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-rw-r--r--absl/base/internal/low_level_alloc.cc4
-rw-r--r--absl/copts/GENERATED_AbseilCopts.cmake2
-rw-r--r--absl/copts/GENERATED_copts.bzl2
-rw-r--r--absl/copts/copts.py1
-rw-r--r--absl/hash/BUILD.bazel2
-rw-r--r--absl/hash/hash_test.cc114
-rw-r--r--absl/hash/internal/hash.cc30
-rw-r--r--absl/hash/internal/hash.h121
-rw-r--r--absl/hash/internal/spy_hash_state.h13
-rw-r--r--absl/strings/str_cat.h3
-rw-r--r--absl/synchronization/internal/create_thread_identity.cc1
11 files changed, 278 insertions, 15 deletions
diff --git a/absl/base/internal/low_level_alloc.cc b/absl/base/internal/low_level_alloc.cc
index f7314ab1..a0638f9e 100644
--- a/absl/base/internal/low_level_alloc.cc
+++ b/absl/base/internal/low_level_alloc.cc
@@ -447,7 +447,7 @@ static inline uintptr_t RoundUp(uintptr_t addr, uintptr_t align) {
// that the freelist is in the correct order, that it
// consists of regions marked "unallocated", and that no two regions
// are adjacent in memory (they should have been coalesced).
-// L < arena->mu
+// L >= arena->mu
static AllocList *Next(int i, AllocList *prev, LowLevelAlloc::Arena *arena) {
ABSL_RAW_CHECK(i < prev->levels, "too few levels in Next()");
AllocList *next = prev->next[i];
@@ -508,8 +508,6 @@ void LowLevelAlloc::Free(void *v) {
if (v != nullptr) {
AllocList *f = reinterpret_cast<AllocList *>(
reinterpret_cast<char *>(v) - sizeof (f->header));
- ABSL_RAW_CHECK(f->header.magic == Magic(kMagicAllocated, &f->header),
- "bad magic number in Free()");
LowLevelAlloc::Arena *arena = f->header.arena;
ArenaLock section(arena);
AddToFreelist(v, arena);
diff --git a/absl/copts/GENERATED_AbseilCopts.cmake b/absl/copts/GENERATED_AbseilCopts.cmake
index 39b79c53..7ef6339b 100644
--- a/absl/copts/GENERATED_AbseilCopts.cmake
+++ b/absl/copts/GENERATED_AbseilCopts.cmake
@@ -23,7 +23,6 @@ list(APPEND ABSL_CLANG_CL_FLAGS
"-Wno-gcc-compat"
"-Wno-global-constructors"
"-Wno-exit-time-destructors"
- "-Wno-nested-anon-types"
"-Wno-non-modular-include-in-module"
"-Wno-old-style-cast"
"-Wno-range-loop-analysis"
@@ -123,7 +122,6 @@ list(APPEND ABSL_LLVM_FLAGS
"-Wno-gcc-compat"
"-Wno-global-constructors"
"-Wno-exit-time-destructors"
- "-Wno-nested-anon-types"
"-Wno-non-modular-include-in-module"
"-Wno-old-style-cast"
"-Wno-range-loop-analysis"
diff --git a/absl/copts/GENERATED_copts.bzl b/absl/copts/GENERATED_copts.bzl
index 7d645cc3..3cc48784 100644
--- a/absl/copts/GENERATED_copts.bzl
+++ b/absl/copts/GENERATED_copts.bzl
@@ -24,7 +24,6 @@ ABSL_CLANG_CL_FLAGS = [
"-Wno-gcc-compat",
"-Wno-global-constructors",
"-Wno-exit-time-destructors",
- "-Wno-nested-anon-types",
"-Wno-non-modular-include-in-module",
"-Wno-old-style-cast",
"-Wno-range-loop-analysis",
@@ -124,7 +123,6 @@ ABSL_LLVM_FLAGS = [
"-Wno-gcc-compat",
"-Wno-global-constructors",
"-Wno-exit-time-destructors",
- "-Wno-nested-anon-types",
"-Wno-non-modular-include-in-module",
"-Wno-old-style-cast",
"-Wno-range-loop-analysis",
diff --git a/absl/copts/copts.py b/absl/copts/copts.py
index a5425415..704ef234 100644
--- a/absl/copts/copts.py
+++ b/absl/copts/copts.py
@@ -56,7 +56,6 @@ LLVM_DISABLE_WARNINGS_FLAGS = [
"-Wno-global-constructors",
"-Wno-exit-time-destructors",
###
- "-Wno-nested-anon-types",
"-Wno-non-modular-include-in-module",
"-Wno-old-style-cast",
# Warns on preferred usage of non-POD types such as string_view
diff --git a/absl/hash/BUILD.bazel b/absl/hash/BUILD.bazel
index c51248a5..ffe8c294 100644
--- a/absl/hash/BUILD.bazel
+++ b/absl/hash/BUILD.bazel
