Add a work queue implementation.

Makefile.am

@@ -26,57 +26,65 @@ SUBDIRS =		os ut btr buf data dict dyn eval fil fsp fut \
 			ha ibuf lock log mach mem mtr page \
 			pars que read rem row srv sync thr trx usr
 
-EXTRA_DIST = 	include/btr0btr.h include/btr0btr.ic include/btr0cur.h include/btr0cur.ic \
-		include/btr0pcur.h include/btr0pcur.ic include/btr0sea.h include/btr0sea.ic \
-		include/btr0types.h \
-		include/buf0buf.h include/buf0buf.ic include/buf0flu.h include/buf0flu.ic \
-		include/buf0lru.h include/buf0lru.ic include/buf0rea.h include/buf0types.h \
-		include/data0data.h include/data0data.ic include/data0type.h include/data0type.ic \
-		include/data0types.h include/db0err.h \
-		include/dict0boot.h include/dict0boot.ic include/dict0crea.h include/dict0crea.ic \
-		include/dict0dict.h include/dict0dict.ic include/dict0load.h include/dict0load.ic \
-		include/dict0mem.h include/dict0mem.ic include/dict0types.h \
-		include/dyn0dyn.h include/dyn0dyn.ic \
-		include/eval0eval.h include/eval0eval.ic include/eval0proc.h include/eval0proc.ic \
-		include/fil0fil.h include/fsp0fsp.h include/fsp0fsp.ic \
-		include/fut0fut.h include/fut0fut.ic include/fut0lst.h include/fut0lst.ic \
-		include/ha0ha.h include/ha0ha.ic include/hash0hash.h include/hash0hash.ic \
+EXTRA_DIST = 	include/btr0btr.h include/btr0btr.ic include/btr0cur.h \
+		include/btr0cur.ic include/btr0pcur.h include/btr0pcur.ic \
+		include/btr0sea.h include/btr0sea.ic include/btr0types.h \
+		include/buf0buf.h include/buf0buf.ic include/buf0flu.h \
+		include/buf0flu.ic include/buf0lru.h include/buf0lru.ic \
+		include/buf0rea.h include/buf0types.h include/data0data.h \
+		include/data0data.ic include/data0type.h include/data0type.ic \
+		include/data0types.h include/db0err.h include/dict0boot.h \
+		include/dict0boot.ic include/dict0crea.h include/dict0crea.ic \
+		include/dict0dict.h include/dict0dict.ic include/dict0load.h \
+		include/dict0load.ic include/dict0mem.h include/dict0mem.ic \
+		include/dict0types.h include/dyn0dyn.h include/dyn0dyn.ic \
+		include/eval0eval.h include/eval0eval.ic include/eval0proc.h \
+		include/eval0proc.ic include/fil0fil.h include/fsp0fsp.h \
+		include/fsp0fsp.ic include/fut0fut.h include/fut0fut.ic \
+		include/fut0lst.h include/fut0lst.ic include/ha0ha.h \
+		include/ha0ha.ic include/hash0hash.h include/hash0hash.ic \
 		include/ibuf0ibuf.h include/ibuf0ibuf.ic include/ibuf0types.h \
 		include/lock0lock.h include/lock0lock.ic include/lock0types.h \
-		include/log0log.h include/log0log.ic include/log0recv.h include/log0recv.ic \
-		include/mach0data.h include/mach0data.ic include/mem0dbg.h include/mem0dbg.ic \
-		include/mem0mem.h include/mem0mem.ic include/mem0pool.h include/mem0pool.ic \
-		include/mtr0log.h include/mtr0log.ic include/mtr0mtr.h include/mtr0mtr.ic \
-		include/mtr0types.h include/os0file.h \
-		include/os0proc.h include/os0proc.ic include/os0sync.h include/os0sync.ic \
-		include/os0thread.h include/os0thread.ic \
-		include/page0cur.h include/page0cur.ic include/page0page.h include/page0page.ic \
-		include/page0types.h \
-		include/pars0grm.h include/pars0opt.h include/pars0opt.ic \
-		include/pars0pars.h include/pars0pars.ic include/pars0sym.h include/pars0sym.ic \
-		include/pars0types.h \
-		include/que0que.h include/que0que.ic include/que0types.h \
-		include/read0read.h include/read0read.ic include/read0types.h \
-		include/rem0cmp.h include/rem0cmp.ic include/rem0rec.h include/rem0rec.ic \
-		include/rem0types.h \
-		include/row0ins.h include/row0ins.ic include/row0mysql.h include/row0mysql.ic \
-		include/row0purge.h include/row0purge.ic include/row0row.h include/row0row.ic \
