diff options
Diffstat (limited to 'Kernel')
-rw-r--r-- | Kernel/Locking/Mutex.cpp | 44 | ||||
-rw-r--r-- | Kernel/Locking/Mutex.h | 13 |
2 files changed, 26 insertions, 31 deletions
diff --git a/Kernel/Locking/Mutex.cpp b/Kernel/Locking/Mutex.cpp index 5e4606add4..26af3ba195 100644 --- a/Kernel/Locking/Mutex.cpp +++ b/Kernel/Locking/Mutex.cpp @@ -39,12 +39,12 @@ void Mutex::lock(Mode mode, [[maybe_unused]] LockLocation const& location) VERIFY(!m_holder); VERIFY(m_shared_holders == 0); if (mode == Mode::Exclusive) { - m_holder = current_thread; + m_holder = bit_cast<uintptr_t>(current_thread); } else { VERIFY(mode == Mode::Shared); ++m_shared_holders; #if LOCK_SHARED_UPGRADE_DEBUG - m_shared_holders_map.set(current_thread, 1); + m_shared_holders_map.set(bit_cast<uintptr_t>(current_thread), 1); #endif } VERIFY(m_times_locked == 0); @@ -59,7 +59,7 @@ void Mutex::lock(Mode mode, [[maybe_unused]] LockLocation const& location) } case Mode::Exclusive: { VERIFY(m_holder); - if (m_holder != current_thread) { + if (m_holder != bit_cast<uintptr_t>(current_thread)) { block(*current_thread, mode, lock, 1); did_block = true; // If we blocked then m_mode should have been updated to what we requested @@ -67,7 +67,7 @@ void Mutex::lock(Mode mode, [[maybe_unused]] LockLocation const& location) } if (m_mode == Mode::Exclusive) { - VERIFY(m_holder == current_thread); + VERIFY(m_holder == bit_cast<uintptr_t>(current_thread)); VERIFY(m_shared_holders == 0); } else if (did_block && mode == Mode::Shared) { // Only if we blocked trying to acquire a shared lock the lock would have been converted @@ -100,7 +100,7 @@ void Mutex::lock(Mode mode, [[maybe_unused]] LockLocation const& location) if (mode == Mode::Exclusive) { dbgln_if(LOCK_TRACE_DEBUG, "Mutex::lock @ {} ({}): blocking for exclusive access, currently shared, locks held {}", this, m_name, m_times_locked); #if LOCK_SHARED_UPGRADE_DEBUG - VERIFY(m_shared_holders_map.size() != 1 || m_shared_holders_map.begin()->key != current_thread); + VERIFY(m_shared_holders_map.size() != 1 || m_shared_holders_map.begin()->key != bit_cast<uintptr_t>(current_thread)); #endif // WARNING: The following block will deadlock if the current thread is the only shared locker of this Mutex // and is asking to upgrade the lock to be exclusive without first releasing the shared lock. We have no @@ -119,7 +119,7 @@ void Mutex::lock(Mode mode, [[maybe_unused]] LockLocation const& location) VERIFY(!did_block); } else if (did_block) { VERIFY(mode == Mode::Exclusive); - VERIFY(m_holder == current_thread); + VERIFY(m_holder == bit_cast<uintptr_t>(current_thread)); VERIFY(m_shared_holders == 0); } @@ -130,11 +130,7 @@ void Mutex::lock(Mode mode, [[maybe_unused]] LockLocation const& location) VERIFY(m_shared_holders > 0); ++m_shared_holders; #if LOCK_SHARED_UPGRADE_DEBUG - auto it = m_shared_holders_map.find(current_thread); - if (it != m_shared_holders_map.end()) - it->value++; - else - m_shared_holders_map.set(current_thread, 1); + m_shared_holders_map.ensure(bit_cast<uintptr_t>(current_thread), [] { return 0; })++; #endif } @@ -175,17 +171,17 @@ void Mutex::unlock() switch (current_mode) { case Mode::Exclusive: - VERIFY(m_holder == current_thread); + VERIFY(m_holder == bit_cast<uintptr_t>(current_thread)); VERIFY(m_shared_holders == 0); if (m_times_locked == 0) - m_holder = nullptr; + m_holder = 0; break; case Mode::Shared: { VERIFY(!m_holder); VERIFY(m_shared_holders > 0); --m_shared_holders; #if LOCK_SHARED_UPGRADE_DEBUG - auto it = m_shared_holders_map.find(current_thread); + auto it = m_shared_holders_map.find(bit_cast<uintptr_t>(current_thread)); if (it->value > 1) it->value--; else @@ -262,7 +258,7 @@ void Mutex::unblock_waiters(Mode previous_mode) auto requested_locks = thread.unblock_from_mutex(*this); m_shared_holders += requested_locks; #if LOCK_SHARED_UPGRADE_DEBUG - auto set_result = m_shared_holders_map.set(&thread, requested_locks); + auto set_result = m_shared_holders_map.set(bit_cast<uintptr_t>(&thread), requested_locks); VERIFY(set_result == AK::HashSetResult::InsertedNewEntry); #endif m_times_locked += requested_locks; @@ -273,7 +269,7 @@ void Mutex::unblock_waiters(Mode previous_mode) if (auto* next_exclusive_thread = list.first()) { m_mode = Mode::Exclusive; m_times_locked = next_exclusive_thread->unblock_from_mutex(*this); - m_holder = next_exclusive_thread; + m_holder = bit_cast<uintptr_t>(next_exclusive_thread); return true; } return false; @@ -303,16 +299,16 @@ auto Mutex::force_unlock_exclusive_if_locked(u32& lock_count_to_restore) -> Mode auto current_mode = m_mode; switch (current_mode) { case Mode::Exclusive: { - if (m_holder != current_thread) { + if (m_holder != bit_cast<uintptr_t>(current_thread)) { lock_count_to_restore = 0; return Mode::Unlocked; } dbgln_if(LOCK_RESTORE_DEBUG, "Mutex::force_unlock_exclusive_if_locked @ {}: unlocking exclusive with lock count: {}", this, m_times_locked); #if LOCK_DEBUG - m_holder->holding_lock(*this, -(int)m_times_locked, {}); + current_thread->holding_lock(*this, -(int)m_times_locked, {}); #endif - m_holder = nullptr; + m_holder = 0; VERIFY(m_times_locked > 0); lock_count_to_restore = m_times_locked; m_times_locked = 0; @@ -340,7 +336,7 @@ void Mutex::restore_exclusive_lock(u32 lock_count, [[maybe_unused]] LockLocation bool did_block = false; SpinlockLocker lock(m_lock); [[maybe_unused]] auto previous_mode = m_mode; - if (m_mode == Mode::Exclusive && m_holder != current_thread) { + if (m_mode == Mode::Exclusive && m_holder != bit_cast<uintptr_t>(current_thread)) { block(*current_thread, Mode::Exclusive, lock, lock_count); did_block = true; // If we blocked then m_mode should have been updated to what we requested @@ -353,24 +349,24 @@ void Mutex::restore_exclusive_lock(u32 lock_count, [[maybe_unused]] LockLocation VERIFY(m_shared_holders == 0); if (did_block) { VERIFY(m_times_locked > 0); - VERIFY(m_holder == current_thread); + VERIFY(m_holder == bit_cast<uintptr_t>(current_thread)); } else { if (m_mode == Mode::Unlocked) { m_mode = Mode::Exclusive; VERIFY(m_times_locked == 0); m_times_locked = lock_count; VERIFY(!m_holder); - m_holder = current_thread; + m_holder = bit_cast<uintptr_t>(current_thread); } else { VERIFY(m_mode == Mode::Exclusive); - VERIFY(m_holder == current_thread); + VERIFY(m_holder == bit_cast<uintptr_t>(current_thread)); VERIFY(m_times_locked > 0); m_times_locked += lock_count; } } #if LOCK_DEBUG - m_holder->holding_lock(*this, (int)lock_count, location); + current_thread->holding_lock(*this, (int)lock_count, location); #endif } diff --git a/Kernel/Locking/Mutex.h b/Kernel/Locking/Mutex.h index 25a2eb3572..d083fb3baa 100644 --- a/Kernel/Locking/Mutex.h +++ b/Kernel/Locking/Mutex.h @@ -57,7 +57,7 @@ public: VERIFY(m_mode != Mode::Shared); // This method should only be used on exclusively-held locks if (m_mode == Mode::Unlocked) return false; - return m_holder == Thread::current(); + return m_holder == bit_cast<uintptr_t>(Thread::current()); } [[nodiscard]] StringView name() const { return m_name; } @@ -96,12 +96,11 @@ private: // lock it again. When locked in shared mode, any thread can do that. u32 m_times_locked { 0 }; - // One of the threads that hold this lock, or nullptr. When locked in shared - // mode, this is stored on best effort basis: nullptr value does *not* mean + // The address of one of the threads that hold this lock, or 0. + // When locked in shared mode, this is stored on best effort basis: 0 does *not* mean // the lock is unlocked, it just means we don't know which threads hold it. - // When locked exclusively, this is always the one thread that holds the - // lock. - RefPtr<Thread> m_holder; + // When locked exclusively, this is always the one thread that holds the lock. + uintptr_t m_holder { 0 }; size_t m_shared_holders { 0 }; struct BlockedThreadLists { @@ -124,7 +123,7 @@ private: mutable Spinlock<LockRank::None> m_lock {}; #if LOCK_SHARED_UPGRADE_DEBUG - HashMap<Thread*, u32> m_shared_holders_map; + HashMap<uintptr_t, u32> m_shared_holders_map; #endif }; |