@@ -71,9 +71,9 @@ cc_test(
deps = [
":hash",
":hash_testing",
+ ":spy_hash_state",
"//absl/base:core_headers",
"//absl/container:flat_hash_set",
- "//absl/hash:spy_hash_state",
"//absl/meta:type_traits",
"//absl/numeric:int128",
"@com_google_googletest//:gtest_main",
diff --git a/absl/hash/hash_test.cc b/absl/hash/hash_test.cc
index 9a667ba7..61f7661f 100644
--- a/absl/hash/hash_test.cc
+++ b/absl/hash/hash_test.cc
@@ -274,8 +274,8 @@ TEST(HashValueTest, Strings) {
const std::string small = "foo";
const std::string dup = "foofoo";
- const std::string large = "large";
- const std::string huge = std::string(5000, 'a');
+ const std::string large = std::string(2048, 'x'); // multiple of chunk size
+ const std::string huge = std::string(5000, 'a'); // not a multiple
EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(std::make_tuple(
std::string(), absl::string_view(),
@@ -378,6 +378,116 @@ struct Private {
}
};
+// Test helper for combine_piecewise_buffer. It holds a string_view to the
+// buffer-to-be-hashed. Its AbslHashValue specialization will split up its
+// contents at the character offsets requested.
+class PiecewiseHashTester {
+ public:
+ // Create a hash view of a buffer to be hashed contiguously.
+ explicit PiecewiseHashTester(absl::string_view buf)
+ : buf_(buf), piecewise_(false), split_locations_() {}
+
+ // Create a hash view of a buffer to be hashed piecewise, with breaks at the
+ // given locations.
+ PiecewiseHashTester(absl::string_view buf, std::set<size_t> split_locations)
+ : buf_(buf),
+ piecewise_(true),
+ split_locations_(std::move(split_locations)) {}
+
+ template <typename H>
+ friend H AbslHashValue(H h, const PiecewiseHashTester& p) {
+ if (!p.piecewise_) {
+ return H::combine_contiguous(std::move(h), p.buf_.data(), p.buf_.size());
+ }
+ absl::hash_internal::PiecewiseCombiner combiner;
+ if (p.split_locations_.empty()) {
+ h = combiner.add_buffer(std::move(h), p.buf_.data(), p.buf_.size());
+ return combiner.finalize(std::move(h));
+ }
+ size_t begin = 0;
+ for (size_t next : p.split_locations_) {
+ absl::string_view chunk = p.buf_.substr(begin, next - begin);
+ h = combiner.add_buffer(std::move(h), chunk.data(), chunk.size());
+ begin = next;
+ }
+ absl::string_view last_chunk = p.buf_.substr(begin);
+ if (!last_chunk.empty()) {
+ h = combiner.add_buffer(std::move(h), last_chunk.data(),
+ last_chunk.size());
+ }
+ return combiner.finalize(std::move(h));
+ }
+
+ private:
+ absl::string_view buf_;
+ bool piecewise_;
+ std::set<size_t> split_locations_;
+};
+
+// Dummy object that hashes as two distinct contiguous buffers, "foo" followed
+// by "bar"
+struct DummyFooBar {
+ template <typename H>
+ friend H AbslHashValue(H h, const DummyFooBar&) {
+ const char* foo = "foo";
+ const char* bar = "bar";
+ h = H::combine_contiguous(std::move(h), foo, 3);
+ h = H::combine_contiguous(std::move(h), bar, 3);
+ return std::move(h);
+ }
+};
+
+TEST(HashValueTest, CombinePiecewiseBuffer) {
+ absl::Hash<PiecewiseHashTester> hash;
+
+ // Check that hashing an empty buffer through the piecewise API works.
+ EXPECT_EQ(hash(PiecewiseHashTester("")), hash(PiecewiseHashTester("", {})));
+
+ // Similarly, small buffers should give consistent results
+ EXPECT_EQ(hash(PiecewiseHashTester("foobar")),
+ hash(PiecewiseHashTester("foobar", {})));
+ EXPECT_EQ(hash(PiecewiseHashTester("foobar")),
+ hash(PiecewiseHashTester("foobar", {3})));
+
+ // But hashing "foobar" in pieces gives a different answer than hashing "foo"
+ // contiguously, then "bar" contiguously.
