add back close_file_interval feature but disable it by default

include/libtorrent/aux_/file_view_pool.hpp

@@ -102,6 +102,8 @@ namespace aux {
 
 		std::vector<open_file_state> get_status(storage_index_t st) const;
 
+		void close_oldest();
+
 	private:
 
 		std::shared_ptr<file_mapping> remove_oldest(std::unique_lock<std::mutex>&);

simulation/test_file_pool.cpp

@@ -44,7 +44,6 @@ using namespace lt;
 
 // the disk I/O thread is not simulated with high enough fidelity for this to
 // work
-/*
 TORRENT_TEST(close_file_interval)
 {
 	bool ran_to_completion = false;
@@ -86,7 +85,6 @@ TORRENT_TEST(close_file_interval)
 		});
 	TEST_CHECK(ran_to_completion);
 }
-*/
 
 TORRENT_TEST(file_pool_size)
 {

src/disk_io_thread.cpp

@@ -316,6 +316,10 @@ private:
 
 	settings_interface const& m_settings;
 
+	// we call close_oldest_file on the file_pool regularly. This is the next
+	// time we should call it
+	time_point m_next_close_oldest_file = min_time();
+
 	// LRU cache of open files
 	aux::file_view_pool m_file_pool;
 
@@ -1409,6 +1413,21 @@ TORRENT_EXPORT std::unique_ptr<disk_interface> mmap_disk_io_constructor(
 						}
 					}
 				}
+
+				if (now > m_next_close_oldest_file)
+				{
+					seconds const interval(m_settings.get_int(settings_pack::close_file_interval));
+					if (interval <= seconds(0))
+					{
+						// check again in one minute, in case the setting changed
+						m_next_close_oldest_file = now + minutes(1);
+					}
+					else
+					{
+						m_next_close_oldest_file = now + interval;
+						m_file_pool.close_oldest();
+					}
+				}
 			}
 
 			execute_job(j);

src/file_view_pool.cpp

@@ -113,7 +113,7 @@ namespace libtorrent { namespace aux {
 		{
 			// the file cache is at its maximum size, close
 			// the least recently used file
-			remove_oldest(l);
+			defer_destruction = remove_oldest(l);
 		}
 
 		l.unlock();
@@ -234,6 +234,9 @@ namespace {
 
 	void file_view_pool::resize(int const size)
 	{
+		// these are destructed _after_ the mutex is released
+		std::vector<std::shared_ptr<file_mapping>> defer_destruction;
+
 		std::unique_lock<std::mutex> l(m_mutex);
 
 		TORRENT_ASSERT(size > 0);
@@ -244,7 +247,17 @@ namespace {
 
 		// close the least recently used files
 		while (int(m_files.size()) > m_size)
-			remove_oldest(l);
+			defer_destruction.emplace_back(remove_oldest(l));
+	}
+
+	void file_view_pool::close_oldest()
+	{
+		// closing a file may be long running operation (mac os x)
+		// destruct it after the mutex is released
+		std::shared_ptr<file_mapping> deferred_destruction;
+
+		std::unique_lock<std::mutex> l(m_mutex);
+		deferred_destruction = remove_oldest(l);
 	}
 }
 }

src/settings_pack.cpp

@@ -104,12 +104,6 @@ namespace libtorrent {
 #else
 #define DEPRECATED_SET(name, default_value, fun) { "", nullptr, 0 }
 #define DEPRECATED_SET_STR(name, default_value, fun) { "", nullptr, nullptr }
-#endif
-
-#ifdef TORRENT_WINDOWS
-constexpr int CLOSE_FILE_INTERVAL = 120;
-#else
-constexpr int CLOSE_FILE_INTERVAL = 0;
 #endif
 
 	namespace {
@@ -347,7 +341,7 @@ constexpr int CLOSE_FILE_INTERVAL = 0;
 		DEPRECATED_SET(cache_size_volatile, 256, nullptr),
 		SET(urlseed_max_request_bytes, 16 * 1024 * 1024, nullptr),
 		SET(web_seed_name_lookup_retry, 1800, nullptr),
-		SET(close_file_interval, CLOSE_FILE_INTERVAL, nullptr),
+		SET(close_file_interval, 0, nullptr),
 		SET(utp_cwnd_reduce_timer, 100, nullptr),
 		SET(max_web_seed_connections, 3, nullptr),
 		SET(resolver_cache_timeout, 1200, &session_impl::update_resolver_cache_timeout),