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kmp_lock.cpp
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kmp_lock.cpp
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/*
* kmp_lock.cpp -- lock-related functions
*/
//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.txt for details.
//
//===----------------------------------------------------------------------===//
#include <stddef.h>
#include "kmp.h"
#include "kmp_itt.h"
#include "kmp_i18n.h"
#include "kmp_lock.h"
#include "kmp_io.h"
#if KMP_OS_LINUX && (KMP_ARCH_X86 || KMP_ARCH_X86_64 || KMP_ARCH_ARM || KMP_ARCH_AARCH64)
# include <unistd.h>
# include <sys/syscall.h>
// We should really include <futex.h>, but that causes compatibility problems on different
// Linux* OS distributions that either require that you include (or break when you try to include)
// <pci/types.h>.
// Since all we need is the two macros below (which are part of the kernel ABI, so can't change)
// we just define the constants here and don't include <futex.h>
# ifndef FUTEX_WAIT
# define FUTEX_WAIT 0
# endif
# ifndef FUTEX_WAKE
# define FUTEX_WAKE 1
# endif
#endif
/* Implement spin locks for internal library use. */
/* The algorithm implemented is Lamport's bakery lock [1974]. */
void
__kmp_validate_locks( void )
{
int i;
kmp_uint32 x, y;
/* Check to make sure unsigned arithmetic does wraps properly */
x = ~((kmp_uint32) 0) - 2;
y = x - 2;
for (i = 0; i < 8; ++i, ++x, ++y) {
kmp_uint32 z = (x - y);
KMP_ASSERT( z == 2 );
}
KMP_ASSERT( offsetof( kmp_base_queuing_lock, tail_id ) % 8 == 0 );
}
/* ------------------------------------------------------------------------ */
/* test and set locks */
//
// For the non-nested locks, we can only assume that the first 4 bytes were
// allocated, since gcc only allocates 4 bytes for omp_lock_t, and the Intel
// compiler only allocates a 4 byte pointer on IA-32 architecture. On
// Windows* OS on Intel(R) 64, we can assume that all 8 bytes were allocated.
//
// gcc reserves >= 8 bytes for nested locks, so we can assume that the
// entire 8 bytes were allocated for nested locks on all 64-bit platforms.
//
static kmp_int32
__kmp_get_tas_lock_owner( kmp_tas_lock_t *lck )
{
return KMP_LOCK_STRIP(TCR_4( lck->lk.poll )) - 1;
}
static inline bool
__kmp_is_tas_lock_nestable( kmp_tas_lock_t *lck )
{
return lck->lk.depth_locked != -1;
}
__forceinline static int
__kmp_acquire_tas_lock_timed_template( kmp_tas_lock_t *lck, kmp_int32 gtid )
{
KMP_MB();
#ifdef USE_LOCK_PROFILE
kmp_uint32 curr = TCR_4( lck->lk.poll );
if ( ( curr != 0 ) && ( curr != gtid + 1 ) )
__kmp_printf( "LOCK CONTENTION: %p\n", lck );
/* else __kmp_printf( "." );*/
#endif /* USE_LOCK_PROFILE */
if ( ( lck->lk.poll == KMP_LOCK_FREE(tas) )
&& KMP_COMPARE_AND_STORE_ACQ32( & ( lck->lk.poll ), KMP_LOCK_FREE(tas), KMP_LOCK_BUSY(gtid+1, tas) ) ) {
KMP_FSYNC_ACQUIRED(lck);
return KMP_LOCK_ACQUIRED_FIRST;
}
kmp_uint32 spins;
KMP_FSYNC_PREPARE( lck );
KMP_INIT_YIELD( spins );
if ( TCR_4( __kmp_nth ) > ( __kmp_avail_proc ? __kmp_avail_proc :
__kmp_xproc ) ) {
KMP_YIELD( TRUE );
}
else {
KMP_YIELD_SPIN( spins );
}
while ( ( lck->lk.poll != KMP_LOCK_FREE(tas) ) ||