+ EXPECT_NE(hash(PiecewiseHashTester("foobar", {3})),
+ absl::Hash<DummyFooBar>()(DummyFooBar{}));
+
+ // Test hashing a large buffer incrementally, broken up in several different
+ // ways. Arrange for breaks on and near the stride boundaries to look for
+ // off-by-one errors in the implementation.
+ //
+ // This test is run on a buffer that is a multiple of the stride size, and one
+ // that isn't.
+ for (size_t big_buffer_size : {1024 * 2 + 512, 1024 * 3}) {
+ SCOPED_TRACE(big_buffer_size);
+ std::string big_buffer;
+ for (int i = 0; i < big_buffer_size; ++i) {
+ // Arbitrary std::string
+ big_buffer.push_back(32 + (i * (i / 3)) % 64);
+ }
+ auto big_buffer_hash = hash(PiecewiseHashTester(big_buffer));
+
+ const int possible_breaks = 9;
+ size_t breaks[possible_breaks] = {1, 512, 1023, 1024, 1025,
+ 1536, 2047, 2048, 2049};
+ for (unsigned test_mask = 0; test_mask < (1u << possible_breaks);
+ ++test_mask) {
+ SCOPED_TRACE(test_mask);
+ std::set<size_t> break_locations;
+ for (int j = 0; j < possible_breaks; ++j) {
+ if (test_mask & (1u << j)) {
+ break_locations.insert(breaks[j]);
+ }
+ }
+ EXPECT_EQ(
+ hash(PiecewiseHashTester(big_buffer, std::move(break_locations))),
+ big_buffer_hash);
+ }
+ }
+}
+
TEST(HashValueTest, PrivateSanity) {
// Sanity check that Private is working as the tests below expect it to work.
EXPECT_TRUE(is_hashable<Private>::value);
diff --git a/absl/hash/internal/hash.cc b/absl/hash/internal/hash.cc
index 4ab7a9f8..c17f3be1 100644
--- a/absl/hash/internal/hash.cc
+++ b/absl/hash/internal/hash.cc
@@ -17,6 +17,36 @@
namespace absl {
namespace hash_internal {
+uint64_t CityHashState::CombineLargeContiguousImpl32(uint64_t state,
+ const unsigned char* first,
+ size_t len) {
+ while (len >= PiecewiseChunkSize()) {
+ state =
+ Mix(state, absl::hash_internal::CityHash32(reinterpret_cast<const char*>(first),
+ PiecewiseChunkSize()));
+ len -= PiecewiseChunkSize();
+ first += PiecewiseChunkSize();
+ }
+ // Handle the remainder.
+ return CombineContiguousImpl(state, first, len,
+ std::integral_constant<int, 4>{});
+}
+
+uint64_t CityHashState::CombineLargeContiguousImpl64(uint64_t state,
+ const unsigned char* first,
+ size_t len) {
+ while (len >= PiecewiseChunkSize()) {
+ state =
+ Mix(state, absl::hash_internal::CityHash64(reinterpret_cast<const char*>(first),
+ PiecewiseChunkSize()));
+ len -= PiecewiseChunkSize();
+ first += PiecewiseChunkSize();
+ }
+ // Handle the remainder.
+ return CombineContiguousImpl(state, first, len,
+ std::integral_constant<int, 8>{});
+}
+
ABSL_CONST_INIT const void* const CityHashState::kSeed = &kSeed;
} // namespace hash_internal
diff --git a/absl/hash/internal/hash.h b/absl/hash/internal/hash.h
index 4ff4a126..e99f8e75 100644
--- a/absl/hash/internal/hash.h
+++ b/absl/hash/internal/hash.h
@@ -52,6 +52,12 @@
namespace absl {
namespace hash_internal {
+class PiecewiseCombiner;
+
+// Internal detail: Large buffers are hashed in smaller chunks. This function
+// returns the size of these chunks.
+constexpr int PiecewiseChunkSize() { return 1024; }
+
// HashStateBase
//
// A hash state object represents an intermediate state in the computation
@@ -68,7 +74,7 @@ namespace hash_internal {
//
// `static H combine_contiguous(H state, const unsigned char*, size_t)`.
