Run multiple session save requests in parallel.

src/Makefile.am

@@ -13,8 +13,6 @@ libsub_root_a_SOURCES = \
 	core/download_factory.h \
 	core/download_list.cc \
 	core/download_list.h \
-	core/download_store.cc \
-	core/download_store.h \
 	core/http_queue.cc \
 	core/http_queue.h \
 	core/manager.cc \
@@ -128,6 +126,8 @@ libsub_root_a_SOURCES = \
 	scgi/thread_scgi.cc \
 	scgi/thread_scgi.h \
 	\
+	session/download_storer.cc \
+	session/download_storer.h \
 	session/session_manager.cc \
 	session/session_manager.h \
 	session/thread_session.cc \

src/command_download.cc

@@ -25,9 +25,9 @@
 #include <torrent/utils/option_strings.h>
 
 #include "core/download.h"
-#include "core/download_store.h"
 #include "core/manager.h"
 #include "rpc/parse.h"
+#include "session/session_manager.h"
 
 #include "globals.h"
 #include "control.h"
@@ -700,8 +700,8 @@ initialize_command_download() {
   CMD2_DL_V       ("d.erase",      std::bind(&core::DownloadList::erase_ptr, control->core()->download_list(), std::placeholders::_1));
   CMD2_DL_V       ("d.check_hash", std::bind(&core::DownloadList::check_hash, control->core()->download_list(), std::placeholders::_1));
 
-  CMD2_DL         ("d.save_resume",       std::bind(&core::DownloadStore::save_resume, control->core()->download_store(), std::placeholders::_1));
-  CMD2_DL         ("d.save_full_session", std::bind(&core::DownloadStore::save_full, control->core()->download_store(), std::placeholders::_1));
+  CMD2_DL_V       ("d.save_resume",       [](core::Download* download, auto) { session_thread::manager()->save_resume_download(download); });
+  CMD2_DL_V       ("d.save_full_session", [](core::Download* download, auto) { session_thread::manager()->save_full_download(download); });
 
   CMD2_DL_V       ("d.update_priorities", CMD2_ON_DL(update_priorities));
 

src/command_local.cc

@@ -17,7 +17,6 @@
 
 #include "core/download.h"
 #include "core/download_list.h"
-#include "core/download_store.h"
 #include "core/manager.h"
 #include "rak/string_manip.h"
 #include "rpc/parse_commands.h"
@@ -212,7 +211,8 @@ initialize_command_local() {
   CMD2_ANY_VALUE_V ("system.files.advise_random.set",         std::bind(&FM_t::set_advise_random, fileManager, std::placeholders::_2));
   CMD2_ANY         ("system.files.advise_random.hashing",     std::bind(&FM_t::advise_random_hashing, fileManager));
   CMD2_ANY_VALUE_V ("system.files.advise_random.hashing.set", std::bind(&FM_t::set_advise_random_hashing, fileManager, std::placeholders::_2));
-  CMD2_VAR_BOOL    ("system.files.session.fdatasync",         true);
+  CMD2_ANY         ("system.files.session.fdatasync",         [](auto, auto)        { return session_thread::manager()->use_fsyncdisk(); });
+  CMD2_ANY_VALUE_V ("system.files.session.fdatasync.set",     [](auto, auto& value) { return session_thread::manager()->set_use_fsyncdisk(value); });
 
   CMD2_ANY         ("system.files.opened_counter",     std::bind(&FM_t::files_opened_counter, fileManager));
   CMD2_ANY         ("system.files.closed_counter",     std::bind(&FM_t::files_closed_counter, fileManager));

src/control.cc

@@ -9,7 +9,6 @@
 #include <torrent/utils/directory_events.h>
 
 #include "core/dht_manager.h"
-#include "core/download_store.h"
 #include "core/http_queue.h"
 #include "core/manager.h"
 #include "core/view_manager.h"
@@ -59,9 +58,7 @@ Control::~Control() {
 
 void
 Control::initialize() {
-  session_thread::manager()->start();
   session_thread::thread()->start_thread();
-
   scgi_thread::thread()->start_thread();
 
   display::Canvas::initialize();

src/core/dht_manager.cc

@@ -13,7 +13,6 @@
 
 #include "control.h"
 #include "download.h"
-#include "download_store.h"
 #include "globals.h"
 #include "manager.h"
 #include "rpc/parse_commands.h"

src/core/download_factory.cc

@@ -20,7 +20,6 @@
 #include "control.h"
 #include "globals.h"
 #include "core/download.h"
-#include "core/download_store.h"
 #include "core/http_queue.h"
 #include "core/manager.h"
 #include "rpc/parse_commands.h"

src/core/download_list.cc

@@ -22,10 +22,10 @@
 #include "view.h"
 #include "view_manager.h"
 
-#include "dht_manager.h"
-#include "download.h"
-#include "download_list.h"
-#include "download_store.h"
+#include "core/dht_manager.h"
+#include "core/download.h"
+#include "core/download_list.h"
+#include "session/session_manager.h"
 #include "ui/root.h"
 
 #define DL_TRIGGER_EVENT(download, event_name) \
@@ -68,10 +68,8 @@ DownloadList::clear() {
 
 void
 DownloadList::session_save() {
-  unsigned int c = std::count_if(begin(), end(), [&](Download* d) { return control->core()->download_store()->save_resume(d); });
-
-  if (c != size())
-    lt_log_print(torrent::LOG_ERROR, "Failed to save session torrents.");
+  for (auto& download : *this)
+    session_thread::manager()->save_resume_download(download);
 
   control->dht_manager()->save_dht_cache();
   control->ui()->save_input_history();
@@ -199,10 +197,10 @@ DownloadList::erase(iterator itr) {
   (*itr)->set_hash_failed(true);
 
   close(*itr);
-
-  control->core()->download_store()->remove(*itr);
+  session_thread::manager()->remove_download(*itr);
 
