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authorMatthew Heon <matthew.heon@pm.me>2020-08-19 16:15:35 -0400
committerMatthew Heon <mheon@redhat.com>2020-10-07 10:00:11 -0400
commit2bb2425704cc7181c5eb924400b351b3a2d9a592 (patch)
tree0a850a365ef085fce496354a241649b7e779877a /pkg/parallel/parallel.go
parenta7500e54a4646c7db477349e2530ac13df77b8fa (diff)
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Move pod jobs to parallel execution
Make Podman pod operations that do not involve starting containers (which needs to be done in a specific order) use the same parallel operation code we use to make `podman stop` on large numbers of containers fast. We were previously stopping containers in a pod serially, which could take up to the timeout (default 15 seconds) for each container - stopping 100 containers that do not respond to SIGTERM would take 25 minutes. To do this, refactor the parallel operation code a bit to remove its dependency on libpod (damn circular import restrictions...) and use parallel functions that just re-use the standard container API operations - maximizes code reuse (previously each pod handler had a separate implementation of the container function it performed). This is a bit of a palate cleanser after fighting CI for two days - nice to be able to return to a land of sanity. Signed-off-by: Matthew Heon <matthew.heon@pm.me>
Diffstat (limited to 'pkg/parallel/parallel.go')
-rw-r--r--pkg/parallel/parallel.go30
1 files changed, 30 insertions, 0 deletions
diff --git a/pkg/parallel/parallel.go b/pkg/parallel/parallel.go
index c9e4da50d..4da7e0f89 100644
--- a/pkg/parallel/parallel.go
+++ b/pkg/parallel/parallel.go
@@ -1,6 +1,7 @@
package parallel
import (
+ "context"
"sync"
"github.com/pkg/errors"
@@ -42,3 +43,32 @@ func SetMaxThreads(threads uint) error {
func GetMaxThreads() uint {
return numThreads
}
+
+// Enqueue adds a single function to the parallel jobs queue. This function will
+// be run when an unused thread is available.
+// Returns a receive-only error channel that will return the error (if any) from
+// the provided function fn when fn has finished executing. The channel will be
+// closed after this.
+func Enqueue(ctx context.Context, fn func() error) <-chan error {
+ retChan := make(chan error)
+
+ go func() {
+ jobControlLock.RLock()
+ defer jobControlLock.RUnlock()
+
+ defer close(retChan)
+
+ if err := jobControl.Acquire(ctx, 1); err != nil {
+ retChan <- errors.Wrapf(err, "error acquiring job control semaphore")
+ return
+ }
+
+ err := fn()
+
+ jobControl.Release(1)
+
+ retChan <- err
+ }()
+
+ return retChan
+}