Merge lp:unity-scopes-api/staging into lp:unity-scopes-api

[Paweł Stołowski]

Fix handling of timeout in debug mode.
Use mtime instead of inotify to detect settings changes.
Revert delayed notification about scope removal.

Merged devel:
Fix handling of timeout in debug mode.
Use mtime instead of inotify to detect settings changes.
Revert delayed notification about scope removal.

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FAILED: Continuous integration, rev:292
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review: Needs Fixing (continuous-integration)

[lp:unity-scopes-api/staging]

293. By Paweł Stołowski on 2015-07-06

Merged devel

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PASSED: Continuous integration, rev:293
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review: Approve (continuous-integration)

[lp:unity-scopes-api/staging]

294. By Paweł Stołowski on 2015-07-06

Merged devel

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PASSED: Continuous integration, rev:294
http://jenkins.qa.ubuntu.com/job/unity-scopes-api-ci/625/
Executed test runs:
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review: Approve (continuous-integration)

[lp:unity-scopes-api/staging]

295. By Paweł Stołowski on 2015-07-08

Merged lp:~stolowski/unity-scopes-api/disable-settings-test

=== modified file 'CONFIGFILES'
--- CONFIGFILES	2015-06-11 11:11:42 +0000
+++ CONFIGFILES	2015-07-08 14:34:02 +0000
@@ -76,22 +76,6 @@
 
   The default value is 10 seconds.
 
-- Process.Timeout
-
-  This parameter determines how the registry will wait for a scope
-  to start and stop. The registry waits for at most Process.Timeout
-  milliseconds before it concludes that a scope failed to initialize
-  or terminate correctly. If a scope does not respond
-  within the allotted time, it is killed with SIGKILL.
-
-  Only values in the range 10 to 15000 milliseconds are accepted.
-
-  The default value is 4000 milliseconds.
-
-  Note that this value must be less than Locate.Timeout in the [<Middleware>]
-  config group, otherwise the middleware can prematurely conclude that
-  a locate() request failed to start a scope.
-
 - CacheDir
 
   The parent directory under which a scope can write scope-specific data files
@@ -306,6 +290,22 @@
 
   The default value is "$HOME/.local/share/unity-scopes".
 
+- Process.Timeout
+
+  This parameter determines how long the registry will wait for a scope
+  to start and stop. The registry waits for at most Process.Timeout
+  milliseconds before it concludes that a scope failed to initialize
+  or terminate correctly. If a scope does not respond
+  within the allotted time, it is killed with SIGKILL.
+
+  Only values in the range 10 to 15000 milliseconds are accepted.
+
+  The default value is 4000 milliseconds.
+
+  Note that this value must be less than Locate.Timeout in the [<Middleware>]
+  config group, otherwise the middleware can prematurely conclude that
+  a locate() request failed to start a scope.
+
 
 Smartscopes.ini
 --------------

=== modified file 'RELEASE_NOTES.md'
--- RELEASE_NOTES.md	2015-06-01 10:15:48 +0000
+++ RELEASE_NOTES.md	2015-07-08 14:34:02 +0000
@@ -1,6 +1,10 @@
 Release notes
 =============
 
+Changes in version 0.6.19
+=========================
+  - Support UNITY_SCOPES_CONFIG_DIR environment variable.
+
 Changes in version 0.6.18
 =========================
   - Allow child_scopes() and set_child_scopes() methods more time to

=== modified file 'include/unity/scopes/ScopeBase.h'
--- include/unity/scopes/ScopeBase.h	2015-06-02 05:06:25 +0000
+++ include/unity/scopes/ScopeBase.h	2015-07-08 14:34:02 +0000
@@ -326,6 +326,8 @@
 
     \return The scope's current settings.
     \throws LogicException if called from the constructor of this instance.
+    \throws ResourceException if settings database file is corrupted.
+    \throws FileException if settings database file is not readable.
     */
     virtual VariantMap settings() const final;
 

