Re^13: Threads sharing global variable

Depending on which thread wins the first lock, the first cond_signal() may be redundant.

That is: If set_positive() won, it proceeds without waiting, and sends the unnecessary signal. This signal is dropped. But the set_zero() thread can then also proceed without cond_wait(), and subsequently sets the ping-pong going with its own cond_signal().

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Re^14: Threads sharing global variable by BrowserUk (Patriarch) on Mar 06, 2016 at 15:34 UTC
It hangs on Windows; and will eventually hang everywhere if you add any useful code to the while loops. As a coding pattern, ikegami's code is broken by design. End of. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' 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". I knew I was on the right track :) In the absence of evidence, opinion is indistinguishable from prejudice.	[reply]
Re^15: Threads sharing global variable by Anonymous Monk on Mar 06, 2016 at 15:45 UTC
It hangs on Windows; and will eventually hang everywhere if you add any useful code to the while loops. I asked why it deadlocks. You are saying "it hangs. End of." Well, there you go. This is the difference between users and experts. The difference between playing and knowing.	[reply]
Re^16: Threads sharing global variable by BrowserUk (Patriarch) on Mar 06, 2016 at 16:04 UTC
Well, there you go. This is the difference between users and experts. The difference between playing and knowing. How would I know? I don't use linux; and I rarely ever rely upon the broken semantics of condition variables. Why would I when there are so many better mechanisms on my platform. As for expertise; if you are so expert, why do you need me to tell you about the limitations of your platform; much less expect me to help you debug them. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' 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". I knew I was on the right track :) In the absence of evidence, opinion is indistinguishable from prejudice.	[reply]