Cleanup: Rewrite block processor to use the libutil thread_pool_t

Throw out the messy thread pool implementation and temporarily also
remove the exact fragment matching for simplicity.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

6 files changed, 304 insertions, 795 deletions

diff --git a/lib/sqfs/Makemodule.am b/lib/sqfs/Makemodule.am
index b770fd4..5a62894 100644
--- a/lib/sqfs/Makemodule.am
+++ b/lib/sqfs/Makemodule.am
@@ -43,6 +43,7 @@ libsquashfs_la_SOURCES += lib/util/xxhash.c
 libsquashfs_la_SOURCES += lib/util/hash_table.c include/hash_table.h
 libsquashfs_la_SOURCES += lib/util/rbtree.c include/rbtree.h
 libsquashfs_la_SOURCES += lib/util/array.c include/array.h
+libsquashfs_la_SOURCES += include/threadpool.h
 
 if CUSTOM_ALLOC
 libsquashfs_la_SOURCES += lib/util/mempool.c include/mempool.h
@@ -50,6 +51,7 @@ endif
 
 if WINDOWS
 libsquashfs_la_SOURCES += lib/sqfs/win32/io_file.c
+libsquashfs_la_SOURCES += lib/util/threadpool.c
 libsquashfs_la_CFLAGS += -DWINVER=0x0600 -D_WIN32_WINNT=0x0600
 libsquashfs_la_CFLAGS += -Wc,-static-libgcc
 libsquashfs_la_LDFLAGS += -no-undefined -avoid-version
@@ -58,14 +60,10 @@ libsquashfs_la_SOURCES += lib/sqfs/unix/io_file.c
 endif
 
 if HAVE_PTHREAD
-libsquashfs_la_SOURCES += lib/sqfs/block_processor/winpthread.c
-libsquashfs_la_CPPFLAGS += -DWITH_PTHREAD
+libsquashfs_la_SOURCES += lib/util/threadpool.c
 else
-if WINDOWS
-libsquashfs_la_SOURCES += lib/sqfs/block_processor/winpthread.c
-else
-libsquashfs_la_SOURCES += lib/sqfs/block_processor/serial.c
-endif
+libsquashfs_la_SOURCES += lib/util/threadpool_serial.c
+libsquashfs_la_CPPFLAGS += -DNO_THREAD_IMPL
 endif
 
 if WITH_GZIP
diff --git a/lib/sqfs/block_processor/common.c b/lib/sqfs/block_processor/common.c
index f1aca1e..62c355b 100644
--- a/lib/sqfs/block_processor/common.c
+++ b/lib/sqfs/block_processor/common.c
@@ -50,8 +50,7 @@ static void release_old_block(sqfs_block_processor_t *proc, sqfs_block_t *blk)
 	proc->free_list = blk;
 }
 
-static int process_completed_block(sqfs_block_processor_t *proc,
-				   sqfs_block_t *blk)
+int process_completed_block(sqfs_block_processor_t *proc, sqfs_block_t *blk)
 {
 	sqfs_u64 location;
 	sqfs_u32 size;
@@ -113,9 +112,12 @@ static bool is_zero_block(unsigned char *ptr, size_t size)
 	return ptr[0] == 0 && memcmp(ptr, ptr + 1, size - 1) == 0;
 }
 
-static int process_block(sqfs_block_t *block, sqfs_compressor_t *cmp,
-			 sqfs_u8 *scratch, size_t scratch_size)
+static int process_block(void *userptr, void *workitem)
 {
+	sqfs_compressor_t *cmp = ((worker_data_t *)userptr)->cmp;
+	sqfs_u8 *scratch = ((worker_data_t *)userptr)->scratch;
+	size_t scratch_size = ((worker_data_t *)userptr)->scratch_size;
+	sqfs_block_t *block = workitem;
 	sqfs_s32 ret;
 
 	if (block->size == 0)
@@ -149,9 +151,9 @@ static int process_block(sqfs_block_t *block, sqfs_compressor_t *cmp,
 	return 0;
 }
 
-static int process_completed_fragment(sqfs_block_processor_t *proc,
-				      sqfs_block_t *frag,
-				      sqfs_block_t **blk_out)
+int process_completed_fragment(sqfs_block_processor_t *proc,
+			       sqfs_block_t *frag,
+			       sqfs_block_t **blk_out)
 {
 	chunk_info_t *chunk, search;
 	struct hash_entry *entry;
@@ -176,10 +178,8 @@ static int process_completed_fragment(sqfs_block_processor_t *proc,
 		search.hash = frag->checksum;
 		search.size = frag->size;
 
-		proc->frag_cmp_current = frag;
 		entry = hash_table_search_pre_hashed(proc->frag_ht,
 						     search.hash, &search);
-		proc->frag_cmp_current = NULL;
 
 		if (entry != NULL) {
 			if (frag->inode != NULL) {
@@ -241,10 +241,8 @@ static int process_completed_fragment(sqfs_block_processor_t *proc,
 		chunk->size = frag->size;
 		chunk->hash = frag->checksum;
 
-		proc->frag_cmp_current = frag;
 		entry = hash_table_insert_pre_hashed(proc->frag_ht, chunk->hash,
 						     chunk, chunk);
-		proc->frag_cmp_current = NULL;
 
 		if (entry == NULL) {
 			free(chunk);
@@ -277,121 +275,122 @@ static uint32_t chunk_info_hash(void *user, const void *key)
 static bool chunk_info_equals(void *user, const void *k, const void *c)
 {
 	const chunk_info_t *key = k, *cmp = c;
-	sqfs_block_processor_t *proc = user;
-	sqfs_fragment_t frag;
-	unsigned char *temp;
-	size_t size;
-	int ret;
-
-	if (key->size != cmp->size || key->hash != cmp->hash)
-		return false;
+	(void)user;
+	return key->size == cmp->size && key->hash == cmp->hash;
+}
 
