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fix: make ProfilerSignalManager::_handler atomic to prevent data race #8451

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fix: make ProfilerSignalManager::_handler atomic to prevent data race #8451

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9 changes: 5 additions & 4 deletions profiler/src/ProfilerEngine/Datadog.Profiler.Native.Linux/ProfilerSignalManager.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -28,7 +28,7 @@ ProfilerSignalManager::~ProfilerSignalManager() noexcept
_isHandlerInPlace = false;
sigaction(_signalToSend, &_previousAction, nullptr);
}
_handler = nullptr;
_handler.store(nullptr, std::memory_order_relaxed);
}

ProfilerSignalManager* ProfilerSignalManager::Get(int signal)
Expand All @@ -49,7 +49,7 @@ ProfilerSignalManager* ProfilerSignalManager::Get(int signal)

bool ProfilerSignalManager::RegisterHandler(HandlerFn_t handler)
{
HandlerFn_t current = _handler;
HandlerFn_t current = _handler.load(std::memory_order_acquire);

if (current != nullptr)
{
Expand All @@ -58,6 +58,7 @@ bool ProfilerSignalManager::RegisterHandler(HandlerFn_t handler)
}
std::unique_lock<std::mutex> lock(_handlerRegisterMutex);

current = _handler.load(std::memory_order_acquire);
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@gleocadie gleocadie Apr 14, 2026

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good catch nice

if (current != nullptr)
{
assert(current == handler);
Expand All @@ -68,7 +69,7 @@ bool ProfilerSignalManager::RegisterHandler(HandlerFn_t handler)

if (_isHandlerInPlace)
{
_handler = handler;
_handler.store(handler, std::memory_order_release);
}

return _isHandlerInPlace;
Expand Down Expand Up @@ -204,7 +205,7 @@ void ProfilerSignalManager::SignalHandler(int signal, siginfo_t* info, void* con

bool ProfilerSignalManager::CallCustomHandler(int32_t signal, siginfo_t* info, void* context)
{
HandlerFn_t handler = _handler;
HandlerFn_t handler = _handler.load(std::memory_order_acquire);
return handler != nullptr && handler(signal, info, context);
}

Expand Down
4 changes: 2 additions & 2 deletions profiler/src/ProfilerEngine/Datadog.Profiler.Native.Linux/ProfilerSignalManager.h
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Original file line number Diff line number Diff line change
Expand Up @@ -27,7 +27,7 @@ class ProfilerSignalManager
#ifdef DD_TEST
void Reset()
{
_handler = nullptr;
_handler.store(nullptr, std::memory_order_relaxed);
sigaction(_signalToSend, &_previousAction, nullptr);
_isHandlerInPlace = false;
_canReplaceSignalHandler = true;
Expand Down Expand Up @@ -56,7 +56,7 @@ class ProfilerSignalManager
private:
bool _canReplaceSignalHandler;
int32_t _signalToSend;
HandlerFn_t _handler;
std::atomic<HandlerFn_t> _handler;
pid_t _processId;
bool _isHandlerInPlace;
struct sigaction _previousAction;
Expand Down