//
-// `HashStateBase` will provide a complete implementations for a hash state
+// `HashStateBase` will provide a complete implementation for a hash state
// object in terms of this method.
//
// Example:
@@ -117,6 +123,9 @@ class HashStateBase {
// for-loop instead.
template <typename T>
static H combine_contiguous(H state, const T* data, size_t size);
+
+ private:
+ friend class PiecewiseCombiner;
};
// is_uniquely_represented
@@ -187,6 +196,61 @@ H hash_bytes(H hash_state, const T& value) {
return H::combine_contiguous(std::move(hash_state), start, sizeof(value));
}
+// PiecewiseCombiner
+//
+// PiecewiseCombiner is an internal-only helper class for hashing a piecewise
+// buffer of `char` or `unsigned char` as though it were contiguous. This class
+// provides two methods:
+//
+// H add_buffer(state, data, size)
+// H finalize(state)
+//
+// `add_buffer` can be called zero or more times, followed by a single call to
+// `finalize`. This will produce the same hash expansion as concatenating each
+// buffer piece into a single contiguous buffer, and passing this to
+// `H::combine_contiguous`.
+//
+// Example usage:
+// PiecewiseCombiner combiner;
+// for (const auto& piece : pieces) {
+// state = combiner.add_buffer(std::move(state), piece.data, piece.size);
+// }
+// return combiner.finalize(std::move(state));
+class PiecewiseCombiner {
+ public:
+ PiecewiseCombiner() : position_(0) {}
+ PiecewiseCombiner(const PiecewiseCombiner&) = delete;
+ PiecewiseCombiner& operator=(const PiecewiseCombiner&) = delete;
+
+ // PiecewiseCombiner::add_buffer()
+ //
+ // Appends the given range of bytes to the sequence to be hashed, which may
+ // modify the provided hash state.
+ template <typename H>
+ H add_buffer(H state, const unsigned char* data, size_t size);
+ template <typename H>
+ H add_buffer(H state, const char* data, size_t size) {
+ return add_buffer(std::move(state),
+ reinterpret_cast<const unsigned char*>(data), size);
+ }
+
+ // PiecewiseCombiner::finalize()
+ //
+ // Finishes combining the hash sequence, which may may modify the provided
+ // hash state.
+ //
+ // Once finalize() is called, add_buffer() may no longer be called. The
+ // resulting hash state will be the same as if the pieces passed to
+ // add_buffer() were concatenated into a single flat buffer, and then provided
+ // to H::combine_contiguous().
+ template <typename H>
+ H finalize(H state);
+
+ private:
+ unsigned char buf_[PiecewiseChunkSize()];
+ size_t position_;
+};
+
// -----------------------------------------------------------------------------
// AbslHashValue for Basic Types
// -----------------------------------------------------------------------------
@@ -709,6 +773,16 @@ class CityHashState : public HashStateBase<CityHashState> {
std::integral_constant<int, 8>
/* sizeof_size_t*/);
+ // Slow dispatch path for calls to CombineContiguousImpl with a size argument
+ // larger than PiecewiseChunkSize(). Has the same effect as calling
+ // CombineContiguousImpl() repeatedly with the chunk stride size.
+ static uint64_t CombineLargeContiguousImpl32(uint64_t state,
+ const unsigned char* first,
+ size_t len);
+ static uint64_t CombineLargeContiguousImpl64(uint64_t state,
+ const unsigned char* first,
+ size_t len);
+
// Reads 9 to 16 bytes from p.
// The first 8 bytes are in .first, the rest (zero padded) bytes are in
// .second.
@@ -776,6 +850,9 @@ inline uint64_t CityHashState::CombineContiguousImpl(
// multiplicative hash.
uint64_t v;
if (len > 8) {
+ if (ABSL_PREDICT_FALSE(len > PiecewiseChunkSize())) {
+ return CombineLargeContiguousImpl32(state, first, len);
+ }
v = absl::hash_internal::CityHash32(reinterpret_cast<const char*>(first), len);
} else if (len >= 4) {
v = Read4To8(first, len);
@@ -796,6 +873,9 @@ inline uint64_t CityHashState::CombineContiguousImpl(
// multiplicative hash.
