vm: overhaul

VM infrastructure currently has several problems:
 - Config struct is complete mess with a superset of params for all VM types
 - verification of Config is mess spread across several places
 - there is no place where VM code could do global initialization
   like creating GCE connection, uploading GCE image to GCS,
   matching adb devices with consoles, etc
 - it hard to add private VM implementations
   such impl would need to add code to config package
   which would lead to constant merge conflicts
 - interface for VM implementation is mixed with interface for VM users
   this does not allow to provide best interface for both of them
 - there is no way to add common code for all VM implementations

This change solves these problems by:
 - splitting VM interface for users (vm package) and VM interface
   for VM implementations (vmimpl pacakge), this in turn allows
   to add common code
 - adding Pool concept that allows to do global initialization
   and config checking at the right time
 - decoupling manager config from VM-specific config
   each VM type now defines own config

Note: manager configs need to be changed after this change:
VM-specific parts are moved to own "vm" subobject.

Note: this change also drops "local" VM type.
Its story was long unclear and there is now syz-stress which solves the same problem.

1 files changed, 19 insertions, 0 deletions

diff --git a/vm/vmimpl/util.go b/vm/vmimpl/util.go
new file mode 100644
index 000000000..f80de8ab1
--- /dev/null
+++ b/vm/vmimpl/util.go
@@ -0,0 +1,19 @@
+// Copyright 2017 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package vmimpl
+
+import (
+	"time"
+)
+
+// Sleep for d.
+// If shutdown is in progress, return false prematurely.
+func SleepInterruptible(d time.Duration) bool {
+	select {
+	case <-time.After(d):
+		return true
+	case <-Shutdown:
+		return false
+	}
+}