   DL_TRIGGER_EVENT(*itr, "event.download.erased");
+
   for (auto v : *control->view_manager())
     v->erase(*itr);
 
@@ -639,10 +637,8 @@ DownloadList::confirm_finished(Download* download) {
   // the download.
   //
   // Obsolete.
-  if (!download->is_active() && rpc::call_command_value("session.on_completion") != 0) {
-    //    torrent::resume_save_progress(*download->download(), download->download()->bencode()->get_key("libtorrent_resume"));
-    control->core()->download_store()->save_resume(download);
-  }
+  if (!download->is_active() && rpc::call_command_value("session.on_completion") != 0)
+    session_thread::manager()->save_resume_download(download);
 
   // Send the completed request before resuming so we don't reset the
   // up/downloaded baseline.
@@ -655,7 +651,7 @@ DownloadList::confirm_finished(Download* download) {
 
   if (find(infohash) == end())
     return;
-      
+
 //   if (download->resume_flags() != ~uint32_t())
 //     throw torrent::internal_error("DownloadList::confirm_finished(...) download->resume_flags() != ~uint32_t().");
 

src/core/download_store.cc

@@ -1,127 +0,0 @@
-// DownloadStore handles the saving and listing of session torrents.
-
-#include "config.h"
-
-#include <fstream>
-#include <stdio.h>
-#include <fcntl.h>
-#include <sstream>
-#include <unistd.h>
-#include <rak/error_number.h>
-#include <rak/path.h>
-#include <rak/string_manip.h>
-#include <torrent/utils/resume.h>
-#include <torrent/object.h>
-#include <torrent/exceptions.h>
-#include <torrent/torrent.h>
-#include <torrent/rate.h>
-#include <torrent/object_stream.h>
-
-#include "download.h"
-#include "download_store.h"
-#include "rpc/parse_commands.h"
-#include "session/session_manager.h"
-#include "utils/directory.h"
-
-namespace core {
-
-bool
-DownloadStore::save(Download* d, int flags) {
-  if (!session_thread::manager()->is_used())
-    return true;
-
-  torrent::Object* resume_base   = &d->download()->bencode()->get_key("libtorrent_resume");
-  torrent::Object* rtorrent_base = &d->download()->bencode()->get_key("rtorrent");
-
-  // Move this somewhere else?
-  rtorrent_base->insert_key("chunks_done",    d->download()->file_list()->completed_chunks());
-  rtorrent_base->insert_key("chunks_wanted",  d->download()->data()->wanted_chunks());
-  rtorrent_base->insert_key("total_uploaded", d->info()->up_rate()->total());
-  rtorrent_base->insert_key("total_downloaded", d->info()->down_rate()->total());
-
-  // Don't save for completed torrents when we've cleared the uncertain_pieces.
-  torrent::resume_save_progress(*d->download(), *resume_base);
-  torrent::resume_save_uncertain_pieces(*d->download(), *resume_base);
-
-  torrent::resume_save_addresses(*d->download(), *resume_base);
-  torrent::resume_save_file_priorities(*d->download(), *resume_base);
-  torrent::resume_save_tracker_settings(*d->download(), *resume_base);
-
-  // Temp fixing of all flags, move to a better place:
-  resume_base->set_flags(torrent::Object::flag_session_data);
-  rtorrent_base->set_flags(torrent::Object::flag_session_data);
-
-  auto download_stream = std::unique_ptr<std::stringstream>();
-  auto resume_stream   = std::make_unique<std::stringstream>();
-  auto rtorrent_stream = std::make_unique<std::stringstream>();
-
-  if (!(flags & flag_skip_static)) {
-    download_stream = std::make_unique<std::stringstream>();
-    torrent::object_write_bencode(&*download_stream, d->bencode(), torrent::Object::flag_session_data);
-
-    if (!download_stream->good())
-      return false;
-  }
-
-  torrent::object_write_bencode(&*resume_stream, resume_base, 0);
-
-  // TODO: Add logging.
-  if (!resume_stream->good())
-    return false;
-
-  torrent::object_write_bencode(&*rtorrent_stream, rtorrent_base, 0);
-
-  if (!rtorrent_stream->good())
-    return false;
-
-  auto base_filename = create_filename(d);
-
-  session_thread::manager()->save_download(d, base_filename, std::move(download_stream), std::move(resume_stream), std::move(rtorrent_stream));
-  return true;
-}
-
-void
-DownloadStore::remove(Download* d) {
-  session_thread::manager()->remove_download(d, create_filename(d));
-}
-
-// This also needs to check that it isn't a directory.
-bool
-not_correct_format(const utils::directory_entry& entry) {
-  return !DownloadStore::is_correct_format(entry.s_name);
-}
-
-utils::Directory
-DownloadStore::get_formated_entries() {
-  if (!session_thread::manager()->is_used())
-    return utils::Directory();
-
-  utils::Directory d(session_thread::manager()->path());
-
-  if (!d.update(utils::Directory::update_hide_dot))
-    throw torrent::storage_error("core::DownloadStore::update() could not open session directory: " + session_thread::manager()->path());
-
-  d.erase(std::remove_if(d.begin(), d.end(), [&](const utils::directory_entry& entry) { return not_correct_format(entry); }), d.end());
-
-  return d;
-}
-
-bool
-DownloadStore::is_correct_format(const std::string& f) {
-  if (f.size() != 48 || f.substr(40) != ".torrent")
-    return false;
-
-  for (std::string::const_iterator itr = f.begin(); itr != f.end() - 8; ++itr)
-    if (!(*itr >= '0' && *itr <= '9') &&
-        !(*itr >= 'A' && *itr <= 'F'))
-      return false;
-
-  return true;
-}
-
-std::string
-DownloadStore::create_filename(Download* d) {
-  return session_thread::manager()->path() + rak::transform_hex(d->info()->hash().begin(), d->info()->hash().end()) + ".torrent";
-}
-
-}

