yo yo there,
wanna know, how many possible "method" to communicate between primary thread to child threads, child thread to child thread and child thread to primary thread.

P thread to C thread
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C thread to C thread
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C thread to P thread
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SendMessage
PostMessage

ps: would update based on reply

PostThreadMessage and any of the unnamed synchronization objects

Concurrent circular queue
http://board.flatassembler.net/topic.php?t=5887

or maybe pipes could help?

http://msdn2.microsoft.com/en-us/library/aa365152.aspx

Or just writing to memory areas, using LOCK prefix and things like cmpxchg, xadd, ... http://www.codeproject.com/useritems/FastReadWriteLock.asp . Depends on what you need to do.

PS: threads are threads, there aren't any such things as "parent" and "child" threads - that is process terminology.