aboutsummaryrefslogtreecommitdiff
path: root/absl/synchronization/internal
diff options
context:
space:
mode:
Diffstat (limited to 'absl/synchronization/internal')
-rw-r--r--absl/synchronization/internal/futex.h37
-rw-r--r--absl/synchronization/internal/graphcycles.cc68
-rw-r--r--absl/synchronization/internal/kernel_timeout.h30
-rw-r--r--absl/synchronization/internal/thread_pool.h9
4 files changed, 85 insertions, 59 deletions
diff --git a/absl/synchronization/internal/futex.h b/absl/synchronization/internal/futex.h
index 06fbd6d0..cb97da09 100644
--- a/absl/synchronization/internal/futex.h
+++ b/absl/synchronization/internal/futex.h
@@ -87,7 +87,7 @@ class FutexImpl {
public:
static int WaitUntil(std::atomic<int32_t> *v, int32_t val,
KernelTimeout t) {
- int err = 0;
+ long err = 0; // NOLINT(runtime/int)
if (t.has_timeout()) {
// https://locklessinc.com/articles/futex_cheat_sheet/
// Unlike FUTEX_WAIT, FUTEX_WAIT_BITSET uses absolute time.
@@ -105,41 +105,44 @@ class FutexImpl {
FUTEX_WAIT | FUTEX_PRIVATE_FLAG, val, nullptr);
}
if (ABSL_PREDICT_FALSE(err != 0)) {
- err = -errno;
+ return -errno;
}
- return err;
+ return 0;
}
static int WaitBitsetAbsoluteTimeout(std::atomic<int32_t> *v, int32_t val,
int32_t bits,
const struct timespec *abstime) {
- int err = syscall(SYS_futex, reinterpret_cast<int32_t *>(v),
- FUTEX_WAIT_BITSET | FUTEX_PRIVATE_FLAG, val, abstime,
- nullptr, bits);
+ // NOLINTNEXTLINE(runtime/int)
+ long err = syscall(SYS_futex, reinterpret_cast<int32_t*>(v),
+ FUTEX_WAIT_BITSET | FUTEX_PRIVATE_FLAG, val, abstime,
+ nullptr, bits);
if (ABSL_PREDICT_FALSE(err != 0)) {
- err = -errno;
+ return -errno;
}
- return err;
+ return 0;
}
static int Wake(std::atomic<int32_t> *v, int32_t count) {
- int err = syscall(SYS_futex, reinterpret_cast<int32_t *>(v),
- FUTEX_WAKE | FUTEX_PRIVATE_FLAG, count);
+ // NOLINTNEXTLINE(runtime/int)
+ long err = syscall(SYS_futex, reinterpret_cast<int32_t*>(v),
+ FUTEX_WAKE | FUTEX_PRIVATE_FLAG, count);
if (ABSL_PREDICT_FALSE(err < 0)) {
- err = -errno;
+ return -errno;
}
- return err;
+ return 0;
}
// FUTEX_WAKE_BITSET
static int WakeBitset(std::atomic<int32_t> *v, int32_t count, int32_t bits) {
- int err = syscall(SYS_futex, reinterpret_cast<int32_t *>(v),
- FUTEX_WAKE_BITSET | FUTEX_PRIVATE_FLAG, count, nullptr,
- nullptr, bits);
+ // NOLINTNEXTLINE(runtime/int)
+ long err = syscall(SYS_futex, reinterpret_cast<int32_t*>(v),
+ FUTEX_WAKE_BITSET | FUTEX_PRIVATE_FLAG, count, nullptr,
+ nullptr, bits);
if (ABSL_PREDICT_FALSE(err < 0)) {
- err = -errno;
+ return -errno;
}
- return err;
+ return 0;
}
};
diff --git a/absl/synchronization/internal/graphcycles.cc b/absl/synchronization/internal/graphcycles.cc
index 27fec216..feec4581 100644
--- a/absl/synchronization/internal/graphcycles.cc
+++ b/absl/synchronization/internal/graphcycles.cc
@@ -181,9 +181,9 @@ class NodeSet {
return true;
}
- void erase(uint32_t v) {
+ void erase(int32_t v) {
uint32_t i = FindIndex(v);
- if (static_cast<uint32_t>(table_[i]) == v) {
+ if (table_[i] == v) {
table_[i] = kDel;
}
}