( ! KMP_COMPARE_AND_STORE_ACQ32( & ( lck->lk.poll ), KMP_LOCK_FREE(tas), KMP_LOCK_BUSY(gtid+1, tas) ) ) ) {
//
// FIXME - use exponential backoff here
//
if ( TCR_4( __kmp_nth ) > ( __kmp_avail_proc ? __kmp_avail_proc :
__kmp_xproc ) ) {
KMP_YIELD( TRUE );
}
else {
KMP_YIELD_SPIN( spins );
}
}
KMP_FSYNC_ACQUIRED( lck );
return KMP_LOCK_ACQUIRED_FIRST;
}
int
__kmp_acquire_tas_lock( kmp_tas_lock_t *lck, kmp_int32 gtid )
{
return __kmp_acquire_tas_lock_timed_template( lck, gtid );
}
static int
__kmp_acquire_tas_lock_with_checks( kmp_tas_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_set_lock";
if ( ( sizeof ( kmp_tas_lock_t ) <= OMP_LOCK_T_SIZE )
&& __kmp_is_tas_lock_nestable( lck ) ) {
KMP_FATAL( LockNestableUsedAsSimple, func );
}
if ( ( gtid >= 0 ) && ( __kmp_get_tas_lock_owner( lck ) == gtid ) ) {
KMP_FATAL( LockIsAlreadyOwned, func );
}
return __kmp_acquire_tas_lock( lck, gtid );
}
int
__kmp_test_tas_lock( kmp_tas_lock_t *lck, kmp_int32 gtid )
{
if ( ( lck->lk.poll == KMP_LOCK_FREE(tas) )
&& KMP_COMPARE_AND_STORE_ACQ32( & ( lck->lk.poll ), KMP_LOCK_FREE(tas), KMP_LOCK_BUSY(gtid+1, tas) ) ) {
KMP_FSYNC_ACQUIRED( lck );
return TRUE;
}
return FALSE;
}
static int
__kmp_test_tas_lock_with_checks( kmp_tas_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_test_lock";
if ( ( sizeof ( kmp_tas_lock_t ) <= OMP_LOCK_T_SIZE )
&& __kmp_is_tas_lock_nestable( lck ) ) {
KMP_FATAL( LockNestableUsedAsSimple, func );
}
return __kmp_test_tas_lock( lck, gtid );
}
int
__kmp_release_tas_lock( kmp_tas_lock_t *lck, kmp_int32 gtid )
{
KMP_MB(); /* Flush all pending memory write invalidates. */
KMP_FSYNC_RELEASING(lck);
KMP_ST_REL32( &(lck->lk.poll), KMP_LOCK_FREE(tas) );
KMP_MB(); /* Flush all pending memory write invalidates. */
KMP_YIELD( TCR_4( __kmp_nth ) > ( __kmp_avail_proc ? __kmp_avail_proc :
__kmp_xproc ) );
return KMP_LOCK_RELEASED;
}
static int
__kmp_release_tas_lock_with_checks( kmp_tas_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_unset_lock";
KMP_MB(); /* in case another processor initialized lock */
if ( ( sizeof ( kmp_tas_lock_t ) <= OMP_LOCK_T_SIZE )
&& __kmp_is_tas_lock_nestable( lck ) ) {
KMP_FATAL( LockNestableUsedAsSimple, func );
}
if ( __kmp_get_tas_lock_owner( lck ) == -1 ) {
KMP_FATAL( LockUnsettingFree, func );
}
if ( ( gtid >= 0 ) && ( __kmp_get_tas_lock_owner( lck ) >= 0 )
&& ( __kmp_get_tas_lock_owner( lck ) != gtid ) ) {
KMP_FATAL( LockUnsettingSetByAnother, func );
}
return __kmp_release_tas_lock( lck, gtid );
}
void
__kmp_init_tas_lock( kmp_tas_lock_t * lck )
{
TCW_4( lck->lk.poll, KMP_LOCK_FREE(tas) );
}
static void
__kmp_init_tas_lock_with_checks( kmp_tas_lock_t * lck )
{
__kmp_init_tas_lock( lck );
}
void
__kmp_destroy_tas_lock( kmp_tas_lock_t *lck )
{
lck->lk.poll = 0;
}
static void
__kmp_destroy_tas_lock_with_checks( kmp_tas_lock_t *lck )
{
char const * const func = "omp_destroy_lock";
if ( ( sizeof ( kmp_tas_lock_t ) <= OMP_LOCK_T_SIZE )
&& __kmp_is_tas_lock_nestable( lck ) ) {
KMP_FATAL( LockNestableUsedAsSimple, func );
}
if ( __kmp_get_tas_lock_owner( lck ) != -1 ) {
KMP_FATAL( LockStillOwned, func );
}
__kmp_destroy_tas_lock( lck );
}
//
// nested test and set locks
//
int
__kmp_acquire_nested_tas_lock( kmp_tas_lock_t *lck, kmp_int32 gtid )
{
