Author: Remi Meier <remi.me...@gmail.com>
Branch: stmgc-c4
Changeset: r67829:7384b3c8c0fc
Date: 2013-11-04 13:16 +0100
http://bitbucket.org/pypy/pypy/changeset/7384b3c8c0fc/
Log: import stmgc with stop_all_other_threads() and partial commit for
inevitable transactions
diff --git a/rpython/translator/stm/src_stm/et.c
b/rpython/translator/stm/src_stm/et.c
--- a/rpython/translator/stm/src_stm/et.c
+++ b/rpython/translator/stm/src_stm/et.c
@@ -1072,11 +1072,12 @@
return d->atomic;
}
-static void init_transaction(struct tx_descriptor *d)
+static void init_transaction(struct tx_descriptor *d, int already_locked)
{
assert(d->atomic == 0);
assert(*d->active_ref == 0);
- stm_start_sharedlock();
+ if (!already_locked)
+ stm_start_sharedlock();
assert(*d->active_ref == 0);
if (clock_gettime(CLOCK_MONOTONIC, &d->start_real_time) < 0) {
@@ -1097,7 +1098,7 @@
void stm_begin_transaction(void *buf, void (*longjmp_callback)(void *))
{
struct tx_descriptor *d = thread_descriptor;
- init_transaction(d);
+ init_transaction(d, 0);
*d->active_ref = 1;
d->setjmp_buf = buf;
d->longjmp_callback = longjmp_callback;
@@ -1426,13 +1427,14 @@
dprintf(("private_from_protected: clear (abort)\n"));
}
-void CommitTransaction(void)
+void CommitTransaction(int stay_inevitable)
{ /* must save roots around this call */
revision_t cur_time;
struct tx_descriptor *d = thread_descriptor;
assert(*d->active_ref >= 1);
assert(d->atomic == 0);
- dprintf(("CommitTransaction(%p)\n", d));
+ dprintf(("CommitTransaction(%d): %p\n", stay_inevitable, d));
+
spinlock_acquire(d->public_descriptor->collection_lock, 'C'); /*committing*/
if (d->public_descriptor->stolen_objects.size != 0)
stm_normalize_stolen_objects(d);
@@ -1446,7 +1448,11 @@
{
stm_fatalerror("global_cur_time modified even though we are inev\n");
}
- inev_mutex_release();
+
+ if (!stay_inevitable) {
+ /* we simply don't release the mutex. */
+ inev_mutex_release();
+ }
}
else
{
@@ -1504,7 +1510,8 @@
spinlock_release(d->public_descriptor->collection_lock);
d->num_commits++;
*d->active_ref = 0;
- stm_stop_sharedlock();
+ if (!stay_inevitable)
+ stm_stop_sharedlock();
/* clear the list of callbacks that would have been called
on abort */
@@ -1569,13 +1576,25 @@
make_inevitable(d); /* cannot abort any more */
}
-void BeginInevitableTransaction(void)
+void BeginInevitableTransaction(int already_inevitable)
{ /* must save roots around this call */
struct tx_descriptor *d = thread_descriptor;
revision_t cur_time;
- init_transaction(d);
- cur_time = acquire_inev_mutex_and_mark_global_cur_time(d);
+ init_transaction(d, already_inevitable);
+
+ if (already_inevitable) {
+ cur_time = ACCESS_ONCE(global_cur_time);
+ assert((cur_time & 1) == 0);
+ if (!bool_cas(&global_cur_time, cur_time, cur_time + 1)) {
+ stm_fatalerror("there was a commit between a partial inevitable "
+ "commit and the continuation of the transaction\n");
+ }
+ }
+ else {
+ cur_time = acquire_inev_mutex_and_mark_global_cur_time(d);
