http://blog.gmane.org/gmane.comp.freedesktop.dbus hourly 1 1901-01-01T00:00+00:00 http://gmane.org/img/gmane-25t.png http://gmane.org http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14728 <pre> Recent Ubuntu versions use a patched version of D-Bus which interacts with Upstart. It seems that upstream versions of D-Bus will not work there: Upstart assumes that a patched version of D-Bus is in use. Either use the Ubuntu-provided binaries (you can get development headers with "apt-get install libdbus-1-dev"), or compile the Ubuntu version of dbus from source ("apt-get source dbus" and build it with dpkg-buildpackage or similar), or use a distribution which doesn't require special D-Bus patches (Debian, Fedora, Mandriva, Gentoo, etc.). In general there's not much point in compiling all the dependencies for something like VLC yourself - particularly true for core system libraries like dbus. The purpose of a distribution is to provide you with versions of various packages which are known to work well together. Use the distribution's packages where possible, and only compile newer versions yourself if the versions provided by the distribution are too old, the versions provided by the distribution have bugs that affect you, you're trying to add features or fix bugs in that particular package (dbus in this case), or you're the distribution's maintainer for it. (Or, if you're trying to compile literally everything, Linux From Scratch still exists...) S _______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> Simon McVittie 2012-05-22T17:26:03 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14727 <pre>i am trying to compile vlc, everything from source, i need the dbus package, after i success install dbus-1.4.20, i reboot, the ubuntu crash, what shall i do please help_______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> Lee Wei han 2012-05-22T17:04:50 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14726 <pre>(Please ask the mailing list rather than asking individual contributors. If you ask me personally, only I can help you, and if I'm too busy, you won't get an answer; if you ask the mailing list, anyone on the list can help you.) On 22/05/12 11:38, Vinoth V wrote: That's possible. That's possible. I'd do this as an asynchronous method call sent by the "server" to the "client". This reverses their usual roles, but that's OK - all processes on D-Bus are treated the same. Telepathy and BlueZ both have situations where the process you'd normally think of as the "server" calls methods on the process you'd normally think of as the "client". It has to be an asynchronous method call (send request, go back to your main loop, get a callback called from your main loop later) because if two processes try to make synchronous method calls to each other, they'll typically deadlock while each waits for the other to reply. You should make asynchronous method calls anyway, though; see &lt;http://smcv.pseudorandom.co.uk/2008/11/nonblocking/&gt;. Export an object with a method from the "client" (e.g. with g_dbus_connection_register_object()); make the "client" tell the "server" its unique name somehow (e.g. call g_dbus_connection_get_unique_name() and send that to the "server"); make the "server" call the client's method by using that unique name. You could do this with signals too, although method calls would probably be easier to understand: * emit signal with your "specific details" every 2 minutes * your client responds to that signal by calling a method on the server You can send nearly any data structure that you can encode into a GVariant (exceptions: you can't send any type involving "maybe", you can only send a dict-entry if it's in an array of dict-entry, and you can't send empty tuples). If you have a complex data structure you will need to work out how to encode it as a D-Bus message (or, equivalently, as a GVariant without using the features I mentioned). S _______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> Simon McVittie 2012-05-22T10:56:11 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14725 <pre>I'm using edge-triggered watches because of boost::asio, which internally does cross platform edge-triggered io, using epoll in linux. Boost::asio is more like a proactor design than a reactor one. This is the kind of library where you just say "Read me 512 bytes" and when it's done it will call your handler with the 512 bytes in a buffer, ready to be used. You can also say "Read data until my custom predicate tells me there is a complete "message" available, then call my handler so i can parse it", with full threading support. It can also act as a regular Reactor, so i can still use it for D-Bus, but only with edge triggered semantics. I haven't looked, but this is maybe the kind of thing libdbus is already doing behind the scenes, with the handle_dispatch thing. I am already dispatching inside the busy read loop, mostly as a hack because of limitations of dbus-c++ bindings. But can't that be fixed by using threads to perform the reads, and concurrently dispatching them in the "main" thread ? The kind of things that asio does. I think i will just replace my busy read hack with your suggestion. That should even be easier to do with boost::asio. Thanks for the pointers. _______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> Nicolas Cavallari 2012-05-21T19:58:18 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14724 <pre> Short answer: don't multi-thread with those versions. For best results, do all your D-Bus interaction from your main thread (the one where main() was called). You can use asynchronous method calls with callbacks to avoid blocking