src/core/download_store.h

@@ -1,35 +0,0 @@
-#ifndef RTORRENT_CORE_DOWNLOAD_STORE_H
-#define RTORRENT_CORE_DOWNLOAD_STORE_H
-
-#include <string>
-#include <torrent/common.h>
-
-namespace utils {
-  class Directory;
-}
-
-namespace core {
-
-class Download;
-
-class DownloadStore {
-public:
-  static const int flag_skip_static = 0x1;
-
-  bool                save(Download* d, int flags);
-  bool                save_full(Download* d)   { return save(d, 0); }
-  bool                save_resume(Download* d) { return save(d, flag_skip_static); }
-  void                remove(Download* d);
-
-  // Currently shows all entries in the correct format.
-  utils::Directory    get_formated_entries();
-
-  static bool         is_correct_format(const std::string& f);
-
-private:
-  std::string         create_filename(Download* d);
-};
-
-}
-
-#endif

src/core/manager.cc

@@ -32,7 +32,6 @@
 #include "control.h"
 #include "core/download.h"
 #include "core/download_factory.h"
-#include "core/download_store.h"
 #include "core/http_queue.h"
 #include "core/manager.h"
 #include "core/view.h"
@@ -50,11 +49,10 @@ Manager::push_log(const char* msg) {
   m_log_complete->lock_and_push_log(msg, strlen(msg), 0);
 }
 
-Manager::Manager() :
-    m_log_important(torrent::log_open_log_buffer("important")),
+Manager::Manager()
+  : m_log_important(torrent::log_open_log_buffer("important")),
     m_log_complete(torrent::log_open_log_buffer("complete")) {
 
-  m_download_store    = std::make_unique<DownloadStore>();
   m_download_list     = std::make_unique<DownloadList>();
   m_file_status_cache = std::make_unique<FileStatusCache>();
   m_http_queue        = std::make_unique<HttpQueue>();

src/core/manager.h

@@ -21,7 +21,6 @@ class FileStatusCache;
 
 namespace core {
 
-class DownloadStore;
 class HttpQueue;
 
 typedef std::map<std::string, torrent::ThrottlePair> ThrottleMap;
@@ -37,7 +36,6 @@ public:
   ~Manager();
 
   DownloadList*       download_list()                     { return m_download_list.get(); }
-  DownloadStore*      download_store()                    { return m_download_store.get(); }
   FileStatusCache*    file_status_cache()                 { return m_file_status_cache.get(); }
 
   HttpQueue*          http_queue()                        { return m_http_queue.get(); }
@@ -95,7 +93,6 @@ private:
   void                receive_hashing_changed();
 
   std::unique_ptr<DownloadList>    m_download_list;
-  std::unique_ptr<DownloadStore>   m_download_store;
   std::unique_ptr<FileStatusCache> m_file_status_cache;
   std::unique_ptr<HttpQueue>       m_http_queue;
 

src/main.cc

@@ -22,7 +22,6 @@
 #include "core/dht_manager.h"
 #include "core/download.h"
 #include "core/download_factory.h"
-#include "core/download_store.h"
 #include "core/manager.h"
 #include "display/canvas.h"
 #include "display/window.h"
@@ -32,7 +31,9 @@
 #include "rpc/command_scheduler_item.h"
 #include "rpc/parse_commands.h"
 #include "scgi/thread_scgi.h"
+#include "session/download_storer.h"
 #include "session/thread_session.h"
+#include "session/session_manager.h"
 #include "ui/root.h"
 #include "utils/directory.h"
 
@@ -112,7 +113,7 @@ initialize_rpc_slots() {
 
 void
 load_session_torrents() {
-  utils::Directory entries = control->core()->download_store()->get_formated_entries();
+  utils::Directory entries = session::DownloadStorer::get_formated_entries(session_thread::manager()->path());
 
   for (const auto& entry : entries) {
     // We don't really support session torrents that are links. These

src/scgi/thread_scgi.cc

@@ -38,11 +38,6 @@ ThreadScgi::thread_scgi() {
   return m_thread_scgi;
 }
 
-// TODO: Remove '= 0'.
-void
-ThreadScgi::init_thread() {
-}
-
 void
 ThreadScgi::cleanup_thread() {
   if (m_scgi != nullptr)

src/scgi/thread_scgi.h

@@ -20,10 +20,7 @@ public:
   static void         destroy_thread();
   static ThreadScgi*  thread_scgi();
 
