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Ship it! I'll add a comment as to why we use atomic before committing. - Joris Van Remoortere On Nov. 20, 2015, 7:16 p.m., Joseph Wu wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/39949/ > ----------------------------------------------------------- > > (Updated Nov. 20, 2015, 7:16 p.m.) > > > Review request for mesos, Benjamin Hindman, Joris Van Remoortere, and Neil > Conway. > > > Bugs: MESOS-3864 > https://issues.apache.org/jira/browse/MESOS-3864 > > > Repository: mesos > > > Description > ------- > > * Renamed `initialized` to `initialize_started`. > * Renamed `initializing` to `initialize_complete`. > * Removed the (2) condition, described below: > > The initialization synchronization logic contains three conditions, which > check: > 1) Was `initialize` called and is it done? > 2) Was `initialize` called and is it not done? > 3) Are you the first to call `initialize`? > > Condition (3) uses `compare_exchange_strong` between `initialized` and > `false`. This returns `true` (and sets `initialized` to true) iff the caller > is the first to reach that expression. > > The second simultaneous caller of `initialize` will either satisify condition > (2) or (3) and then wait on `initializing`. For the second caller, (2) and > (3) are identical because `compare_exchange_strong` between `true` and > `false` will always return false, thereby putting the second caller into the > waiting loop. > > > Diffs > ----- > > 3rdparty/libprocess/src/process.cpp > 8fa0594b671969c2713d1b361f2dbbb07d25b3a8 > > Diff: https://reviews.apache.org/r/39949/diff/ > > > Testing > ------- > > `make check` > > Replaced `process::initialize();` in `3rdparty/libprocess/src/tests/main.cpp` > with: > ``` > > const size_t numThreads = 50; > > std::thread* runningThreads[numThreads]; > > // Create additional threads. > for (size_t i = 0; i < numThreads; i++) { > runningThreads[i] = new std::thread([]() { > process::initialize(); > }); > } > > for (size_t i = 0; i < numThreads; i++) { > runningThreads[i]->join(); > delete runningThreads[i]; > } > ``` > (Also added `#include <thread>` to the header). > > Rebuilt `libprocess-tests` with the modification and ran it a few times. > `3rdparty/libprocess/libprocess-tests` > > > Thanks, > > Joseph Wu > >
