Remove safe_reader_lock, safe_writer_lock

It worked as a simple recursive locker for shared_mutex
But its design is flawed and thus can't be fully implemented
This commit is contained in:
Nekotekina 2018-09-11 19:03:51 +03:00
parent e8b5555630
commit 445e5def42
2 changed files with 0 additions and 107 deletions

View File

@ -5,9 +5,6 @@
#include <vector>
#include <algorithm>
// TLS variable for tracking owned mutexes
thread_local std::vector<shared_mutex*> g_tls_locks;
void shared_mutex::imp_lock_shared(s64 _old)
{
verify("shared_mutex overflow" HERE), _old <= c_max;
@ -257,78 +254,3 @@ bool shared_mutex::try_lock_degrade()
// TODO
return m_value.compare_and_swap_test(0, c_one - c_min);
}
safe_reader_lock::safe_reader_lock(shared_mutex& mutex)
: m_mutex(mutex)
, m_is_owned(false)
{
if (std::count(g_tls_locks.cbegin(), g_tls_locks.cend(), &m_mutex) == 0)
{
m_is_owned = true;
if (m_is_owned)
{
m_mutex.lock_shared();
g_tls_locks.emplace_back(&m_mutex);
return;
}
// TODO: order locks
}
}
safe_reader_lock::~safe_reader_lock()
{
if (m_is_owned)
{
m_mutex.unlock_shared();
g_tls_locks.erase(std::remove(g_tls_locks.begin(), g_tls_locks.end(), &m_mutex), g_tls_locks.cend());
return;
}
// TODO: order locks
}
safe_writer_lock::safe_writer_lock(shared_mutex& mutex)
: m_mutex(mutex)
, m_is_owned(false)
, m_is_upgraded(false)
{
if (std::count(g_tls_locks.cbegin(), g_tls_locks.cend(), &m_mutex) == 0)
{
m_is_owned = true;
if (m_is_owned)
{
m_mutex.lock();
g_tls_locks.emplace_back(&m_mutex);
return;
}
// TODO: order locks
}
if (m_mutex.is_reading())
{
m_is_upgraded = true;
m_mutex.lock_upgrade();
}
}
safe_writer_lock::~safe_writer_lock()
{
if (m_is_upgraded)
{
m_mutex.lock_degrade();
return;
}
if (m_is_owned)
{
m_mutex.unlock();
g_tls_locks.erase(std::remove(g_tls_locks.begin(), g_tls_locks.end(), &m_mutex), g_tls_locks.cend());
return;
}
// TODO: order locks
}

View File

@ -138,32 +138,3 @@ public:
m_upgraded ? m_mutex.unlock() : m_mutex.unlock_shared();
}
};
// Safe reader lock. Can be recursive above other safe locks (reader or writer).
class safe_reader_lock final
{
shared_mutex& m_mutex;
bool m_is_owned;
public:
safe_reader_lock(const safe_reader_lock&) = delete;
explicit safe_reader_lock(shared_mutex& mutex);
~safe_reader_lock();
};
// Safe writer lock. Can be recursive above other safe locks. Performs upgrade and degrade operations above existing reader lock if necessary.
class safe_writer_lock final
{
shared_mutex& m_mutex;
bool m_is_owned;
bool m_is_upgraded;
public:
safe_writer_lock(const safe_writer_lock&) = delete;
explicit safe_writer_lock(shared_mutex& mutex);
~safe_writer_lock();
};