From 89a1e7db39ed1015762d733379a4a5d443b1f4de Mon Sep 17 00:00:00 2001 From: Matthew Heon Date: Thu, 4 Jun 2020 14:28:01 -0400 Subject: Add parallel execution code for container operations This code will run container operations in parallel, up to a given maximum number of threads. Currently, it has only been enabled for local `podman rm` as a proof of concept. Signed-off-by: Matthew Heon --- pkg/parallel/parallel.go | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 pkg/parallel/parallel.go (limited to 'pkg/parallel/parallel.go') diff --git a/pkg/parallel/parallel.go b/pkg/parallel/parallel.go new file mode 100644 index 000000000..c9e4da50d --- /dev/null +++ b/pkg/parallel/parallel.go @@ -0,0 +1,44 @@ +package parallel + +import ( + "sync" + + "github.com/pkg/errors" + "github.com/sirupsen/logrus" + "golang.org/x/sync/semaphore" +) + +var ( + // Maximum number of jobs that will be used. + // Set a low, but non-zero, default. We'll be overriding it by default + // anyways. + numThreads uint = 8 + // Semaphore to control thread creation and ensure numThreads is + // respected. + jobControl *semaphore.Weighted + // Lock to control changing the semaphore - we don't want to do it + // while anyone is using it. + jobControlLock sync.RWMutex +) + +// SetMaxThreads sets the number of threads that will be used for parallel jobs. +func SetMaxThreads(threads uint) error { + if threads == 0 { + return errors.New("must give a non-zero number of threads to execute with") + } + + jobControlLock.Lock() + defer jobControlLock.Unlock() + + numThreads = threads + jobControl = semaphore.NewWeighted(int64(threads)) + logrus.Infof("Setting parallel job count to %d", threads) + + return nil +} + +// GetMaxThreads returns the current number of threads that will be used for +// parallel jobs. +func GetMaxThreads() uint { + return numThreads +} -- cgit v1.2.3-54-g00ecf