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Move atomics and base wait files
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19 files changed

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lines changed

19 files changed

+2713
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‎src/backend/port/Makefile

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -21,7 +21,7 @@ subdir = src/backend/port
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top_builddir = ../../..
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include $(top_builddir)/src/Makefile.global
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24-
OBJS = dynloader.o pg_sema.o pg_shmem.o pg_latch.o $(TAS)
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OBJS = dynloader.o pg_sema.o pg_shmem.o pg_latch.o atomics.o $(TAS)
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ifeq ($(PORTNAME), darwin)
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SUBDIRS += darwin

‎src/backend/port/atomics.c

Lines changed: 148 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,148 @@
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/*-------------------------------------------------------------------------
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*
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* atomics.c
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* Non-Inline parts of the atomics implementation
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*
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* Portions Copyright (c) 2013-2015, PostgreSQL Global Development Group
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*
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*
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* IDENTIFICATION
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* src/backend/port/atomics.c
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "miscadmin.h"
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#include "port/atomics.h"
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#include "storage/spin.h"
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#ifdef PG_HAVE_MEMORY_BARRIER_EMULATION
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#ifdef WIN32
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#error "barriers are required (and provided) on WIN32 platforms"
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#endif
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#include <sys/types.h>
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#include <signal.h>
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#endif
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#ifdef PG_HAVE_MEMORY_BARRIER_EMULATION
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void
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pg_spinlock_barrier(void)
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{
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/*
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* NB: we have to be reentrant here, some barriers are placed in signal
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* handlers.
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*
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* We use kill(0) for the fallback barrier as we assume that kernels on
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* systems old enough to require fallback barrier support will include an
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* appropriate barrier while checking the existence of the postmaster
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* pid.
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*/
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(void) kill(PostmasterPid, 0);
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}
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#endif
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#ifdef PG_HAVE_COMPILER_BARRIER_EMULATION
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void
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pg_extern_compiler_barrier(void)
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{
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/* do nothing */
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}
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#endif
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#ifdef PG_HAVE_ATOMIC_FLAG_SIMULATION
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void
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pg_atomic_init_flag_impl(volatile pg_atomic_flag *ptr)
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{
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StaticAssertStmt(sizeof(ptr->sema) >= sizeof(slock_t),
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"size mismatch of atomic_flag vs slock_t");
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#ifndef HAVE_SPINLOCKS
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/*
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* NB: If we're using semaphore based TAS emulation, be careful to use a
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* separate set of semaphores. Otherwise we'd get in trouble if an atomic
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* var would be manipulated while spinlock is held.
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*/
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s_init_lock_sema((slock_t *) &ptr->sema, true);
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#else
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SpinLockInit((slock_t *) &ptr->sema);
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#endif
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}
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bool
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pg_atomic_test_set_flag_impl(volatile pg_atomic_flag *ptr)
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{
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return TAS((slock_t *) &ptr->sema);
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}
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void
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pg_atomic_clear_flag_impl(volatile pg_atomic_flag *ptr)
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{
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S_UNLOCK((slock_t *) &ptr->sema);
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}
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#endif /* PG_HAVE_ATOMIC_FLAG_SIMULATION */
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#ifdef PG_HAVE_ATOMIC_U32_SIMULATION
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void
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pg_atomic_init_u32_impl(volatile pg_atomic_uint32 *ptr, uint32 val_)
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{
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StaticAssertStmt(sizeof(ptr->sema) >= sizeof(slock_t),
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"size mismatch of atomic_flag vs slock_t");
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/*
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* If we're using semaphore based atomic flags, be careful about nested
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* usage of atomics while a spinlock is held.
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*/
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#ifndef HAVE_SPINLOCKS
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s_init_lock_sema((slock_t *) &ptr->sema, true);
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#else
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SpinLockInit((slock_t *) &ptr->sema);
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#endif
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ptr->value = val_;
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}
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bool
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pg_atomic_compare_exchange_u32_impl(volatile pg_atomic_uint32 *ptr,
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uint32 *expected, uint32 newval)
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{
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bool ret;
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/*
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* Do atomic op under a spinlock. It might look like we could just skip
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* the cmpxchg if the lock isn't available, but that'd just emulate a
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* 'weak' compare and swap. I.e. one that allows spurious failures. Since
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* several algorithms rely on a strong variant and that is efficiently
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* implementable on most major architectures let's emulate it here as
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* well.
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*/
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SpinLockAcquire((slock_t *) &ptr->sema);
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/* perform compare/exchange logic */
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ret = ptr->value == *expected;
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*expected = ptr->value;
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if (ret)
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ptr->value = newval;
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/* and release lock */
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SpinLockRelease((slock_t *) &ptr->sema);
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return ret;
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}
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uint32
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pg_atomic_fetch_add_u32_impl(volatile pg_atomic_uint32 *ptr, int32 add_)
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{
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uint32 oldval;
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SpinLockAcquire((slock_t *) &ptr->sema);
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oldval = ptr->value;
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ptr->value += add_;
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SpinLockRelease((slock_t *) &ptr->sema);
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return oldval;
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}
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#endif /* PG_HAVE_ATOMIC_U32_SIMULATION */

‎src/backend/storage/lmgr/Makefile

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -12,7 +12,8 @@ subdir = src/backend/storage/lmgr
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top_builddir = ../../../..
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include $(top_builddir)/src/Makefile.global
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15-
OBJS = lmgr.o lock.o proc.o deadlock.o lwlock.o spin.o s_lock.o predicate.o
15+
OBJS = lmgr.o lock.o proc.o deadlock.o lwlock.o spin.o s_lock.o \
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predicate.o wait.o
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include $(top_srcdir)/src/backend/common.mk
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