Files
MaxScale/server/core/spinlock.cc
Niclas Antti c447e5cf15 Uncrustify maxscale
See script directory for method. The script to run in the top level
MaxScale directory is called maxscale-uncrustify.sh, which uses
another script, list-src, from the same directory (so you need to set
your PATH). The uncrustify version was 0.66.
2018-09-09 22:26:19 +03:00

121 lines
2.8 KiB
C++

/*
* Copyright (c) 2016 MariaDB Corporation Ab
*
* Use of this software is governed by the Business Source License included
* in the LICENSE.TXT file and at www.mariadb.com/bsl11.
*
* Change Date: 2022-01-01
*
* On the date above, in accordance with the Business Source License, use
* of this software will be governed by version 2 or later of the General
* Public License.
*/
#include <maxscale/spinlock.h>
#include <maxbase/assert.h>
#include <maxbase/atomic.h>
#include <time.h>
void spinlock_init(SPINLOCK* lock)
{
lock->lock = 0;
#if SPINLOCK_PROFILE
lock->spins = 0;
lock->maxspins = 0;
lock->acquired = 0;
lock->waiting = 0;
lock->max_waiting = 0;
lock->contended = 0;
lock->owner = 0;
#endif
}
void spinlock_acquire(const SPINLOCK* const_lock)
{
SPINLOCK* lock = (SPINLOCK*)const_lock;
#if SPINLOCK_PROFILE
int spins = 0;
atomic_add(&(lock->waiting), 1);
#endif
while (__sync_lock_test_and_set(&(lock->lock), 1))
{
#if SPINLOCK_PROFILE
atomic_add(&(lock->spins), 1);
spins++;
#endif
}
#if SPINLOCK_PROFILE
if (spins)
{
lock->contended++;
if (lock->maxspins < spins)
{
lock->maxspins = spins;
}
}
lock->acquired++;
lock->owner = thread_self();
atomic_add(&(lock->waiting), -1);
#endif
}
bool spinlock_acquire_nowait(const SPINLOCK* const_lock)
{
SPINLOCK* lock = (SPINLOCK*)const_lock;
if (__sync_lock_test_and_set(&(lock->lock), 1))
{
return false;
}
#if SPINLOCK_PROFILE
lock->acquired++;
lock->owner = thread_self();
#endif
return true;
}
void spinlock_release(const SPINLOCK* const_lock)
{
SPINLOCK* lock = (SPINLOCK*)const_lock;
mxb_assert(lock->lock != 0);
#if SPINLOCK_PROFILE
if (lock->waiting > lock->max_waiting)
{
lock->max_waiting = lock->waiting;
}
#endif
__sync_lock_release(&lock->lock);
}
void spinlock_stats(const SPINLOCK* lock, void (* reporter)(void*, char*, int), void* hdl)
{
#if SPINLOCK_PROFILE
reporter(hdl, "Spinlock acquired", lock->acquired);
if (lock->acquired)
{
reporter(hdl, "Total no. of spins", lock->spins);
if (lock->acquired)
{
reporter(hdl, "Average no. of spins (overall)", lock->spins / lock->acquired);
}
if (lock->contended)
{
reporter(hdl, "Average no. of spins (when contended)", lock->spins / lock->contended);
}
reporter(hdl, "Maximum no. of spins", lock->maxspins);
reporter(hdl, "Maximim no. of blocked threads", lock->max_waiting);
reporter(hdl, "Contended locks", lock->contended);
if (lock->acquired)
{
reporter(hdl, "Contention percentage", (lock->contended * 100) / lock->acquired);
}
}
#endif
}