blob: 9f29b2ca87211f24a3fe1893d2f37be89573766a (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
// Copyright 2017 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// This file is a no-op if the required LowLevelAlloc support is missing.
#include "y_absl/base/internal/low_level_alloc.h"
#ifndef Y_ABSL_LOW_LEVEL_ALLOC_MISSING
#include "y_absl/synchronization/internal/per_thread_sem.h"
#include <atomic>
#include "y_absl/base/attributes.h"
#include "y_absl/base/internal/thread_identity.h"
#include "y_absl/synchronization/internal/waiter.h"
namespace y_absl {
Y_ABSL_NAMESPACE_BEGIN
namespace synchronization_internal {
void PerThreadSem::SetThreadBlockedCounter(std::atomic<int> *counter) {
base_internal::ThreadIdentity *identity;
identity = GetOrCreateCurrentThreadIdentity();
identity->blocked_count_ptr = counter;
}
std::atomic<int> *PerThreadSem::GetThreadBlockedCounter() {
base_internal::ThreadIdentity *identity;
identity = GetOrCreateCurrentThreadIdentity();
return identity->blocked_count_ptr;
}
void PerThreadSem::Tick(base_internal::ThreadIdentity *identity) {
const int ticker =
identity->ticker.fetch_add(1, std::memory_order_relaxed) + 1;
const int wait_start = identity->wait_start.load(std::memory_order_relaxed);
const bool is_idle = identity->is_idle.load(std::memory_order_relaxed);
if (wait_start && (ticker - wait_start > Waiter::kIdlePeriods) && !is_idle) {
// Wakeup the waiting thread since it is time for it to become idle.
Y_ABSL_INTERNAL_C_SYMBOL(AbslInternalPerThreadSemPoke)(identity);
}
}
} // namespace synchronization_internal
Y_ABSL_NAMESPACE_END
} // namespace y_absl
extern "C" {
Y_ABSL_ATTRIBUTE_WEAK void Y_ABSL_INTERNAL_C_SYMBOL(AbslInternalPerThreadSemInit)(
y_absl::base_internal::ThreadIdentity *identity) {
new (y_absl::synchronization_internal::Waiter::GetWaiter(identity))
y_absl::synchronization_internal::Waiter();
}
Y_ABSL_ATTRIBUTE_WEAK void Y_ABSL_INTERNAL_C_SYMBOL(AbslInternalPerThreadSemPost)(
y_absl::base_internal::ThreadIdentity *identity) {
y_absl::synchronization_internal::Waiter::GetWaiter(identity)->Post();
}
Y_ABSL_ATTRIBUTE_WEAK void Y_ABSL_INTERNAL_C_SYMBOL(AbslInternalPerThreadSemPoke)(
y_absl::base_internal::ThreadIdentity *identity) {
y_absl::synchronization_internal::Waiter::GetWaiter(identity)->Poke();
}
Y_ABSL_ATTRIBUTE_WEAK bool Y_ABSL_INTERNAL_C_SYMBOL(AbslInternalPerThreadSemWait)(
y_absl::synchronization_internal::KernelTimeout t) {
bool timeout = false;
y_absl::base_internal::ThreadIdentity *identity;
identity = y_absl::synchronization_internal::GetOrCreateCurrentThreadIdentity();
// Ensure wait_start != 0.
int ticker = identity->ticker.load(std::memory_order_relaxed);
identity->wait_start.store(ticker ? ticker : 1, std::memory_order_relaxed);
identity->is_idle.store(false, std::memory_order_relaxed);
if (identity->blocked_count_ptr != nullptr) {
// Increment count of threads blocked in a given thread pool.
identity->blocked_count_ptr->fetch_add(1, std::memory_order_relaxed);
}
timeout =
!y_absl::synchronization_internal::Waiter::GetWaiter(identity)->Wait(t);
if (identity->blocked_count_ptr != nullptr) {
identity->blocked_count_ptr->fetch_sub(1, std::memory_order_relaxed);
}
identity->is_idle.store(false, std::memory_order_relaxed);
identity->wait_start.store(0, std::memory_order_relaxed);
return !timeout;
}
} // extern "C"
#endif // Y_ABSL_LOW_LEVEL_ALLOC_MISSING
|
