remove support for using a pool allocator for disk buffers (#2257)

ChangeLog

@@ -18,6 +18,7 @@
 	* added support for retrieval of DHT live nodes
 	* complete UNC path support
 	* add packets pool allocator
+	* remove disk buffer pool allocator
 	* fix last_upload and last_download overflow after 9 hours in past
 	* python binding add more add_torrent_params fields and an invalid key check
 	* introduce introduce distinct types for peer_class_t, piece_index_t and

include/libtorrent/disk_buffer_pool.hpp

@@ -35,15 +35,6 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #include "libtorrent/config.hpp"
 
-#include "libtorrent/aux_/disable_warnings_push.hpp"
-
-#ifndef TORRENT_DISABLE_POOL_ALLOCATOR
-#include "libtorrent/allocator.hpp" // for page_aligned_allocator
-#include <boost/pool/pool.hpp>
-#endif
-
-#include "libtorrent/aux_/disable_warnings_pop.hpp"
-
 #if TORRENT_USE_INVARIANT_CHECKS
 #include <set>
 #endif
@@ -87,8 +78,6 @@ namespace libtorrent {
 
 		int block_size() const { return m_block_size; }
 
-		void release_memory();
-
 		int in_use() const
 		{
 			std::unique_lock<std::mutex> l(m_pool_mutex);
@@ -144,28 +133,6 @@ namespace libtorrent {
 
 		int m_cache_buffer_chunk_size;
 
-#ifndef TORRENT_DISABLE_POOL_ALLOCATOR
-		// if this is true, all buffers are allocated
-		// from m_pool. If this is false, all buffers
-		// are allocated using page_aligned_allocator.
-		// if the settings change to prefer the other
-		// allocator, this bool will not switch over
-		// to match the settings until all buffers have
-		// been freed. That way, we never have a mixture
-		// of buffers allocated from different sources.
-		// in essence, this make the setting only take
-		// effect after a restart (which seems fine).
-		// or once the client goes idle for a while.
-		bool m_using_pool_allocator;
-
-		// this is the actual user setting
-		bool m_want_pool_allocator;
-
-		// memory pool for read and write operations
-		// and disk cache
-		boost::pool<page_aligned_allocator> m_pool;
-#endif
-
 		// this is specifically exempt from release_asserts
 		// since it's a quite costly check. Only for debug
 		// builds.

include/libtorrent/settings_pack.hpp

@@ -642,11 +642,15 @@ namespace libtorrent {
 			// failure is preferred, set this to false.
 			listen_system_port_fallback,
 
+#ifndef TORRENT_NO_DEPRECATE
 			// ``use_disk_cache_pool`` enables using a pool allocator for disk
 			// cache blocks. Enabling it makes the cache perform better at high
 			// throughput. It also makes the cache less likely and slower at
 			// returning memory back to the system, once allocated.
 			use_disk_cache_pool,
+#else
+			deprecated24,
+#endif
 
 			// when this is true, and incoming encrypted connections are enabled,
 			// &supportcrypt=1 is included in http tracker announces

include/libtorrent/storage.hpp

@@ -293,7 +293,6 @@ namespace libtorrent {
 		//
 		//			int block_size() const { return m_block_size; }
 		//
-		//			void release_memory();
 		//		};
 		virtual void delete_files(remove_flags_t options, storage_error& ec) = 0;
 

src/block_cache.cpp

@@ -692,9 +692,6 @@ cached_piece_entry* block_cache::allocate_piece(disk_io_job const* j, std::uint1
 
 cached_piece_entry* block_cache::add_dirty_block(disk_io_job* j)
 {
-#if !defined TORRENT_DISABLE_POOL_ALLOCATOR
-	TORRENT_ASSERT(is_disk_buffer(boost::get<disk_buffer_holder>(j->argument).get()));
-#endif
 #ifdef TORRENT_EXPENSIVE_INVARIANT_CHECKS
 	INVARIANT_CHECK;
 #endif
@@ -1616,14 +1613,6 @@ void block_cache::check_invariant() const
 		{
 			if (p.blocks[k].buf)
 			{
-#if !defined TORRENT_DISABLE_POOL_ALLOCATOR && defined TORRENT_EXPENSIVE_INVARIANT_CHECKS
-				TORRENT_PIECE_ASSERT(is_disk_buffer(p.blocks[k].buf), &p);
-
-				// make sure we don't have the same buffer
-				// in the cache twice
-				TORRENT_PIECE_ASSERT(buffers.count(p.blocks[k].buf) == 0, &p);
-				buffers.insert(p.blocks[k].buf);
-#endif
 				++num_blocks;
 				if (p.blocks[k].dirty)
 				{

src/disk_buffer_pool.cpp

@@ -77,11 +77,6 @@ namespace libtorrent {
 		, m_exceeded_max_size(false)
 		, m_ios(ios)
 		, m_cache_buffer_chunk_size(0)
-#ifndef TORRENT_DISABLE_POOL_ALLOCATOR
-		, m_using_pool_allocator(false)
-		, m_want_pool_allocator(false)
-		, m_pool(block_size, 32)
-#endif
 	{
 #if TORRENT_USE_ASSERTS
 		m_magic = 0x1337;
@@ -145,13 +140,9 @@ namespace libtorrent {
 		return m_buffers_in_use.count(buffer) == 1;
 #elif defined TORRENT_DEBUG_BUFFERS
 		return page_aligned_allocator::in_use(buffer);
-#elif defined TORRENT_DISABLE_POOL_ALLOCATOR
-		return true;
 #else
-		if (m_using_pool_allocator)
+		TORRENT_UNUSED(buffer);
-			return m_pool.is_from(buffer);
+		return true;
-		else
-			return true;
 #endif
 	}
 
