mksquashfs: replace generic queue with specialised "sequential queue"

Replace the use of a generic queue and associated code in mksquashfs.c
to re-order out of order buffers (see previous commit) received from
the deflate threads (and reader thread) with a specialised
"sequential queue" that guarantees buffers are delivered in the
order specified in the "sequence" field, and which minimises
unnecessary wake-ups.

It will also ensure that pending queued buffers are held in the
queue rather than being "popped" off and held invisibly in a
structure private to mksquashfs.c.  This will also ensure a more
accurate display of queue status when in the queue and cache
dump (generated if control \ is hit twice within one second).

Currently queue status dumping of the seq_queue isn't implemented
so comment that out for the time being.

Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>

1 files changed, 2 insertions, 2 deletions

diff --git a/squashfs-tools/info.c b/squashfs-tools/info.c
index fd15b5c..219c6fb 100644
--- a/squashfs-tools/info.c
+++ b/squashfs-tools/info.c
@@ -96,8 +96,8 @@ void dump_state()
 	printf("from_reader queue (reader thread -> deflate thread(s))\n");
 	dump_queue(from_reader);
 
-	printf("\nfrom_deflate queue (deflate thread(s) -> main thread)\n");
-	dump_queue(from_deflate);
+	//printf("\nfrom_deflate queue (deflate thread(s) -> main thread)\n");
+	//dump_queue(from_deflate);
 
 	printf("\nto_frag queue (main thread -> fragment deflate thread(s))\n");
 	dump_queue(to_frag);