KMP_DEBUG_ASSERT( gtid >= 0 );
if ( __kmp_get_tas_lock_owner( lck ) == gtid ) {
lck->lk.depth_locked += 1;
return KMP_LOCK_ACQUIRED_NEXT;
}
else {
__kmp_acquire_tas_lock_timed_template( lck, gtid );
lck->lk.depth_locked = 1;
return KMP_LOCK_ACQUIRED_FIRST;
}
}
static int
__kmp_acquire_nested_tas_lock_with_checks( kmp_tas_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_set_nest_lock";
if ( ! __kmp_is_tas_lock_nestable( lck ) ) {
KMP_FATAL( LockSimpleUsedAsNestable, func );
}
return __kmp_acquire_nested_tas_lock( lck, gtid );
}
int
__kmp_test_nested_tas_lock( kmp_tas_lock_t *lck, kmp_int32 gtid )
{
int retval;
KMP_DEBUG_ASSERT( gtid >= 0 );
if ( __kmp_get_tas_lock_owner( lck ) == gtid ) {
retval = ++lck->lk.depth_locked;
}
else if ( !__kmp_test_tas_lock( lck, gtid ) ) {
retval = 0;
}
else {
KMP_MB();
retval = lck->lk.depth_locked = 1;
}
return retval;
}
static int
__kmp_test_nested_tas_lock_with_checks( kmp_tas_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_test_nest_lock";
if ( ! __kmp_is_tas_lock_nestable( lck ) ) {
KMP_FATAL( LockSimpleUsedAsNestable, func );
}
return __kmp_test_nested_tas_lock( lck, gtid );
}
int
__kmp_release_nested_tas_lock( kmp_tas_lock_t *lck, kmp_int32 gtid )
{
KMP_DEBUG_ASSERT( gtid >= 0 );
KMP_MB();
if ( --(lck->lk.depth_locked) == 0 ) {
__kmp_release_tas_lock( lck, gtid );
return KMP_LOCK_RELEASED;
}
return KMP_LOCK_STILL_HELD;
}
static int
__kmp_release_nested_tas_lock_with_checks( kmp_tas_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_unset_nest_lock";
KMP_MB(); /* in case another processor initialized lock */
if ( ! __kmp_is_tas_lock_nestable( lck ) ) {
KMP_FATAL( LockSimpleUsedAsNestable, func );
}
if ( __kmp_get_tas_lock_owner( lck ) == -1 ) {
KMP_FATAL( LockUnsettingFree, func );
}
if ( __kmp_get_tas_lock_owner( lck ) != gtid ) {
KMP_FATAL( LockUnsettingSetByAnother, func );
}
return __kmp_release_nested_tas_lock( lck, gtid );
}
void
__kmp_init_nested_tas_lock( kmp_tas_lock_t * lck )
{
__kmp_init_tas_lock( lck );
lck->lk.depth_locked = 0; // >= 0 for nestable locks, -1 for simple locks
}
static void
__kmp_init_nested_tas_lock_with_checks( kmp_tas_lock_t * lck )
{
__kmp_init_nested_tas_lock( lck );
}
void
__kmp_destroy_nested_tas_lock( kmp_tas_lock_t *lck )
{
__kmp_destroy_tas_lock( lck );
lck->lk.depth_locked = 0;
}
static void
__kmp_destroy_nested_tas_lock_with_checks( kmp_tas_lock_t *lck )
{
char const * const func = "omp_destroy_nest_lock";
if ( ! __kmp_is_tas_lock_nestable( lck ) ) {
KMP_FATAL( LockSimpleUsedAsNestable, func );
}
if ( __kmp_get_tas_lock_owner( lck ) != -1 ) {
KMP_FATAL( LockStillOwned, func );
}
__kmp_destroy_nested_tas_lock( lck );
}
#if KMP_OS_LINUX && (KMP_ARCH_X86 || KMP_ARCH_X86_64 || KMP_ARCH_ARM || KMP_ARCH_AARCH64)
/* ------------------------------------------------------------------------ */
/* futex locks */
// futex locks are really just test and set locks, with a different method
// of handling contention. They take the same amount of space as test and
// set locks, and are allocated the same way (i.e. use the area allocated by
// the compiler for non-nested locks / allocate nested locks on the heap).