-	if (proc->file == NULL || proc->uncmp == NULL)
-		return true;
+static void ht_delete_function(struct hash_entry *entry)
+{
+	free(entry->data);
+}
 
-	ret = proc->compare_frag_in_flight(proc, proc->frag_cmp_current,
-					   cmp->index, cmp->offset);
-	if (ret == 0)
-		return true;
+static void block_processor_destroy(sqfs_object_t *base)
+{
+	sqfs_block_processor_t *proc = (sqfs_block_processor_t *)base;
+	sqfs_block_t *it;
 
-	if (proc->buffered_index != cmp->index ||
-	    proc->buffered_blk_size == 0) {
-		if (sqfs_frag_table_lookup(proc->frag_tbl, cmp->index, &frag))
-			return false;
+	if (proc->frag_block != NULL)
+		release_old_block(proc, proc->frag_block);
 
-		proc->buffered_index = 0xFFFFFFFF;
-		size = SQFS_ON_DISK_BLOCK_SIZE(frag.size);
+	free(proc->blk_current);
 
-		if (SQFS_IS_BLOCK_COMPRESSED(frag.size)) {
-			temp = proc->frag_buffer + proc->max_block_size;
+	while (proc->free_list != NULL) {
+		it = proc->free_list;
+		proc->free_list = it->next;
+		free(it);
+	}
 
-			ret = proc->file->read_at(proc->file, frag.start_offset,
-						  temp, size);
-			if (ret != 0)
-				return false;
+	hash_table_destroy(proc->frag_ht, ht_delete_function);
 
-			ret = proc->uncmp->do_block(proc->uncmp, temp, size,
-						    proc->frag_buffer,
-						    proc->max_block_size);
-			if (ret <= 0)
-				return false;
+	/* XXX: shut down the pool first before cleaning up the worker data */
+	proc->pool->destroy(proc->pool);
 
-			size = ret;
-		} else {
-			ret = proc->file->read_at(proc->file, frag.start_offset,
-						  proc->frag_buffer, size);
-			if (ret != 0)
-				return false;
-		}
+	while (proc->workers != NULL) {
+		worker_data_t *worker = proc->workers;
+		proc->workers = worker->next;
 
-		proc->buffered_index = cmp->index;
-		proc->buffered_blk_size = size;
+		sqfs_destroy(worker->cmp);
+		free(worker);
 	}
 
-	if (cmp->offset >= proc->buffered_blk_size)
-		return false;
-
-	if (cmp->size > (proc->buffered_blk_size - cmp->offset))
-		return false;
-
-	return memcmp(proc->frag_buffer + cmp->offset,
-		      proc->frag_cmp_current->data,
-		      cmp->size) == 0;
+	free(proc);
 }
 
-static void ht_delete_function(struct hash_entry *entry)
+int sqfs_block_processor_create_ex(const sqfs_block_processor_desc_t *desc,
+				   sqfs_block_processor_t **out)
 {
-	free(entry->data);
-}
-
-void block_processor_cleanup(sqfs_block_processor_t *base)
-{
-	sqfs_block_t *it;
+	sqfs_block_processor_t *proc;
+	size_t i, count;
+	int ret;
 
-	if (base->frag_block != NULL)
-		release_old_block(base, base->frag_block);
+	if (desc->size != sizeof(sqfs_block_processor_desc_t))
+		return SQFS_ERROR_ARG_INVALID;
 
-	free(base->blk_current);
-	free(base->frag_buffer);
+	proc = calloc(1, sizeof(*proc));
+	if (proc == NULL)
+		return SQFS_ERROR_ALLOC;
 
-	while (base->free_list != NULL) {
-		it = base->free_list;
-		base->free_list = it->next;
-		free(it);
+	proc->max_backlog = desc->max_backlog;
+	proc->max_block_size = desc->max_block_size;
+	proc->frag_tbl = desc->tbl;
+	proc->wr = desc->wr;
+	proc->file = desc->file;
+	proc->uncmp = desc->uncmp;
+	proc->stats.size = sizeof(proc->stats);
+	((sqfs_object_t *)proc)->destroy = block_processor_destroy;
+
+	/* create the thread pool */
+	proc->pool = thread_pool_create(desc->num_workers, process_block);
+	if (proc->pool == NULL) {
+		free(proc);
+		return SQFS_ERROR_INTERNAL;
 	}
 
-	hash_table_destroy(base->frag_ht, ht_delete_function);
-}
+	/* create the worker compressors & scratch buffer */
+	count = proc->pool->get_worker_count(proc->pool);
 
-int block_processor_init(sqfs_block_processor_t *base,
-			 const sqfs_block_processor_desc_t *desc)
-{
-	base->process_completed_block = process_completed_block;
-	base->process_completed_fragment = process_completed_fragment;
-	base->process_block = process_block;
-	base->max_block_size = desc->max_block_size;
-	base->cmp = desc->cmp;
-	base->frag_tbl = desc->tbl;
-	base->wr = desc->wr;
-	base->file = desc->file;
-	base->uncmp = desc->uncmp;
-	base->buffered_index = 0xFFFFFFFF;
-	base->stats.size = sizeof(base->stats);
-
-	if (desc->file != NULL && desc->uncmp != NULL && desc->tbl != NULL) {
-		base->frag_buffer = malloc(2 * desc->max_block_size);
-		if (base->frag_buffer == NULL)
-			return SQFS_ERROR_ALLOC;
+	for (i = 0; i < count; ++i) {
+		worker_data_t *worker = alloc_flex(sizeof(*worker), 1,
+						   desc->max_block_size);
+		if (worker == NULL) {
+			ret = SQFS_ERROR_ALLOC;
+			goto fail_pool;
+		}
+
+		worker->scratch_size = desc->max_block_size;
+		worker->next = proc->workers;
+		proc->workers = worker;
+
+		worker->cmp = sqfs_copy(desc->cmp);
+		if (worker->cmp == NULL)
+			goto fail_pool;
+
+		proc->pool->set_worker_ptr(proc->pool, i, worker);
 	}
 