your main thread. If you're using libdbus (dbus_* functions) in your multi-threaded application, libdbus 1.4.16 has known thread-safety bugs. They were fixed in 1.5.10, so in principle, what you're doing might work with that version. I am not aware of any thread-safety bugs in 1.5.10 or newer, but that doesn't mean there aren't any! If you're using GDBus (g_dbus_* or g_bus_* functions) in your multi-threaded application, the version of GDBus in GLib 2.30 also has known thread-safety bugs. They were fixed in 2.32. In general GDBus has a pretty good design for thread-safety, so if you must use D-Bus from multiple threads, it's a good choice. If you're using dbus-glib (dbus_g_* functions) in your multi-threaded application, don't. It isn't thread safe and never will be. It also has serious design flaws, and I recommend using GDBus instead. S _______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> Simon McVittie 2012-05-21T17:27:39 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14723 <pre> Correct; it doesn't do that. Is there any particular reason why you want an edge-triggered watch? This... ... would essentially be equivalent to this, but inside libdbus. As far as I'm aware, the reason for the max_bytes_*_per_iteration variables is mainly to avoid main loop "starvation": if your process sees/produces sufficiently rapid D-Bus traffic that there is always something to read/write, then none of your other fds (including, perhaps, the one telling you to slow down or exit!) will ever be polled. Relatedly, it avoids arbitrary memory consumption under extremely heavy traffic: if you keep reading from a fd indefinitely, without ever pausing to do what libdbus calls "dispatching" (sending in-memory messages to their consumers), and there's always another message to read, then the messages will be queued in memory forever, and will never actually be dispatched to their consumers and (hopefully) freed. If you use edge-triggered watches with busy-reading like this, you're basically always going to be vulnerable to those problems. If you're OK with that, call dbus_watch_handle() in a loop, I suppose. Alternatively, use level-triggered polling, or wrap an edge-triggered epoll in a higher-level construct that remembers that the D-Bus socket is still readable/writeable and interleaves reads/writes/dispatching with polling other sockets (with the timeout set to zero for as long as you know reads/writes are pending). S _______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> Simon McVittie 2012-05-21T17:18:56 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14722 <pre>Hi All, I am using dbus-1.4.16 (glib binding is done using the library glib-2.30 ) in a multi-threaded environment, like a server(different process) runs in one end, and a client(different process) in one end, but if i run a client, calling a same synchronous function for multiple times using threads, i am getting error like "Error in called_function name, msg="GDBus.Error:org.freedesktop.DBus.Error.NoReply: Message did not receive a reply (timeout by message bus)". (process:2064): GLib-CRITICAL **: g_variant_get_fixed_array: assertion `g_variant_is_of_type (value, G_VARIANT_TYPE_ARRAY)' failed but if i call this function only once, i am gettin my output properly. so i have a doubt like, whether dbus allows simultaneous execution of synchronise functions ? or it is only serial execution. kindly help me. Regards Vinoth _______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> Vinoth V 2012-05-21T15:01:57 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14721 <pre>Hi, I am trying to use D-Bus in a C++(11) application. I tried using dbus-c++, and integrated it with a external mainloop (boost::asio) which internally uses edge triggered epoll. But i found that some signal handlers are deferred, so watches are not always working. I am using the custom watch API from dbus-c++, which is essentially a thin wrapper around the DBusWatch API from libdbus. Looking at the code, libdbus does not seem to support edge triggered watches. Edge triggered support would essentially mean that libdbus must read()/write() from/to the fd until it returns EAGAIN. From what i see, the only limitation seems to come from the default value of the max_bytes_{read,written}_per_iteration variables. I think that setting them to an arbitrary high number should be enough to make libdbus work with edge triggered epoll. Am i correct ? And how could i change these variables ? The alternative would be to call the (wrapped) dbus_watch_handle() repeatedly until the fd is not readable/writable anymore, but that would be an ugly hack to busyloop like that, considering it shouldn't be hard to make libdbus work with edge triggered watches. _______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> Nicolas Cavallari 2012-05-21T12:58:46 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14720 <pre> No, there is no one working on fixing that bug. It requires someone with interest in the result. Maybe that could be you. </pre> Thiago Macieira 2012-05-21T10:14:42 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14719 <pre>Thanks for your reply. By the way, is there a plan to fix this bug in future version ? Cheers Liang. _______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> 007900800083-m4dJw2ia6OdeoWH0uzbU5w< at >public.gmane.org 2012-05-21T08:39:53 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14718 <pre> It's a bug. </pre> Thiago Macieira 2012-05-21T07:15:13 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14717 <pre>Hi: I use dbus-monitor to monitor method call and reply message on system dbus. But I only get method call message, but can not any reply message. However i can get both types of messages on session dbus with dbus-monitor. I find someone has meet similiar issue in early version http://lists.freedesktop.org/archives/dbus/2009-April/011146.html. Could someone kindly tell me how to fix it or it is a bug in system dbus. Thanks a lot. I am using dbus-1.5.8, and system.conf is : &lt;policy context="default"&gt; &lt;!