-  const char*         name() const override      { return "rtorrent-scgi"; }
-
-  void                init_thread() override;
-  void                cleanup_thread() override;
+  const char*         name() const override  { return "rtorrent-scgi"; }
 
   rpc::SCgi*          scgi();
   bool                set_scgi(rpc::SCgi* scgi);
@@ -37,6 +34,8 @@ protected:
 
   static auto         internal_thread_scgi() { return m_thread_scgi; }
 
+  void                cleanup_thread() override;
+
   void                      call_events() override;
   std::chrono::microseconds next_timeout() override;
 
@@ -46,10 +45,8 @@ private:
 
   static ThreadScgi*  m_thread_scgi;
 
-  std::atomic<rpc::SCgi*>   m_scgi{nullptr};
-  std::string               m_rpc_log_filename;
-
-  // std::unique_ptr<ScgiManager> m_manager;
+  std::atomic<rpc::SCgi*> m_scgi{nullptr};
+  std::string             m_rpc_log_filename;
 };
 
 } // namespace scgi

src/session/download_storer.cc

@@ -0,0 +1,112 @@
+#include "config.h"
+
+#include "download_storer.h"
+
+#include <torrent/exceptions.h>
+#include <torrent/object.h>
+#include <torrent/object_stream.h>
+#include <torrent/utils/log.h>
+#include <torrent/utils/resume.h>
+
+#include "globals.h"
+#include "core/download.h"
+#include "utils/directory.h"
+
+namespace session {
+
+DownloadStorer::DownloadStorer(core::Download* download)
+  : m_download(download) {
+}
+
+void
+DownloadStorer::build_streams(bool skip_static) {
+  auto* download = m_download->download();
+
+  auto& resume_base   = download->bencode()->get_key("libtorrent_resume");
+  auto& rtorrent_base = download->bencode()->get_key("rtorrent");
+
+  rtorrent_base.insert_key("chunks_done",      download->file_list()->completed_chunks());
+  rtorrent_base.insert_key("chunks_wanted",    download->data()->wanted_chunks());
+  rtorrent_base.insert_key("total_uploaded",   m_download->info()->up_rate()->total());
+  rtorrent_base.insert_key("total_downloaded", m_download->info()->down_rate()->total());
+
+  // Don't save for completed torrents when we've cleared the uncertain_pieces.
+  torrent::resume_save_progress(*download, resume_base);
+  torrent::resume_save_uncertain_pieces(*download, resume_base);
+
+  torrent::resume_save_addresses(*download, resume_base);
+  torrent::resume_save_file_priorities(*download, resume_base);
+  torrent::resume_save_tracker_settings(*download, resume_base);
+
+  // Temp fixing of all flags, move to a better place:
+  resume_base.set_flags(torrent::Object::flag_session_data);
+  rtorrent_base.set_flags(torrent::Object::flag_session_data);
+
+  auto torrent_stream  = std::unique_ptr<std::stringstream>();
+  auto resume_stream   = std::make_unique<std::stringstream>();
+  auto rtorrent_stream = std::make_unique<std::stringstream>();
+
+  if (!skip_static) {
+    torrent_stream = std::make_unique<std::stringstream>();
+    torrent::object_write_bencode(&*torrent_stream, m_download->bencode(), torrent::Object::flag_session_data);
+
+    if (!torrent_stream->good())
+      throw torrent::internal_error("DownloadStorer::build_streams() failed to write torrent stream.");
+  }
+
+  torrent::object_write_bencode(&*resume_stream, &resume_base, 0);
+
+  if (!resume_stream->good())
+    throw torrent::internal_error("DownloadStorer::build_streams() failed to write resume stream.");
+
+  torrent::object_write_bencode(&*rtorrent_stream, &rtorrent_base, 0);
+
+  if (!rtorrent_stream->good())
+    throw torrent::internal_error("DownloadStorer::build_streams() failed to write rtorrent stream.");
+
+  m_torrent_stream    = std::move(torrent_stream);
+  m_rtorrent_stream   = std::move(rtorrent_stream);
+  m_libtorrent_stream = std::move(resume_stream);
+}
+
+std::string
+DownloadStorer::build_path(const std::string& session_path) {
+  auto info_hash = m_download->info()->info_hash();
+
+  if (session_path.empty())
+    throw torrent::internal_error("DownloadStorer::build_path() called with empty session path.");
+
+  if (session_path.back() != '/')
+    throw torrent::internal_error("DownloadStorer::build_path() session path missing trailing slash.");
+
+  return session_path + torrent::hash_string_to_hex_str(info_hash);
+}
+
+bool
+is_correct_format(const std::string& f) {
+  if (f.size() != 48 || f.substr(40) != ".torrent")
+    return false;
+
+  for (std::string::const_iterator itr = f.begin(); itr != f.end() - 8; ++itr)
+    if (!(*itr >= '0' && *itr <= '9') &&
+        !(*itr >= 'A' && *itr <= 'F'))
+      return false;
+
+  return true;
+}
+
+utils::Directory
+DownloadStorer::get_formated_entries(const std::string& session_path) {
+  if (session_path.empty())
+    return utils::Directory();
+
+  utils::Directory d(session_path);
+
+  if (!d.update(utils::Directory::update_hide_dot))
+    throw torrent::storage_error("session::DownloadStorer::update() could not open session directory: " + session_path);
+
+  d.erase(std::remove_if(d.begin(), d.end(), [](auto& entry) { return !is_correct_format(entry.s_name); }), d.end());
+  return d;
+}
+
+} // namespace session