-	base->frag_ht = hash_table_create(chunk_info_hash, chunk_info_equals);
-	if (base->frag_ht == NULL) {
-		free(base->frag_buffer);
-		return SQFS_ERROR_ALLOC;
+	/* create the fragment hash table */
+	proc->frag_ht = hash_table_create(chunk_info_hash, chunk_info_equals);
+	if (proc->frag_ht == NULL) {
+		ret = SQFS_ERROR_ALLOC;
+		goto fail_pool;
 	}
 
-	base->frag_ht->user = base;
+	proc->frag_ht->user = proc;
+	*out = proc;
 	return 0;
+fail_pool:
+	proc->pool->destroy(proc->pool);
+	while (proc->workers != NULL) {
+		worker_data_t *worker = proc->workers;
+		proc->workers = worker->next;
+
+		if (worker->cmp != NULL)
+			sqfs_destroy(worker->cmp);
+
+		free(worker);
+	}
+	free(proc);
+	return ret;
 }
 
 sqfs_block_processor_t *sqfs_block_processor_create(size_t max_block_size,
diff --git a/lib/sqfs/block_processor/frontend.c b/lib/sqfs/block_processor/frontend.c
index f6aeffa..8bd6cf2 100644
--- a/lib/sqfs/block_processor/frontend.c
+++ b/lib/sqfs/block_processor/frontend.c
@@ -24,26 +24,159 @@ static sqfs_block_t *get_new_block(sqfs_block_processor_t *proc)
 	return blk;
 }
 
+static int dequeue_block(sqfs_block_processor_t *proc)
+{
+	sqfs_block_t *blk, *fragblk, *it, *prev;
+	bool have_dequeued = false;
+	int status;
+retry:
+	while (proc->io_queue != NULL) {
+		if (proc->io_queue->io_seq_num != proc->io_deq_seq_num)
+			break;
+
+		blk = proc->io_queue;
+		proc->io_queue = blk->next;
+		proc->io_deq_seq_num += 1;
+		proc->backlog -= 1;
+		have_dequeued = true;
+
+		status = process_completed_block(proc, blk);
+		if (status != 0)
+			return status;
+	}
+
+	if (have_dequeued)
+		return 0;
+
+	blk = proc->pool->dequeue(proc->pool);
+
+	if (blk == NULL) {
+		status = proc->pool->get_status(proc->pool);
+		if (status == 0)
+			status = SQFS_ERROR_INTERNAL;
+
+		return status;
+	}
+
+	proc->backlog -= 1;
+	have_dequeued = true;
+
+	if (blk->flags & SQFS_BLK_IS_FRAGMENT) {
+		fragblk = NULL;
+		status = process_completed_fragment(proc, blk, &fragblk);
+
+		if (status != 0) {
+			free(fragblk);
+			return status;
+		}
+
+		if (fragblk != NULL) {
+			fragblk->io_seq_num = proc->io_seq_num++;
+
+			if (proc->pool->submit(proc->pool, fragblk) != 0) {
+				free(fragblk);
+
+				if (status == 0) {
+					status = proc->pool->
+						get_status(proc->pool);
+
+					if (status == 0)
+						status = SQFS_ERROR_ALLOC;
+				}
+
+				return status;
+			}
+
+			proc->backlog += 1;
+			have_dequeued = false;
+		}
+	} else {
+		if (!(blk->flags & SQFS_BLK_FRAGMENT_BLOCK))
+			blk->io_seq_num = proc->io_seq_num++;
+
+		prev = NULL;
+		it = proc->io_queue;
+
+		while (it != NULL) {
+			if (it->io_seq_num >= blk->io_seq_num)
+				break;
+
+			prev = it;
+			it = it->next;
+		}
+
+		if (prev == NULL) {
+			blk->next = proc->io_queue;
+			proc->io_queue = blk;
+		} else {
+			blk->next = prev->next;
+			prev->next = blk;
+		}
+
+		proc->backlog += 1;
+		have_dequeued = false;
+	}
+
+	if (!have_dequeued)
+		goto retry;
+
+	return 0;
+}
+
+static int enqueue_block(sqfs_block_processor_t *proc, sqfs_block_t *blk)
+{
+	int status;
+
+	if (proc->pool->submit(proc->pool, blk) != 0) {
+		status = proc->pool->get_status(proc->pool);
+
+		if (status == 0)
+			status = SQFS_ERROR_ALLOC;
+
+		free(blk);
+		return status;
+	}
+
+	proc->backlog += 1;
+	return 0;
+}
+
 static int add_sentinel_block(sqfs_block_processor_t *proc)
 {
-	sqfs_block_t *blk = get_new_block(proc);
+	sqfs_block_t *blk;
+	int ret;
+
+	if (proc->backlog == proc->max_backlog) {
+		ret = dequeue_block(proc);
+		if (ret != 0)
+			return ret;
+	}
 
+	blk = get_new_block(proc);
 	if (blk == NULL)
 		return SQFS_ERROR_ALLOC;
 
 	blk->inode = proc->inode;
 	blk->flags = proc->blk_flags | SQFS_BLK_LAST_BLOCK;
 
-	return proc->append_to_work_queue(proc, blk);
+	return enqueue_block(proc, blk);
 }
 
 static int flush_block(sqfs_block_processor_t *proc)
 {
-	sqfs_block_t *block = proc->blk_current;
+	sqfs_block_t *block;
+	int ret;
+
+	if (proc->backlog == proc->max_backlog) {
+		ret = dequeue_block(proc);
+		if (ret != 0)
+			return ret;
+	}
 