-		include/row0sel.h include/row0sel.ic include/row0types.h \
-		include/row0uins.h include/row0uins.ic include/row0umod.h include/row0umod.ic \
-		include/row0undo.h include/row0undo.ic include/row0upd.h include/row0upd.ic \
-		include/row0vers.h include/row0vers.ic \
-		include/srv0que.h include/srv0srv.h include/srv0srv.ic include/srv0start.h \
-		include/sync0arr.h include/sync0arr.ic include/sync0rw.h include/sync0rw.ic \
-		include/sync0sync.h include/sync0sync.ic include/sync0types.h \
-		include/thr0loc.h include/thr0loc.ic \
-		include/trx0purge.h include/trx0purge.ic include/trx0rec.h include/trx0rec.ic \
-		include/trx0roll.h include/trx0roll.ic include/trx0rseg.h include/trx0rseg.ic \
-		include/trx0sys.h include/trx0sys.ic include/trx0trx.h include/trx0trx.ic \
-		include/trx0types.h include/trx0undo.h include/trx0undo.ic include/trx0xa.h \
-		include/univ.i include/usr0sess.h include/usr0sess.ic include/usr0types.h \
-		include/ut0byte.h include/ut0byte.ic include/ut0dbg.h include/ut0lst.h \
-		include/ut0mem.h include/ut0mem.ic include/ut0rnd.h include/ut0rnd.ic \
-		include/ut0sort.h include/ut0ut.h include/ut0ut.ic include/ut0vec.h include/ut0vec.ic include/ut0list.h include/ut0list.ic cmakelists.txt
+		include/log0log.h include/log0log.ic include/log0recv.h \
+		include/log0recv.ic include/mach0data.h include/mach0data.ic \
+		include/mem0dbg.h include/mem0dbg.ic include/mem0mem.h \
+		include/mem0mem.ic include/mem0pool.h include/mem0pool.ic \
+		include/mtr0log.h include/mtr0log.ic include/mtr0mtr.h \
+		include/mtr0mtr.ic include/mtr0types.h include/os0file.h \
+		include/os0proc.h include/os0proc.ic include/os0sync.h \
+		include/os0sync.ic include/os0thread.h include/os0thread.ic \
+		include/page0cur.h include/page0cur.ic include/page0page.h \
+		include/page0page.ic include/page0types.h include/pars0grm.h \
+		include/pars0opt.h include/pars0opt.ic include/pars0pars.h \
+		include/pars0pars.ic include/pars0sym.h include/pars0sym.ic \
+		include/pars0types.h include/que0que.h include/que0que.ic \
+		include/que0types.h include/read0read.h include/read0read.ic \
+		include/read0types.h include/rem0cmp.h include/rem0cmp.ic \
+		include/rem0rec.h include/rem0rec.ic include/rem0types.h \
+		include/row0ins.h include/row0ins.ic include/row0mysql.h \
+		include/row0mysql.ic include/row0purge.h include/row0purge.ic \
+		include/row0row.h include/row0row.ic include/row0sel.h \
+		include/row0sel.ic include/row0types.h include/row0uins.h \
+		include/row0uins.ic include/row0umod.h include/row0umod.ic \
+		include/row0undo.h include/row0undo.ic include/row0upd.h \
+		include/row0upd.ic include/row0vers.h include/row0vers.ic \
+		include/srv0que.h include/srv0srv.h include/srv0srv.ic \
+		include/srv0start.h include/sync0arr.h include/sync0arr.ic \
+		include/sync0rw.h include/sync0rw.ic include/sync0sync.h \
+		include/sync0sync.ic include/sync0types.h include/thr0loc.h \
+		include/thr0loc.ic include/trx0purge.h include/trx0purge.ic \
+		include/trx0rec.h include/trx0rec.ic include/trx0roll.h \
+		include/trx0roll.ic include/trx0rseg.h include/trx0rseg.ic \
+		include/trx0sys.h include/trx0sys.ic include/trx0trx.h \
+		include/trx0trx.ic include/trx0types.h include/trx0undo.h \
+		include/trx0undo.ic include/trx0xa.h include/univ.i \
+		include/usr0sess.h include/usr0sess.ic include/usr0types.h \
+		include/ut0byte.h include/ut0byte.ic include/ut0dbg.h \
+		include/ut0lst.h include/ut0mem.h include/ut0mem.ic \
+		include/ut0rnd.h include/ut0rnd.ic include/ut0sort.h \
+		include/ut0ut.h include/ut0ut.ic include/ut0vec.h \
+		include/ut0vec.ic include/ut0list.h include/ut0list.ic \
+		include/ut0wqueue.h cmakelists.txt
 