src/session/download_storer.h

@@ -0,0 +1,44 @@
+#ifndef RTORRENT_SESSION_DOWNLOAD_STORER_H
+#define RTORRENT_SESSION_DOWNLOAD_STORER_H
+
+#include <memory>
+#include <sstream>
+#include <string>
+#include <torrent/common.h>
+
+namespace core {
+class Download;
+}
+
+namespace utils {
+  class Directory;
+}
+
+namespace session {
+
+class DownloadStorer {
+public:
+  DownloadStorer(core::Download* download);
+
+  core::Download*     download() const { return m_download; }
+
+  void                build_streams(bool skip_static);
+  std::string         build_path(const std::string& session_path);
+
+  auto                torrent_stream()    { return std::move(m_torrent_stream); }
+  auto                rtorrent_stream()   { return std::move(m_rtorrent_stream); }
+  auto                libtorrent_stream() { return std::move(m_libtorrent_stream); }
+
+  static utils::Directory get_formated_entries(const std::string& session_path);
+
+private:
+  core::Download*     m_download;
+
+  std::unique_ptr<std::stringstream> m_torrent_stream;
+  std::unique_ptr<std::stringstream> m_rtorrent_stream;
+  std::unique_ptr<std::stringstream> m_libtorrent_stream;
+};
+
+} // namespace session
+
+#endif // RTORRENT_SESSION_DOWNLOAD_STORER_H

src/session/session_manager.cc

@@ -1,6 +1,6 @@
 #include "config.h"
 
-#include "session_manager.h"
+#include "session/session_manager.h"
 
 #include <cassert>
 #include <cerrno>
@@ -11,6 +11,7 @@
 #include <torrent/utils/log.h>
 
 #include "globals.h"
+#include "session/download_storer.h"
 #include "utils/lockfile.h"
 
 #define LT_LOG(log_fmt, ...)                                            \
@@ -27,18 +28,6 @@ SessionManager::SessionManager(torrent::utils::Thread* thread)
 
 SessionManager::~SessionManager() = default;
 
-// TODO:
-//  * Lock session directory.
-//  * On shutdown, wait for all saves to finish.
-//    * Add is_empty_and_done() that also include async fdisksync tasks.
-//  * Then unlock session directory.
-
-bool
-SessionManager::is_empty() {
-  std::lock_guard<std::mutex> guard(m_mutex);
-  return m_save_requests.empty();
-}
-
 void
 SessionManager::set_path(const std::string& path) {
   assert(torrent::this_thread::thread() == torrent::main_thread::thread());
@@ -52,6 +41,16 @@ SessionManager::set_path(const std::string& path) {
     m_path = path + '/';
 }
 
+void
+SessionManager::set_use_fsyncdisk(bool use_fsyncdisk) {
+  assert(torrent::this_thread::thread() == torrent::main_thread::thread());
+
+  if (m_freeze_info)
+    throw torrent::input_error("Session fsyncdisk option cannot be changed after startup.");
+
+  m_use_fsyncdisk = use_fsyncdisk;
+}
+
 void
 SessionManager::set_use_lock(bool use_lock) {
   assert(torrent::this_thread::thread() == torrent::main_thread::thread());
@@ -62,65 +61,62 @@ SessionManager::set_use_lock(bool use_lock) {
   m_use_lock = use_lock;
 }
 
-// TODO: Derive path from download info hash.
-// TODO: Generate streams here, not in download store.
+// TODO: Add separate mutex for queuing save requests in session save.
+
 void
-SessionManager::save_download(core::Download* download, std::string path, stream_ptr torrent_stream, stream_ptr rtorrent_stream, stream_ptr libtorrent_stream) {
+SessionManager::save_download(core::Download* download, bool skip_static) {
   assert(torrent::this_thread::thread() == torrent::main_thread::thread());
 
   if (m_path.empty())
     return;
 
-  {
-    std::lock_guard<std::mutex> guard(m_mutex);
+  DownloadStorer storer(download);
 
-    LT_LOG("requesting save : download:%p path:%s", download, path.c_str());
+  storer.build_streams(skip_static);
+
+  auto save_request = SaveRequest{
+    download,
+    storer.build_path(m_path),
+    storer.torrent_stream(),
+    storer.rtorrent_stream(),
+    storer.libtorrent_stream()
+  };
+
+  {
+    std::unique_lock<std::mutex> lock(m_mutex);
+
+    LT_LOG("requesting save : download:%p path:%s", download, save_request.path.c_str());
 
     if (!m_active)
       throw torrent::internal_error("SessionManager::save_download() called while not active.");
 
-    // TODO: Remove is already queued entries.
+    if (remove_save_request_unsafe(download, lock))
+      LT_LOG("replacing pending save request : download:%p", download);
 
-    // TODO: Add these to a temp structure
-    // TODO: When a download already exists, replace it.
-
-    m_save_requests.push_back(SaveRequest{
-        download,
-        std::move(path),
-        std::move(torrent_stream),
-        std::move(rtorrent_stream),
-        std::move(libtorrent_stream)
-      });
+    m_save_requests.push_back(std::move(save_request));
   }
 
-  session_thread::callback(nullptr, [this]() { process_save_request(); });
+  session_thread::callback(this, [this]() { process_save_request(); });
 }
 
+// TODO: Move various low-level stuff to DownloadStorer.
+
 void
-SessionManager::remove_download(core::Download* download, std::string base_path) {
+SessionManager::remove_download(core::Download* download) {
   assert(torrent::this_thread::thread() == torrent::main_thread::thread());
 
   if (m_path.empty())
     return;
 
-  std::lock_guard<std::mutex> guard(m_mutex);
+  auto base_path = DownloadStorer(download).build_path(m_path);
+
+  std::unique_lock<std::mutex> lock(m_mutex);
 
   if (!m_active)
     throw torrent::internal_error("SessionManager::remove_download() called while not active.");
 