+	block = proc->blk_current;
 	proc->blk_current = NULL;
 
-	return proc->append_to_work_queue(proc, block);
+	return enqueue_block(proc, block);
 }
 
 int sqfs_block_processor_begin_file(sqfs_block_processor_t *proc,
@@ -177,6 +310,7 @@ int sqfs_block_processor_submit_block(sqfs_block_processor_t *proc, void *user,
 				      size_t size)
 {
 	sqfs_block_t *blk;
+	int ret;
 
 	if (proc->begin_called)
 		return SQFS_ERROR_SEQUENCE;
@@ -187,6 +321,12 @@ int sqfs_block_processor_submit_block(sqfs_block_processor_t *proc, void *user,
 	if (flags & ~SQFS_BLK_FLAGS_ALL)
 		return SQFS_ERROR_UNSUPPORTED;
 
+	if (proc->backlog == proc->max_backlog) {
+		ret = dequeue_block(proc);
+		if (ret != 0)
+			return ret;
+	}
+
 	blk = get_new_block(proc);
 	if (blk == NULL)
 		return SQFS_ERROR_ALLOC;
@@ -196,12 +336,25 @@ int sqfs_block_processor_submit_block(sqfs_block_processor_t *proc, void *user,
 	blk->size = size;
 	memcpy(blk->data, data, size);
 
-	return proc->append_to_work_queue(proc, blk);
+	ret = proc->pool->submit(proc->pool, blk);
+	if (ret != 0)
+		free(blk);
+
+	proc->backlog += 1;
+	return ret;
 }
 
 int sqfs_block_processor_sync(sqfs_block_processor_t *proc)
 {
-	return proc->sync(proc);
+	int ret;
+
+	while (proc->backlog > 0) {
+		ret = dequeue_block(proc);
+		if (ret != 0)
+			return ret;
+	}
+
+	return 0;
 }
 
 int sqfs_block_processor_finish(sqfs_block_processor_t *proc)
@@ -209,18 +362,30 @@ int sqfs_block_processor_finish(sqfs_block_processor_t *proc)
 	sqfs_block_t *blk;
 	int status;
 
-	status = proc->sync(proc);
+	status = sqfs_block_processor_sync(proc);
+	if (status != 0)
+		return status;
 
-	if (status == 0 && proc->frag_block != NULL) {
+	if (proc->frag_block != NULL) {
 		blk = proc->frag_block;
 		blk->next = NULL;
-		blk->flags |= BLK_FLAG_MANUAL_SUBMISSION;
 		proc->frag_block = NULL;
 
-		status = proc->append_to_work_queue(proc, blk);
+		blk->io_seq_num = proc->io_seq_num++;
 
-		if (status == 0)
-			status = proc->sync(proc);
+		status = proc->pool->submit(proc->pool, blk);
+		if (status != 0) {
+			status = proc->pool->get_status(proc->pool);
+
+			if (status == 0)
+				status = SQFS_ERROR_ALLOC;
+
+			free(blk);
+			return status;
+		}
+
+		proc->backlog += 1;
+		status = sqfs_block_processor_sync(proc);
 	}
 
 	return status;
diff --git a/lib/sqfs/block_processor/internal.h b/lib/sqfs/block_processor/internal.h
index 4699dc6..2393380 100644
--- a/lib/sqfs/block_processor/internal.h
+++ b/lib/sqfs/block_processor/internal.h
@@ -20,6 +20,7 @@
 #include "sqfs/io.h"
 
 #include "hash_table.h"
+#include "threadpool.h"
 #include "util.h"
 
 #include <string.h>
@@ -42,7 +43,6 @@ typedef struct sqfs_block_t {
 	struct sqfs_block_t *next;
 	sqfs_inode_generic_t **inode;
 
-	sqfs_u32 proc_seq_num;
 	sqfs_u32 io_seq_num;
 	sqfs_u32 flags;
 	sqfs_u32 size;
@@ -58,11 +58,18 @@ typedef struct sqfs_block_t {
 	sqfs_u8 data[];
 } sqfs_block_t;
 
+typedef struct worker_data_t {
+	struct worker_data_t *next;
+	sqfs_compressor_t *cmp;
+
+	size_t scratch_size;
+	sqfs_u8 scratch[];
+} worker_data_t;
+
 struct sqfs_block_processor_t {
 	sqfs_object_t obj;
 
 	sqfs_frag_table_t *frag_tbl;
-	sqfs_compressor_t *cmp;
 	sqfs_block_t *frag_block;
 	sqfs_block_writer_t *wr;
 
@@ -78,39 +85,30 @@ struct sqfs_block_processor_t {
 	sqfs_block_t *free_list;
 
 	size_t max_block_size;
+	size_t max_backlog;
+	size_t backlog;
 
 	bool begin_called;
 
 	sqfs_file_t *file;
 	sqfs_compressor_t *uncmp;
-	sqfs_block_t *frag_cmp_current;
-	sqfs_u8 *frag_buffer;
-	sqfs_u32 buffered_index;
-	sqfs_u32 buffered_blk_size;
 
-	int (*process_completed_block)(sqfs_block_processor_t *proc,
-				       sqfs_block_t *block);
+	thread_pool_t *pool;
+	worker_data_t *workers;
 
-	int (*process_completed_fragment)(sqfs_block_processor_t *proc,
-					  sqfs_block_t *frag,
-					  sqfs_block_t **blk_out);
 
-	int (*process_block)(sqfs_block_t *block, sqfs_compressor_t *cmp,
-			     sqfs_u8 *scratch, size_t scratch_size);
 
