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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
commit | 6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /security/sandbox/chromium/base/threading/thread_collision_warner.cc | |
parent | Initial commit. (diff) | |
download | thunderbird-upstream.tar.xz thunderbird-upstream.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'security/sandbox/chromium/base/threading/thread_collision_warner.cc')
-rw-r--r-- | security/sandbox/chromium/base/threading/thread_collision_warner.cc | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/security/sandbox/chromium/base/threading/thread_collision_warner.cc b/security/sandbox/chromium/base/threading/thread_collision_warner.cc new file mode 100644 index 0000000000..547e11ca66 --- /dev/null +++ b/security/sandbox/chromium/base/threading/thread_collision_warner.cc @@ -0,0 +1,64 @@ +// Copyright (c) 2010 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "base/threading/thread_collision_warner.h" + +#include "base/logging.h" +#include "base/threading/platform_thread.h" + +namespace base { + +void DCheckAsserter::warn() { + NOTREACHED() << "Thread Collision"; +} + +static subtle::Atomic32 CurrentThread() { + const PlatformThreadId current_thread_id = PlatformThread::CurrentId(); + // We need to get the thread id into an atomic data type. This might be a + // truncating conversion, but any loss-of-information just increases the + // chance of a fault negative, not a false positive. + const subtle::Atomic32 atomic_thread_id = + static_cast<subtle::Atomic32>(current_thread_id); + + return atomic_thread_id; +} + +void ThreadCollisionWarner::EnterSelf() { + // If the active thread is 0 then I'll write the current thread ID + // if two or more threads arrive here only one will succeed to + // write on valid_thread_id_ the current thread ID. + subtle::Atomic32 current_thread_id = CurrentThread(); + + int previous_value = subtle::NoBarrier_CompareAndSwap(&valid_thread_id_, + 0, + current_thread_id); + if (previous_value != 0 && previous_value != current_thread_id) { + // gotcha! a thread is trying to use the same class and that is + // not current thread. + asserter_->warn(); + } + + subtle::NoBarrier_AtomicIncrement(&counter_, 1); +} + +void ThreadCollisionWarner::Enter() { + subtle::Atomic32 current_thread_id = CurrentThread(); + + if (subtle::NoBarrier_CompareAndSwap(&valid_thread_id_, + 0, + current_thread_id) != 0) { + // gotcha! another thread is trying to use the same class. + asserter_->warn(); + } + + subtle::NoBarrier_AtomicIncrement(&counter_, 1); +} + +void ThreadCollisionWarner::Leave() { + if (subtle::Barrier_AtomicIncrement(&counter_, -1) == 0) { + subtle::NoBarrier_Store(&valid_thread_id_, 0); + } +} + +} // namespace base |