[pypy-commit] stmgc default: Improve the logic behind stm_collect(1)

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r899:410c7a4975d0
Date: 2014-02-27 19:51 +0100
http://bitbucket.org/pypy/stmgc/changeset/410c7a4975d0/

Log:	Improve the logic behind stm_collect(1)

diff --git a/c7/stm/gcpage.c b/c7/stm/gcpage.c
--- a/c7/stm/gcpage.c
+++ b/c7/stm/gcpage.c
@@ -110,10 +110,10 @@
 /************************************************************/
 
 
-static void major_collection(bool forced)
+static void major_collection_if_requested(void)
 {
     assert(!_has_mutex());
-    if (!forced && !is_major_collection_requested())
+    if (!is_major_collection_requested())
         return;
 
     mutex_lock();
@@ -121,7 +121,7 @@
     assert(STM_PSEGMENT->safe_point == SP_RUNNING);
     STM_PSEGMENT->safe_point = SP_SAFE_POINT;
 
-    while (forced || is_major_collection_requested()) {
+    while (is_major_collection_requested()) {
         /* wait until the other thread is at a safe-point */
         if (try_wait_for_other_safe_points()) {
             /* ok */
diff --git a/c7/stm/gcpage.h b/c7/stm/gcpage.h
--- a/c7/stm/gcpage.h
+++ b/c7/stm/gcpage.h
@@ -33,7 +33,7 @@
 static void teardown_gcpage(void);
 static char *allocate_outside_nursery_large(uint64_t size);
 
-static void major_collection(bool forced);
+static void major_collection_if_requested(void);
 static void major_collection_now_at_safe_point(void);
 
 
diff --git a/c7/stm/nursery.c b/c7/stm/nursery.c
--- a/c7/stm/nursery.c
+++ b/c7/stm/nursery.c
@@ -282,8 +282,11 @@
 
 void stm_collect(long level)
 {
+    if (level > 0)
+        force_major_collection_request();
+
     minor_collection(/*commit=*/ false);
-    major_collection(/*forced=*/ level > 0);
+    major_collection_if_requested();
 }
 
 
diff --git a/c7/stm/pages.c b/c7/stm/pages.c
--- a/c7/stm/pages.c
+++ b/c7/stm/pages.c
@@ -8,7 +8,7 @@
 static union {
     struct {
         uint8_t mutex_pages;
-        bool major_collection_requested;
+        volatile bool major_collection_requested;
         uint64_t total_allocated;  /* keep track of how much memory we're
                                       using, ignoring nurseries */
         uint64_t total_allocated_bound;
@@ -61,6 +61,11 @@
     return pages_ctl.major_collection_requested;
 }
 
+static void force_major_collection_request(void)
+{
+    pages_ctl.major_collection_requested = true;
+}
+
 static void reset_major_collection_requested(void)
 {
     assert(_has_mutex());
diff --git a/c7/stm/pages.h b/c7/stm/pages.h
--- a/c7/stm/pages.h
+++ b/c7/stm/pages.h
@@ -25,6 +25,7 @@
 static void mutex_pages_unlock(void);
 static uint64_t increment_total_allocated(ssize_t add_or_remove);
 static bool is_major_collection_requested(void);
+static void force_major_collection_request(void);
 static void reset_major_collection_requested(void);
 
 inline static void pages_privatize(uintptr_t pagenum, uintptr_t count,