iox-eclipse-iceoryx#2301 Ensure SpinLock is inter-process safe

elBoberido · Sep 21, 2024 · bbc5f04 · bbc5f04
1 parent d3182ac
commit bbc5f04
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Showing 2 changed files with 11 additions and 3 deletions.
diff --git a/iceoryx_hoofs/concurrent/sync/include/iox/spin_lock.hpp b/iceoryx_hoofs/concurrent/sync/include/iox/spin_lock.hpp
@@ -17,6 +17,7 @@
 #ifndef IOX_HOOFS_CONCURRENT_SYNC_SPIN_LOCK_HPP
 #define IOX_HOOFS_CONCURRENT_SYNC_SPIN_LOCK_HPP
 
+#include "iceoryx_platform/unistd.hpp"
 #include "iox/atomic.hpp"
 #include "iox/lock_interface.hpp"
 
@@ -63,6 +64,7 @@ class SpinLock : public LockInterface<SpinLock>
  concurrent::AtomicFlag m_lock_flag =
  ATOMIC_FLAG_INIT; // NOTE: only initialization via assignment is guaranteed to work
  const concurrent::Atomic<bool> m_recursive{false};
+ concurrent::Atomic<pid_t> m_pid{0};
  concurrent::Atomic<uint64_t> m_recursive_count{0};
  concurrent::Atomic<std::thread::id> m_tid{};
 };

diff --git a/iceoryx_hoofs/concurrent/sync/source/spin_lock.cpp b/iceoryx_hoofs/concurrent/sync/source/spin_lock.cpp
@@ -41,9 +41,10 @@ SpinLock::SpinLock(const LockBehavior lock_behavior) noexcept
 
 expected<void, LockError> SpinLock::lock_impl() noexcept
 {
+ auto pid = getpid();
  auto tid = std::this_thread::get_id();
 
- if (m_tid.load() == tid)
+ if (m_pid.load() == pid && m_tid.load() == tid)
  {
  if (m_recursive.load(std::memory_order_relaxed))
  {
@@ -58,6 +59,7 @@ expected<void, LockError> SpinLock::lock_impl() noexcept
  detail::adaptive_wait spinner;
  spinner.wait_loop([this] { return this->m_lock_flag.test_and_set(std::memory_order_acquire); });
 
+ m_pid.store(pid);
  m_tid.store(tid);
  m_recursive_count.store(1);
 
@@ -66,9 +68,10 @@ expected<void, LockError> SpinLock::lock_impl() noexcept
 
 expected<void, UnlockError> SpinLock::unlock_impl() noexcept
 {
+ auto pid = getpid();
  auto tid = std::this_thread::get_id();
 
- if (m_tid.load() != tid)
+ if (m_pid.load() != pid || m_tid.load() != tid)
  {
  return err(UnlockError::NOT_OWNED_BY_THREAD);
  }
@@ -81,6 +84,7 @@ expected<void, UnlockError> SpinLock::unlock_impl() noexcept
  auto old_recursive_count = m_recursive_count.fetch_sub(1);
  if (old_recursive_count == 1)
  {
+ m_pid.store(0);
  m_tid.store(std::thread::id());
  m_lock_flag.clear(std::memory_order_release);
  }
@@ -90,9 +94,10 @@ expected<void, UnlockError> SpinLock::unlock_impl() noexcept
 
 expected<TryLock, TryLockError> SpinLock::try_lock_impl() noexcept
 {
+ auto pid = getpid();
  auto tid = std::this_thread::get_id();
 
- if (m_tid.load() == tid)
+ if (m_pid.load() == pid && m_tid.load() == tid)
  {
  if (m_recursive.load(std::memory_order_relaxed))
  {
@@ -105,6 +110,7 @@ expected<TryLock, TryLockError> SpinLock::try_lock_impl() noexcept
 
  if (!m_lock_flag.test_and_set(std::memory_order_acquire))
  {
+ m_pid.store(pid);
  m_tid.store(tid);
  m_recursive_count.store(1);