static kmp_int32
__kmp_get_futex_lock_owner( kmp_futex_lock_t *lck )
{
return KMP_LOCK_STRIP(( TCR_4( lck->lk.poll ) >> 1 )) - 1;
}
static inline bool
__kmp_is_futex_lock_nestable( kmp_futex_lock_t *lck )
{
return lck->lk.depth_locked != -1;
}
__forceinline static int
__kmp_acquire_futex_lock_timed_template( kmp_futex_lock_t *lck, kmp_int32 gtid )
{
kmp_int32 gtid_code = ( gtid + 1 ) << 1;
KMP_MB();
#ifdef USE_LOCK_PROFILE
kmp_uint32 curr = TCR_4( lck->lk.poll );
if ( ( curr != 0 ) && ( curr != gtid_code ) )
__kmp_printf( "LOCK CONTENTION: %p\n", lck );
/* else __kmp_printf( "." );*/
#endif /* USE_LOCK_PROFILE */
KMP_FSYNC_PREPARE( lck );
KA_TRACE( 1000, ("__kmp_acquire_futex_lock: lck:%p(0x%x), T#%d entering\n",
lck, lck->lk.poll, gtid ) );
kmp_int32 poll_val;
while ( ( poll_val = KMP_COMPARE_AND_STORE_RET32( & ( lck->lk.poll ), KMP_LOCK_FREE(futex),
KMP_LOCK_BUSY(gtid_code, futex) ) ) != KMP_LOCK_FREE(futex) ) {
kmp_int32 cond = KMP_LOCK_STRIP(poll_val) & 1;
KA_TRACE( 1000, ("__kmp_acquire_futex_lock: lck:%p, T#%d poll_val = 0x%x cond = 0x%x\n",
lck, gtid, poll_val, cond ) );
//
// NOTE: if you try to use the following condition for this branch
//
// if ( poll_val & 1 == 0 )
//
// Then the 12.0 compiler has a bug where the following block will
// always be skipped, regardless of the value of the LSB of poll_val.
//
if ( ! cond ) {
//
// Try to set the lsb in the poll to indicate to the owner
// thread that they need to wake this thread up.
//
if ( ! KMP_COMPARE_AND_STORE_REL32( & ( lck->lk.poll ), poll_val, poll_val | KMP_LOCK_BUSY(1, futex) ) ) {
KA_TRACE( 1000, ("__kmp_acquire_futex_lock: lck:%p(0x%x), T#%d can't set bit 0\n",
lck, lck->lk.poll, gtid ) );
continue;
}
poll_val |= KMP_LOCK_BUSY(1, futex);
KA_TRACE( 1000, ("__kmp_acquire_futex_lock: lck:%p(0x%x), T#%d bit 0 set\n",
lck, lck->lk.poll, gtid ) );
}
KA_TRACE( 1000, ("__kmp_acquire_futex_lock: lck:%p, T#%d before futex_wait(0x%x)\n",
lck, gtid, poll_val ) );
kmp_int32 rc;
if ( ( rc = syscall( __NR_futex, & ( lck->lk.poll ), FUTEX_WAIT,
poll_val, NULL, NULL, 0 ) ) != 0 ) {
KA_TRACE( 1000, ("__kmp_acquire_futex_lock: lck:%p, T#%d futex_wait(0x%x) failed (rc=%d errno=%d)\n",
lck, gtid, poll_val, rc, errno ) );
continue;
}
KA_TRACE( 1000, ("__kmp_acquire_futex_lock: lck:%p, T#%d after futex_wait(0x%x)\n",
lck, gtid, poll_val ) );
//
// This thread has now done a successful futex wait call and was
// entered on the OS futex queue. We must now perform a futex
// wake call when releasing the lock, as we have no idea how many
// other threads are in the queue.
