109 lines
1.7 KiB
C++
109 lines
1.7 KiB
C++
#pragma once
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#include <kernel/Lock/Mutex.h>
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#include <kernel/Lock/LockGuard.h>
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namespace Kernel
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{
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class RWLock
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{
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BAN_NON_COPYABLE(RWLock);
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BAN_NON_MOVABLE(RWLock);
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public:
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RWLock() = default;
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void rd_lock()
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{
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LockGuard _(m_mutex);
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while (m_writers_waiting > 0 || m_writer != -1)
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m_thread_blocker.block_indefinite(&m_mutex);
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m_readers_active++;
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}
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void rd_unlock()
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{
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LockGuard _(m_mutex);
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if (--m_readers_active == 0)
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m_thread_blocker.unblock();
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}
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void wr_lock()
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{
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if (m_writer == Thread::current_tid())
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{
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m_writer_depth++;
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return;
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}
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LockGuard _(m_mutex);
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m_writers_waiting++;
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while (m_readers_active > 0 || m_writer != -1)
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m_thread_blocker.block_indefinite(&m_mutex);
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m_writers_waiting--;
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m_writer = Thread::current_tid();
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m_writer_depth = 1;
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}
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void wr_unlock()
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{
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if (--m_writer_depth != 0)
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return;
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LockGuard _(m_mutex);
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m_writer = -1;
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m_thread_blocker.unblock();
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}
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private:
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Mutex m_mutex;
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ThreadBlocker m_thread_blocker;
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uint32_t m_readers_active { 0 };
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uint32_t m_writers_waiting { 0 };
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pid_t m_writer { -1 };
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uint32_t m_writer_depth { 0 };
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};
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class RWLockRDGuard
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{
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BAN_NON_COPYABLE(RWLockRDGuard);
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BAN_NON_MOVABLE(RWLockRDGuard);
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public:
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RWLockRDGuard(RWLock& lock)
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: m_lock(lock)
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{
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m_lock.rd_lock();
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}
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~RWLockRDGuard()
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{
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m_lock.rd_unlock();
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}
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private:
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RWLock& m_lock;
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};
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class RWLockWRGuard
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{
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BAN_NON_COPYABLE(RWLockWRGuard);
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BAN_NON_MOVABLE(RWLockWRGuard);
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public:
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RWLockWRGuard(RWLock& lock)
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: m_lock(lock)
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{
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m_lock.wr_lock();
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}
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~RWLockWRGuard()
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{
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m_lock.wr_unlock();
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}
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private:
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RWLock& m_lock;
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};
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}
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