-	int (*compare_frag_in_flight)(sqfs_block_processor_t *proc,
-				      sqfs_block_t *frag, sqfs_u32 index,
-				      sqfs_u32 offset);
-
-	int (*append_to_work_queue)(sqfs_block_processor_t *proc,
-				    sqfs_block_t *block);
-
-	int (*sync)(sqfs_block_processor_t *proc);
+	sqfs_block_t *io_queue;
+	sqfs_u32 io_seq_num;
+	sqfs_u32 io_deq_seq_num;
 };
 
-SQFS_INTERNAL void block_processor_cleanup(sqfs_block_processor_t *base);
+SQFS_INTERNAL
+int process_completed_block(sqfs_block_processor_t *proc, sqfs_block_t *blk);
 
-SQFS_INTERNAL int block_processor_init(sqfs_block_processor_t *base,
-				       const sqfs_block_processor_desc_t *desc);
+SQFS_INTERNAL
+int process_completed_fragment(sqfs_block_processor_t *proc,
+			       sqfs_block_t *frag,
+			       sqfs_block_t **blk_out);
 
 #endif /* INTERNAL_H */
diff --git a/lib/sqfs/block_processor/serial.c b/lib/sqfs/block_processor/serial.c
deleted file mode 100644
index b20d5b0..0000000
--- a/lib/sqfs/block_processor/serial.c
+++ /dev/null
@@ -1,106 +0,0 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
-/*
- * serial.c
- *
- * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
- */
-#define SQFS_BUILDING_DLL
-#include "internal.h"
-
-typedef struct {
-	sqfs_block_processor_t base;
-	int status;
-	sqfs_u8 scratch[];
-} serial_block_processor_t;
-
-static void block_processor_destroy(sqfs_object_t *obj)
-{
-	sqfs_block_processor_t *proc = (sqfs_block_processor_t *)obj;
-
-	block_processor_cleanup(proc);
-	free(proc);
-}
-
-static int append_to_work_queue(sqfs_block_processor_t *proc,
-				sqfs_block_t *block)
-{
-	serial_block_processor_t *sproc = (serial_block_processor_t *)proc;
-	sqfs_block_t *fragblk = NULL;
-
-	if (sproc->status != 0)
-		goto fail;
-
-	sproc->status = proc->process_block(block, proc->cmp, sproc->scratch,
-					    proc->max_block_size);
-	if (sproc->status != 0)
-		goto fail;
-
-	if (block->flags & SQFS_BLK_IS_FRAGMENT) {
-		sproc->status = proc->process_completed_fragment(proc, block,
-								 &fragblk);
-		if (fragblk == NULL)
-			return sproc->status;
-
-		block = fragblk;
-		sproc->status = proc->process_block(block, proc->cmp,
-						    sproc->scratch,
-						    proc->max_block_size);
-		if (sproc->status != 0)
-			goto fail;
-	}
-
-	sproc->status = proc->process_completed_block(proc, block);
-	return sproc->status;
-fail:
-	free(block);
-	return sproc->status;
-}
-
-static int block_processor_sync(sqfs_block_processor_t *proc)
-{
-	return ((serial_block_processor_t *)proc)->status;
-}
-
-static int compare_frag_in_flight(sqfs_block_processor_t *proc,
-				  sqfs_block_t *frag, sqfs_u32 index,
-				  sqfs_u32 offset)
-{
-	if (proc->frag_block == NULL || index != proc->frag_block->index)
-		return -1;
-
-	if (offset >= proc->frag_block->size)
-		return -1;
-
-	if (frag->size > (proc->frag_block->size - offset))
-		return -1;
-
-	return memcmp(proc->frag_block->data + offset, frag->data, frag->size);
-}
-
-int sqfs_block_processor_create_ex(const sqfs_block_processor_desc_t *desc,
-				   sqfs_block_processor_t **out)
-{
-	serial_block_processor_t *proc;
-	int ret;
-
-	if (desc->size != sizeof(sqfs_block_processor_desc_t))
-		return SQFS_ERROR_ARG_INVALID;
-
-	proc = alloc_flex(sizeof(*proc), 1, desc->max_block_size);
-	if (proc == NULL)
-		return SQFS_ERROR_ALLOC;
-
-	ret = block_processor_init(&proc->base, desc);
-	if (ret != 0) {
-		free(proc);
-		return ret;
-	}
-
-	proc->base.sync = block_processor_sync;
-	proc->base.append_to_work_queue = append_to_work_queue;
-	proc->base.compare_frag_in_flight = compare_frag_in_flight;
-	((sqfs_object_t *)proc)->destroy = block_processor_destroy;
-
-	*out = (sqfs_block_processor_t *)proc;
-	return 0;
-}
diff --git a/lib/sqfs/block_processor/winpthread.c b/lib/sqfs/block_processor/winpthread.c
deleted file mode 100644
index 806c749..0000000
--- a/lib/sqfs/block_processor/winpthread.c
+++ /dev/null
@@ -1,545 +0,0 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
-/*
- * winpthread.c
- *
- * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
- */
-#define SQFS_BUILDING_DLL
-#include "internal.h"
-
-#if defined(_WIN32) || defined(__WINDOWS__)
-#	define WIN32_LEAN_AND_MEAN
-#	include <windows.h>
-#	define LOCK EnterCriticalSection
-#	define UNLOCK LeaveCriticalSection
