Changeset: 3a9b4f6b4a20 for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB/rev/3a9b4f6b4a20
Modified Files:
gdk/gdk.h
Branch: default
Log Message:
When locking for bat iterator, also lock parent bats.
Do this in a particular order: first view, then theap parent (if any),
then tvheap parent (if any and different from theap parent).
diffs (275 lines):
diff --git a/gdk/gdk.h b/gdk/gdk.h
--- a/gdk/gdk.h
+++ b/gdk/gdk.h
@@ -781,7 +781,9 @@ typedef enum {
* the following fields: theap, tvheap, batInserted, batCapacity. There
* is no need for the lock if the bat cannot possibly be modified
* concurrently, e.g. when it is new and not yet returned to the
- * interpreter or during system initialization. */
+ * interpreter or during system initialization.
+ * If multiple bats need to be locked at the same time by the same
+ * thread, first lock the view, then the view's parent(s). */
typedef struct BAT {
/* static bat properties */
oid hseqbase; /* head seq base */
@@ -909,6 +911,111 @@ gdk_export void HEAPincref(Heap *h);
(((x)->theap && (x)->theap->parentid != (x)->batCacheid) || \
((x)->tvheap && (x)->tvheap->parentid != (x)->batCacheid))
+/*
+ * @+ BAT Buffer Pool
+ * @multitable @columnfractions 0.08 0.7
+ * @item int
+ * @tab BBPfix (bat bi)
+ * @item int
+ * @tab BBPunfix (bat bi)
+ * @item int
+ * @tab BBPretain (bat bi)
+ * @item int
+ * @tab BBPrelease (bat bi)
+ * @item bat
+ * @tab BBPindex (str nme)
+ * @item BAT*
+ * @tab BATdescriptor (bat bi)
+ * @end multitable
+ *
+ * The BAT Buffer Pool module contains the code to manage the storage
+ * location of BATs.
+ *
+ * The remaining BBP tables contain status information to load, swap
+ * and migrate the BATs. The core table is BBPcache which contains a
+ * pointer to the BAT descriptor with its heaps. A zero entry means
+ * that the file resides on disk. Otherwise it has been read or mapped
+ * into memory.
+ *
+ * BATs loaded into memory are retained in a BAT buffer pool. They
+ * retain their position within the cache during their life cycle,
+ * which make indexing BATs a stable operation.
+ *
+ * The BBPindex routine checks if a BAT with a certain name is
+ * registered in the buffer pools. If so, it returns its BAT id. The
+ * BATdescriptor routine has a BAT id parameter, and returns a pointer
+ * to the corresponding BAT record (after incrementing the reference
+ * count). The BAT will be loaded into memory, if necessary.
+ *
+ * The structure of the BBP file obeys the tuple format for GDK.
+ *
+ * The status and BAT persistency information is encoded in the status
+ * field.
+ */
+typedef struct {
+ BAT *cache; /* if loaded: BAT* handle */
+ char *logical; /* logical name (may point at bak) */
+ char bak[16]; /* logical name backup (tmp_%o) */
+ BAT *desc; /* the BAT descriptor */
+ char *options; /* A string list of options */
+#if SIZEOF_VOID_P == 4
+ char physical[20]; /* dir + basename for storage */
+#else
+ char physical[24]; /* dir + basename for storage */
+#endif
+ bat next; /* next BBP slot in linked list */
+ int refs; /* in-memory references on which the loaded
status of a BAT relies */
+ int lrefs; /* logical references on which the existence of
a BAT relies */
+ ATOMIC_TYPE status; /* status mask used for spin locking */
+ MT_Id pid; /* creator of this bat while "private" */
+} BBPrec;
+
+gdk_export bat BBPlimit;
+#if SIZEOF_VOID_P == 4
