more UNBUF fixes

try to keep compat better, remove the single-thread-first-tile idea

TODO

@@ -1,15 +1,9 @@
 - seq no longer stalls ahead threads ... instead, we rely on sinkdisk 
   interlocks to limit how far ahead or behind threads can get
 
-  deprecate UNBUFFERED? it will probably not work now
-
-  remove single-thread-first-tile thing
-
   the readbehind option to many loaders is no longer needed
 
-  do we need to restore the UNBUFFERED enum member to keep binary compat? we
-  need to make sure old code using UNBUFF now uses regular SEQ (and not RAND)
-
+	  check pforeign.h 
 
 
 

libvips/conversion/sequential.c

@@ -262,6 +262,7 @@ vips_sequential_init( VipsSequential *sequential )
 	sequential->lock = vips_g_mutex_new();
 	sequential->tile_height = 1;
 	sequential->error = 0;
+	sequential->access = VIPS_ACCESS_SEQUENTIAL;
 }
 
 /**

libvips/conversion/tilecache.c

@@ -280,6 +280,7 @@ vips_tile_search_recycle( gpointer key, gpointer value, gpointer user_data )
 			break;
 
 		case VIPS_ACCESS_SEQUENTIAL:
+		case VIPS_ACCESS_SEQUENTIAL_UNBUFFERED:
 			if( tile->pos.top < search->topmost ) {
 				search->topmost = tile->pos.top;
 				search->tile = tile;

libvips/include/vips/image.h

@@ -129,13 +129,10 @@ typedef enum {
 typedef enum {
 	VIPS_ACCESS_RANDOM,
 	VIPS_ACCESS_SEQUENTIAL,
+	VIPS_ACCESS_SEQUENTIAL_UNBUFFERED,
 	VIPS_ACCESS_LAST
 } VipsAccess;
 
-/* Compat for a mode we used to support.
- */
-#define VIPS_ACCESS_SEQUENTIAL_UNBUFFERED VIPS_ACCESS_SEQUENTIAL
-
 struct _VipsImage; 
 struct _VipsRegion; 
 

libvips/iofuncs/enumtypes.c

@@ -669,6 +669,7 @@ vips_access_get_type( void )
 		static const GEnumValue values[] = {
 			{VIPS_ACCESS_RANDOM, "VIPS_ACCESS_RANDOM", "random"},
 			{VIPS_ACCESS_SEQUENTIAL, "VIPS_ACCESS_SEQUENTIAL", "sequential"},
+			{VIPS_ACCESS_SEQUENTIAL_UNBUFFERED, "VIPS_ACCESS_SEQUENTIAL_UNBUFFERED", "sequential-unbuffered"},
 			{VIPS_ACCESS_LAST, "VIPS_ACCESS_LAST", "last"},
 			{0, NULL, NULL}
 		};

libvips/iofuncs/object.c

@@ -1816,6 +1816,7 @@ vips_object_set_argument_from_string( VipsObject *object,
 	if( g_type_is_a( otype, VIPS_TYPE_IMAGE ) ) { 
 		VipsImage *out;
 		VipsOperationFlags flags;
+		VipsAccess access;
 
 		if( !value ) {
 			vips_object_no_value( object, name );
@@ -1827,12 +1828,15 @@ vips_object_set_argument_from_string( VipsObject *object,
 			flags = vips_operation_get_flags( 
 				VIPS_OPERATION( object ) );
 
-		/* Read the filename. 
-		 */
+		if( flags & 
+			(VIPS_OPERATION_SEQUENTIAL | 
+			 VIPS_OPERATION_SEQUENTIAL_UNBUFFERED) )
+			access = VIPS_ACCESS_SEQUENTIAL;
+		else
+			access = VIPS_ACCESS_RANDOM;
 
 		if( !(out = vips_image_new_from_file( value, 
-			"access", flags & VIPS_OPERATION_SEQUENTIAL ? 
-				VIPS_ACCESS_SEQUENTIAL : VIPS_ACCESS_RANDOM,
+			"access", access, 
 			NULL )) )
 			return( -1 );
 
@@ -1851,6 +1855,7 @@ vips_object_set_argument_from_string( VipsObject *object,
 		 */
 		VipsArrayImage *array_image;
 		VipsOperationFlags flags;
+		VipsAccess access;
 
 		if( !value ) {
 			vips_object_no_value( object, name );
@@ -1862,9 +1867,15 @@ vips_object_set_argument_from_string( VipsObject *object,
 			flags = vips_operation_get_flags( 
 				VIPS_OPERATION( object ) );
 