-#	define AWAIT(cond, mtx) SleepConditionVariableCS(cond, mtx, INFINITE)
-#	define SIGNAL_ALL WakeAllConditionVariable
-#	define THREAD_CREATE(hndptr, proc, arg) \
-		  ((*hndptr) = CreateThread(NULL, 0, proc, arg, 0, 0), \
-		   ((*hndptr) == NULL) ? -1 : 0)
-#	define THREAD_JOIN(t) \
-		do { \
-			WaitForSingleObject(t, INFINITE); \
-			CloseHandle(t); \
-		} while (0)
-#	define MUTEX_INIT InitializeCriticalSection
-#	define MUTEX_DESTROY DeleteCriticalSection
-#	define CONDITION_INIT InitializeConditionVariable
-#	define CONDITION_DESTROY(cond)
-#	define THREAD_EXIT_SUCCESS 0
-#	define THREAD_INVALID NULL
-#	define THREAD_TYPE DWORD WINAPI
-#	define SIGNAL_DISABLE(oldset) (void)oldset
-#	define SIGNAL_ENABLE(oldset) (void)oldset
-
-typedef int sigset_t;
-typedef LPVOID THREAD_ARG;
-typedef HANDLE THREAD_HANDLE;
-typedef CRITICAL_SECTION MUTEX_TYPE;
-typedef CONDITION_VARIABLE CONDITION_TYPE;
-#else
-#	include <pthread.h>
-#	include <signal.h>
-#	define LOCK pthread_mutex_lock
-#	define UNLOCK pthread_mutex_unlock
-#	define AWAIT pthread_cond_wait
-#	define SIGNAL_ALL pthread_cond_broadcast
-#	define THREAD_CREATE(hndptr, proc, arg) \
-		  pthread_create((hndptr), NULL, (proc), (arg))
-#	define THREAD_JOIN(t) pthread_join((t), NULL)
-#	define MUTEX_INIT(mtx) \
-		*(mtx) = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER
-#	define MUTEX_DESTROY pthread_mutex_destroy
-#	define CONDITION_INIT(cond) \
-		*(cond) = (pthread_cond_t)PTHREAD_COND_INITIALIZER
-#	define CONDITION_DESTROY pthread_cond_destroy
-#	define THREAD_EXIT_SUCCESS NULL
-#	define THREAD_INVALID (pthread_t)0
-#	define SIGNAL_ENABLE(oldset) pthread_sigmask(SIG_SETMASK, oldset, NULL)
-
-typedef void *THREAD_TYPE;
-typedef void *THREAD_ARG;
-typedef pthread_t THREAD_HANDLE;
-typedef pthread_mutex_t MUTEX_TYPE;
-typedef pthread_cond_t CONDITION_TYPE;
-
-static inline void SIGNAL_DISABLE(sigset_t *oldset)
-{
-	sigset_t set;
-	sigfillset(&set);
-	pthread_sigmask(SIG_SETMASK, &set, oldset);
-}
-#endif
-
-typedef struct compress_worker_t compress_worker_t;
-typedef struct thread_pool_processor_t thread_pool_processor_t;
-
-struct compress_worker_t {
-	thread_pool_processor_t *shared;
-	sqfs_compressor_t *cmp;
-	THREAD_HANDLE thread;
-	sqfs_u32 frag_blk_index;
-	sqfs_u32 frag_blk_size;
-	sqfs_u8 scratch[];
-};
-
-struct thread_pool_processor_t {
-	sqfs_block_processor_t base;
-
-	MUTEX_TYPE mtx;
-	CONDITION_TYPE queue_cond;
-	CONDITION_TYPE done_cond;
-
-	sqfs_block_t *proc_queue;
-	sqfs_block_t *proc_queue_last;
-
-	sqfs_block_t *io_queue;
-	sqfs_block_t *done;
-	size_t backlog;
-	int status;
-
-	sqfs_u32 proc_enq_id;
-	sqfs_u32 proc_deq_id;
-
-	sqfs_u32 io_enq_id;
-	sqfs_u32 io_deq_id;
-
-	unsigned int num_workers;
-	size_t max_backlog;
-
-	compress_worker_t *workers[];
-};
-
-static void free_blk_list(sqfs_block_t *list)
-{
-	sqfs_block_t *it;
-
-	while (list != NULL) {
-		it = list;
-		list = list->next;
-		free(it);
-	}
-}
-
-static sqfs_block_t *get_next_work_item(thread_pool_processor_t *shared)
-{
-	sqfs_block_t *blk = NULL;
-
-	while (shared->proc_queue == NULL && shared->status == 0)
-		AWAIT(&shared->queue_cond, &shared->mtx);
-
-	if (shared->status == 0) {
-		blk = shared->proc_queue;
-		shared->proc_queue = blk->next;
-		blk->next = NULL;
-
-		if (shared->proc_queue == NULL)
-			shared->proc_queue_last = NULL;
-	}
-
-	return blk;
-}
-
-static void store_completed_block(thread_pool_processor_t *shared,
-				  sqfs_block_t *blk, int status)
-{
-	sqfs_block_t *it = shared->done, *prev = NULL;
-
-	while (it != NULL) {
-		if (it->proc_seq_num >= blk->proc_seq_num)
-			break;
-		prev = it;
-		it = it->next;
-	}
-
-	if (prev == NULL) {
-		blk->next = shared->done;
-		shared->done = blk;
-	} else {
-		blk->next = prev->next;
-		prev->next = blk;
-	}
-
-	if (status != 0 && shared->status == 0)
-		shared->status = status;
-
-	SIGNAL_ALL(&shared->done_cond);
-}
-
-static THREAD_TYPE worker_proc(THREAD_ARG arg)
-{
-	compress_worker_t *worker = arg;
-	thread_pool_processor_t *shared = worker->shared;
-	sqfs_block_processor_t *proc = (sqfs_block_processor_t *)shared;
-	sqfs_block_t *blk = NULL;
-	int status = 0;
-
-	for (;;) {
-		LOCK(&shared->mtx);
-		if (blk != NULL)
-			store_completed_block(shared, blk, status);
-
-		blk = get_next_work_item(shared);
-