//
gtid_code |= 1;
}
KMP_FSYNC_ACQUIRED( lck );
KA_TRACE( 1000, ("__kmp_acquire_futex_lock: lck:%p(0x%x), T#%d exiting\n",
lck, lck->lk.poll, gtid ) );
return KMP_LOCK_ACQUIRED_FIRST;
}
int
__kmp_acquire_futex_lock( kmp_futex_lock_t *lck, kmp_int32 gtid )
{
return __kmp_acquire_futex_lock_timed_template( lck, gtid );
}
static int
__kmp_acquire_futex_lock_with_checks( kmp_futex_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_set_lock";
if ( ( sizeof ( kmp_futex_lock_t ) <= OMP_LOCK_T_SIZE )
&& __kmp_is_futex_lock_nestable( lck ) ) {
KMP_FATAL( LockNestableUsedAsSimple, func );
}
if ( ( gtid >= 0 ) && ( __kmp_get_futex_lock_owner( lck ) == gtid ) ) {
KMP_FATAL( LockIsAlreadyOwned, func );
}
return __kmp_acquire_futex_lock( lck, gtid );
}
int
__kmp_test_futex_lock( kmp_futex_lock_t *lck, kmp_int32 gtid )
{
if ( KMP_COMPARE_AND_STORE_ACQ32( & ( lck->lk.poll ), KMP_LOCK_FREE(futex), KMP_LOCK_BUSY(gtid+1, futex) << 1 ) ) {
KMP_FSYNC_ACQUIRED( lck );
return TRUE;
}
return FALSE;
}
static int
__kmp_test_futex_lock_with_checks( kmp_futex_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_test_lock";
if ( ( sizeof ( kmp_futex_lock_t ) <= OMP_LOCK_T_SIZE )
&& __kmp_is_futex_lock_nestable( lck ) ) {
KMP_FATAL( LockNestableUsedAsSimple, func );
}
return __kmp_test_futex_lock( lck, gtid );
}
int
__kmp_release_futex_lock( kmp_futex_lock_t *lck, kmp_int32 gtid )
{
KMP_MB(); /* Flush all pending memory write invalidates. */
KA_TRACE( 1000, ("__kmp_release_futex_lock: lck:%p(0x%x), T#%d entering\n",
lck, lck->lk.poll, gtid ) );
KMP_FSYNC_RELEASING(lck);
kmp_int32 poll_val = KMP_XCHG_FIXED32( & ( lck->lk.poll ), KMP_LOCK_FREE(futex) );
KA_TRACE( 1000, ("__kmp_release_futex_lock: lck:%p, T#%d released poll_val = 0x%x\n",
lck, gtid, poll_val ) );
if ( KMP_LOCK_STRIP(poll_val) & 1 ) {
KA_TRACE( 1000, ("__kmp_release_futex_lock: lck:%p, T#%d futex_wake 1 thread\n",
lck, gtid ) );
syscall( __NR_futex, & ( lck->lk.poll ), FUTEX_WAKE, KMP_LOCK_BUSY(1, futex), NULL, NULL, 0 );
}
KMP_MB(); /* Flush all pending memory write invalidates. */
KA_TRACE( 1000, ("__kmp_release_futex_lock: lck:%p(0x%x), T#%d exiting\n",
lck, lck->lk.poll, gtid ) );
KMP_YIELD( TCR_4( __kmp_nth ) > ( __kmp_avail_proc ? __kmp_avail_proc :
__kmp_xproc ) );
return KMP_LOCK_RELEASED;
}
static int
__kmp_release_futex_lock_with_checks( kmp_futex_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_unset_lock";
KMP_MB(); /* in case another processor initialized lock */
if ( ( sizeof ( kmp_futex_lock_t ) <= OMP_LOCK_T_SIZE )
&& __kmp_is_futex_lock_nestable( lck ) ) {
KMP_FATAL( LockNestableUsedAsSimple, func );
}
if ( __kmp_get_futex_lock_owner( lck ) == -1 ) {
KMP_FATAL( LockUnsettingFree, func );
}
if ( ( gtid >= 0 ) && ( __kmp_get_futex_lock_owner( lck ) >= 0 )
&& ( __kmp_get_futex_lock_owner( lck ) != gtid ) ) {
KMP_FATAL( LockUnsettingSetByAnother, func );
}
return __kmp_release_futex_lock( lck, gtid );
}
void
__kmp_init_futex_lock( kmp_futex_lock_t * lck )
{
TCW_4( lck->lk.poll, KMP_LOCK_FREE(futex) );
}
static void
__kmp_init_futex_lock_with_checks( kmp_futex_lock_t * lck )
{
__kmp_init_futex_lock( lck );
}
void
__kmp_destroy_futex_lock( kmp_futex_lock_t *lck )
{
lck->lk.poll = 0;
}
static void
__kmp_destroy_futex_lock_with_checks( kmp_futex_lock_t *lck )
{
char const * const func = "omp_destroy_lock";
if ( ( sizeof ( kmp_futex_lock_t ) <= OMP_LOCK_T_SIZE )
&& __kmp_is_futex_lock_nestable( lck ) ) {
KMP_FATAL( LockNestableUsedAsSimple, func );
}
if ( __kmp_get_futex_lock_owner( lck ) != -1 ) {
