Re^5: need a thread to wait until a buffer is full.

Why don't you design to avoid the locking altogether? Just have 2 buffers, one in each thread. Have the first thread signal the second to start filling it's buffer, and when it's done, set a shared variable to "filled". Have your first thread watch the shared variable, and when it says "filled", copy the buffer and reset.

I'm sure there probably is a way to avoid the copying, by sharing the buffer too, but unless there are performance issues with the extra in-memory copy, it's safer and easier to keep things separate.

I'm not really a human, but I play one on earth. Cogito ergo sum a bum

Comment on Re^5: need a thread to wait until a buffer is full.

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Re^6: need a thread to wait until a buffer is full. by BrowserUk (Patriarch) on Jul 25, 2007 at 12:45 UTC
Why "watch" when you can 'signal'? Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. "Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."	[reply]
Re^7: need a thread to wait until a buffer is full. by zentara (Cardinal) on Jul 25, 2007 at 16:34 UTC
I thought signals and threads were an iffy combination? Meaning that the main thread tends to intercept all signals? So what if you wanted 2 or 3 buffers? A shared variable can be buffer specific, whereas a signal may be non-specific. (I may have mistakenly used the word "signal" in my node above, in a generic manner, where I really meant "set a shared variable which would signal......." I'm not really a human, but I play one on earth. Cogito ergo sum a bum	[reply]
Re^8: need a thread to wait until a buffer is full. by BrowserUk (Patriarch) on Jul 25, 2007 at 17:46 UTC
They aren't signals in that sense of the word. In the sense of `cond_signal()`. Basically, the thread in waiting on `cond_wait()` will not be allocated any timeslices by the scheduler until the other thread calls `cond_signal()` (or broadcast). So, no polling a second shared var to see if the first is ready yet. Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. "Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."	[reply] [d/l] [select]
Re^9: need a thread to wait until a buffer is full. by zentara (Cardinal) on Jul 26, 2007 at 12:57 UTC
Re^10: need a thread to wait until a buffer is full. by BrowserUk (Patriarch) on Jul 26, 2007 at 13:30 UTC