=== modified file 'include/unity/scopes/internal/RegistryObject.h'
--- include/unity/scopes/internal/RegistryObject.h	2015-04-23 10:11:51 +0000
+++ include/unity/scopes/internal/RegistryObject.h	2015-07-08 14:34:02 +0000
@@ -29,7 +29,6 @@
 #include <condition_variable>
 #include <mutex>
 #include <thread>
-#include <chrono>
 
 namespace unity
 {
@@ -153,12 +152,6 @@
     mutable std::mutex mutex_;
 
     MWPublisher::SPtr publisher_;
-    std::thread publisher_notify_thread_;
-    std::condition_variable publisher_notify_cond_;
-    std::chrono::system_clock::time_point publisher_notify_timepoint_;
-    bool publisher_notify_reset_timer_;
-    bool publisher_notify_exit_;
-
     MWSubscriber::SPtr ss_list_update_subscriber_;
     std::shared_ptr<core::ScopedConnection> ss_list_update_connection_;
     bool generate_desktop_files_;

=== modified file 'include/unity/scopes/internal/SettingsDB.h'
--- include/unity/scopes/internal/SettingsDB.h	2014-11-20 05:32:53 +0000
+++ include/unity/scopes/internal/SettingsDB.h	2015-07-08 14:34:02 +0000
@@ -25,11 +25,7 @@
 #include <unity/util/NonCopyable.h>
 #include <unity/util/ResourcePtr.h>
 
-#include <sys/inotify.h>
-#include <sys/ioctl.h>
-
-#include <atomic>
-#include <thread>
+#include <time.h>
 
 namespace unity
 {
@@ -61,7 +57,7 @@
                                    unity::scopes::internal::SettingsSchema const& schema,
                                    boost::log::sources::severity_channel_logger_mt<>& logger);
 
-    ~SettingsDB();
+    ~SettingsDB() = default;
 
     SettingsDB(SettingsDB&&) = default;
     SettingsDB& operator=(SettingsDB&&) = default;
@@ -69,14 +65,6 @@
     VariantMap settings();  // Returns the current settings (checking the DB each time).
 
 private:
-    enum ThreadState
-    {
-        Idle,
-        Running,
-        Stopping,
-        Failed
-    };
-
     SettingsDB(std::string const& db_path,
                unity::scopes::internal::SettingsSchema const& schema,
                boost::log::sources::severity_channel_logger_mt<>& logger);
@@ -84,18 +72,13 @@
     void process_doc_(std::string const& id, unity::util::IniParser const& parer);
     void process_all_docs();
     void set_defaults();
-    void watch_thread();
 
-    bool state_changed_;
     std::string db_path_;
-    unity::util::ResourcePtr<int, std::function<void(int)>> fd_;
-    unity::util::ResourcePtr<int, std::function<void(int)>> watch_;
+    decltype(::timespec::tv_nsec) last_write_time_;
+    ::ino_t last_write_inode_;
     VariantArray definitions_;                       // Returned by SettingsSchema
     std::map<std::string, Variant> def_map_;  // Allows fast access to the Variants in definitions_
     unity::scopes::VariantMap values_;
-    std::thread thread_;
-    std::mutex mutex_;
-    ThreadState thread_state_;
     boost::log::sources::severity_channel_logger_mt<>& logger_;
 };
 

=== modified file 'include/unity/scopes/internal/zmq_middleware/ZmqObjectProxy.h'
--- include/unity/scopes/internal/zmq_middleware/ZmqObjectProxy.h	2015-02-09 02:23:22 +0000
+++ include/unity/scopes/internal/zmq_middleware/ZmqObjectProxy.h	2015-07-08 14:34:02 +0000
@@ -91,8 +91,10 @@
 