KMP_FATAL( LockStillOwned, func );
}
__kmp_destroy_futex_lock( lck );
}
//
// nested futex locks
//
int
__kmp_acquire_nested_futex_lock( kmp_futex_lock_t *lck, kmp_int32 gtid )
{
KMP_DEBUG_ASSERT( gtid >= 0 );
if ( __kmp_get_futex_lock_owner( lck ) == gtid ) {
lck->lk.depth_locked += 1;
return KMP_LOCK_ACQUIRED_NEXT;
}
else {
__kmp_acquire_futex_lock_timed_template( lck, gtid );
lck->lk.depth_locked = 1;
return KMP_LOCK_ACQUIRED_FIRST;
}
}
static int
__kmp_acquire_nested_futex_lock_with_checks( kmp_futex_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_set_nest_lock";
if ( ! __kmp_is_futex_lock_nestable( lck ) ) {
KMP_FATAL( LockSimpleUsedAsNestable, func );
}
return __kmp_acquire_nested_futex_lock( lck, gtid );
}
int
__kmp_test_nested_futex_lock( kmp_futex_lock_t *lck, kmp_int32 gtid )
{
int retval;
KMP_DEBUG_ASSERT( gtid >= 0 );
if ( __kmp_get_futex_lock_owner( lck ) == gtid ) {
retval = ++lck->lk.depth_locked;
}
else if ( !__kmp_test_futex_lock( lck, gtid ) ) {
retval = 0;
}
else {
KMP_MB();
retval = lck->lk.depth_locked = 1;
}
return retval;
}
static int
__kmp_test_nested_futex_lock_with_checks( kmp_futex_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_test_nest_lock";
if ( ! __kmp_is_futex_lock_nestable( lck ) ) {
KMP_FATAL( LockSimpleUsedAsNestable, func );
}
return __kmp_test_nested_futex_lock( lck, gtid );
}
int
__kmp_release_nested_futex_lock( kmp_futex_lock_t *lck, kmp_int32 gtid )
{
KMP_DEBUG_ASSERT( gtid >= 0 );
KMP_MB();
if ( --(lck->lk.depth_locked) == 0 ) {
__kmp_release_futex_lock( lck, gtid );
return KMP_LOCK_RELEASED;
}
return KMP_LOCK_STILL_HELD;
}
static int
__kmp_release_nested_futex_lock_with_checks( kmp_futex_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_unset_nest_lock";
KMP_MB(); /* in case another processor initialized lock */
if ( ! __kmp_is_futex_lock_nestable( lck ) ) {
KMP_FATAL( LockSimpleUsedAsNestable, func );
}
if ( __kmp_get_futex_lock_owner( lck ) == -1 ) {
KMP_FATAL( LockUnsettingFree, func );
}
if ( __kmp_get_futex_lock_owner( lck ) != gtid ) {
KMP_FATAL( LockUnsettingSetByAnother, func );
}
return __kmp_release_nested_futex_lock( lck, gtid );
}
void
__kmp_init_nested_futex_lock( kmp_futex_lock_t * lck )
{
__kmp_init_futex_lock( lck );
lck->lk.depth_locked = 0; // >= 0 for nestable locks, -1 for simple locks
}
static void
__kmp_init_nested_futex_lock_with_checks( kmp_futex_lock_t * lck )
{
__kmp_init_nested_futex_lock( lck );
}
void
__kmp_destroy_nested_futex_lock( kmp_futex_lock_t *lck )
{
__kmp_destroy_futex_lock( lck );
lck->lk.depth_locked = 0;
}
static void
__kmp_destroy_nested_futex_lock_with_checks( kmp_futex_lock_t *lck )
{
char const * const func = "omp_destroy_nest_lock";
if ( ! __kmp_is_futex_lock_nestable( lck ) ) {
KMP_FATAL( LockSimpleUsedAsNestable, func );
}
if ( __kmp_get_futex_lock_owner( lck ) != -1 ) {
KMP_FATAL( LockStillOwned, func );
}
__kmp_destroy_nested_futex_lock( lck );
}
#endif // KMP_OS_LINUX && (KMP_ARCH_X86 || KMP_ARCH_X86_64 || KMP_ARCH_ARM)
/* ------------------------------------------------------------------------ */
/* ticket (bakery) locks */
static kmp_int32
__kmp_get_ticket_lock_owner( kmp_ticket_lock_t *lck )
{
return TCR_4( lck->lk.owner_id ) - 1;
}
static inline bool
__kmp_is_ticket_lock_nestable( kmp_ticket_lock_t *lck )
{
return lck->lk.depth_locked != -1;
}
static kmp_uint32
__kmp_bakery_check(kmp_uint value, kmp_uint checker)
{
register kmp_uint32 pause;
if (value == checker) {
return TRUE;
}
for (pause = checker - value; pause != 0; --pause);
