Author: Remi Meier <remi.me...@gmail.com>
Branch: c7
Changeset: r637:cae45c13aee6
Date: 2014-01-18 11:39 +0100
http://bitbucket.org/pypy/stmgc/changeset/cae45c13aee6/
Log: add spinlock implementation of reader-writer lock
diff --git a/c7/Makefile b/c7/Makefile
--- a/c7/Makefile
+++ b/c7/Makefile
@@ -14,9 +14,9 @@
rm -f $(BUILD_EXE) $(DEBUG_EXE) $(RELEASE_EXE)
-H_FILES = core.h list.h pagecopy.h
+H_FILES = core.h list.h pagecopy.h reader_writer_lock.h
-C_FILES = core.c list.c pagecopy.c
+C_FILES = core.c list.c pagecopy.c reader_writer_lock.c
DEBUG = -g
diff --git a/c7/core.c b/c7/core.c
--- a/c7/core.c
+++ b/c7/core.c
@@ -13,6 +13,7 @@
#include "core.h"
#include "list.h"
#include "pagecopy.h"
+#include "reader_writer_lock.h"
#define NB_PAGES (256*256) // 256MB
@@ -142,41 +143,40 @@
/************************************************************/
+rwticket rw_shared_lock;
+
/* a multi-reader, single-writer lock: transactions normally take a reader
lock, so don't conflict with each other; when we need to do a global GC,
we take a writer lock to "stop the world". Note the initializer here,
which should give the correct priority for stm_possible_safe_point(). */
-static pthread_rwlock_t rwlock_shared;
+
struct tx_descriptor *in_single_thread = NULL;
void stm_start_shared_lock(void)
{
- int err = pthread_rwlock_rdlock(&rwlock_shared);
- if (err != 0)
- abort();
+ rwticket_rdlock(&rw_shared_lock);
}
-void stm_stop_lock(void)
+void stm_stop_shared_lock(void)
{
- int err = pthread_rwlock_unlock(&rwlock_shared);
- if (err != 0)
- abort();
+ rwticket_rdunlock(&rw_shared_lock);
+}
+
+void stm_stop_exclusive_lock(void)
+{
+ rwticket_wrunlock(&rw_shared_lock);
}
void stm_start_exclusive_lock(void)
{
- int err = pthread_rwlock_wrlock(&rwlock_shared);
- if (err != 0)
- abort();
- if (_STM_TL2->need_abort)
- stm_abort_transaction();
+ rwticket_wrlock(&rw_shared_lock);
}
void _stm_start_safe_point(void)
{
assert(!_STM_TL2->need_abort);
- stm_stop_lock();
+ stm_stop_shared_lock();
}
void _stm_stop_safe_point(void)
@@ -376,9 +376,12 @@
uintptr_t lock_idx = (((uintptr_t)obj) >> 4) - READMARKER_START;
uint8_t previous;
while ((previous = __sync_lock_test_and_set(&write_locks[lock_idx], 1))) {
- usleep(1); /* XXXXXX */
- if (!(previous = __sync_lock_test_and_set(&write_locks[lock_idx], 1)))
- break;
+ /* XXXXXX */
+ //_stm_start_semi_safe_point();
+ usleep(1);
+ //_stm_stop_semi_safe_point();
+ //if (!(previous = __sync_lock_test_and_set(&write_locks[lock_idx],
1)))
+ // break;
stm_abort_transaction();
/* XXX: only abort if we are younger */
spin_loop();
@@ -583,13 +586,8 @@
void stm_setup(void)
-{
- pthread_rwlockattr_t attr;
- pthread_rwlockattr_init(&attr);
- pthread_rwlockattr_setkind_np(&attr,
-
PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP);
- pthread_rwlock_init(&rwlock_shared, &attr);
- pthread_rwlockattr_destroy(&attr);
+{
+ memset(&rw_shared_lock, 0, sizeof(rwticket));
/* Check that some values are acceptable */
assert(4096 <= ((uintptr_t)_STM_TL1));
@@ -685,8 +683,8 @@
void _stm_teardown_thread(void)
{
- assert(!pthread_rwlock_trywrlock(&rwlock_shared));
- assert(!pthread_rwlock_unlock(&rwlock_shared));
+ assert(!rwticket_wrtrylock(&rw_shared_lock));
+ assert(!rwticket_wrunlock(&rw_shared_lock));
stm_list_free(_STM_TL2->modified_objects);
_STM_TL2->modified_objects = NULL;
@@ -708,7 +706,6 @@
munmap(object_pages, TOTAL_MEMORY);
memset(flag_page_private, 0, sizeof(flag_page_private));
memset(write_locks, 0, sizeof(write_locks));
- pthread_rwlock_destroy(&rwlock_shared);
object_pages = NULL;
}
@@ -794,7 +791,7 @@
void stm_stop_transaction(void)
{
assert(_STM_TL2->running_transaction);
- stm_stop_lock();
+ stm_stop_shared_lock();
stm_start_exclusive_lock();
_STM_TL1->jmpbufptr = NULL; /* cannot abort any more */
@@ -899,7 +896,7 @@
/* } */
_STM_TL2->running_transaction = 0;
- stm_stop_lock();
+ stm_stop_exclusive_lock();
fprintf(stderr, "%c", 'C'+_STM_TL2->thread_num*32);
}
@@ -978,7 +975,7 @@
assert(_STM_TL1->jmpbufptr != NULL);
assert(_STM_TL1->jmpbufptr != (jmpbufptr_t *)-1); /* for tests only */
_STM_TL2->running_transaction = 0;
- stm_stop_lock();
+ stm_stop_shared_lock();
fprintf(stderr, "%c", 'A'+_STM_TL2->thread_num*32);
/* reset all the modified objects (incl. re-adding GCFLAG_WRITE_BARRIER) */
diff --git a/c7/demo2.c b/c7/demo2.c
--- a/c7/demo2.c
+++ b/c7/demo2.c
@@ -57,7 +57,9 @@
r_n = r_n->next;
stm_read((objptr_t)r_n);
sum += r_n->value;
-
+
+ _stm_start_safe_point();
+ _stm_stop_safe_point();
if (prev >= r_n->value) {
stm_stop_transaction();
return -1;
@@ -184,7 +186,6 @@
sem_post(&initialized);
status = sem_wait(&go);
assert(status == 0);
-
}
while (check_sorted() == -1) {
diff --git a/c7/test/support.py b/c7/test/support.py
--- a/c7/test/support.py
+++ b/c7/test/support.py
@@ -7,9 +7,9 @@
parent_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
header_files = [os.path.join(parent_dir, _n) for _n in
- "core.h pagecopy.h list.h".split()]
+ "core.h pagecopy.h list.h reader_writer_lock.h".split()]
source_files = [os.path.join(parent_dir, _n) for _n in
- "core.c pagecopy.c list.c".split()]
+ "core.c pagecopy.c list.c reader_writer_lock.c".split()]
_pycache_ = os.path.join(parent_dir, 'test', '__pycache__')
if os.path.exists(_pycache_):
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