-- All users can connect to system bus --&gt; &lt;allow user="*"/&gt; &lt;!-- Holes must be punched in service configuration files for name ownership and sending method calls --&gt; &lt;deny own="*"/&gt; &lt;deny send_type="method_call"/&gt; &lt;!-- Signals and reply messages (method returns, errors) are allowed by default --&gt; &lt;allow send_type="signal"/&gt; &lt;allow send_requested_reply="true" send_type="method_return"/&gt; &lt;allow send_requested_reply="true" send_type="error"/&gt; &lt;!-- All messages may be received by default --&gt; &lt;allow receive_type="method_call"/&gt; &lt;allow receive_type="method_return"/&gt; &lt;allow receive_type="error"/&gt; &lt;allow receive_type="signal"/&gt; &lt;!-- Allow anyone to talk to the message bus --&gt; &lt;allow send_destination="org.freedesktop.DBus"/&gt; &lt;!-- But disallow some specific bus services --&gt; &lt;deny send_destination="org.freedesktop.DBus" send_interface="org.freedesktop.DBus" send_member="UpdateActivationEnvironment"/&gt; &lt;!-- Allow everything to be sent --&gt; &lt;allow send_destination="*" eavesdrop="true"/&gt; &lt;!-- Allow everything to be received --&gt; &lt;allow eavesdrop="true"/&gt; &lt;!-- Allow anyone to own anything --&gt; &lt;allow own="*"/&gt; &lt;/policy&gt; Cheers Liang. _______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> 007900800083-m4dJw2ia6OdeoWH0uzbU5w< at >public.gmane.org 2012-05-21T00:25:18 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14716 <pre>_______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> Martin Vidner 2012-05-17T11:25:13 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14715 <pre>_______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> Sruthi M 2012-05-17T07:15:27 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14714 <pre> First of all, please don't write HTML-only email. I'd recommend avoiding HTML completely, since the text portion of your email is what counts. Second, I'm sorry but there's no way to retrieve the information about which connections have demonstrated interest in a particular signal. If you really wish to get this information, you can modify the daemon so that you can retrieve the list of match rules and the connections they apply to. Then use the rules to determine which connections are interested in those signals. Note that rules like "type='signal'" will match for any and all signals. </pre> Thiago Macieira 2012-05-14T16:43:47 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14713 <pre>_______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> 007900800083-m4dJw2ia6OdeoWH0uzbU5w< at >public.gmane.org 2012-05-14T15:44:10 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14712 <pre> You don't read/write messages like that using dbus-java, that's just an internal class for reading the wire protocol. You interact with dbus on an object/method level. Read the documentation: http://dbus.freedesktop.org/doc/dbus-java/dbus-java/ Matt _______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> Matthew Johnson 2012-05-09T16:58:21 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14711 <pre>Hello guys, I am new to Dbus world. I would highly appreciate if someone would react to my email. I m using ubuntu 12.04 and making a program with Dbus java. I could connect successfully to the session bus but when i am trying to read or write i get strange errors. I should mention that i got all the jar files by installing directly from ubuntu so I didnt not build anything special. just apt-get install libdbus-java. the peace of code that i have is here. mDBusConn = DBusConnection.getConnection("tcp:host=xxx.xxx.xxx.xxx,port=123544"); InputStream in = new ByteArrayInputStream(data); MessageReader mReader = MessageReader(in); the error that i get during the compilation is *[javac] DbusChannel.java:39: cannot find symbol [javac] symbol : method MessageReader(java.io.InputStream) [javac] location: class com.tomtom.reflection2.dbus.DbusChannel [javac] MessageReader mReader = MessageReader(in); [javac] ^ [javac] 1 error* I dont understand why it is complaining about the constructor, since based on documentation(http://dbus.freedesktop.org/doc/dbus-java/api/) it should be there. I am using just gedit for implementing classes so i cant see immediately if it is there or not. Thanks in advance, Kind regards, Lusy _______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> Lusy Hakobyan 2012-05-09T15:48:55 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14710 <pre>Hello dbus guys, I am new to dbus and need some help please. I have some performance concerns about a dbus app I am working on. callgrind indicates that many posix mutex locks are being taken on the server side during message validation. These calls are in alloc_link (and the corresponding call to free_link). I did a temporary hack to these functions, making them use malloc and free instead. This caused the mutex locks to drop off the radar (hurrah!) but it also caused malloc to feature much higher in the costs (boo!). I know that the code is the way it is because originally the cost of lots of small allocates via direct calls to malloc was found to be expensive. Heap fragmentation springs to mind. This was solved using a memory pool which was later made thread-safe by adding