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Kernel: Make RecursiveSpinLock thread safe

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also SpinLock is now implemented with gcc builtins
This commit is contained in:
Bananymous
2023-05-29 19:38:09 +03:00
parent 998999a755
commit ff83f967d8
4 changed files with 35 additions and 39 deletions
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52
kernel/kernel/SpinLock.cpp
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@@ -4,17 +4,16 @@
namespace Kernel
{
extern "C" void spinlock_lock_asm(int*);
extern "C" void spinlock_unlock_asm(int*);
void SpinLock::lock()
{
spinlock_lock_asm(&m_lock);
while (__sync_lock_test_and_set(&m_lock, 1))
while (m_lock)
__builtin_ia32_pause();
}
void SpinLock::unlock()
{
spinlock_unlock_asm(&m_lock);
__sync_lock_release(&m_lock);
}
bool SpinLock::is_locked() const
@@ -24,35 +23,50 @@ namespace Kernel
void RecursiveSpinLock::lock()
{
// FIXME: is this thread safe?
if (m_locker == Scheduler::current_tid())
{
m_lock_depth++;
}
else
pid_t tid = Scheduler::current_tid();
while (true)
{
// Wait for us to be the locker or the lock being free
while (m_locker != -1 && m_locker != tid)
__builtin_ia32_pause();
m_lock.lock();
ASSERT(m_locker == 0);
m_locker = Scheduler::current_tid();
m_lock_depth = 1;
if (m_locker == tid)
{
m_lock_depth++;
break;
}
if (m_locker == -1)
{
m_locker = tid;
m_lock_depth = 1;
break;
}
m_lock.unlock();
}
m_lock.unlock();
}
void RecursiveSpinLock::unlock()
{
m_lock.lock();
ASSERT(m_lock_depth > 0);
ASSERT(m_locker == Scheduler::current_tid());
m_lock_depth--;
if (m_lock_depth == 0)
{
m_locker = 0;
m_lock.unlock();
}
m_locker = -1;
m_lock.unlock();
}
bool RecursiveSpinLock::is_locked() const
{
return m_lock.is_locked();
return m_locker != -1;
}
}