@@ -195,7 +195,7 @@ class NodeSet {
for (int32_t elem, _cursor = 0; (eset).Next(&_cursor, &elem); )
bool Next(int32_t* cursor, int32_t* elem) {
while (static_cast<uint32_t>(*cursor) < table_.size()) {
- int32_t v = table_[*cursor];
+ int32_t v = table_[static_cast<uint32_t>(*cursor)];
(*cursor)++;
if (v >= 0) {
*elem = v;
@@ -210,24 +210,26 @@ class NodeSet {
Vec<int32_t> table_;
uint32_t occupied_; // Count of non-empty slots (includes deleted slots)
- static uint32_t Hash(uint32_t a) { return a * 41; }
+ static uint32_t Hash(int32_t a) { return static_cast<uint32_t>(a * 41); }
// Return index for storing v. May return an empty index or deleted index
- int FindIndex(int32_t v) const {
+ uint32_t FindIndex(int32_t v) const {
// Search starting at hash index.
const uint32_t mask = table_.size() - 1;
uint32_t i = Hash(v) & mask;
- int deleted_index = -1; // If >= 0, index of first deleted element we see
+ uint32_t deleted_index = 0; // index of first deleted element we see
+ bool seen_deleted_element = false;
while (true) {
int32_t e = table_[i];
if (v == e) {
return i;
} else if (e == kEmpty) {
// Return any previously encountered deleted slot.
- return (deleted_index >= 0) ? deleted_index : i;
- } else if (e == kDel && deleted_index < 0) {
+ return seen_deleted_element ? deleted_index : i;
+ } else if (e == kDel && !seen_deleted_element) {
// Keep searching since v might be present later.
deleted_index = i;
+ seen_deleted_element = true;
}
i = (i + 1) & mask; // Linear probing; quadratic is slightly slower.
}
@@ -268,7 +270,7 @@ inline GraphId MakeId(int32_t index, uint32_t version) {
}
inline int32_t NodeIndex(GraphId id) {
- return static_cast<uint32_t>(id.handle & 0xfffffffful);
+ return static_cast<int32_t>(id.handle);
}
inline uint32_t NodeVersion(GraphId id) {
@@ -298,7 +300,7 @@ class PointerMap {
int32_t Find(void* ptr) {
auto masked = base_internal::HidePtr(ptr);
for (int32_t i = table_[Hash(ptr)]; i != -1;) {
- Node* n = (*nodes_)[i];
+ Node* n = (*nodes_)[static_cast<uint32_t>(i)];
if (n->masked_ptr == masked) return i;
i = n->next_hash;
}
@@ -307,7 +309,7 @@ class PointerMap {
void Add(void* ptr, int32_t i) {
int32_t* head = &table_[Hash(ptr)];
- (*nodes_)[i]->next_hash = *head;
+ (*nodes_)[static_cast<uint32_t>(i)]->next_hash = *head;
*head = i;
}
@@ -317,7 +319,7 @@ class PointerMap {
auto masked = base_internal::HidePtr(ptr);
for (int32_t* slot = &table_[Hash(ptr)]; *slot != -1; ) {
int32_t index = *slot;
- Node* n = (*nodes_)[index];
+ Node* n = (*nodes_)[static_cast<uint32_t>(index)];
if (n->masked_ptr == masked) {
*slot = n->next_hash; // Remove n from linked list
n->next_hash = -1;
@@ -358,7 +360,7 @@ struct GraphCycles::Rep {
};
static Node* FindNode(GraphCycles::Rep* rep, GraphId id) {
- Node* n = rep->nodes_[NodeIndex(id)];
+ Node* n = rep->nodes_[static_cast<uint32_t>(NodeIndex(id))];
return (n->version == NodeVersion(id)) ? n : nullptr;
}
@@ -393,7 +395,7 @@ bool GraphCycles::CheckInvariants() const {
ABSL_RAW_LOG(FATAL, "Duplicate occurrence of rank %d", nx->rank);
}