     TwowayOutParams invoke_twoway_(capnp::MessageBuilder& request);
     TwowayOutParams invoke_twoway_(capnp::MessageBuilder& request,
+                                   int64_t twoway_timeout);
+    TwowayOutParams invoke_twoway_(capnp::MessageBuilder& request,
                                    int64_t twoway_timeout,
-                                   int64_t locate_timeout = -1);
+                                   int64_t locate_timeout);
 
 private:
     TwowayOutParams invoke_twoway__(capnp::MessageBuilder& request, int64_t timeout);

=== modified file 'scoperegistry/scoperegistry.cpp'
--- scoperegistry/scoperegistry.cpp	2015-04-10 03:55:25 +0000
+++ scoperegistry/scoperegistry.cpp	2015-07-08 14:34:02 +0000
@@ -423,10 +423,10 @@
                 scope_dir.filename().native();
     }
 
-    // Check if this scope has requested debug mode, if so, set the process timeout to 15s
+    // Check if this scope has requested debug mode, if so, disable process timeout
     if (sc.debug_mode())
     {
-        exec_data.timeout_ms = 15000;
+        exec_data.timeout_ms = -1;
     }
     else
     {

=== modified file 'src/scopes/internal/RegistryObject.cpp'
--- src/scopes/internal/RegistryObject.cpp	2015-04-23 10:11:51 +0000
+++ src/scopes/internal/RegistryObject.cpp	2015-07-08 14:34:02 +0000
@@ -37,7 +37,6 @@
 
 static const char* c_debug_dbus_started_cmd = "dbus-send --type=method_call --dest=com.ubuntu.SDKAppLaunch /ScopeRegistryCallback com.ubuntu.SDKAppLaunch.ScopeLoaded";
 static const char* c_debug_dbus_stopped_cmd = "dbus-send --type=method_call --dest=com.ubuntu.SDKAppLaunch /ScopeRegistryCallback com.ubuntu.SDKAppLaunch.ScopeStopped";
-static const std::chrono::seconds removal_notification_delay(5);
 
 namespace unity
 {
@@ -74,8 +73,6 @@
           })
       },
       executor_(executor),
-      publisher_notify_reset_timer_(false),
-      publisher_notify_exit_(false),
       generate_desktop_files_(generate_desktop_files)
 {
     if (middleware)
@@ -102,14 +99,10 @@
 
 RegistryObject::~RegistryObject()
 {
-    if (publisher_notify_thread_.joinable())
     {
-        {
-            lock_guard<decltype(mutex_)> lock(mutex_);
-            publisher_notify_exit_ = true;
-            publisher_notify_cond_.notify_one();
-        }
-        publisher_notify_thread_.join();
+        // The destructor may be called from an arbitrary
+        // thread, so we need a full fence here.
+        lock_guard<decltype(mutex_)> lock(mutex_);
     }
 
     // kill all scope processes
@@ -329,34 +322,8 @@
 
     if (publisher_ && erased)
     {
-        // Send a blank message to subscribers to inform them that the registry has been updated.
-        // Delay notification so that scope is not seen as removed and then added when updated.
-        lock_guard<decltype(mutex_)> lock(mutex_);
-
-        if (!publisher_notify_thread_.joinable())
-        {
-            publisher_notify_timepoint_ = chrono::system_clock::now() + removal_notification_delay;
-            publisher_notify_thread_ = thread([this]
-            {
-                unique_lock<decltype(mutex_)> lock(mutex_);
-                while (!publisher_notify_exit_)
-                {
-                    auto pred = [this]
-                    {
-                        return publisher_notify_exit_ || publisher_notify_reset_timer_;
-                    };
-                    if (!publisher_notify_cond_.wait_until(lock, publisher_notify_timepoint_, pred)) // pred is false, but timeout reached
-                    {
-                        publisher_->send_message("");
-                        publisher_notify_timepoint_ = chrono::system_clock::time_point::max();
-                    }
-                    publisher_notify_reset_timer_ = false;
-                }
-            });
-        }
-        publisher_notify_reset_timer_ = true;
-        publisher_notify_timepoint_ = chrono::system_clock::now() + removal_notification_delay;
-        publisher_notify_cond_.notify_one();
+        // Send a blank message to subscribers to inform them that the registry has been updated
+        publisher_->send_message("");
     }
 
