Kernel: Make spinlocks more safe

Kernel now makes sure thread is not holding any spinlocks when it tries
to lock a mutex or yield. Spinlocks are supposed to be only used for
short times without the possibility of yielding
This commit is contained in:
2025-05-30 21:59:07 +03:00
parent 9f4b451501
commit 6542a037df
7 changed files with 72 additions and 34 deletions

View File

@@ -0,0 +1,55 @@
#include <kernel/Lock/SpinLock.h>
#include <kernel/Thread.h>
namespace Kernel
{
InterruptState SpinLock::lock()
{
auto state = Processor::get_interrupt_state();
Processor::set_interrupt_state(InterruptState::Disabled);
auto id = Processor::current_id().as_u32();
ASSERT(m_locker.load(BAN::MemoryOrder::memory_order_relaxed) != id);
auto expected = PROCESSOR_NONE.as_u32();
while (!m_locker.compare_exchange(expected, id, BAN::MemoryOrder::memory_order_acquire))
{
Processor::pause();
expected = PROCESSOR_NONE.as_u32();
}
if (Thread::current_tid())
Thread::current().add_spinlock();
return state;
}
bool SpinLock::try_lock_interrupts_disabled()
{
ASSERT(Processor::get_interrupt_state() == InterruptState::Disabled);
auto id = Processor::current_id().as_u32();
ASSERT(m_locker.load(BAN::MemoryOrder::memory_order_relaxed) != id);
auto expected = PROCESSOR_NONE.as_u32();
if (!m_locker.compare_exchange(expected, id, BAN::MemoryOrder::memory_order_acquire))
return false;
if (Thread::current_tid())
Thread::current().add_spinlock();
return true;
}
void SpinLock::unlock(InterruptState state)
{
ASSERT(Processor::get_interrupt_state() == InterruptState::Disabled);
ASSERT(current_processor_has_lock());
m_locker.store(PROCESSOR_NONE.as_u32(), BAN::MemoryOrder::memory_order_release);
if (Thread::current_tid())
Thread::current().remove_spinlock();
Processor::set_interrupt_state(state);
}
}