CODEWITHSUNDEEP
install4j
Hardie82
Hardie82

Reputation: 880

Mac: attach commandline parameters to a running application on Mac failed

Today I have a strange problem on MacOs. I hope I can explain the precondition exactly for understanding. We are using the install4j version 6.0.1.

Our application is implemented with an install4j silent update check application as the main "launcher" to check for updates during the startup process of our application. This application is totally configured by the install4j IDE. It checks whether an update exists and for that downloads the new installer and executes it. That's working fine. If the application is up-to-date the "main" application launcher will be executed by the Execute Launcher-action. Therefore the "extraCommandLineArguments" will be passed to the launcher and the application will be started. That's working also fine and the parameters will be passed correctly to our main class.

Now the strange behavior: when I start the application twice with several parameters during the first instance is always running the parameters will not be passed to the first instance neither a second instance will be created. The launcher is configured by install4j to allow multiple instances of the application and the single-instance option is implemented by our application itself. Therefore the main-class checks whether an instance is always running and will pass the parameters to the first instance. Now it seems that the second instance will never be created because I can't attach to the vm-process by IDE at debug mode. Therefore I set the debug vm parameters to the vmoption file. I tried several options to start the second instance:

For all options the running instance will get the focus but do not receive any parameter and I can not attach the second process by the IDE to debug the behavior. It seems our application (main-class) will not be executed a second time. At the Info.plist file there is the MacLauncher class recognized as the main-class. Is tere any logic implemented to search for a running instance and ignore a second one?

The strange thing is: at windows everything works fine. The second process passes the parameter to the running instance. What could be different on mac? How can I check whether install4j is calling our main application class configured at the launcher? Are there any debug-options?

Thanks in advance for any help.

Upvotes: 1

Views: 125

Answers (1)

Ingo Kegel
Ingo Kegel

Reputation: 48015

On Mac OS X, GUI applications are in single instance mode by default. This is a property of the Mac OS X desktop environment. The only way to open a second instance, is to call

open -n my.app

Upvotes: 0

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