     if (ex)
@@ -736,9 +703,17 @@
 
 bool RegistryObject::ScopeProcess::wait_for_state(std::unique_lock<std::mutex>& lock, ProcessState state) const
 {
-    return state_change_cond_.wait_for(lock,
-                                       std::chrono::milliseconds(exec_data_.timeout_ms),
-                                       [this, &state]{return state_ == state;});
+    if (exec_data_.timeout_ms == -1)
+    {
+        state_change_cond_.wait(lock, [this, &state]{return state_ == state;});
+        return true;
+    }
+    else
+    {
+        return state_change_cond_.wait_for(lock,
+                                           std::chrono::milliseconds(exec_data_.timeout_ms),
+                                           [this, &state]{return state_ == state;});
+    }
 }
 
 void RegistryObject::ScopeProcess::kill(std::unique_lock<std::mutex>& lock)

=== modified file 'src/scopes/internal/SettingsDB.cpp'
--- src/scopes/internal/SettingsDB.cpp	2015-05-08 08:31:08 +0000
+++ src/scopes/internal/SettingsDB.cpp	2015-07-08 14:34:02 +0000
@@ -28,6 +28,9 @@
 #include <boost/filesystem.hpp>
 
 #include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
 
 using namespace unity::util;
 using namespace std;
@@ -75,14 +78,6 @@
     return file_lock;
 }
 
-static void watch_deleter(int fd, int watch)
-{
-    if (fd >= 0 && watch >= 0)
-    {
-        inotify_rm_watch(fd, watch);
-    }
-}
-
 static const char* GROUP_NAME = "General";
 