the locks. So going back to direct malloc is only an experimental hack. I am not proposing that this is done officially. Indeed, my profile results demonstrate that the repeated allocates are an issue. But I have a few thoughts about how to deal with this issue that I want to discuss in this mailinglist. First, has anyone looked at replacing the memory pool with a more efficient allocator than malloc? I came across one called nedmalloc, at http://www.nedprod.com/programs/portable/nedmalloc. This seems to compare very favourably with hoard but with a more permissive license. Has anyone tried that? What do people think? Second, I notice from my callgrind results that the memory pool is used extensively during message validation. Would it not be possible to change the message validation so it used its own memory management. A validation memory management package might still use a memory pool but might also take a parameter to say whether or not to lock the pool. I am just guessing here, since I dont know enough about the dbus code, but I am wondering about specifying such a flag in my server since I know my server is single-threaded. Maybe there should be a set flag routine that a server can call during initialisation that says whether or not it is single-threaded. What do people think about this please? Third, a hybrid approach could be used. alloc_link could continue to use the memory pool but the pool could employ a flag that controls whether or not it locks the pool. Single threaded servers can set this flag to false. This is slightly more dangerous because it assumes that a single-threaded server will not have any threads started behind the dbus scenes that calls alloc_link. -- Regards, Andrew Marlow This transmission contains information that may be confidential and contain personal views which are not necessarily those of YouView TV Ltd. YouView TV Ltd (Co No:7308805) is a limited liability company registered in England and Wales with its registered address at B6, Ground Floor Broadcast Centre, 201 Wood Lane, London, UK, W12 7TP. For details see our web site at http://www.youview.com. _______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> Andrew Marlow 2012-05-03T13:21:17 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14709 <pre>hello. I am trying to set up dbus activation for a service (running on system bus). The service file looks like this: [D-BUS Service] Name=... Exec=... User=root The Exec= line specifies a shell script, which basically read options from a config file, and then launch a daemon with these options as arguments. I found that if my script's hashbang is #!/bin/sh, dbus won't do activation. When I launch a client, it will attempt to activate the service, but then will show an error: ERROR: Failed to connect to XXXXX: org.freedesktop.DBus.Error.Spawn.ExecFailed: Cannot launch daemon, file not found or permissions invalid ERROR: Failed to connect to daemon (bus: 'system')! However if the hashbang is #!/usr/bin/env sh, activation works. Why does the hashbang make a difference? Thanks. _______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> Dave Lee 2012-04-21T09:55:09 http://permalink.gmane.org/gmane.comp.freedesktop.dbus/14708 <pre>Hi, I have runned an application, on the robot MarXbot, that call these 2 functions in the same time and wait for their replies.  First function: QDBusConnection connection = QDBusConnection::systemBus();  ch::epfl::mobots::AsebaNetwork network(DBUS_SERVICE_ASEBA, DBUS_PATH_ASEBA, connection);  QDBusPendingReply&lt;Values&gt; reply = network.GetVariable("base-sensors","proximity.corrected");  reply.waitForFinished();  if (reply.isError()){      qDebug() &lt;&lt; "error proxy \n";    }  Second function: QDBusConnection connection = QDBusConnection::systemBus(); ch::epfl::mobots::AsebaNetwork network(DBUS_SERVICE_ASEBA, DBUS_PATH_ASEBA, connection); QDBusPendingReply&lt;Values&gt; replyV = network.GetVariable("sensor-turret","sharp.value");  replyV.waitForFinished();    QDBusPendingReply&lt;Values&gt; replyA = network.GetVariable("sensor-turret","sharp.angle"); replyA.waitForFinished(); if (replyV.isError()||replyA.isError()){      qDebug() &lt;&lt; "error sharp \n";   }  but some times I get this message: QDBusConnectionPrivate::connectSignal: received error from D-Bus server while connecting signal to QDBusAbstractInterface::_q_serviceOwnerChanged(QString,QString,QString): org.freedesktop.DBus.Error.NoMemory (Not enough memory) QDBusConnectionPrivate::connectSignal: received error from D-Bus server while connecting signal to QDBusAbstractInterface::_q_serviceOwnerChanged(QString,QString,QString): org.freedesktop.DBus.Error.NoMemory (Not enough memory) error proxy   QDBusConnectionPrivate::connectSignal: received error from D-Bus server while connecting signal to QDBusAbstractInterface::_q_serviceOwnerChanged(QString,QString,QString): org.freedesktop.DBus.Error.NoMemory (Not enough memory) error sharp   QDBusConnectionPrivate::connectSignal: received error from D-Bus server while connecting signal to QDBusAbstractInterface::_q_serviceOwnerChanged(QString,QString,QString): org.freedesktop.DBus.Error.NoMemory (Not enough memory) When I run only one function in a time, I don't get this message and the execution go very well. Is there any way to avoid this problem? Best regards_______________________________________________ dbus mailing list dbus-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW&lt; at &gt;public.gmane.org http://lists.freedesktop.org/mailman/listinfo/dbus </pre> ben ayed wiem 2012-04-18T15:05:14 Search the mailing list at Gmane query http://search.gmane.org/?group=$group=gmane.comp.freedesktop.dbus