return FALSE;
}
__forceinline static int
__kmp_acquire_ticket_lock_timed_template( kmp_ticket_lock_t *lck, kmp_int32 gtid )
{
kmp_uint32 my_ticket;
KMP_MB();
my_ticket = KMP_TEST_THEN_INC32( (kmp_int32 *) &lck->lk.next_ticket );
#ifdef USE_LOCK_PROFILE
if ( TCR_4( lck->lk.now_serving ) != my_ticket )
__kmp_printf( "LOCK CONTENTION: %p\n", lck );
/* else __kmp_printf( "." );*/
#endif /* USE_LOCK_PROFILE */
if ( TCR_4( lck->lk.now_serving ) == my_ticket ) {
KMP_FSYNC_ACQUIRED(lck);
return KMP_LOCK_ACQUIRED_FIRST;
}
KMP_WAIT_YIELD( &lck->lk.now_serving, my_ticket, __kmp_bakery_check, lck );
KMP_FSYNC_ACQUIRED(lck);
return KMP_LOCK_ACQUIRED_FIRST;
}
int
__kmp_acquire_ticket_lock( kmp_ticket_lock_t *lck, kmp_int32 gtid )
{
return __kmp_acquire_ticket_lock_timed_template( lck, gtid );
}
static int
__kmp_acquire_ticket_lock_with_checks( kmp_ticket_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_set_lock";
if ( lck->lk.initialized != lck ) {
KMP_FATAL( LockIsUninitialized, func );
}
if ( __kmp_is_ticket_lock_nestable( lck ) ) {
KMP_FATAL( LockNestableUsedAsSimple, func );
}
if ( ( gtid >= 0 ) && ( __kmp_get_ticket_lock_owner( lck ) == gtid ) ) {
KMP_FATAL( LockIsAlreadyOwned, func );
}
__kmp_acquire_ticket_lock( lck, gtid );
lck->lk.owner_id = gtid + 1;
return KMP_LOCK_ACQUIRED_FIRST;
}
int
__kmp_test_ticket_lock( kmp_ticket_lock_t *lck, kmp_int32 gtid )
{
kmp_uint32 my_ticket = TCR_4( lck->lk.next_ticket );
if ( TCR_4( lck->lk.now_serving ) == my_ticket ) {
kmp_uint32 next_ticket = my_ticket + 1;
if ( KMP_COMPARE_AND_STORE_ACQ32( (kmp_int32 *) &lck->lk.next_ticket,
my_ticket, next_ticket ) ) {
KMP_FSYNC_ACQUIRED( lck );
return TRUE;
}
}
return FALSE;
}
static int
__kmp_test_ticket_lock_with_checks( kmp_ticket_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_test_lock";
if ( lck->lk.initialized != lck ) {
KMP_FATAL( LockIsUninitialized, func );
}
if ( __kmp_is_ticket_lock_nestable( lck ) ) {
KMP_FATAL( LockNestableUsedAsSimple, func );
}
int retval = __kmp_test_ticket_lock( lck, gtid );
if ( retval ) {
lck->lk.owner_id = gtid + 1;
}
return retval;
}
int
__kmp_release_ticket_lock( kmp_ticket_lock_t *lck, kmp_int32 gtid )
{
kmp_uint32 distance;
KMP_MB(); /* Flush all pending memory write invalidates. */
KMP_FSYNC_RELEASING(lck);
distance = ( TCR_4( lck->lk.next_ticket ) - TCR_4( lck->lk.now_serving ) );
KMP_ST_REL32( &(lck->lk.now_serving), lck->lk.now_serving + 1 );
KMP_MB(); /* Flush all pending memory write invalidates. */
KMP_YIELD( distance
> (kmp_uint32) (__kmp_avail_proc ? __kmp_avail_proc : __kmp_xproc) );
return KMP_LOCK_RELEASED;
}
static int
__kmp_release_ticket_lock_with_checks( kmp_ticket_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_unset_lock";
KMP_MB(); /* in case another processor initialized lock */
if ( lck->lk.initialized != lck ) {
KMP_FATAL( LockIsUninitialized, func );
}
if ( __kmp_is_ticket_lock_nestable( lck ) ) {
KMP_FATAL( LockNestableUsedAsSimple, func );
}
if ( __kmp_get_ticket_lock_owner( lck ) == -1 ) {
KMP_FATAL( LockUnsettingFree, func );
}
if ( ( gtid >= 0 ) && ( __kmp_get_ticket_lock_owner( lck ) >= 0 )
&& ( __kmp_get_ticket_lock_owner( lck ) != gtid ) ) {
KMP_FATAL( LockUnsettingSetByAnother, func );
}
lck->lk.owner_id = 0;
return __kmp_release_ticket_lock( lck, gtid );
}
void
__kmp_init_ticket_lock( kmp_ticket_lock_t * lck )
{
lck->lk.location = NULL;
TCW_4( lck->lk.next_ticket, 0 );
TCW_4( lck->lk.now_serving, 0 );
lck->lk.owner_id = 0; // no thread owns the lock.