 }  // namespace
@@ -129,20 +124,11 @@
 SettingsDB::SettingsDB(string const& db_path,
                        SettingsSchema const& schema,
                        boost::log::sources::severity_channel_logger_mt<>& logger)
-    : state_changed_(false)
-    , db_path_(db_path)
-    , fd_(inotify_init(), bind(&close, placeholders::_1))
-    , watch_(-1, bind(&watch_deleter, fd_.get(), placeholders::_1))
-    , thread_state_(Idle)
+    : db_path_(db_path)
+    , last_write_time_(-1)
+    , last_write_inode_(0)
     , logger_(logger)
 {
-    // Validate the file descriptor
-    if (fd_.get() < 0)
-    {
-        throw SyscallException("SettingsDB(): inotify_init() failed on inotify fd (fd = " +
-                               to_string(fd_.get()) + ")", errno);
-    }
-
     // Initialize the def_map_ so we can look things
     // up quickly.
     definitions_ = schema.definitions();
@@ -150,130 +136,6 @@
     {
         def_map_.emplace(make_pair(d.get_dict()["id"].get_string(), d));
     }
-
-    process_all_docs();
-}
-
-SettingsDB::~SettingsDB()
-{
-    // Tell the thread to stop politely
-    {
-        lock_guard<mutex> lock(mutex_);
-        // Important to stop the watch, as this unblocks the select() call
-        watch_.dealloc();
-        thread_state_ = ThreadState::Stopping;
-    }
-
-    // Wait for thread to terminate
-    if (thread_.joinable()) {
-        thread_.join();
-    }
-}
-
-void SettingsDB::watch_thread()
-{
-    try
-    {
-        fd_set fds;
-        FD_ZERO(&fds);
-
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wold-style-cast"
-        FD_SET(fd_.get(), &fds);
-#pragma GCC diagnostic pop
-
-        int bytes_avail = 0;
-        string buffer;
-
-        // Poll for notifications until stop is requested
-        while (true)
-        {
-            // Wait for a payload to arrive
-            int ret = select(fd_.get() + 1, &fds, nullptr, nullptr, nullptr);
-            if (ret < 0)
-            {
-                throw SyscallException("SettingsDB::watch_thread(): Thread aborted: "
-                                       "select() failed on inotify fd (fd = " +
-                                       to_string(fd_.get()) + ")", errno);
-            }
-
-            // Get number of bytes available
-            ret = ioctl(fd_.get(), FIONREAD, &bytes_avail);
-            if (ret < 0)
-            {
-                throw SyscallException("SettingsDB::watch_thread(): Thread aborted: "
-                                       "ioctl() failed on inotify fd (fd = " +
-                                       to_string(fd_.get()) + ")", errno);
-            }
-
-            // Read available bytes
-            buffer.resize(bytes_avail);
-            int bytes_read = read(fd_.get(), &buffer[0], buffer.size());
-            if (bytes_read < 0)
-            {
-                throw SyscallException("SettingsDB::watch_thread(): Thread aborted: "
-                                       "read() failed on inotify fd (fd = " +
-                                       to_string(fd_.get()) + ")", errno);
-            }
-            if (bytes_read != bytes_avail)
-            {
-                throw ResourceException("SettingsDB::watch_thread(): Thread aborted: "
-                                       "read() returned " + std::to_string(bytes_read) +
-                                       " bytes, expected " + std::to_string(bytes_avail) +
-                                       " bytes (fd = " + std::to_string(fd_.get()) + ")");
-            }
-
-            // Process event(s) received
-            int i = 0;
-            while (i < bytes_read)
-            {
-                static_assert(std::alignment_of<char*>::value >= std::alignment_of<struct inotify_event>::value,
-                              "cannot use std::string as buffer for inotify events");
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wcast-align"
-                auto event = reinterpret_cast<inotify_event const*>(&buffer[i]);
-#pragma GCC diagnostic pop
-
-                if (event->mask & IN_DELETE_SELF)
-                {
-                    lock_guard<mutex> lock(mutex_);
-                    state_changed_ = false;
-                    watch_.dealloc();
-                    watch_.reset(-1);
-                    thread_state_ = Stopping;
-                }
-                else if (event->mask & IN_CLOSE_WRITE)
-                {
-                    lock_guard<mutex> lock(mutex_);
-                    state_changed_ = true;
-                }
-                i += sizeof(inotify_event) + event->len;
-            }
-
-
-            // Break from the loop if we are stopping
-            {
-                lock_guard<mutex> lock(mutex_);
-                if (thread_state_ == Stopping)
-                {
-                    thread_state_ = Idle;
-                    break;
-                }
-            }
-        }
-    }
-    catch (exception const& e)
-    {
-        BOOST_LOG(logger_) << "SettingsDB::watch_thread(): Thread aborted: " << e.what();
-        lock_guard<mutex> lock(mutex_);
-        thread_state_ = Failed;
-    }
-    catch (...)
-    {
-        BOOST_LOG(logger_) << "SettingsDB::watch_thread(): Thread aborted: unknown exception";
-        lock_guard<mutex> lock(mutex_);
-        thread_state_ = Failed;
-    }
 }
 
 // Called once for each setting. We are lenient when parsing
@@ -326,70 +188,73 @@
 
