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Change spinlock to use gcc atomic function when available; enhanced spinlock tests.

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This commit is contained in:
counterpoint
2014-09-30 16:08:51 +01:00
parent 32d66e6f84
commit 7dc9cf78f6
2 changed files with 159 additions and 33 deletions
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78
server/core/spinlock.c
View File

@ -30,6 +30,7 @@
#include <spinlock.h>
#include <atomic.h>
#include <time.h>
/**
* Initialise a spinlock.
@ -39,13 +40,13 @@
void
spinlock_init(SPINLOCK *lock)
{
lock->lock = 0;
lock->lock = 0;
#if SPINLOCK_PROFILE
lock->spins = 0;
lock->acquired = 0;
lock->waiting = 0;
lock->max_waiting = 0;
lock->contended = 0;
lock->spins = 0;
lock->acquired = 0;
lock->waiting = 0;
lock->max_waiting = 0;
lock->contended = 0;
#endif
}
@ -62,24 +63,30 @@ int spins = 0;
atomic_add(&(lock->waiting), 1);
#endif
while (atomic_add(&(lock->lock), 1) != 0)
{
atomic_add(&(lock->lock), -1);
#ifdef __GNUC__
while (__sync_lock_test_and_set(&(lock->lock), 1))
while (lock->lock) {
#else
while (atomic_add(&(lock->lock), 1) != 0)
{
atomic_add(&(lock->lock), -1);
#endif
#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_SHELF();
atomic_add(&(lock->waiting), -1);
if (spins)
{
lock->contended++;
if (lock->maxspins < spins)
lock->maxspins = spins;
}
lock->acquired++;
lock->owner = THREAD_SHELF();
atomic_add(&(lock->waiting), -1);
#endif
}
@ -92,16 +99,20 @@ int spins = 0;
int
spinlock_acquire_nowait(SPINLOCK *lock)
{
if (atomic_add(&(lock->lock), 1) != 0)
{
atomic_add(&(lock->lock), -1);
return FALSE;
}
#if SPINLOCK_PROFILE
lock->acquired++;
lock->owner = THREAD_SHELF();
#ifdef __GNUC__
if (__sync_lock_test_and_set(&(lock->lock), 1)) return FALSE;
#else
if (atomic_add(&(lock->lock), 1) != 0)
{
atomic_add(&(lock->lock), -1);
return FALSE;
}
#endif
return TRUE;
#if SPINLOCK_PROFILE
lock->acquired++;
lock->owner = THREAD_SHELF();
#endif
return TRUE;
}
/*
@ -112,11 +123,16 @@ spinlock_acquire_nowait(SPINLOCK *lock)
void
spinlock_release(SPINLOCK *lock)
{
#if SPINLOCK_PROFILE
if (lock->waiting > lock->max_waiting)
lock->max_waiting = lock->waiting;
#if SPINLOCK_PROFILE
if (lock->waiting > lock->max_waiting)
lock->max_waiting = lock->waiting;
#endif
#ifdef __GNUC__
__sync_synchronize(); // Memory barrier.
lock->lock = 0;
#else
atomic_add(&(lock->lock), -1);
#endif
atomic_add(&(lock->lock), -1);
}
/**