HASH_FOR_EACH(y, nx->out) {
- Node* ny = r->nodes_[y];
+ Node* ny = r->nodes_[static_cast<uint32_t>(y)];
if (nx->rank >= ny->rank) {
ABSL_RAW_LOG(FATAL, "Edge %u->%d has bad rank assignment %d->%d", x, y,
nx->rank, ny->rank);
@@ -406,14 +408,14 @@ bool GraphCycles::CheckInvariants() const {
GraphId GraphCycles::GetId(void* ptr) {
int32_t i = rep_->ptrmap_.Find(ptr);
if (i != -1) {
- return MakeId(i, rep_->nodes_[i]->version);
+ return MakeId(i, rep_->nodes_[static_cast<uint32_t>(i)]->version);
} else if (rep_->free_nodes_.empty()) {
Node* n =
new (base_internal::LowLevelAlloc::AllocWithArena(sizeof(Node), arena))
Node;
n->version = 1; // Avoid 0 since it is used by InvalidGraphId()
n->visited = false;
- n->rank = rep_->nodes_.size();
+ n->rank = static_cast<int32_t>(rep_->nodes_.size());
n->masked_ptr = base_internal::HidePtr(ptr);
n->nstack = 0;
n->priority = 0;
@@ -425,7 +427,7 @@ GraphId GraphCycles::GetId(void* ptr) {
// a permutation of [0,rep_->nodes_.size()-1].
int32_t r = rep_->free_nodes_.back();
rep_->free_nodes_.pop_back();
- Node* n = rep_->nodes_[r];
+ Node* n = rep_->nodes_[static_cast<uint32_t>(r)];
n->masked_ptr = base_internal::HidePtr(ptr);
n->nstack = 0;
n->priority = 0;
@@ -439,12 +441,12 @@ void GraphCycles::RemoveNode(void* ptr) {
if (i == -1) {
return;
}
- Node* x = rep_->nodes_[i];
+ Node* x = rep_->nodes_[static_cast<uint32_t>(i)];
HASH_FOR_EACH(y, x->out) {
- rep_->nodes_[y]->in.erase(i);
+ rep_->nodes_[static_cast<uint32_t>(y)]->in.erase(i);
}
HASH_FOR_EACH(y, x->in) {
- rep_->nodes_[y]->out.erase(i);
+ rep_->nodes_[static_cast<uint32_t>(y)]->out.erase(i);
}
x->in.clear();
x->out.clear();
@@ -520,7 +522,7 @@ bool GraphCycles::InsertEdge(GraphId idx, GraphId idy) {
// Since we do not call Reorder() on this path, clear any visited
// markers left by ForwardDFS.
for (const auto& d : r->deltaf_) {
- r->nodes_[d]->visited = false;
+ r->nodes_[static_cast<uint32_t>(d)]->visited = false;
}
return false;
}
@@ -538,14 +540,14 @@ static bool ForwardDFS(GraphCycles::Rep* r, int32_t n, int32_t upper_bound) {
while (!r->stack_.empty()) {
n = r->stack_.back();
r->stack_.pop_back();
- Node* nn = r->nodes_[n];
+ Node* nn = r->nodes_[static_cast<uint32_t>(n)];
if (nn->visited) continue;
nn->visited = true;
r->deltaf_.push_back(n);
HASH_FOR_EACH(w, nn->out) {
- Node* nw = r->nodes_[w];
+ Node* nw = r->nodes_[static_cast<uint32_t>(w)];
if (nw->rank == upper_bound) {
return false; // Cycle
}
@@ -564,14 +566,14 @@ static void BackwardDFS(GraphCycles::Rep* r, int32_t n, int32_t lower_bound) {
while (!r->stack_.empty()) {
n = r->stack_.back();
r->stack_.pop_back();
- Node* nn = r->nodes_[n];
+ Node* nn = r->nodes_[static_cast<uint32_t>(n)];
if (nn->visited) continue;
nn->visited = true;
r->deltab_.push_back(n);
HASH_FOR_EACH(w, nn->in) {
- Node* nw = r->nodes_[w];
+ Node* nw = r->nodes_[static_cast<uint32_t>(w)];
if (!nw->visited && lower_bound < nw->rank) {
r->stack_.push_back(w);
}
@@ -596,7 +598,7 @@ static void Reorder(GraphCycles::Rep* r) {
// Assign the ranks in order to the collected list.
