August 2009 - launchd-dev - lists.macosforge.org

Mac OS-X 10.5 and "two icons bouncing in the dock" problem
by Hans-Peter Jansen 17 Aug '09

17 Aug '09

[Probably, this is the wrong list, but launchd is definitely involved; Any pointer to more appropriate lists are welcome] Hi, attached PyQt script demonstrates an ugly issue, I'm fighting with since a couple of days :-(. Issue: when starting the app via double click or single click on dock icon or dropping a plain/text file on dock or application icon, all actions lead to two bouncing icons. The one with the blue spot is the good one, that stops bouncing after start-up. The bad one will stop bouncing eventually, and shows "Application not responding" in its context menu then. As long as the bad one exists, dropping files on the good one will be ignored. After killing (and sometimes removing from the dock is necessary) all is well - one can drop files one the good one and on the app icon, all behaves well, up to the point of being terminated, then this ugly game starts again. The issue is not depending on the arch, but on OS-X 10.5. It does not happen with 10.4. It may be related to pyinstaller, but since I need to deploy the app on arbitrary 10.4 and later systems, omitting it is not an option. Termination of this process is accompanied with these syslog messages: Aug 13 19:01:26 g5 com.apple.launchd[124] ([0x0-0x130130]..local.LaunchProb[9611]): Stray process with PGID equal to this dead job: PID 9612 PPID 1 LaunchProb Aug 13 19:01:26 g5 com.apple.launchd[124] ([0x0-0x130130]..local.LaunchProb[9611]): Exited: Terminated BTW: pyinstaller does a fork in start up, see pyinstaller/source/linux/main.c around line 120; #ifdef __APPLE__ /* add workpath to DYLD_LIBRARY_PATH */ exportWorkpath(workpath, "DYLD_LIBRARY_PATH"); #endif pid = fork(); if (pid == 0) execvp(thisfile, argv); wait(&rc); rc = WEXITSTATUS(rc); VS("Back to parent...\n"); if (strcmp(workpath, homepath) != 0) clear(workpath); It seems to be the culprit, what what could be done to get this working nicely with 10.5, too? Should I set the same pgid on both processes? Any pointer to examples? Pre conditions: OS-X 10.5(.7/.8) with ppc or x86 arch Xcode 3.1.3 Python-2.6.2 Qt-4.5.2 sip-4.8.2 PyQt-4.5.4 Build it this way: tar xvzf launchprob.tar.gz && cd launchprob && ./build.sh -debug This command will fetch pyinstaller's SVN trunk, build pyinstaller, generate the app itself: LaunchProb.app. It can be moved to any system, as long as all required packages are cleanly built for both archs(*) and the minimum OS-X release is 10.4. Any ideas how to solve this issue are greatly appreciated. Thanks, Pete (*) I can provide more details for this on request

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is it possible to have behaviors based on OS versions?
by Iceberg-Dev 16 Aug '09

16 Aug '09

Is there any feature in launchd plist to have different behaviors depending on OS versions? For instance, on Mac OS X 10.5 and later, I would like the daemon to be launched by a mach port message and on Mac OS X 10.4, I would like it to be started at boot time (since mach_port are not supported).

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SampleD failure with dynamic SockServiceName
by David Anderson 13 Aug '09

13 Aug '09

My intention is have launchd start a daemon on a dynamic port, publish the port number via bonjour, and then connect to this port after determining the port number using CFNetService (Bonjour). Starting from SampleD (and using the included client.pl), I can advertise the service on a hard-coded port via bonjour, lookup the port number using Bonjour Browser, modify client.pl to use this port, and connect using client.pl. The SampleD binary starts correctly in an OnDemand fashion correctly. If I change <key>SockServiceName</key> <string>12345</string> to <key>SockServiceName</key> <string>0</string> then lookup the dynamic port number using Bonjour Browser and configure client.pl to use this port, client.pl will NOT connect to this port and outputs this error: connect: Connection refused at ./client.pl line 77. With a dynamic port, I am unable to connect to this port using a modified client.pl. I can find no evidence that the SampleD binary is starting in an OnDemand fashion. Adding <key>OnDemand</key> <false/> has no effect. Is there anything different about the default configuration of a dynamic port vs a hard-coded port that would impeded the ability to connect to the dynamically assigned port? Thanks, Dave

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Possible to work around 10.4 LaunchAgent bugs?
by Sidney San Martín 12 Aug '09

12 Aug '09

My current project needs an agent to run whenever a user is logged in. A LaunchAgent would be perfect for this, and in 10.5, it is. If I can't use a LaunchAgent on 10.4, the alternative isn't so appealing: * I'd need to use barely-supported procedures to install a global login item. * There would be separate install, update, and uninstall code paths for 10.4, 10.5+, and a 10.4 to 10.5+ migration * The daemon would need to be able to detect a migration from 10.4 to 10.5+ and convert the global login item to a LaunchAgent on first boot That's a little more complexity (and potential for a failure) than I want. Has anyone found workarounds for the issues in 10.4? Can I program my agent to handle the error conditions that lead to a failed launch (detect non-gui sessions, for instance) and exit gracefully before launchd rips it out?

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launchd check-in: Where's the documentation?
by Sidney San Martín 11 Aug '09

11 Aug '09

I can't find any documentation on the launchd checkin process. Using SampleD, launch.h, and other people's documentation of their discoveries it's possible to put together a working daemon, but with no guarantee that you're doing everything right. (Even though launchd is open source, its APIs need documentation.) launchd.plist(5) is the first place I even saw the check-in process mentioned: "The job must check-in to get a copy of the file descriptors using APIs outlined in launch(3)". launch(3) doesn't exist (<rdar://problem/7130390>). It seems like the following, at least, should be documented: 1) What check-in is and when it is necessary 2) The consequences of a job not checking in when launchd expects it 3) What keys in the response dictionary are filled in at runtime 4) How to memory manage launch data returned by check-in functions (i.e. what needs to be released) 5) Error conditions and how to handle them What do you think? Has this come up before? Is there some secret store of documentation I'm missing? Is this API so intuitive that documentation is redundant?

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launchd & mDNSResponder: "Policy denied Mach service lookup"
by Björn Giesler 10 Aug '09

10 Aug '09

Hi, I've recently migrated to a new MacBook Pro, and since that migration, found that Bonjour no longer worked, and indeed that all applications that used Bonjour just hang. I've traced this to what looks like a problem in the interaction of mDNSResponder and launchd; the log messages I get are lots of com.apple.launchd[1] (com.apple.mDNSResponder[2551]): Policy denied Mach service lookup: com.apple.distributed_notifications.2 etc.etc. with different services. I don't yet quite understand how launchd and launched processes interact. Why is launchd responsible for service lookups for other applications? Where are policies stored? etc. The manpage says nothing about this. I've tried looking for the above message in the launchd code and found it in launchd_core_logic.c in the SULeopard branch, which introduces the mspolicy_* functions, but I'm afraid I can't make much sense of it. I'll try to compile my own launchd and step through it, but it would be nice if somebody could push me in the right direction. (Is there even some documentation on this?) As a Unix rc guy, launchd is a twisty maze of passages, all alike... Thanks in advance & Regards, Björn

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TimeOut key — how long should a job really stay alive?
by Sidney San Martín 07 Aug '09

07 Aug '09

I'm building a daemon that uses a launchd-provided socket, it seems like a good idea to exit when nothing's connected. I've read that jobs must stay alive for 60 seconds, but launchd is giving me a 30 second timeout at checkin. What's right? How are daemon timeouts supposed to work?

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