+ }
+
d->start_time = cur_time;
make_inevitable(d);
}
diff --git a/rpython/translator/stm/src_stm/et.h
b/rpython/translator/stm/src_stm/et.h
--- a/rpython/translator/stm/src_stm/et.h
+++ b/rpython/translator/stm/src_stm/et.h
@@ -124,7 +124,8 @@
#define ABRT_VALIDATE_INEV 5
#define ABRT_COLLECT_MINOR 6
#define ABRT_COLLECT_MAJOR 7
-#define ABORT_REASONS 8
+#define ABRT_OTHER_THREADS 8
+#define ABORT_REASONS 9
#define ABORT_NAMES { "MANUAL", \
"COMMIT", \
"STOLEN_MODIFIED", \
@@ -133,6 +134,7 @@
"VALIDATE_INEV", \
"COLLECT_MINOR", \
"COLLECT_MAJOR", \
+ "OTHER_THREADS", \
}
#define SPLP_ABORT 0
@@ -208,8 +210,8 @@
/************************************************************/
-void BeginInevitableTransaction(void); /* must save roots around this call */
-void CommitTransaction(void); /* must save roots around this call */
+void BeginInevitableTransaction(int); /* must save roots around this call */
+void CommitTransaction(int); /* must save roots around this call */
void BecomeInevitable(const char *why); /* must save roots around this call */
void AbortTransaction(int);
void AbortTransactionAfterCollect(struct tx_descriptor *, int);
diff --git a/rpython/translator/stm/src_stm/gcpage.c
b/rpython/translator/stm/src_stm/gcpage.c
--- a/rpython/translator/stm/src_stm/gcpage.c
+++ b/rpython/translator/stm/src_stm/gcpage.c
@@ -1030,8 +1030,14 @@
if (ACCESS_ONCE(countdown_next_major_coll) > 0)
return;
- stm_start_single_thread();
-
+ /* in case we run in single_thread mode already and we are the
+ single thread, we must not try to enter it again.
+ This can happen after manually entering the mode by calling
+ stm_stop_all_other_threads(). */
+ int single_threaded = in_single_thread == thread_descriptor;
+ if (!single_threaded)
+ stm_start_single_thread();
+
/* If several threads were blocked on the previous line, the first
one to proceed sees 0 in 'countdown_next_major_coll'. It's the
thread that will do the major collection. Afterwards the other
@@ -1040,7 +1046,8 @@
if (countdown_next_major_coll == 0)
major_collect();
- stm_stop_single_thread();
+ if (!single_threaded)
+ stm_stop_single_thread();
AbortNowIfDelayed();
}
diff --git a/rpython/translator/stm/src_stm/revision
b/rpython/translator/stm/src_stm/revision
--- a/rpython/translator/stm/src_stm/revision
+++ b/rpython/translator/stm/src_stm/revision
@@ -1,1 +1,1 @@
-89a1de501060
+79aa5685d286
diff --git a/rpython/translator/stm/src_stm/stmgc.h
b/rpython/translator/stm/src_stm/stmgc.h
--- a/rpython/translator/stm/src_stm/stmgc.h
+++ b/rpython/translator/stm/src_stm/stmgc.h
@@ -196,6 +196,14 @@
/* only user currently is stm_allocate_public_integer_address() */
void stm_register_integer_address(intptr_t);
+/* enter single-threaded mode. Used e.g. when patching assembler
+ code that mustn't be executed in another thread while being
+ patched. This can be used to atomically update non-transactional
+ memory.