for (uint32_t i = 0; i < r->list_.size(); i++) {
- r->nodes_[r->list_[i]]->rank = r->merged_[i];
+ r->nodes_[static_cast<uint32_t>(r->list_[i])]->rank = r->merged_[i];
}
}
@@ -604,7 +606,8 @@ static void Sort(const Vec<Node*>& nodes, Vec<int32_t>* delta) {
struct ByRank {
const Vec<Node*>* nodes;
bool operator()(int32_t a, int32_t b) const {
- return (*nodes)[a]->rank < (*nodes)[b]->rank;
+ return (*nodes)[static_cast<uint32_t>(a)]->rank <
+ (*nodes)[static_cast<uint32_t>(b)]->rank;
}
};
ByRank cmp;
@@ -616,8 +619,10 @@ static void MoveToList(
GraphCycles::Rep* r, Vec<int32_t>* src, Vec<int32_t>* dst) {
for (auto& v : *src) {
int32_t w = v;
- v = r->nodes_[w]->rank; // Replace v entry with its rank
- r->nodes_[w]->visited = false; // Prepare for future DFS calls
+ // Replace v entry with its rank
+ v = r->nodes_[static_cast<uint32_t>(w)]->rank;
+ // Prepare for future DFS calls
+ r->nodes_[static_cast<uint32_t>(w)]->visited = false;
dst->push_back(w);
}
}
@@ -647,7 +652,8 @@ int GraphCycles::FindPath(GraphId idx, GraphId idy, int max_path_len,
}
if (path_len < max_path_len) {
- path[path_len] = MakeId(n, rep_->nodes_[n]->version);
+ path[path_len] =
+ MakeId(n, rep_->nodes_[static_cast<uint32_t>(n)]->version);
}
path_len++;
r->stack_.push_back(-1); // Will remove tentative path entry
@@ -656,7 +662,7 @@ int GraphCycles::FindPath(GraphId idx, GraphId idy, int max_path_len,
return path_len;
}
- HASH_FOR_EACH(w, r->nodes_[n]->out) {
+ HASH_FOR_EACH(w, r->nodes_[static_cast<uint32_t>(n)]->out) {
if (seen.insert(w)) {
r->stack_.push_back(w);
}
diff --git a/absl/synchronization/internal/kernel_timeout.h b/absl/synchronization/internal/kernel_timeout.h
index bbd4d2d7..f5c2c0ef 100644
--- a/absl/synchronization/internal/kernel_timeout.h
+++ b/absl/synchronization/internal/kernel_timeout.h
@@ -19,8 +19,8 @@
// Constructible from a absl::Time (for a timeout to be respected) or {}
// (for "no timeout".)
// This is a private low-level API for use by a handful of low-level
-// components that are friends of this class. Higher-level components
-// should build APIs based on absl::Time and absl::Duration.
+// components. Higher-level components should build APIs based on
+// absl::Time and absl::Duration.
#ifndef ABSL_SYNCHRONIZATION_INTERNAL_KERNEL_TIMEOUT_H_
#define ABSL_SYNCHRONIZATION_INTERNAL_KERNEL_TIMEOUT_H_
@@ -28,6 +28,7 @@
#include <time.h>
#include <algorithm>
+#include <cstdint>
#include <limits>
#include "absl/base/internal/raw_logging.h"
@@ -38,7 +39,6 @@ namespace absl {
ABSL_NAMESPACE_BEGIN
namespace synchronization_internal {
-class Futex;
class Waiter;
class KernelTimeout {
@@ -60,7 +60,10 @@ class KernelTimeout {
// Convert to parameter for sem_timedwait/futex/similar. Only for approved
// users. Do not call if !has_timeout.