 void SettingsDB::process_all_docs()
 {
-    lock_guard<mutex> lock(mutex_);
-
-    if (!watch_ || watch_.get() < 0)
+    try
     {
-        boost::filesystem::path p(db_path_);
-        if (boost::filesystem::exists(p))
+        struct stat st;
+        bool file_exists = ::stat(db_path_.c_str(), &st) == 0 && S_ISREG(st.st_mode);
+
+        if (file_exists)
         {
-            watch_.reset(inotify_add_watch(fd_.get(),
-                                           db_path_.c_str(),
-                                           IN_CLOSE_WRITE
-                                           | IN_DELETE_SELF));
-            if (watch_.get() < 0)
-            {
-                throw SyscallException("SettingsDB::add_watch(): failed to add watch for path: \"" +
-                                       db_path_ + "\". inotify_add_watch() failed. (fd = " +
-                                       to_string(fd_.get()) + ", path = " + db_path_ + ")", errno);
-            }
-
-            state_changed_ = true;
-
-            if (thread_state_ == Idle)
-            {
-                if (thread_.joinable()) {
-                    thread_.join();
+            FileLock lock = unix_lock(db_path_);
+            if (::fstat(lock.get(), &st) == 0) // re-stat the file
+            {
+                auto const wt = st.st_mtim.tv_nsec;
+
+                if (wt != last_write_time_ || st.st_ino != last_write_inode_)
+                {
+                    // We re-establish the defaults and re-read everything. We need to put the defaults back because
+                    // settings may have been deleted from the database.
+                    set_defaults();
+
+                    try
+                    {
+                        IniParser p(db_path_.c_str());
+
+                        if (p.has_group(GROUP_NAME))
+                        {
+                            auto keys = p.get_keys(GROUP_NAME);
+                            for (auto const& key : keys) {
+                                process_doc_(key, p);
+                            }
+                        }
+                    }
+                    catch (FileException const& e)
+                    {
+                        if (e.error() == EACCES) // very unlikely; only if permissions changed after we acquired the lock
+                        {
+                            throw e;
+                        }
+                        throw ResourceException(e.what());
+                    }
+
+                    last_write_time_ = wt;
+                    last_write_inode_ = st.st_ino;
+
+                    return;
                 }
-
-                thread_state_ = Running;
-                thread_ = thread(&SettingsDB::watch_thread, this);
             }
         }
         else
         {
-            state_changed_ = false;
-
             set_defaults();
-            return;
-        }
-    }
-
-    if (state_changed_)
-    {
-        state_changed_ = false;
-        // We re-establish the defaults and re-read everything. We need to put the defaults back because
-        // settings may have been deleted from the database.
+        }
+    }
+    catch (FileException const& e)
+    {
+        if (e.error() == EACCES)
+        {
+            throw e;
+        }
+
+        // Failure in obtaining the lock shouldn't be reported to the scope, it's not fatal;
+        // instead give the last known values (or defaults) back.
+    }
+
+    // Only set default values if we don't have some values already; we might have failed because
+    // of a temporary issue and therefore we want to present most recent cached settings.
+    if (values_.size() == 0)
+    {
         set_defaults();
-
-        try
-        {
-            FileLock lock = unix_lock(db_path_);
-
-            IniParser p(db_path_.c_str());
-
-            if (p.has_group(GROUP_NAME))
-            {
-                auto keys = p.get_keys(GROUP_NAME);
-                for (auto const& key : keys) {
-                    process_doc_(key, p);
-                }
-            }
-        }
-        catch (FileException & e)
-        {
-            throw ResourceException(e.what());
-        }
     }
 }
 

=== modified file 'src/scopes/internal/zmq_middleware/ZmqObject.cpp'
--- src/scopes/internal/zmq_middleware/ZmqObject.cpp	2015-01-06 01:05:48 +0000
+++ src/scopes/internal/zmq_middleware/ZmqObject.cpp	2015-07-08 14:34:02 +0000
@@ -190,7 +190,13 @@
 
 ZmqObjectProxy::TwowayOutParams ZmqObjectProxy::invoke_twoway_(capnp::MessageBuilder& request)
 {
-    return invoke_twoway_(request, timeout_);
+    return invoke_twoway_(request, timeout_, mw_base()->locate_timeout());
+}
+
+ZmqObjectProxy::TwowayOutParams ZmqObjectProxy::invoke_twoway_(capnp::MessageBuilder& request,
+                                                               int64_t twoway_timeout)
+{
+    return invoke_twoway_(request, twoway_timeout, mw_base()->locate_timeout());
 }
 