-		if (blk != NULL && (blk->flags & SQFS_BLK_FRAGMENT_BLOCK) &&
-		    shared->base.uncmp != NULL && shared->base.file != NULL) {
-			memcpy(worker->scratch + shared->base.max_block_size,
-			       blk->data, blk->size);
-			worker->frag_blk_index = blk->index;
-			worker->frag_blk_size = blk->size;
-		}
-		UNLOCK(&shared->mtx);
-
-		if (blk == NULL)
-			break;
-
-		status = proc->process_block(blk, worker->cmp, worker->scratch,
-					     proc->max_block_size);
-	}
-
-	return THREAD_EXIT_SUCCESS;
-}
-
-static void block_processor_destroy(sqfs_object_t *obj)
-{
-	thread_pool_processor_t *proc = (thread_pool_processor_t *)obj;
-	unsigned int i;
-
-	LOCK(&proc->mtx);
-	proc->status = -1;
-	SIGNAL_ALL(&proc->queue_cond);
-	UNLOCK(&proc->mtx);
-
-	for (i = 0; i < proc->num_workers; ++i) {
-		if (proc->workers[i] != NULL) {
-			if (proc->workers[i]->thread != THREAD_INVALID)
-				THREAD_JOIN(proc->workers[i]->thread);
-
-			if (proc->workers[i]->cmp != NULL)
-				sqfs_destroy(proc->workers[i]->cmp);
-
-			free(proc->workers[i]);
-		}
-	}
-
-	CONDITION_DESTROY(&proc->done_cond);
-	CONDITION_DESTROY(&proc->queue_cond);
-	MUTEX_DESTROY(&proc->mtx);
-
-	free_blk_list(proc->proc_queue);
-	free_blk_list(proc->io_queue);
-	free_blk_list(proc->done);
-	block_processor_cleanup(&proc->base);
-	free(proc);
-}
-
-static void store_io_block(thread_pool_processor_t *proc, sqfs_block_t *blk)
-{
-	sqfs_block_t *it = proc->io_queue, *prev = NULL;
-
-	while (it != NULL && it->io_seq_num < blk->io_seq_num) {
-		prev = it;
-		it = it->next;
-	}
-
-	if (prev == NULL) {
-		blk->next = proc->io_queue;
-		proc->io_queue = blk;
-	} else {
-		blk->next = prev->next;
-		prev->next = blk;
-	}
-
-	proc->backlog += 1;
-}
-
-static sqfs_block_t *try_dequeue_io(thread_pool_processor_t *proc)
-{
-	sqfs_block_t *out;
-
-	if (proc->io_queue == NULL)
-		return NULL;
-
-	if (proc->io_queue->io_seq_num != proc->io_deq_id)
-		return NULL;
-
-	out = proc->io_queue;
-	proc->io_queue = out->next;
-	out->next = NULL;
-	proc->io_deq_id += 1;
-	proc->backlog -= 1;
-	return out;
-}
-
-static sqfs_block_t *try_dequeue_done(thread_pool_processor_t *proc)
-{
-	sqfs_block_t *out;
-
-	if (proc->done == NULL)
-		return NULL;
-
-	if (proc->done->proc_seq_num != proc->proc_deq_id)
-		return NULL;
-
-	out = proc->done;
-	proc->done = out->next;
-	out->next = NULL;
-	proc->proc_deq_id += 1;
-	proc->backlog -= 1;
-	return out;
-}
-
-static void append_block(thread_pool_processor_t *proc, sqfs_block_t *block)
-{
-	if (proc->proc_queue_last == NULL) {
-		proc->proc_queue = proc->proc_queue_last = block;
-	} else {
-		proc->proc_queue_last->next = block;
-		proc->proc_queue_last = block;
-	}
-
-	block->proc_seq_num = proc->proc_enq_id++;
-	block->next = NULL;
-	proc->backlog += 1;
-}
-
-static int handle_io_queue(thread_pool_processor_t *proc, sqfs_block_t *list)
-{
-	sqfs_block_t *it;
-	int status = 0;
-
-	while (status == 0 && list != NULL) {
-		it = list;
-		list = list->next;
-		status = proc->base.process_completed_block(&proc->base, it);
-
-		if (status != 0) {
-			LOCK(&proc->mtx);
-			if (proc->status == 0)
-				proc->status = status;
-			SIGNAL_ALL(&proc->queue_cond);
-			UNLOCK(&proc->mtx);
-		}
-	}
-
-	return status;
-}
-
-static int append_to_work_queue(sqfs_block_processor_t *proc,
-				sqfs_block_t *block)
-{
-	thread_pool_processor_t *thproc = (thread_pool_processor_t *)proc;
-	sqfs_block_t *io_list = NULL, *io_list_last = NULL;
-	sqfs_block_t *blk, *fragblk;
-	int status;
-
-	LOCK(&thproc->mtx);
-	for (;;) {
-		status = thproc->status;
-		if (status != 0)
-			break;
-
-		if (block == NULL) {
-			if (thproc->backlog == 0)
-				break;
-		} else {
-			if (thproc->backlog < thproc->max_backlog) {
-				append_block(thproc, block);
-				block = NULL;
-				break;
-			}
-		}
-
-		blk = try_dequeue_io(thproc);
-		if (blk != NULL) {
-			if (io_list_last == NULL) {
-				io_list = io_list_last = blk;
-			} else {
-				io_list_last->next = blk;
-				io_list_last = blk;
-			}
-			continue;
-		}
-
-		blk = try_dequeue_done(thproc);
-		if (blk == NULL) {
-			AWAIT(&thproc->done_cond, &thproc->mtx);
-			continue;
-		}
-
-		if (blk->flags & SQFS_BLK_IS_FRAGMENT) {
-			fragblk = NULL;
-			thproc->status =
-				proc->process_completed_fragment(proc, blk,
-								 &fragblk);
-
-			if (fragblk != NULL) {