-  // TODO: Add these to a temp structure, and remove from to-be-added temp struct.
-
-  auto itr = std::remove_if(m_save_requests.begin(), m_save_requests.end(), [download](auto& req) {
-      return req.download == download;
-    });
-
-  if (itr != m_save_requests.end()) {
-    LT_LOG("canceling save request : download:%p", download);
-    m_save_requests.erase(itr, m_save_requests.end());
-  }
-
-  // TODO: Use atomic download ptr to check if we're currently processing this download
-  // TODO: If so, use a lock to wait for save to finish before returning
+  if (remove_save_request_unsafe(download, lock))
+    LT_LOG("canceled pending save request : download:%p", download);
 
   auto torrent_path    = base_path;
   auto libtorrent_path = base_path + ".libtorrent_resume";
@@ -135,7 +131,7 @@ void
 SessionManager::start() {
   assert(torrent::this_thread::thread() == torrent::main_thread::thread());
 
-  std::lock_guard<std::mutex> guard(m_mutex);
+  std::unique_lock<std::mutex> lock(m_mutex);
 
   if (m_active || m_freeze_info)
     throw torrent::internal_error("SessionManager::start() called while already started.");
@@ -168,7 +164,7 @@ void
 SessionManager::cleanup() {
   assert(m_thread == torrent::this_thread::thread());
 
-  std::lock_guard<std::mutex> guard(m_mutex);
+  std::unique_lock<std::mutex> lock(m_mutex);
 
   if (!m_active)
     throw torrent::internal_error("SessionManager::cleanup() called while not active.");
@@ -182,12 +178,18 @@ SessionManager::cleanup() {
 
   LT_LOG("cleaning up session manager with path: %s", m_path.c_str());
 
+  flush_all_and_wait_unsafe(lock);
+
   if (m_use_lock) {
     if (!m_lockfile->unlock())
       LT_LOG("could not unlock session directory: %s", m_path.c_str());
 
     LT_LOG("unlocked session directory: %s", m_path.c_str());
   }
+
+  LT_LOG("session manager cleaned up", 0);
+
+  session_thread::cancel_callback(this);
 }
 
 void
@@ -197,36 +199,138 @@ SessionManager::process_save_request() {
   if (m_path.empty())
     return;
 
-  std::lock_guard<std::mutex> guard(m_mutex);
+  std::unique_lock<std::mutex> lock(m_mutex);
 
   if (!m_active)
     throw torrent::internal_error("SessionManager::process_save_request() called while not active.");
 
-  if (m_save_requests.empty())
+  if (m_save_requests.empty() || m_processing_saves.size() >= max_concurrent_saves)
     return;
 
-  // pick first request
-  // process it
-  // add us back to callbacks? we need to disable shutdown while processing all saves... do we do it at thread cleanup?
+  process_next_save_request_unsafe();
 
+  if (!m_save_requests.empty())
+    session_thread::callback(this, [this]() { process_save_request(); });
+}
+
+void
+SessionManager::process_next_save_request_unsafe() {
   auto request = std::move(m_save_requests.front());
   m_save_requests.pop_front();
 
-  // Keep lock while processing to ensure cancellations do not interfere.
+  auto itr = m_processing_saves.insert(m_processing_saves.end(), ProcessingSave{});
 
-  save_download_unsafe(request);
+  itr->second = std::move(request);
+  itr->first = std::async(std::launch::async, [this, itr]() {
+      // TODO: Properly handle errors here, and report back to session thread.
+      // TODO: Consider adding a failed_saves with error info.
 
-  if (!m_save_requests.empty())
-    session_thread::callback(nullptr, [this]() { process_save_request(); });
+      save_download_unsafe(itr->second);
+
+      {
+        std::unique_lock<std::mutex> lock(m_mutex);
+
+        if (m_finished_saves.empty())
+          session_thread::callback(this, [this]() { process_finished_saves(); });
+
+        m_finished_saves.push_back(std::move(*itr));
+        m_processing_saves.erase(itr);
+
+        m_finished_condition.notify_all();
+      }
+    });
 }
 