 # Don't update the files from bitkeeper
 %::SCCS/s.%

cmakelists.txt

@@ -32,4 +32,4 @@ ADD_LIBRARY(innobase btr/btr0btr.c btr/btr0cur.c btr/btr0pcur.c btr/btr0sea.c
 					 thr/thr0loc.c 
 					 trx/trx0purge.c trx/trx0rec.c trx/trx0roll.c trx/trx0rseg.c trx/trx0sys.c trx/trx0trx.c trx/trx0undo.c 
 					 usr/usr0sess.c 
-					 ut/ut0byte.c ut/ut0dbg.c ut/ut0mem.c ut/ut0rnd.c ut/ut0ut.c ut/ut0vec.c ut/ut0list.c)
+					 ut/ut0byte.c ut/ut0dbg.c ut/ut0mem.c ut/ut0rnd.c ut/ut0ut.c ut/ut0vec.c ut/ut0list.c ut/ut0wqueue.c)

include/sync0sync.h

@@ -426,6 +426,7 @@ or row lock! */
 #define SYNC_TRX_SYS_HEADER	290
 #define SYNC_LOG		170
 #define SYNC_RECV		168
+#define SYNC_WORK_QUEUE		161
 #define	SYNC_SEARCH_SYS		160	/* NOTE that if we have a memory
 					heap that can be extended to the
 					buffer pool, its logical level is

include/ut0wqueue.h

+/***********************************************************************
+A Work queue. Threads can add work items to the queue and other threads can
+wait for work items to be available and take them off the queue for
+processing.
+
+************************************************************************/
+
+#ifndef IB_WORK_QUEUE_H
+#define IB_WORK_QUEUE_H
+
+#include "ut0list.h"
+#include "mem0mem.h"
+#include "os0sync.h"
+#include "sync0types.h"
+
+typedef struct ib_wqueue_struct ib_wqueue_t;
+
+/********************************************************************
+Create a new work queue. */
+
+ib_wqueue_t*
+ib_wqueue_create(void);
+/*===================*/
+			/* out: work queue */
+
+/********************************************************************
+Free a work queue. */
+
+void
+ib_wqueue_free(
+/*===========*/
+	ib_wqueue_t*	wq);	/* in: work queue */
+
+/********************************************************************
+Add a work item to the queue. */
+
+void
+ib_wqueue_add(
+/*==========*/
+	ib_wqueue_t*	wq,	/* in: work queue */
+	void*		item,	/* in: work item */
+	mem_heap_t*	heap);	/* in: memory heap to use for allocating the
+				list node */
+
+/********************************************************************
+Wait for a work item to appear in the queue. */
+
+void*
+ib_wqueue_wait(
+				/* out: work item */
+	ib_wqueue_t*	wq);	/* in: work queue */
+
+/* Work queue. */
+struct ib_wqueue_struct {
+	mutex_t		mutex;	/* mutex protecting everything */
+	ib_list_t*	items;	/* work item list */
+	os_event_t	event;	/* event we use to signal additions to list */
+};
+
+#endif

