", "-9223372036854775808-0-7", utc, &tp)); + EXPECT_FALSE(parse("%Y-%U-%u", "9223372036854775807-53-7", utc, &tp)); } TEST(Parse, MaxRange) { diff --git a/absl/time/internal/cctz/src/time_zone_libc.cc b/absl/time/internal/cctz/src/time_zone_libc.cc index 47cf84c6..3fcc75bd 100644 --- a/absl/time/internal/cctz/src/time_zone_libc.cc +++ b/absl/time/internal/cctz/src/time_zone_libc.cc @@ -223,11 +223,10 @@ time_zone::civil_lookup TimeZoneLibC::MakeTime(const civil_second& cs) const { civil_second() + ToUnixSeconds(time_point<seconds>::min()); static const civil_second max_tp_cs = civil_second() + ToUnixSeconds(time_point<seconds>::max()); - const time_point<seconds> tp = - (cs < min_tp_cs) - ? time_point<seconds>::min() - : (cs > max_tp_cs) ? time_point<seconds>::max() - : FromUnixSeconds(cs - civil_second()); + const time_point<seconds> tp = (cs < min_tp_cs) ? time_point<seconds>::min() + : (cs > max_tp_cs) + ? time_point<seconds>::max() + : FromUnixSeconds(cs - civil_second()); return {time_zone::civil_lookup::UNIQUE, tp, tp, tp}; } diff --git a/absl/time/internal/cctz/src/tzfile.h b/absl/time/internal/cctz/src/tzfile.h index 269fa36c..659f84cf 100644 --- a/absl/time/internal/cctz/src/tzfile.h +++ b/absl/time/internal/cctz/src/tzfile.h @@ -108,15 +108,15 @@ struct tzhead { #ifndef TZ_MAX_TYPES /* This must be at least 17 for Europe/Samara and Europe/Vilnius. */ #define TZ_MAX_TYPES 256 /* Limited by what (unsigned char)'s can hold */ -#endif /* !defined TZ_MAX_TYPES */ +#endif /* !defined TZ_MAX_TYPES */ #ifndef TZ_MAX_CHARS #define TZ_MAX_CHARS 50 /* Maximum number of abbreviation characters */ - /* (limited by what unsigned chars can hold) */ -#endif /* !defined TZ_MAX_CHARS */ +/* (limited by what unsigned chars can hold) */ +#endif /* !defined TZ_MAX_CHARS */ #ifndef TZ_MAX_LEAPS #define TZ_MAX_LEAPS 50 /* Maximum number of leap second corrections */ -#endif /* !defined TZ_MAX_LEAPS */ +#endif /* !defined TZ_MAX_LEAPS */ #endif /* !defined TZFILE_H */ diff --git a/absl/types/CMakeLists.txt b/absl/types/CMakeLists.txt index 0dc0d2c7..3f99ad8a 100644 --- a/absl/types/CMakeLists.txt +++ b/absl/types/CMakeLists.txt @@ -259,7 +259,7 @@ absl_cc_library( absl::strings absl::utility gmock_main - PUBLIC + TESTONLY ) absl_cc_test( |