-// TODO: Add threads/tasklets that calls fdisksync on shutdown.
-// TODO: Parallelize saves.
+void
+SessionManager::process_finished_saves() {
+  assert(m_thread == torrent::this_thread::thread());
+
+  std::unique_lock<std::mutex> lock(m_mutex);
+
+  if (!m_active)
+    throw torrent::internal_error("SessionManager::process_finished_saves() called while not active.");
+
+  for (auto& request : m_finished_saves)
+    LT_LOG("finished saving download : download:%p path:%s", request.second.download, request.second.path.c_str());
+
+  m_finished_saves.clear();
+}
+
+void
+SessionManager::wait_for_one_save_unsafe(std::unique_lock<std::mutex>& lock) {
+  assert(m_thread == torrent::this_thread::thread());
+
+  if (m_processing_saves.empty())
+    return;
+
+  m_finished_condition.wait(lock);
+}
+
+void
+SessionManager::flush_all_and_wait_unsafe(std::unique_lock<std::mutex>& lock) {
+  LT_LOG("flushing all pending saves", 0);
+
+  while (!m_save_requests.empty()) {
+    if (m_processing_saves.size() >= max_cleanup_saves) {
+      wait_for_one_save_unsafe(lock);
+      continue;
+    }
+
+    process_next_save_request_unsafe();
+  }
+
+  while (!m_processing_saves.empty())
+    wait_for_one_save_unsafe(lock);
+
+  for (auto& request : m_finished_saves)
+    LT_LOG("finished saving download : download:%p path:%s", request.second.download, request.second.path.c_str());
+
+  m_finished_saves.clear();
+
+  LT_LOG("flushed all pending saves", 0);
+}
+
+bool
+SessionManager::remove_save_request_unsafe(core::Download* download, std::unique_lock<std::mutex>& lock) {
+  // Can be run in any thread.
+
+  {
+    auto itr = std::remove_if(m_save_requests.begin(), m_save_requests.end(), [download](auto& req) {
+        return req.download == download;
+      });
+
+    if (itr == m_save_requests.end())
+      return false;
+
+    m_save_requests.erase(itr, m_save_requests.end());
+  }
+
+  // check if in processing saves, then wait for it to finish using wait_for_one_save_unsafe()
+  while (true) {
+    auto itr = std::find_if(m_processing_saves.begin(), m_processing_saves.end(), [download](auto& req) {
+        return req.second.download == download;
+      });
+
+    if (itr == m_processing_saves.end())
+      break;
+
+    wait_for_one_save_unsafe(lock);
+  }
+
+  // Checking active after remove_save_request_unsafe to ensure we're calling this after shutdown.
+  if (!m_active)
+    throw torrent::internal_error("SessionManager::remove_save_request_unsafe() called while not active");
+
+  return true;
+}
 
 // TODO: Properly handle errors.
+// TODO: If no more sockets can be opened, wait for a job to finish. if all is finished, use a
+// timeout nad try again.
+
 void
 SessionManager::save_download_unsafe(const SaveRequest& request) {
-  LT_LOG("saving download : download:%p path:%s", request.download, request.path.c_str());
+  // LT_LOG("saving download : download:%p path:%s", request.download, request.path.c_str());
 
   if (m_path.empty())
     throw torrent::internal_error("SessionManager::save_download_unsafe() called with empty session path.");
@@ -248,18 +352,18 @@ SessionManager::save_download_unsafe(const SaveRequest& request) {
 
   if (request.torrent_stream) {
     if (::rename((torrent_path + ".new").c_str(), torrent_path.c_str()) == -1) {
-      LT_LOG("failed to rename torrent file : %s", torrent_path.c_str());
+      // LT_LOG("failed to rename torrent file : %s", torrent_path.c_str());
       return;
     }
   }
 
   if (::rename((libtorrent_path + ".new").c_str(), libtorrent_path.c_str()) == -1) {
-    LT_LOG("failed to rename libtorrent resume file : %s", libtorrent_path.c_str());
+    // LT_LOG("failed to rename libtorrent resume file : %s", libtorrent_path.c_str());
     return;
   }
 
   if (::rename((rtorrent_path + ".new").c_str(), rtorrent_path.c_str()) == -1) {
-    LT_LOG("failed to rename rtorrent resume file : %s", rtorrent_path.c_str());
+    // LT_LOG("failed to rename rtorrent resume file : %s", rtorrent_path.c_str());
     return;
   }
 }
@@ -270,15 +374,17 @@ bool
 SessionManager::save_download_stream_unsafe(const std::string& path, const std::unique_ptr<std::stringstream>& stream) {
   std::fstream output(path.c_str(), std::ios::out | std::ios::trunc);
 
+  // TODO: If we cannot open more files, wait for some to finish and try again.
+
   if (!output.is_open()) {
-    LT_LOG("failed to open file for writing : path:%s", path.c_str());
+    // LT_LOG("failed to open file for writing : path:%s", path.c_str());
     return false;
   }
 
   output << stream->rdbuf();
 
   if (!output.good()) {
-    LT_LOG("failed to write stream to file : path:%s", path.c_str());
+    // LT_LOG("failed to write stream to file : path:%s", path.c_str());
     return false;
   }
 
@@ -288,19 +394,11 @@ SessionManager::save_download_stream_unsafe(const std::string& path, const std::
   int fd = ::open(path.c_str(), O_WRONLY);
 
   if (fd < 0) {
-    LT_LOG("failed to open file descriptor for fdatasync : path:%s", path.c_str());
+    // LT_LOG("failed to open file descriptor for fdatasync : path:%s", path.c_str());
     return false;
   }
 
-  // We don't care about cancelation here, as the underlying file gets deleted / replaced anyway.
-
-  // TODO: We can use std::async for these, and only wait for them if we're shutting down.
-
-  // TODO: Use an atomic counter / conditional variable to keep track of async operations count, and
-  // wait for finished operations on shutdown.
-
-  // if (rpc::call_command_value("system.files.session.fdatasync")) {
-  if (true) {
+  if (m_use_fsyncdisk) {
 #ifdef __APPLE__
     ::fsync(fd);
 #else

src/session/session_manager.h

@@ -1,11 +1,15 @@
 #ifndef RTORRENT_SESSION_SESSION_MANAGER_H
 #define RTORRENT_SESSION_SESSION_MANAGER_H
 
+#include <condition_variable>
 #include <deque>
+#include <future>
+#include <list>
 #include <memory>
 #include <mutex>
 #include <sstream>
 #include <string>
+#include <vector>
 #include <torrent/common.h>
 
 namespace core {
@@ -32,36 +36,48 @@ class SessionManager {
 public:
   typedef std::unique_ptr<std::stringstream> stream_ptr;
 