lck->lk.depth_locked = -1; // -1 => not a nested lock.
lck->lk.initialized = (kmp_ticket_lock *)lck;
}
static void
__kmp_init_ticket_lock_with_checks( kmp_ticket_lock_t * lck )
{
__kmp_init_ticket_lock( lck );
}
void
__kmp_destroy_ticket_lock( kmp_ticket_lock_t *lck )
{
lck->lk.initialized = NULL;
lck->lk.location = NULL;
lck->lk.next_ticket = 0;
lck->lk.now_serving = 0;
lck->lk.owner_id = 0;
lck->lk.depth_locked = -1;
}
static void
__kmp_destroy_ticket_lock_with_checks( kmp_ticket_lock_t *lck )
{
char const * const func = "omp_destroy_lock";
if ( lck->lk.initialized != lck ) {
KMP_FATAL( LockIsUninitialized, func );
}
if ( __kmp_is_ticket_lock_nestable( lck ) ) {
KMP_FATAL( LockNestableUsedAsSimple, func );
}
if ( __kmp_get_ticket_lock_owner( lck ) != -1 ) {
KMP_FATAL( LockStillOwned, func );
}
__kmp_destroy_ticket_lock( lck );
}
//
// nested ticket locks
//
int
__kmp_acquire_nested_ticket_lock( kmp_ticket_lock_t *lck, kmp_int32 gtid )
{
KMP_DEBUG_ASSERT( gtid >= 0 );
if ( __kmp_get_ticket_lock_owner( lck ) == gtid ) {
lck->lk.depth_locked += 1;
return KMP_LOCK_ACQUIRED_NEXT;
}
else {
__kmp_acquire_ticket_lock_timed_template( lck, gtid );
KMP_MB();
lck->lk.depth_locked = 1;
KMP_MB();
lck->lk.owner_id = gtid + 1;
return KMP_LOCK_ACQUIRED_FIRST;
}
}
static int
__kmp_acquire_nested_ticket_lock_with_checks( kmp_ticket_lock_t *lck, kmp_int32 gtid )
{
char const * const func = "omp_set_nest_lock";
if ( lck->lk.initialized != lck ) {
KMP_FATAL( LockIsUninitialized, func );
}
if ( ! __kmp_is_ticket_lock_nestable( lck ) ) {
KMP_FATAL( LockSimpleUsedAsNestable, func );
}
return __kmp_acquire_nested_ticket_lock( lck, gtid );
}
int
__kmp_test_nested_ticket_lock( kmp_ticket_lock_t *lck, kmp_int32 gtid )
{
int retval;
KMP_DEBUG_ASSERT( gtid >= 0 );
if ( __kmp_get_ticket_lock_owner( lck ) == gtid ) {
retval = ++lck->lk.depth_locked;
}
else if ( !__kmp_test_ticket_lock( lck, gtid ) ) {
retval = 0;
}
else {
KMP_MB();
retval = lck->lk.depth_locked = 1;
KMP_MB();
lck->lk.owner_id = gtid + 1;
}
return retval;
}
static int
__kmp_test_nested_ticket_lock_with_checks( kmp_ticket_lock_t *lck,
kmp_int32 gtid )
{
char const * const func = "omp_test_nest_lock";
if ( lck->lk.initialized != lck ) {
KMP_FATAL( LockIsUninitialized, func );
}
if ( ! __kmp_is_ticket_lock_nestable( lck ) ) {
KMP_FATAL( LockSimpleUsedAsNestable, func );
}
return __kmp_test_nested_ticket_lock( lck, gtid );
}
int
__kmp_release_nested_ticket_lock( kmp_ticket_lock_t *lck, kmp_int32 gtid )
{
KMP_DEBUG_ASSERT( gtid >= 0 );
KMP_MB();
if ( --(lck->lk.depth_locked) == 0 ) {
KMP_MB();
lck->lk.owner_id = 0;
__kmp_release_ticket_lock( lck, gtid );
return KMP_LOCK_RELEASED;
}
return KMP_LOCK_STILL_HELD;
}
static int
__kmp_release_nested_ticket_lock_with_checks( kmp_ticket_lock_t *lck, kmp_int32 gtid )