Multi-threading support for MuPDF

When we moved over to a context based system, we laid the foundation
for a thread-safe mupdf. This commit should complete that process.

Firstly, fz_clone_context is properly implemented so that it
makes a new context, but shares certain sections (currently
just the allocator, and the store).

Secondly, we add locking (to parts of the code that have
previously just had placeholder LOCK/UNLOCK comments). Functions
to lock and unlock a mutex are added to the allocator structure;
omit these (as is the case today) and no multithreading is
(safely) possible. The context will refuse to clone if these are
not provided.

Finally we flesh out the LOCK/UNLOCK comments to be real calls of
the functions - unfortunately this requires us to plumb fz_context
into the fz_keep_storable function (and all the fz_keep_xxx
functions that call it). This is the largest section of the patch.

No changes expected to any test files.

1 files changed, 5 insertions, 5 deletions

diff --git a/fitz/dev_list.c b/fitz/dev_list.c
index 0c273c57..7f36ce88 100644
--- a/fitz/dev_list.c
+++ b/fitz/dev_list.c
@@ -80,7 +80,7 @@ fz_new_display_node(fz_context *ctx, fz_display_command cmd, fz_matrix ctm,
 	node->ctm = ctm;
 	if (colorspace)
 	{
-		node->colorspace = fz_keep_colorspace(colorspace);
+		node->colorspace = fz_keep_colorspace(ctx, colorspace);
 		if (color)
 		{
 			for (i = 0; i < node->colorspace->n; i++)
@@ -430,7 +430,7 @@ fz_list_fill_shade(fz_device *dev, fz_shade *shade, fz_matrix ctm, float alpha)
 	fz_context *ctx = dev->ctx;
 	node = fz_new_display_node(ctx, FZ_CMD_FILL_SHADE, ctm, NULL, NULL, alpha);
 	node->rect = fz_bound_shade(shade, ctm);
-	node->item.shade = fz_keep_shade(shade);
+	node->item.shade = fz_keep_shade(ctx, shade);
 	fz_append_display_node(dev->user, node);
 }
 
@@ -440,7 +440,7 @@ fz_list_fill_image(fz_device *dev, fz_pixmap *image, fz_matrix ctm, float alpha)
 	fz_display_node *node;
 	node = fz_new_display_node(dev->ctx, FZ_CMD_FILL_IMAGE, ctm, NULL, NULL, alpha);
 	node->rect = fz_transform_rect(ctm, fz_unit_rect);
-	node->item.image = fz_keep_pixmap(image);
+	node->item.image = fz_keep_pixmap(dev->ctx, image);
 	fz_append_display_node(dev->user, node);
 }
 
@@ -451,7 +451,7 @@ fz_list_fill_image_mask(fz_device *dev, fz_pixmap *image, fz_matrix ctm,
 	fz_display_node *node;
 	node = fz_new_display_node(dev->ctx, FZ_CMD_FILL_IMAGE_MASK, ctm, colorspace, color, alpha);
 	node->rect = fz_transform_rect(ctm, fz_unit_rect);
-	node->item.image = fz_keep_pixmap(image);
+	node->item.image = fz_keep_pixmap(dev->ctx, image);
 	fz_append_display_node(dev->user, node);
 }
 
@@ -463,7 +463,7 @@ fz_list_clip_image_mask(fz_device *dev, fz_pixmap *image, fz_rect *rect, fz_matr
 	node->rect = fz_transform_rect(ctm, fz_unit_rect);
 	if (rect)
 		node->rect = fz_intersect_rect(node->rect, *rect);
-	node->item.image = fz_keep_pixmap(image);
+	node->item.image = fz_keep_pixmap(dev->ctx, image);
 	fz_append_display_node(dev->user, node);
 }