L4 IPC doubt

Tiago Jorge tjpj at lasige.di.fc.ul.pt
Mon May 2 15:40:41 CEST 2005


Espen Skoglund wrote:

>[Tiago Jorge]
>  
>
>>>The problem is here... my server blocks in the ipc_send when
>>>calling flips, but when i remove the call from the client it works
>>>fine, meaning that the client is not blocked waiting for ipc to
>>>return. My questions are... why can't i do IPC while another one
>>>that has nothing to do with my server is blocked? there can be only
>>>one ipc call in the whole system at a time? they all must be
>>>sequential?
>>>      
>>>
>
>[Ronald Aigner]
>  
>
>>I will try to describe the scenario as I understood it:
>>There exist:
>>- The Flips Server (F)
>>- The Server (S) with one server thread
>>- One or more Clients (C1, C2, ...).
>>    
>>
>
>  
>
>>Now C1 calls S, which receives the message, decodes it, calls your
>>server function, makes a call to F and blocks, waiting for the reply
>>from F. The C2 tries to call the same server S.
>>    
>>
>
>  
>
>>If this is correct, then yes, C2 and all following clients will
>>block, because the server-thread is blocked waiting for F.
>>    
>>
>
>I believe the problem was that S blocks (in the send part) when
>calling F, but only when a client is waiting for a reply from S.
>
>	eSk
>  
>
thats true :)

Tiago




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