+ These calls may collect! */
+void stm_stop_all_other_threads(void);
+void stm_partial_commit_and_resume_other_threads(void);
+
/* macro functionality */
extern __thread gcptr *stm_shadowstack;
diff --git a/rpython/translator/stm/src_stm/stmsync.c
b/rpython/translator/stm/src_stm/stmsync.c
--- a/rpython/translator/stm/src_stm/stmsync.c
+++ b/rpython/translator/stm/src_stm/stmsync.c
@@ -96,7 +96,7 @@
init_shadowstack();
stmgcpage_release_global_lock();
}
- BeginInevitableTransaction();
+ BeginInevitableTransaction(0);
return token;
}
@@ -106,7 +106,7 @@
if (token == 1)
stmgc_minor_collect(); /* force everything out of the nursery */
- CommitTransaction();
+ CommitTransaction(0);
if (token == 1) {
stmgcpage_acquire_global_lock();
@@ -141,7 +141,7 @@
stm_push_root(END_MARKER_OFF);
if (!thread_descriptor->atomic)
- CommitTransaction();
+ CommitTransaction(0);
#ifdef _GC_ON_CPYTHON
volatile PyThreadState *v_ts = PyGILState_GetThisThreadState();
@@ -193,7 +193,7 @@
assert(stm_shadowstack == v_saved_value + 2);
if (!d->atomic)
- CommitTransaction();
+ CommitTransaction(0);
counter = 0;
}
@@ -205,7 +205,7 @@
}
}
else {
- BeginInevitableTransaction();
+ BeginInevitableTransaction(0);
}
gcptr x = stm_pop_root(); /* pop the END_MARKER */
@@ -222,7 +222,7 @@
stm_possible_safe_point();
}
else {
- CommitTransaction();
+ CommitTransaction(0);
unsigned long limit = d->reads_size_limit_nonatomic;
if (limit != 0 && limit < (stm_regular_length_limit >> 1))
@@ -247,7 +247,7 @@
{ /* must save roots around this call */
struct tx_descriptor *d = thread_descriptor;
if (!d->atomic)
- CommitTransaction();
+ CommitTransaction(0);
else
BecomeInevitable("stm_commit_transaction but atomic");
}
@@ -256,7 +256,7 @@
{ /* must save roots around this call */
struct tx_descriptor *d = thread_descriptor;
if (!d->atomic)
- BeginInevitableTransaction();
+ BeginInevitableTransaction(0);
}
void stm_become_inevitable(const char *reason)
@@ -279,7 +279,7 @@
static pthread_rwlock_t rwlock_shared =
PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP;
-static struct tx_descriptor *in_single_thread = NULL; /* for debugging */
+struct tx_descriptor *in_single_thread = NULL;
void stm_start_sharedlock(void)
{
@@ -319,8 +319,45 @@
"pthread_rwlock_unlock failure\n");
}
+
+void stm_stop_all_other_threads(void)
+{ /* push gc roots! */
+ struct tx_descriptor *d;
+
+ BecomeInevitable("stop_all_other_threads");
+ stm_start_single_thread();
+
+ for (d = stm_tx_head; d; d = d->tx_next) {
+ if (*d->active_ref == 1) // && d != thread_descriptor) <- TRUE
+ AbortTransactionAfterCollect(d, ABRT_OTHER_THREADS);
+ }
+}
+
+
+void stm_partial_commit_and_resume_other_threads(void)
+{ /* push gc roots! */
+ struct tx_descriptor *d = thread_descriptor;
+ assert(*d->active_ref == 2);
+ int atomic = d->atomic;
+
+ /* Give up atomicity during commit. This still works because
+ we keep the inevitable status, thereby being guaranteed to
+ commit before all others. */
+ stm_atomic(-atomic);
+
+ /* Commit and start new inevitable transaction while never
+ giving up the inevitable status. */
+ CommitTransaction(1); /* 1=stay_inevitable! */
+ BeginInevitableTransaction(1);
+
+ /* restore atomic-count */
+ stm_atomic(atomic);
+
+ stm_stop_single_thread();
+}
+
void stm_start_single_thread(void)
-{
+{ /* push gc roots! */
/* Called by the GC, just after a minor collection, when we need to do
a major collection. When it returns, it acquired the "write lock"
which prevents any other thread from running in a transaction.
@@ -337,7 +374,7 @@
}
void stm_stop_single_thread(void)
-{
+{ /* push gc roots! */
/* Warning, may block waiting for rwlock_in_transaction while another
thread runs a major GC */
assert(in_single_thread == thread_descriptor);
diff --git a/rpython/translator/stm/src_stm/stmsync.h
b/rpython/translator/stm/src_stm/stmsync.h
--- a/rpython/translator/stm/src_stm/stmsync.h
+++ b/rpython/translator/stm/src_stm/stmsync.h
@@ -7,11 +7,14 @@
void stm_start_sharedlock(void);
void stm_stop_sharedlock(void);
+void stm_stop_all_other_threads(void);
+void stm_partial_commit_and_resume_other_threads(void);
void stm_start_single_thread(void);
void stm_stop_single_thread(void);
void stm_possible_safe_point(void);
+extern struct tx_descriptor *in_single_thread;
extern struct GcPtrList stm_prebuilt_gcroots;
void stm_add_prebuilt_root(gcptr);
void stm_clear_between_tests(void);
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