[Feature] Support for testing upload/download in parallel

Use the `--rpm.parallel` to test in parallel mode. The default testing
mode is serial.

Signed-off-by: Will Hawkins <[email protected]>

1 files changed, 53 insertions, 0 deletions

diff --git a/executor/executor.go b/executor/executor.go
new file mode 100644
index 0000000..22c1235
--- /dev/null
+++ b/executor/executor.go
@@ -0,0 +1,53 @@
+package executor
+
+import (
+	"sync"
+)
+
+type ExecutionMethod int
+
+const (
+	Parallel ExecutionMethod = iota
+	Serial
+)
+
+type ExecutionUnit func()
+
+func (ep ExecutionMethod) ToString() string {
+	switch ep {
+	case Parallel:
+		return "Parallel"
+	case Serial:
+		return "Serial"
+	}
+	return "Unrecognized execution method"
+}
+
+func Execute(executionMethod ExecutionMethod, executionUnits []ExecutionUnit) *sync.WaitGroup {
+	waiter := &sync.WaitGroup{}
+
+	// Make sure that we Add to the wait group all the execution units
+	// before starting to run any -- there is a potential race condition
+	// otherwise.
+	(*waiter).Add(len(executionUnits))
+
+	for _, executionUnit := range executionUnits {
+		// Stupid capture in Go! Argh.
+		executionUnit := executionUnit
+
+		invoker := func() {
+			executionUnit()
+			(*waiter).Done()
+		}
+		switch executionMethod {
+		case Parallel:
+			go invoker()
+		case Serial:
+			invoker()
+		default:
+			panic("Invalid execution method value given.")
+		}
+	}
+
+	return waiter
+}