+#define N_BBPINIT 1000
+#define BBPINITLOG 11
+#else
+#define N_BBPINIT 10000
+#define BBPINITLOG 14
+#endif
+#define BBPINIT (1 << BBPINITLOG)
+/* absolute maximum number of BATs is N_BBPINIT * BBPINIT
+ * this also gives the longest possible "physical" name and "bak" name
+ * of a BAT: the "bak" name is "tmp_%o", so at most 14 + \0 bytes on 64
+ * bit architecture and 11 + \0 on 32 bit architecture; the physical
+ * name is a bit more complicated, but the longest possible name is 22 +
+ * \0 bytes (16 + \0 on 32 bits), the longest possible extension adds
+ * another 17 bytes (.thsh(grp|uni)(l|b)%08x) */
+gdk_export BBPrec *BBP[N_BBPINIT];
+
+/* fast defines without checks; internal use only */
+#define BBP_record(i) BBP[(i)>>BBPINITLOG][(i)&(BBPINIT-1)]
+#define BBP_cache(i) BBP_record(i).cache
+#define BBP_logical(i) BBP_record(i).logical
+#define BBP_bak(i) BBP_record(i).bak
+#define BBP_next(i) BBP_record(i).next
+#define BBP_physical(i) BBP_record(i).physical
+#define BBP_options(i) BBP_record(i).options
+#define BBP_desc(i) BBP_record(i).desc
+#define BBP_refs(i) BBP_record(i).refs
+#define BBP_lrefs(i) BBP_record(i).lrefs
+#define BBP_status(i) ((unsigned) ATOMIC_GET(&BBP_record(i).status))
+#define BBP_pid(i) BBP_record(i).pid
+#define BATgetId(b) BBP_logical((b)->batCacheid)
+#define BBPvalid(i) (BBP_logical(i) != NULL && *BBP_logical(i) != '.')
+
+#define BBPRENAME_ALREADY (-1)
+#define BBPRENAME_ILLEGAL (-2)
+#define BBPRENAME_LONG (-3)
+#define BBPRENAME_MEMORY (-4)
+
+gdk_export void BBPlock(void);
+gdk_export void BBPunlock(void);
+gdk_export void BBPtmlock(void);
+gdk_export void BBPtmunlock(void);
+
+gdk_export BAT *BBPquickdesc(bat b);
+
/* BAT iterator, also protects use of BAT heaps with reference counts.
*
* A BAT iterator has to be used with caution, but it does have to be
@@ -1037,7 +1144,25 @@ bat_iterator(BAT *b)
/* needs matching bat_iterator_end */
BATiter bi;
if (b) {
+ BAT *pb = NULL, *pvb = NULL;
+ /* for a view, always first lock the view and then the
+ * parent(s)
+ * note that a varsized bat can have two different
+ * parents and that the parent for the tail can itself
+ * have a parent for its vheap (which would have to be
+ * our own vheap parent), so lock the vheap after the
+ * tail */
MT_lock_set(&b->theaplock);
+ if (b->theap->parentid != b->batCacheid) {
+ pb = BBP_desc(b->theap->parentid);
+ MT_lock_set(&pb->theaplock);
+ }
+ if (b->tvheap &&
+ b->tvheap->parentid != b->batCacheid &&
+ b->tvheap->parentid != b->theap->parentid) {
+ pvb = BBP_desc(b->tvheap->parentid);
+ MT_lock_set(&pvb->theaplock);
+ }
bi = bat_iterator_nolock(b);
#ifndef NDEBUG
bi.locked = true;
@@ -1045,6 +1170,10 @@ bat_iterator(BAT *b)
HEAPincref(bi.h);
if (bi.vh)
HEAPincref(bi.vh);
+ if (pvb)
+ MT_lock_unset(&pvb->theaplock);
+ if (pb)
+ MT_lock_unset(&pb->theaplock);
MT_lock_unset(&b->theaplock);
} else {
bi = (BATiter) {
@@ -1502,111 +1631,6 @@ BATsettrivprop(BAT *b)
}
/*
- * @+ BAT Buffer Pool
- * @multitable @columnfractions 0.08 0.7
- * @item int
- * @tab BBPfix (bat bi)
- * @item int
- * @tab BBPunfix (bat bi)
- * @item int
- * @tab BBPretain (bat bi)
- * @item int
- * @tab BBPrelease (bat bi)
- * @item bat
- * @tab BBPindex (str nme)
- * @item BAT*
- * @tab BATdescriptor (bat bi)
- * @end multitable
- *
- * The BAT Buffer Pool module contains the code to manage the storage
- * location of BATs.
