Add GNU make jobserver master support #2260
Open
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
- add new TokenPool interface - GNU make implementation for TokenPool parses and verifies the magic information from the MAKEFLAGS environment variable - RealCommandRunner tries to acquire TokenPool * if no token pool is available then there is no change in behaviour - When a token pool is available then RealCommandRunner behaviour changes as follows * CanRunMore() only returns true if TokenPool::Acquire() returns true * StartCommand() calls TokenPool::Reserve() * WaitForCommand() calls TokenPool::Release() Documentation for GNU make jobserver http://make.mad-scientist.net/papers/jobserver-implementation/ Fixes ninja-build#1139
Improve on the original jobserver client implementation. This makes ninja a more aggressive GNU make jobserver client. - add monitor interface to TokenPool - TokenPool is passed down when main loop indicates that more work is ready and would be allowed to start if a token becomes available - posix: update DoWork() to monitor TokenPool read file descriptor - WaitForCommand() exits when DoWork() sets token flag - Main loop starts over when WaitForCommand() sets token exit status
This emulates the behaviour of GNU make. - add parallelism_from_cmdline flag to build configuration - set the flag when -jN is given on command line - pass the flag to TokenPool::Get() - GNUmakeTokenPool::Setup() * prints a warning when the flag is true and jobserver was detected * returns false, i.e. jobserver will be ignored - ignore config.parallelism in CanRunMore() when we have a valid TokenPool, because it gets always initialized to a default when not given on the command line
This emulates the behaviour of GNU make. - build: make a copy of max_load_average and pass it to TokenPool. - GNUmakeTokenPool: if we detect a jobserver and a valid -lN argument in MAKEFLAGS then set max_load_average to N.
- replace printf() with calls to LinePrinter - print GNU make jobserver message only when verbose build is requested
- fix Windows build error in no-op TokenPool implementation - improve Acquire() to block for a maximum of 100ms - address review comments
- TokenPool setup - GetMonitorFd() API - implicit token and tokens in jobserver pipe - Acquire() / Reserve() / Release() protocol - Clear() API
- add TokenPoolTest stub to provide TokenPool::GetMonitorFd() - add two tests * both tests set up a dummy GNUmake jobserver pipe * both tests call DoWork() with TokenPoolTest * test 1: verify that DoWork() detects when a token is available * test 2: verify that DoWork() works as before without a token - the tests are not compiled in under Windows
Add tests that verify the token functionality of the builder main loop. We replace the default fake command runner with a special version where the tests can control each call to AcquireToken(), CanRunMore() and WaitForCommand().
GNU make uses a semaphore as jobserver protocol on Win32. See also https://www.gnu.org/software/make/manual/html_node/Windows-Jobserver.html Usage is pretty simple and straightforward, i.e. WaitForSingleObject() to obtain a token and ReleaseSemaphore() to return it. Unfortunately subprocess-win32.cc uses an I/O completion port (IOCP). IOCPs aren't waitable objects, i.e. we can't use WaitForMultipleObjects() to wait on the IOCP and the token semaphore at the same time. Therefore GNUmakeTokenPoolWin32 creates a child thread that waits on the token semaphore and posts a dummy I/O completion status on the IOCP when it was able to obtain a token. That unblocks SubprocessSet::DoWork() and it can then check if a token became available or not. - split existing GNUmakeTokenPool into common and platform bits - add GNUmakeTokenPool interface - move the Posix bits to GNUmakeTokenPoolPosix - add the Win32 bits as GNUmakeTokenPoolWin32 - move Setup() method up to TokenPool interface - update Subprocess & TokenPool tests accordingly
- remove unnecessary "struct" from TokenPool - add PAPCFUNC cast to QueryUserAPC() - remove hard-coded MAKEFLAGS string from win32 - remove useless build test CompleteNoWork - rename TokenPoolTest to TestTokenPool - add tokenpool modules to CMake build - remove unused no-op TokenPool implementation - fix errors flagged by codespell & clang-tidy - POSIX GNUmakeTokenPool should return same token - address review comments from ninja-build#1140 (comment) ninja-build#1140 (review) ninja-build#1140 (review) ninja-build#1140 (comment) ninja-build#1140 (comment)
Make space to add new API to set up token pool master.
This method will set up to the token pool master.
When this option is given on the command line then ninja will set up a token pool master instead of being a token pool client.
- don't set up token pool for serial builds - add implementation specific CreatePool() & SetEnv() methods - generate contents for MAKEFLAGS variable to pass down to children
Set up a pipe (POSIX) or semaphore (win32) with N tokens.
|
Is there any possibility of having the selection between jobserver and client being done automatically, instead of requiring a command line option? In most cases, I'll want ninja to provide a jobserver by default (for integration with e.g. gcc lto or rustc), and the extra option is easy to forget. It's also extra work to pass the option when ninja is being used as a backend for e.g. cmake or meson. The behaviour I'm hoping for is:
|
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Part 2 in the implementation series for PR #1139: with these changes ninja can take the same role as GNU make at the root of a load balanced build.
-m/--tokenpool-master-j Njobs in parallelMAKEFLAGSenvironment variable to its child processes, which communicates the jobserver parameters to them.Documentation for GNU make jobserver
http://make.mad-scientist.net/papers/jobserver-implementation/
https://www.gnu.org/software/make/manual/html_node/Job-Slots.html#Job-Slots
Fixes #1139