experimental threadpool

libvips/include/vips/Makefile.am

@@ -39,6 +39,7 @@ pkginclude_HEADERS = \
 	semaphore.h \
 	struct.h \
 	threadgroup.h \
+	threadpool.h \
 	thread.h \
 	transform.h \
 	util.h \

libvips/include/vips/threadpool.h

@@ -0,0 +1,120 @@
+/* Thread eval for VIPS.
+ *
+ * 29/9/99 JC
+ *	- from thread.h
+ * 17/3/10
+ * 	- from threadgroup
+ * 	- rework with a simpler distributed work allocation model
+ */
+
+/*
+
+    This file is part of VIPS.
+    
+    VIPS is free software; you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+ */
+
+/*
+
+    These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
+
+ */
+
+#ifndef IM_THREADPOOL_H
+#define IM_THREADPOOL_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif /*__cplusplus*/
+
+#include <vips/semaphore.h>
+
+/* What we track for each thread in the pool.
+ */
+typedef struct {
+	/* All private.
+	 */
+	/*< private >*/
+	REGION *reg;		/* Region this thread operates on */
+	struct _VipsTreadPool *pool; /* Pool we are part of */
+
+        GThread *thread;  	/* Thread for this region */
+        im_semaphore_t go;   	/* Thread waits here to start work */
+	int kill;		/* Set this to make thread exit */
+	int error;		/* Set by thread if work fn fails */
+
+	REGION *oreg;		/* If part of an inplace threadgroup, */
+	Rect pos;		/* Where this thread should write */
+	int x, y;		/* Its result */
+
+        void *a, *b, *c; 	/* User arguments to work fns */
+
+#ifdef TIME_THREAD
+	hrtime_t *btime, *etime;
+	int tpos;
+#endif /*TIME_THREAD*/
+} VipsThread;
+
+/* A work function. This does a unit of work (eg. processing a tile or
+ * whatever).
+ */
+typedef int (*VipsThreadPoolWork)( VipsThread *thr,
+	REGION *, void *, void *, void * );
+
+/* A work allocate function. This is run single-threaded by a worker to
+ * set up a new work unit.
+ */
+typedef void (*VipsThreadPoolAllocate)( VipsThread *thr );
+
+/* What we track for a group of threads working together.
+ */
+typedef struct _VipsThreadPool {
+	/* All private.
+	 */
+	/*< private >*/
+	IMAGE *im;		/* Image we are calculating */
+	int pw, ph;		/* Tile size */
+	int nlines;		/* Scanlines-at-once we prefer for iteration */
+
+	/* Do a unit of work (runs in parallel) and allocate a unit of work
+	 * (serial). Plus the mutex we use to serialize work allocation.
+	 */
+	VipsThreadPoolWork work;
+	VipsThreadPoolAllocate allocate;
+	GMutex *allocate_lock;
+
+	int nthr;		/* Number of threads in group */
+	im_thread_t **thr;	/* Threads */
+
+	/* The caller blocks here until the last worker is done.
+	 */
+	im_semaphore_t *main;	
+
+	int kill;		/* Set this to stop threadgroup early */
+	int progress;		/* Set this to get eval progress feedback */
+} VipsThreadPool;
+
+/* Thread pool functions.
+ */
+VipsThreadPool *vips_thread_pool_new( IMAGE *im );
+int vips_thread_pool_free( VipsThreadPool *pool );
+void vips_thread_pool_run( VipsThreadPool *pool );
+
+#ifdef __cplusplus
+}
+#endif /*__cplusplus*/
+
+#endif /*IM_THREADPOOL_H*/