- *
- * The remaining BBP tables contain status information to load, swap
- * and migrate the BATs. The core table is BBPcache which contains a
- * pointer to the BAT descriptor with its heaps. A zero entry means
- * that the file resides on disk. Otherwise it has been read or mapped
- * into memory.
- *
- * BATs loaded into memory are retained in a BAT buffer pool. They
- * retain their position within the cache during their life cycle,
- * which make indexing BATs a stable operation.
- *
- * The BBPindex routine checks if a BAT with a certain name is
- * registered in the buffer pools. If so, it returns its BAT id. The
- * BATdescriptor routine has a BAT id parameter, and returns a pointer
- * to the corresponding BAT record (after incrementing the reference
- * count). The BAT will be loaded into memory, if necessary.
- *
- * The structure of the BBP file obeys the tuple format for GDK.
- *
- * The status and BAT persistency information is encoded in the status
- * field.
- */
-typedef struct {
- BAT *cache; /* if loaded: BAT* handle */
- char *logical; /* logical name (may point at bak) */
- char bak[16]; /* logical name backup (tmp_%o) */
- BAT *desc; /* the BAT descriptor */
- char *options; /* A string list of options */
-#if SIZEOF_VOID_P == 4
- char physical[20]; /* dir + basename for storage */
-#else
- char physical[24]; /* dir + basename for storage */
-#endif
- bat next; /* next BBP slot in linked list */
- int refs; /* in-memory references on which the loaded
status of a BAT relies */
- int lrefs; /* logical references on which the existence of
a BAT relies */
- ATOMIC_TYPE status; /* status mask used for spin locking */
- MT_Id pid; /* creator of this bat while "private" */
-} BBPrec;
-
-gdk_export bat BBPlimit;
-#if SIZEOF_VOID_P == 4
-#define N_BBPINIT 1000
-#define BBPINITLOG 11
-#else
-#define N_BBPINIT 10000
-#define BBPINITLOG 14
-#endif
-#define BBPINIT (1 << BBPINITLOG)
-/* absolute maximum number of BATs is N_BBPINIT * BBPINIT
- * this also gives the longest possible "physical" name and "bak" name
- * of a BAT: the "bak" name is "tmp_%o", so at most 14 + \0 bytes on 64
- * bit architecture and 11 + \0 on 32 bit architecture; the physical
- * name is a bit more complicated, but the longest possible name is 22 +
- * \0 bytes (16 + \0 on 32 bits), the longest possible extension adds
- * another 17 bytes (.thsh(grp|uni)(l|b)%08x) */
-gdk_export BBPrec *BBP[N_BBPINIT];
-
-/* fast defines without checks; internal use only */
-#define BBP_record(i) BBP[(i)>>BBPINITLOG][(i)&(BBPINIT-1)]
-#define BBP_cache(i) BBP_record(i).cache
-#define BBP_logical(i) BBP_record(i).logical
-#define BBP_bak(i) BBP_record(i).bak
-#define BBP_next(i) BBP_record(i).next
-#define BBP_physical(i) BBP_record(i).physical
-#define BBP_options(i) BBP_record(i).options
-#define BBP_desc(i) BBP_record(i).desc
-#define BBP_refs(i) BBP_record(i).refs
-#define BBP_lrefs(i) BBP_record(i).lrefs
-#define BBP_status(i) ((unsigned) ATOMIC_GET(&BBP_record(i).status))
-#define BBP_pid(i) BBP_record(i).pid
-#define BATgetId(b) BBP_logical((b)->batCacheid)
-#define BBPvalid(i) (BBP_logical(i) != NULL && *BBP_logical(i) != '.')
-
-#define BBPRENAME_ALREADY (-1)
-#define BBPRENAME_ILLEGAL (-2)
-#define BBPRENAME_LONG (-3)
-#define BBPRENAME_MEMORY (-4)
-
-gdk_export void BBPlock(void);
-gdk_export void BBPunlock(void);
-gdk_export void BBPtmlock(void);
-gdk_export void BBPtmunlock(void);
-
-gdk_export BAT *BBPquickdesc(bat b);
-
-/*
* @- GDK error handling
* @multitable @columnfractions 0.08 0.7
* @item str
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