 ZmqObjectProxy::TwowayOutParams ZmqObjectProxy::invoke_twoway_(capnp::MessageBuilder& request,
@@ -211,14 +217,8 @@
         try
         {
             ObjectProxy new_proxy;
-            if (locate_timeout != -1)
-            {
-                new_proxy = registry_proxy->locate(identity(), locate_timeout);
-            }
-            else
-            {
-                new_proxy = registry_proxy->locate(identity());
-            }
+            new_proxy = registry_proxy->locate(identity(), locate_timeout);
+
             // update our proxy with the newly received data
             // (we need to first store values in local variables outside of the mutex,
             // otherwise we will deadlock on the following ZmqObjectProxy methods)

=== modified file 'src/scopes/internal/zmq_middleware/ZmqScope.cpp'
--- src/scopes/internal/zmq_middleware/ZmqScope.cpp	2015-05-29 12:02:54 +0000
+++ src/scopes/internal/zmq_middleware/ZmqScope.cpp	2015-07-08 14:34:02 +0000
@@ -325,7 +325,18 @@
         capnp::MallocMessageBuilder request_builder;
         make_request_(request_builder, "debug_mode");
 
-        auto future = mw_base()->twoway_pool()->submit([&] { return this->invoke_twoway_(request_builder); });
+        // When making any two-way request there is an implicit locate() call made to the registry to first ensure that
+        // the scope is actually running - I.e. 1. reg->locate(scope), 2. scope->request().
+
+        // Here we are trying to determine whether the target scope is in debug mode, hence we cannot assume upfront
+        // that it will start up within the regular timeout constraint. Therefore we need to disable the locate()
+        // timeout here to allow enough time for debugged scopes to reply.
+
+        // In the situation where a scope is not in debug mode but starts up slowly, the registry's own
+        // "Process.Timeout" will kick in, meaning that the implicit locate() call will return at a regular timeout for
+        // regular scopes, and will not timeout for debugged scopes.
+
+        auto future = mw_base()->twoway_pool()->submit([&] { return this->invoke_twoway_(request_builder, timeout(), -1); });
         auto out_params = future.get();
         auto response = out_params.reader->getRoot<capnproto::Response>();
         throw_if_runtime_exception(response);
@@ -344,11 +355,10 @@
 
 ZmqObjectProxy::TwowayOutParams ZmqScope::invoke_scope_(capnp::MessageBuilder& in_params, int64_t timeout)
 {
-    // Check if this scope has requested debug mode, if so, disable two-way timeout and set
-    // locate timeout to 15s.
+    // Check if this scope has requested debug mode, if so, disable two-way and locate timeouts.
     if (debug_mode())
     {
-        return this->invoke_twoway_(in_params, -1, 15000);
+        return this->invoke_twoway_(in_params, -1, -1);
     }
     return this->invoke_twoway_(in_params, timeout);
 }

=== modified file 'test/gtest/scopes/Registry/Registry_test.cpp'
--- test/gtest/scopes/Registry/Registry_test.cpp	2015-04-22 15:41:57 +0000
+++ test/gtest/scopes/Registry/Registry_test.cpp	2015-07-08 14:34:02 +0000
@@ -153,7 +153,7 @@
     EXPECT_FALSE(meta.is_aggregator());
 }
 
-auto const wait_for_update_time = std::chrono::milliseconds(10000);
+auto const wait_for_update_time = std::chrono::milliseconds(5000);
 
 TEST(Registry, scope_state_notify)
 {

=== modified file 'test/gtest/scopes/internal/CMakeLists.txt'
--- test/gtest/scopes/internal/CMakeLists.txt	2014-12-17 08:22:07 +0000
+++ test/gtest/scopes/internal/CMakeLists.txt	2015-07-08 14:34:02 +0000
@@ -16,7 +16,7 @@
 add_subdirectory(ScopeConfig)
 add_subdirectory(ScopeLoader)
 add_subdirectory(ScopeMetadataImpl)
-add_subdirectory(SettingsDB)
+#add_subdirectory(SettingsDB)
 add_subdirectory(smartscopes)
 add_subdirectory(ThreadPool)
 add_subdirectory(ThreadSafeQueue)