@@ -237,28 +228,8 @@ namespace libtorrent {
 		TORRENT_ASSERT(l.owns_lock());
 		TORRENT_UNUSED(l);
 
-		char* ret;
+		char* ret = page_aligned_allocator::malloc(m_block_size);
-#if defined TORRENT_DISABLE_POOL_ALLOCATOR
 
-		ret = page_aligned_allocator::malloc(m_block_size);
-
-#else
-		if (m_using_pool_allocator)
-		{
-			int const effective_block_size
-				= m_in_use >= m_max_use
-				? 20 // use small increments once we've exceeded the cache size
-				: m_cache_buffer_chunk_size
-				? m_cache_buffer_chunk_size
-				: std::max(m_max_use / 10, 1);
-			m_pool.set_next_size(effective_block_size);
-			ret = static_cast<char*>(m_pool.malloc());
-		}
-		else
-		{
-			ret = page_aligned_allocator::malloc(m_block_size);
-		}
-#endif
 		if (ret == nullptr)
 		{
 			m_exceeded_max_size = true;
@@ -324,14 +295,6 @@ namespace libtorrent {
 		// 0 cache_buffer_chunk_size means 'automatic' (i.e.
 		// proportional to the total disk cache size)
 		m_cache_buffer_chunk_size = sett.get_int(settings_pack::cache_buffer_chunk_size);
-#ifndef TORRENT_DISABLE_POOL_ALLOCATOR
-		// if the chunk size is set to 1, there's no point in creating a pool
-		m_want_pool_allocator = sett.get_bool(settings_pack::use_disk_cache_pool)
-			&& (m_cache_buffer_chunk_size != 1);
-		// if there are no allocated blocks, it's OK to switch allocator
-		if (m_in_use == 0)
-			m_using_pool_allocator = m_want_pool_allocator;
-#endif
 
 		int const cache_size = sett.get_int(settings_pack::cache_size);
 		if (cache_size < 0)
@@ -419,37 +382,9 @@ namespace libtorrent {
 		TORRENT_ASSERT(l.owns_lock());
 		TORRENT_UNUSED(l);
 
-#if defined TORRENT_DISABLE_POOL_ALLOCATOR
-
 		page_aligned_allocator::free(buf);
 
-#else
-		if (m_using_pool_allocator)
-			m_pool.free(buf);
-		else
-			page_aligned_allocator::free(buf);
-#endif // TORRENT_DISABLE_POOL_ALLOCATOR
-
 		--m_in_use;
-
-#ifndef TORRENT_DISABLE_POOL_ALLOCATOR
-		// should we switch which allocator to use?
-		if (m_in_use == 0 && m_want_pool_allocator != m_using_pool_allocator)
-		{
-			m_pool.release_memory();
-			m_using_pool_allocator = m_want_pool_allocator;
-		}
-#endif
-	}
-
-	void disk_buffer_pool::release_memory()
-	{
-		TORRENT_ASSERT(m_magic == 0x1337);
-#ifndef TORRENT_DISABLE_POOL_ALLOCATOR
-		std::unique_lock<std::mutex> l(m_pool_mutex);
-		if (m_using_pool_allocator)
-			m_pool.release_memory();
-#endif
 	}
 
 }

src/disk_io_thread.cpp

@@ -2569,8 +2569,6 @@ namespace libtorrent {
 			, completed_jobs, l);
 		l.unlock();
 
-		m_disk_cache.release_memory();
-
 		j->storage->release_files(j->error);
 		return j->error ? status_t::fatal_disk_error : status_t::no_error;
 	}

src/session.cpp

@@ -240,8 +240,6 @@ namespace libtorrent {
 		// of a resumed file
 		set.set_int(settings_pack::checking_mem_usage, 320);
 
-		// the disk cache performs better with the pool allocator
-		set.set_bool(settings_pack::use_disk_cache_pool, true);
 		return set;
 	}
 

src/session_impl.cpp

@@ -3547,8 +3547,6 @@ namespace {
 				}
 			}
 		}
-
-//		m_peer_pool.release_memory();
 	}
 
 	namespace {

src/settings_pack.cpp

@@ -189,7 +189,7 @@ constexpr int CLOSE_FILE_INTERVAL = 0;
 		SET(support_merkle_torrents, true, nullptr),
 		SET(report_redundant_bytes, true, nullptr),
 		SET(listen_system_port_fallback, true, nullptr),
-		SET(use_disk_cache_pool, true, nullptr),
+		DEPRECATED_SET(use_disk_cache_pool, false, nullptr),
 		SET(announce_crypto_support, true, nullptr),
 		SET(enable_upnp, true, &session_impl::update_upnp),
 		SET(enable_natpmp, true, &session_impl::update_natpmp),