-				fragblk->io_seq_num = thproc->io_enq_id++;
-				append_block(thproc, fragblk);
-				SIGNAL_ALL(&thproc->queue_cond);
-			}
-		} else {
-			if (!(blk->flags & SQFS_BLK_FRAGMENT_BLOCK) ||
-			    blk->flags & BLK_FLAG_MANUAL_SUBMISSION)
-				blk->io_seq_num = thproc->io_enq_id++;
-			store_io_block(thproc, blk);
-		}
-	}
-	SIGNAL_ALL(&thproc->queue_cond);
-	UNLOCK(&thproc->mtx);
-	free(block);
-
-	if (status == 0) {
-		status = handle_io_queue(thproc, io_list);
-	} else {
-		free_blk_list(io_list);
-	}
-
-	return status;
-}
-
-static sqfs_block_t *find_frag_blk_in_queue(sqfs_block_t *q, sqfs_u32 index)
-{
-	while (q != NULL) {
-		if ((q->flags & SQFS_BLK_FRAGMENT_BLOCK) && q->index == index)
-			break;
-		q = q->next;
-	}
-	return q;
-}
-
-static int compare_frag_in_flight(sqfs_block_processor_t *proc,
-				  sqfs_block_t *frag, sqfs_u32 index,
-				  sqfs_u32 offset)
-{
-	thread_pool_processor_t *thproc = (thread_pool_processor_t *)proc;
-	sqfs_block_t *it = NULL;
-	void *blockbuf = NULL;
-	size_t i, size = 0;
-	int ret;
-
-	if (proc->frag_block != NULL && proc->frag_block->index == index)
-		it = proc->frag_block;
-
-	if (it == NULL)
-		it = find_frag_blk_in_queue(thproc->proc_queue, index);
-
-	if (it == NULL)
-		it = find_frag_blk_in_queue(thproc->io_queue, index);
-
-	if (it == NULL)
-		it = find_frag_blk_in_queue(thproc->done, index);
-
-	if (it == NULL) {
-		for (i = 0; i < thproc->num_workers; ++i) {
-			if (thproc->workers[i]->frag_blk_index == index) {
-				size = thproc->workers[i]->frag_blk_size;
-				blockbuf = thproc->workers[i]->scratch +
-					proc->max_block_size;
-				break;
-			}
-		}
-	} else if (it->flags & SQFS_BLK_IS_COMPRESSED) {
-		proc->buffered_index = 0xFFFFFFFF;
-		blockbuf = proc->frag_buffer;
-		ret = proc->uncmp->do_block(proc->uncmp, it->data, it->size,
-					    blockbuf, proc->max_block_size);
-		if (ret <= 0)
-			return -1;
-		proc->buffered_index = it->index;
-		size = ret;
-	} else {
-		blockbuf = it->data;
-		size = it->size;
-	}
-
-	if (blockbuf == NULL || size == 0)
-		return -1;
-
-	if (offset >= size || frag->size > (size - offset))
-		return -1;
-
-	return memcmp((const char *)blockbuf + offset, frag->data, frag->size);
-}
-
-static int block_processor_sync(sqfs_block_processor_t *proc)
-{
-	return append_to_work_queue(proc, NULL);
-}
-
-int sqfs_block_processor_create_ex(const sqfs_block_processor_desc_t *desc,
-				   sqfs_block_processor_t **out)
-{
-	thread_pool_processor_t *proc;
-	unsigned int i, num_workers;
-	size_t scratch_size;
-	sigset_t oldset;
-	int ret;
-
-	if (desc->size != sizeof(sqfs_block_processor_desc_t))
-		return SQFS_ERROR_ARG_INVALID;
-
-	num_workers = desc->num_workers < 1 ? 1 : desc->num_workers;
-
-	proc = alloc_flex(sizeof(*proc),
-			  sizeof(proc->workers[0]), num_workers);
-	if (proc == NULL)
-		return SQFS_ERROR_ALLOC;
-
-	ret = block_processor_init(&proc->base, desc);
-	if (ret != 0) {
-		free(proc);
-		return ret;
-	}
-
-	proc->base.sync = block_processor_sync;
-	proc->base.append_to_work_queue = append_to_work_queue;
-	proc->base.compare_frag_in_flight = compare_frag_in_flight;
-	proc->num_workers = num_workers;
-	proc->max_backlog = desc->max_backlog;
-	((sqfs_object_t *)proc)->destroy = block_processor_destroy;
-
-	MUTEX_INIT(&proc->mtx);
-	CONDITION_INIT(&proc->queue_cond);
-	CONDITION_INIT(&proc->done_cond);
-
-	SIGNAL_DISABLE(&oldset);
-
-	for (i = 0; i < num_workers; ++i) {
-		scratch_size = desc->max_block_size;
-		if (desc->uncmp != NULL && desc->file != NULL)
-			scratch_size *= 2;
-
-		proc->workers[i] = alloc_flex(sizeof(compress_worker_t),
-					      1, scratch_size);
-
-		if (proc->workers[i] == NULL) {
-			ret = SQFS_ERROR_ALLOC;
-			goto fail;
-		}
-
-		proc->workers[i]->shared = proc;
-		proc->workers[i]->cmp = sqfs_copy(desc->cmp);
-		proc->workers[i]->frag_blk_index = 0xFFFFFFFF;
-
-		if (proc->workers[i]->cmp == NULL) {
-			ret = SQFS_ERROR_ALLOC;
-			goto fail;
-		}
-
-		ret = THREAD_CREATE(&proc->workers[i]->thread,
-				    worker_proc, proc->workers[i]);
-		if (ret != 0) {
-			ret = SQFS_ERROR_INTERNAL;
-			goto fail;
-		}
-	}
-
-	SIGNAL_ENABLE(&oldset);
-	*out = (sqfs_block_processor_t *)proc;
-	return 0;
-fail:
-	SIGNAL_ENABLE(&oldset);
-	block_processor_destroy((sqfs_object_t *)proc);
-	return ret;
-}