On 10/10/2014 07:45 AM, Ruslan Baratov wrote: > file(TRY_LOCK "/path/to/file" result) # try to lock and return TRUE on > success (needed?) > file(LOCK ...) # lock until unlock (unlock by further code (what if > exit/crashed?) or by deamon)
The LOCK signature should have a timeout after which it returns failure instead of blocking forever. One can just use a timeout of 0 to get TRY_LOCK behavior without a separate signature for it. Or, by leaving out the timeout, one can ask to block forever waiting for the lock. > file(LOCK_GUARD ...) # lock for scope of current function or until exit I think the GUARD part can be an option to file(LOCK). We may need more than one to determine the scope, e.g. file(LOCK GUARD_FUNCTION ...) file(LOCK GUARD_PROCESS ...) > file(UNLOCK ...) # explicit unlock of LOCK/LOCK_GUARD Perhaps file(LOCK RELEASE ...) # unlock now file(LOCK UNGUARD ...) # drop guard > Locking directory is equivalent to locking file `cmake.lock` in > directory "/path/to/shared/directory/": I think this can be activated buy a DIRECTORY option. > If any of this commands failed (e.g. have no permissions) - exit with > unsuccessful code (i.e. FATAL_ERROR) ? The commands should all have an optional result argument so callers can find out what happened. If it is not provided, then failure can result in a FATAL_ERROR. With all the above in mind, please brainstorm and propose a more complete signature set. You can use the keyword/value pairing common in other commands to avoid needing a positional argument for every value. Also, please post a summary of how the implementation will work on each platform. Thanks, -Brad -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake-developers