uint64_t v;
if (len > 16) {
+ if (ABSL_PREDICT_FALSE(len > PiecewiseChunkSize())) {
+ return CombineLargeContiguousImpl64(state, first, len);
+ }
v = absl::hash_internal::CityHash64(reinterpret_cast<const char*>(first), len);
} else if (len > 8) {
auto p = Read9To16(first, len);
@@ -812,7 +892,6 @@ inline uint64_t CityHashState::CombineContiguousImpl(
return Mix(state, v);
}
-
struct AggregateBarrier {};
// HashImpl
@@ -849,6 +928,44 @@ template <typename T>
H HashStateBase<H>::combine_contiguous(H state, const T* data, size_t size) {
return hash_internal::hash_range_or_bytes(std::move(state), data, size);
}
+
+// HashStateBase::PiecewiseCombiner::add_buffer()
+template <typename H>
+H PiecewiseCombiner::add_buffer(H state, const unsigned char* data,
+ size_t size) {
+ if (position_ + size < PiecewiseChunkSize()) {
+ // This partial chunk does not fill our existing buffer
+ memcpy(buf_ + position_, data, size);
+ position_ += size;
+ return std::move(state);
+ }
+
+ // Complete the buffer and hash it
+ const size_t bytes_needed = PiecewiseChunkSize() - position_;
+ memcpy(buf_ + position_, data, bytes_needed);
+ state = H::combine_contiguous(std::move(state), buf_, PiecewiseChunkSize());
+ data += bytes_needed;
+ size -= bytes_needed;
+
+ // Hash whatever chunks we can without copying
+ while (size >= PiecewiseChunkSize()) {
+ state = H::combine_contiguous(std::move(state), data, PiecewiseChunkSize());
+ data += PiecewiseChunkSize();
+ size -= PiecewiseChunkSize();
+ }
+ // Fill the buffer with the remainder
+ memcpy(buf_, data, size);
+ position_ = size;
+ return std::move(state);
+}
+
+// HashStateBase::PiecewiseCombiner::finalize()
+template <typename H>
+H PiecewiseCombiner::finalize(H state) {
+ // Hash the remainder left in the buffer, which may be empty
+ return H::combine_contiguous(std::move(state), buf_, position_);
+}
+
} // namespace hash_internal
} // namespace absl
diff --git a/absl/hash/internal/spy_hash_state.h b/absl/hash/internal/spy_hash_state.h
index c4cc8d07..05c7cafe 100644
--- a/absl/hash/internal/spy_hash_state.h
+++ b/absl/hash/internal/spy_hash_state.h
@@ -146,6 +146,19 @@ class SpyHashStateImpl : public HashStateBase<SpyHashStateImpl<T>> {
static SpyHashStateImpl combine_contiguous(SpyHashStateImpl hash_state,
const unsigned char* begin,
size_t size) {
+ const size_t large_chunk_stride = PiecewiseChunkSize();
+ if (size > large_chunk_stride) {
+ // Combining a large contiguous buffer must have the same effect as
+ // doing it piecewise by the stride length, followed by the (possibly
+ // empty) remainder.
+ while (size >= large_chunk_stride) {
+ hash_state = SpyHashStateImpl::combine_contiguous(
+ std::move(hash_state), begin, large_chunk_stride);
+ begin += large_chunk_stride;
+ size -= large_chunk_stride;
+ }
+ }
+
hash_state.hash_representation_.emplace_back(
reinterpret_cast<const char*>(begin), size);
return hash_state;
diff --git a/absl/strings/str_cat.h b/absl/strings/str_cat.h
index a99aac01..663a1945 100644
--- a/absl/strings/str_cat.h
+++ b/absl/strings/str_cat.h
@@ -290,7 +290,8 @@ class AlphaNum {
// StrCat()
// -----------------------------------------------------------------------------
//
-// Merges given strings or numbers, using no delimiter(s).
+// Merges given strings or numbers, using no delimiter(s), returning the merged
+// result as a string.
//
// `StrCat()` is designed to be the fastest possible way to construct a string
// out of a mix of raw C strings, string_views, strings, bool values,
diff --git a/absl/synchronization/internal/create_thread_identity.cc b/absl/synchronization/internal/create_thread_identity.cc
index eef661f2..ec49d1ca 100644
--- a/absl/synchronization/internal/create_thread_identity.cc
+++ b/absl/synchronization/internal/create_thread_identity.cc
@@ -86,7 +86,6 @@ static void ResetThreadIdentity(base_internal::ThreadIdentity* identity) {
pts->wake = false;
pts->cond_waiter = false;
pts->all_locks = nullptr;
- identity->waiter_state = {};
identity->blocked_count_ptr = nullptr;
identity->ticker.store(0, std::memory_order_relaxed);
identity->wait_start.store(0, std::memory_order_relaxed);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-29 21:56:59 +0000