sync/sync0sync.c

@@ -1050,6 +1050,9 @@ sync_thread_add_level(
 	case SYNC_RECV:
 		ut_a(sync_thread_levels_g(array, SYNC_RECV));
 		break;
+	case SYNC_WORK_QUEUE:
+		ut_a(sync_thread_levels_g(array, SYNC_WORK_QUEUE));
+		break;
 	case SYNC_LOG:
 		ut_a(sync_thread_levels_g(array, SYNC_LOG));
 		break;

ut/Makefile.am

@@ -19,6 +19,6 @@ include ../include/Makefile.i
 
 noinst_LIBRARIES =	libut.a
 
-libut_a_SOURCES =	ut0byte.c ut0dbg.c ut0mem.c ut0rnd.c ut0ut.c ut0vec.c ut0list.c
+libut_a_SOURCES =	ut0byte.c ut0dbg.c ut0mem.c ut0rnd.c ut0ut.c ut0vec.c ut0list.c ut0wqueue.c
 
 EXTRA_PROGRAMS =	

ut/ut0wqueue.c

+#include "ut0wqueue.h"
+
+/********************************************************************
+Create a new work queue. */
+
+ib_wqueue_t*
+ib_wqueue_create(void)
+/*===================*/
+			/* out: work queue */
+{
+	ib_wqueue_t*	wq = mem_alloc(sizeof(ib_wqueue_t));
+
+	mutex_create(&wq->mutex);
+	mutex_set_level(&wq->mutex, SYNC_WORK_QUEUE);
+
+	wq->items = ib_list_create();
+	wq->event = os_event_create(NULL);
+
+	return(wq);
+}
+
+/********************************************************************
+Free a work queue. */
+
+void
+ib_wqueue_free(
+/*===========*/
+	ib_wqueue_t*	wq)	/* in: work queue */
+{
+	ut_a(!ib_list_get_first(wq->items));
+
+	mutex_free(&wq->mutex);
+	ib_list_free(wq->items);
+	os_event_free(wq->event);
+
+	mem_free(wq);
+}
+
+/********************************************************************
+Add a work item to the queue. */
+
+void
+ib_wqueue_add(
+/*==========*/
+	ib_wqueue_t*	wq,	/* in: work queue */
+	void*		item,	/* in: work item */
+	mem_heap_t*	heap)	/* in: memory heap to use for allocating the
+				list node */
+{
+	mutex_enter(&wq->mutex);
+
+	ib_list_add_last(wq->items, item, heap);
+	os_event_set(wq->event);
+
+	mutex_exit(&wq->mutex);
+}
+
+/********************************************************************
+Wait for a work item to appear in the queue. */
+
+void*
+ib_wqueue_wait(
+				/* out: work item */
+	ib_wqueue_t*	wq)	/* in: work queue */
+{
+	ib_list_node_t*	node;
+
+	for (;;) {
+		os_event_wait(wq->event);
+
+		mutex_enter(&wq->mutex);
+
+		node = ib_list_get_first(wq->items);
+
+		if (node) {
+			ib_list_remove(wq->items, node);
+
+			if (!ib_list_get_first(wq->items)) {
+				/* We must reset the event when the list
+				 gets emptied. */
+				os_event_reset(wq->event);
+			}
+
+			break;
+		}
+
+		mutex_exit(&wq->mutex);
+	}
+
+	mutex_exit(&wq->mutex);
+
+	return(node->data);
+}