October 2012 - Darwin-dev - lists.apple.com

Re: signaling a non-realtime thread from a realtime one
by Joel Reymont 26 Oct '12

26 Oct '12

I was talking about #include <semaphore.h> int sem_trywait(sem_t *sem); int sem_wait(sem_t *sem); Thanks, Joel On Fri, Oct 26, 2012 at 1:25 AM, Shantonu Sen <ssen(a)apple.com> wrote: > What POSIX semaphore? Are you talking about PThread condition variables? > > You can use the Mach semaphore functions in <mach/semaphore.h>, or better yet dispatch semaphores. > > Shantonu > > On Oct 25, 2012, at 3:19 PM, Joel Reymont <joelr1(a)gmail.com> wrote: > >> What is the best way to signal a non-realtime thread from a realtime one? >> >> I'm loath to use a POSIX semaphore but maybe I should not be. >> >> Thanks in advance, Joel >> >> -------------------------------------------------------------------------- >> for hire: mac osx device driver ninja. kernel, usb and coreaudio drivers >> ---------------------+------------+--------------------------------------- >> http://wagerlabs.com | @wagerlabs | http://www.linkedin.com/in/joelreymont >> ---------------------+------------+--------------------------------------- >> _______________________________________________ >> Do not post admin requests to the list. They will be ignored. >> Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) >> Help/Unsubscribe/Update your Subscription: >> https://lists.apple.com/mailman/options/darwin-dev/ssen%40apple.com >> >> This email sent to ssen(a)apple.com > -- -------------------------------------------------------------------------- for hire: mac osx device driver ninja. kernel, usb and coreaudio drivers ---------------------+------------+--------------------------------------- http://wagerlabs.com | @wagerlabs | http://www.linkedin.com/in/joelreymont ---------------------+------------+--------------------------------------- _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Re: signaling a non-realtime thread from a realtime one
by Shantonu Sen 25 Oct '12

25 Oct '12

What POSIX semaphore? Are you talking about PThread condition variables? You can use the Mach semaphore functions in <mach/semaphore.h>, or better yet dispatch semaphores. Shantonu On Oct 25, 2012, at 3:19 PM, Joel Reymont <joelr1(a)gmail.com> wrote: > What is the best way to signal a non-realtime thread from a realtime one? > > I'm loath to use a POSIX semaphore but maybe I should not be. > > Thanks in advance, Joel > > -------------------------------------------------------------------------- > for hire: mac osx device driver ninja. kernel, usb and coreaudio drivers > ---------------------+------------+--------------------------------------- > http://wagerlabs.com | @wagerlabs | http://www.linkedin.com/in/joelreymont > ---------------------+------------+--------------------------------------- > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/darwin-dev/ssen%40apple.com > > This email sent to ssen(a)apple.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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signaling a non-realtime thread from a realtime one
by Joel Reymont 25 Oct '12

25 Oct '12

What is the best way to signal a non-realtime thread from a realtime one? I'm loath to use a POSIX semaphore but maybe I should not be. Thanks in advance, Joel -------------------------------------------------------------------------- for hire: mac osx device driver ninja. kernel, usb and coreaudio drivers ---------------------+------------+--------------------------------------- http://wagerlabs.com | @wagerlabs | http://www.linkedin.com/in/joelreymont ---------------------+------------+--------------------------------------- _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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How does the "restart on freeze" functionality work?
by Jonathan Rice 09 Oct '12

09 Oct '12

Since Lion (I believe), Apple have folded the "Restart automatically if the computer freezes" functionality into the "Energy Saver" settings of the main OS. Before that, IIRC, it used to be available only in the Server version of the OS, where it was controlled by a daemon called "watchdogtimerd". My understanding of watchdogtimerd is that it would periodically reset a hardware countdown timer in the power supply hardware. If the timer got down to 0, the machine would restart. So a frozen system would get rebooted within a certain time period. Fast-forward to Lion, and we have the "Energy Saver" settings, or "systemsetup -setrestartfreeze", enabling or disabling very similar functionality. But what are the nuts and bolts of how this works? Presumably it still has the same underpinnings of a h/w countdown timer that will restart the machine if it isn't continually reset. But what is doing that - some other "launchd" daemon, or some new code in the kernel? And how does "Energy Saver" or "systemsetup" activate or deactivate that functionality? Any insight on this is appreciated. Thanks! -- Jonathan _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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How does the "restart on freeze" functionality work?
by Jonathan Rice 09 Oct '12

09 Oct '12

Since Lion (I believe), Apple have folded the "Restart automatically if the computer freezes" functionality into the "Energy Saver" settings of the main OS. Before that, IIRC, it used to be available only in the Server version of the OS, where it was controlled by a daemon called "watchdogtimerd". My understanding of watchdogtimerd is that it would periodically reset a hardware countdown timer in the power supply hardware. If the timer got down to 0, the machine would restart. So a frozen system would get rebooted within a certain time period. Fast-forward to Lion, and we have the "Energy Saver" settings, or "systemsetup -setrestartfreeze", enabling or disabling very similar functionality. But what are the nuts and bolts of how this works? Presumably it still has the same underpinnings of a h/w countdown timer that will restart the machine if it isn't continually reset. But what is doing that - some other "launchd" daemon, or some new code in the kernel? And how does "Energy Saver" or "systemsetup" activate or deactivate that functionality? Any insight on this is appreciated. Thanks! -- Jonathan _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Open Source Releases
by William Siegrist 01 Oct '12

01 Oct '12

We have released the open source components for the following on opensource.apple.com: OS X 10.7.5 OS X 10.8.2 Xcode 4.5 iOS 6.0 http://opensource.apple.com/ -- William Siegrist _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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