-		if( !(array_image = vips_array_image_new_from_string( value, 
-			flags & VIPS_OPERATION_SEQUENTIAL ? 
-				VIPS_ACCESS_SEQUENTIAL : VIPS_ACCESS_RANDOM )) ) 
+		if( flags & 
+			(VIPS_OPERATION_SEQUENTIAL | 
+			 VIPS_OPERATION_SEQUENTIAL_UNBUFFERED) )
+			access = VIPS_ACCESS_SEQUENTIAL;
+		else
+			access = VIPS_ACCESS_RANDOM;
+
+		if( !(array_image = 
+			vips_array_image_new_from_string( value, access )) ) 
 			return( -1 ); 
 
 		g_value_init( &gvalue, VIPS_TYPE_ARRAY_IMAGE );

libvips/iofuncs/threadpool.c

@@ -548,12 +548,6 @@ typedef struct _VipsThreadpool {
 	/* Set by Allocate (via an arg) to indicate normal end of computation.
 	 */
 	gboolean stop;
-
-	/* Set by the first thread to hit allocate. The first work unit runs
-	 * single-threaded to give loaders a change to get to the right spot
-	 * in the input.
-	 */
-	gboolean done_first;
 } VipsThreadpool;
 
 /* Junk a thread.
@@ -635,8 +629,7 @@ vips_thread_work_unit( VipsThread *thr )
 		return;
 	}
 
-	if( pool->done_first )
-		g_mutex_unlock( pool->allocate_lock );
+	g_mutex_unlock( pool->allocate_lock );
 
 	/* Process a work unit.
 	 */
@@ -644,11 +637,6 @@ vips_thread_work_unit( VipsThread *thr )
 		thr->error = TRUE;
 		pool->error = TRUE;
 	}
-
-	if( !pool->done_first ) {
-		pool->done_first = TRUE;
-		g_mutex_unlock( pool->allocate_lock );
-	}
 }
 
 /* What runs as a thread ... loop, waiting to be told to do stuff.
@@ -781,7 +769,6 @@ vips_threadpool_new( VipsImage *im )
 	vips_semaphore_init( &pool->tick, 0, "tick" );
 	pool->error = FALSE;
 	pool->stop = FALSE;
-	pool->done_first = FALSE;
 
 	/* If this is a tiny image, we won't need all nthr threads. Guess how
 	 * many tiles we might need to cover the image and use that to limit

libvips/resample/reduceh.cpp

@@ -562,7 +562,7 @@ vips_reduceh_class_init( VipsReducehClass *reduceh_class )
 	vobject_class->description = _( "shrink an image horizontally" );
 	vobject_class->build = vips_reduceh_build;
 
-	operation_class->flags = VIPS_OPERATION_SEQUENTIAL_UNBUFFERED;
+	operation_class->flags = VIPS_OPERATION_SEQUENTIAL;
 
 	VIPS_ARG_DOUBLE( reduceh_class, "hshrink", 3, 
 		_( "Hshrink" ), 

libvips/resample/reducev.cpp

@@ -895,7 +895,7 @@ vips_reducev_class_init( VipsReducevClass *reducev_class )
 	vobject_class->description = _( "shrink an image vertically" );
 	vobject_class->build = vips_reducev_build;
 
-	operation_class->flags = VIPS_OPERATION_SEQUENTIAL_UNBUFFERED;
+	operation_class->flags = VIPS_OPERATION_SEQUENTIAL;
 
 	VIPS_ARG_DOUBLE( reducev_class, "vshrink", 3, 
 		_( "Vshrink" ), 

libvips/resample/thumbnail.c

@@ -631,8 +631,6 @@ vips_thumbnail_file_open( VipsThumbnail *thumbnail, int shrink, double scale )
 {
 	VipsThumbnailFile *file = (VipsThumbnailFile *) thumbnail;
 
-	/* We can't use UNBUFERRED safely on very-many-core systems.
-	 */
 	if( shrink != 1 ) 
 		return( vips_image_new_from_file( file->filename, 
 			"access", VIPS_ACCESS_SEQUENTIAL,
@@ -795,8 +793,6 @@ vips_thumbnail_buffer_open( VipsThumbnail *thumbnail,
 {
 	VipsThumbnailBuffer *buffer = (VipsThumbnailBuffer *) thumbnail;
 
-	/* We can't use UNBUFERRED safely on very-many-core systems.
-	 */
 	if( shrink != 1 ) 
 		return( vips_image_new_from_buffer( 
 			buffer->buf->data, buffer->buf->length, "",