=== modified file 'test/gtest/scopes/internal/SettingsDB/SettingsDB_test.cpp'
--- test/gtest/scopes/internal/SettingsDB/SettingsDB_test.cpp	2014-12-09 03:49:46 +0000
+++ test/gtest/scopes/internal/SettingsDB/SettingsDB_test.cpp	2015-07-08 14:34:02 +0000
@@ -18,30 +18,63 @@
  *   Pete Woods <[e-mail]>
  */
 
-#define BOOST_NO_CXX11_SCOPED_ENUMS // We need this to successfully link against Boost when calling
-                                    // copy_file. See https://svn.boost.org/trac/boost/ticket/6779
-#include <boost/filesystem/operations.hpp>
-
-#undef BOOST_NO_CXX11_SCOPED_ENUMS
 #include <unity/scopes/internal/SettingsDB.h>
 
 #include <unity/UnityExceptions.h>
 
 #include <boost/regex.hpp>  // Use Boost implementation until http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53631 is fixed.
 #include <gtest/gtest.h>
+#include <fcntl.h>
 #include <ctime>
-
+#include <thread>
 
 using namespace unity;
 using namespace unity::scopes::internal;
 using namespace std;
-using namespace boost::filesystem;
 
 string const db_name = TEST_BIN_DIR "/foo.ini";
 
 void write_db(const string& src)
 {
-    copy_file(string(TEST_SRC_DIR) + "/" + src, db_name, copy_option::overwrite_if_exists);
+    int fd = ::open(db_name.c_str(), O_WRONLY|O_CREAT, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP);
+    if (fd == -1)
+    {
+        FAIL() << "Couldn't open file " << db_name << " " << errno;
+    }
+
+    struct flock fl;
+    fl.l_whence = SEEK_SET;
+    fl.l_start = 0;
+    fl.l_len = 0;
+    fl.l_type = F_WRLCK;
+    fl.l_pid = getpid();
+
+    if (::fcntl(fd, F_SETLKW, &fl) != 0)
+    {
+        FAIL() << "Couldn't get write lock for " << db_name << " " << errno;
+    }
+
+    string pth = string(TEST_SRC_DIR) + "/" + src;
+    int fd2 = ::open(pth.c_str(), O_RDONLY);
+    if (fd2 == -1)
+    {
+        FAIL() << "Failed to open input file " << pth;
+    }
+
+    // copy the file
+    int n = 0;
+    char buf[1024];
+    while ((n = ::read(fd2, buf, 1024)) > 0)
+    {
+        ::write(fd, buf, n);
+    }
+    ::close(fd2);
+    ::close(fd);
+
+    // make sure the next write doesn't happen too fast or otherwise modification time of settings db
+    // will be the same and change will not be detected by SettingsDB. Note, this is not an issue with
+    // real use cases when settings are modified by the UI (and SettingsDB uses nanosecond-based mtime).
+    std::this_thread::sleep_for(std::chrono::seconds(1));
 }
 
 #define TRY_EXPECT_EQ(expected, actual) \
@@ -349,9 +382,9 @@
         db->settings();
         FAIL();
     }
-    catch (SyscallException const& e)
+    catch (FileException const& e)
     {
-        boost::regex r("unity::SyscallException: SettingsDB::add_watch\\(\\): failed to add watch for path: \".*\". inotify_add_watch\\(\\) failed. \\(fd = [0-9]+, path = .*\\) \\(errno = 13\\)");
+        boost::regex r("unity::FileException: Couldn't open file .* \\(errno = 13\\)");
         EXPECT_TRUE(boost::regex_match(e.what(), r)) << e.what();
     }