- struct timespec MakeAbsTimespec();
+ struct timespec MakeAbsTimespec() const;
+
+ // Convert to unix epoch nanos. Do not call if !has_timeout.
+ int64_t MakeAbsNanos() const;
private:
// internal rep, not user visible: ns after unix epoch.
@@ -111,7 +114,8 @@ class KernelTimeout {
constexpr uint64_t max_nanos =
(std::numeric_limits<int64_t>::max)() - 999999u;
uint64_t ms_from_now =
- (std::min<uint64_t>(max_nanos, ns_ - now) + 999999u) / 1000000u;
+ ((std::min)(max_nanos, static_cast<uint64_t>(ns_ - now)) + 999999u) /
+ 1000000u;
if (ms_from_now > kInfinite) {
return kInfinite;
}
@@ -119,13 +123,12 @@ class KernelTimeout {
}
return 0;
}
-#endif
- friend class Futex;
friend class Waiter;
+#endif
};
-inline struct timespec KernelTimeout::MakeAbsTimespec() {
+inline struct timespec KernelTimeout::MakeAbsTimespec() const {
int64_t n = ns_;
static const int64_t kNanosPerSecond = 1000 * 1000 * 1000;
if (n == 0) {
@@ -149,6 +152,17 @@ inline struct timespec KernelTimeout::MakeAbsTimespec() {
return abstime;
}
+inline int64_t KernelTimeout::MakeAbsNanos() const {
+ if (ns_ == 0) {
+ ABSL_RAW_LOG(
+ ERROR, "Tried to create a timeout from a non-timeout; never do this.");
+ // But we'll try to continue sanely. no-timeout ~= saturated timeout.
+ return (std::numeric_limits<int64_t>::max)();
+ }
+
+ return ns_;
+}
+
} // namespace synchronization_internal
ABSL_NAMESPACE_END
} // namespace absl
diff --git a/absl/synchronization/internal/thread_pool.h b/absl/synchronization/internal/thread_pool.h
index 0cb96dac..5eb0bb60 100644
--- a/absl/synchronization/internal/thread_pool.h
+++ b/absl/synchronization/internal/thread_pool.h
@@ -20,9 +20,11 @@
#include <functional>
#include <queue>
#include <thread> // NOLINT(build/c++11)
+#include <utility>
#include <vector>
#include "absl/base/thread_annotations.h"
+#include "absl/functional/any_invocable.h"
#include "absl/synchronization/mutex.h"
namespace absl {
@@ -33,6 +35,7 @@ namespace synchronization_internal {
class ThreadPool {
public:
explicit ThreadPool(int num_threads) {
+ threads_.reserve(num_threads);
for (int i = 0; i < num_threads; ++i) {
threads_.push_back(std::thread(&ThreadPool::WorkLoop, this));
}
@@ -54,7 +57,7 @@ class ThreadPool {
}
// Schedule a function to be run on a ThreadPool thread immediately.
- void Schedule(std::function<void()> func) {
+ void Schedule(absl::AnyInvocable<void()> func) {
assert(func != nullptr);
absl::MutexLock l(&mu_);
queue_.push(std::move(func));
@@ -67,7 +70,7 @@ class ThreadPool {
void WorkLoop() {
while (true) {
- std::function<void()> func;
+ absl::AnyInvocable<void()> func;
{
absl::MutexLock l(&mu_);
mu_.Await(absl::Condition(this, &ThreadPool::WorkAvailable));
@@ -82,7 +85,7 @@ class ThreadPool {
}
absl::Mutex mu_;
- std::queue<std::function<void()>> queue_ ABSL_GUARDED_BY(mu_);
+ std::queue<absl::AnyInvocable<void()>> queue_ ABSL_GUARDED_BY(mu_);
std::vector<std::thread> threads_;
};
generated by cgit v1.2.3 (git 2.39.1) at 2025-06-12 04:30:40 +0000