+  // TODO: This should depend on max open sockets / be configurable.
+  constexpr static int max_concurrent_saves = 16;
+  constexpr static int max_cleanup_saves    = 64;
+
   SessionManager(torrent::utils::Thread* thread);
   ~SessionManager();
 
   bool                is_used() const;
 
-  // TODO: Replace with protected `bool shutdown_if_done()`.
-  bool                is_empty();
-  // bool                is_empty_and_done();
-
-  void                start();
-
   std::string         path() const;
   void                set_path(const std::string& path);
 
+  bool                use_fsyncdisk() const;
+  void                set_use_fsyncdisk(bool use_fsyncdisk);
+
   bool                use_lock() const;
   void                set_use_lock(bool use_lock);
 
-  void                freeze_info();
-
-  void                save_download(core::Download* download, std::string path, stream_ptr torrent_stream, stream_ptr rtorrent_stream, stream_ptr libtorrent_stream);
-  void                remove_download(core::Download* download, std::string path);
+  void                save_full_download(core::Download* download)   { save_download(download, false); }
+  void                save_resume_download(core::Download* download) { save_download(download, true);  }
+  void                remove_download(core::Download* download);
 
 protected:
   friend class Control;
   friend class ThreadSession;
 
+  void                save_download(core::Download* download, bool skip_static);
+
+  void                start();
   void                cleanup();
 
 private:
   void                process_save_request();
+  void                process_next_save_request_unsafe();
+  void                process_finished_saves();
+
+  void                wait_for_one_save_unsafe(std::unique_lock<std::mutex>& lock);
+
+  // Requires a higher number of open sockets, and should only be used during shutdown.
+  void                flush_all_and_wait_unsafe(std::unique_lock<std::mutex>& lock);
+
+  bool                remove_save_request_unsafe(core::Download* download, std::unique_lock<std::mutex>& lock);
 
   void                save_download_unsafe(const SaveRequest& request);
   bool                save_download_stream_unsafe(const std::string& path, const std::unique_ptr<std::stringstream>& stream);
@@ -70,18 +86,28 @@ private:
 
   bool                m_freeze_info{};
   std::string         m_path;
+  bool                m_use_fsyncdisk{true};
   bool                m_use_lock{true};
 
   std::mutex          m_mutex;
   bool                m_active{};
 
-  std::deque<SaveRequest>          m_save_requests;
+  typedef std::pair<std::future<void>, SaveRequest> ProcessingSave;
+
+  // TODO: Add deque of DownloadStorers requests that have yet to build streams.
+
+  std::deque<SaveRequest>     m_save_requests;
+  std::list<ProcessingSave>   m_processing_saves;
+  std::condition_variable     m_finished_condition;
+  std::vector<ProcessingSave> m_finished_saves;
+
   std::unique_ptr<utils::Lockfile> m_lockfile;
 };
 
-inline bool        SessionManager::is_used() const  { return !m_path.empty(); }
-inline std::string SessionManager::path() const     { return m_path; }
-inline bool        SessionManager::use_lock() const { return m_use_lock; }
+inline bool        SessionManager::is_used() const       { return !m_path.empty(); }
+inline std::string SessionManager::path() const          { return m_path; }
+inline bool        SessionManager::use_fsyncdisk() const { return true; }
+inline bool        SessionManager::use_lock() const      { return m_use_lock; }
 
 } // namespace session
 

src/session/thread_session.cc

@@ -36,9 +36,9 @@ ThreadSession::thread_session() {
   return m_thread_session;
 }
 
-// TODO: Remove '= 0'.
 void
-ThreadSession::init_thread() {
+ThreadSession::init_thread_pre_start() {
+  m_manager->start();
 }
 
 // TODO: Make sure we trigger session save before main thread exits, that it adds all required
@@ -52,18 +52,9 @@ void
 ThreadSession::call_events() {
   // lt_log_print_locked(torrent::LOG_THREAD_NOTICE, "Got thread_disk tick.");
 
-  // TODO: Wait with shutdown until all session data is saved.
-
   process_callbacks();
 
   if ((m_flags & flag_do_shutdown)) {
-    if (!m_manager->is_empty()) {
-      // TODO: Figure out a better way to wait for session save to complete.
-      // TODO: Sanity check to avoid getting stuck not shutting down.
-      // TODO: Should we depend on next_timeout() instead of callbacks?
-      return;
-    }
-
     if ((m_flags & flag_did_shutdown))
       throw torrent::internal_error("Already trigged shutdown.");
 

src/session/thread_session.h

@@ -15,12 +15,9 @@ public:
   static void           destroy_thread();
   static ThreadSession* thread_session();
 
-  const char*         name() const override      { return "rtorrent-session"; }
+  const char*         name() const override     { return "rtorrent-session"; }
 
-  void                init_thread() override;
-  void                cleanup_thread() override;
-
-  SessionManager*     manager() const { return m_manager.get(); }
+  SessionManager*     manager() const           { return m_manager.get(); }
 
 protected:
   friend class ThreadSessionInternal;
@@ -29,6 +26,9 @@ protected:
 
   static auto         internal_thread_session() { return m_thread_session; }
 
+  void                init_thread_pre_start() override;
+  void                cleanup_thread() override;
+
   void                      call_events() override;
   std::chrono::microseconds next_timeout() override;
 

src/ui/root.cc

@@ -13,7 +13,6 @@
 
 #include "control.h"
 #include "core/download_list.h"
-#include "core/download_store.h"
 #include "core/manager.h"
 #include "display/frame.h"
 #include "display/window_http_queue.h"