VOL-1334 : Fixed concurrency issues
- Semaphores were added at the different layers of the model
- Made the proxy interfaces more robust
- Eliminated problems while retrieving latest data in concurrent mode
Change-Id: I7854105d7effa10e5cb704f5d9917569ab184f84
diff --git a/db/model/proxy_access_control.go b/db/model/proxy_access_control.go
index 7f4fad5..e9a4ffa 100644
--- a/db/model/proxy_access_control.go
+++ b/db/model/proxy_access_control.go
@@ -13,6 +13,7 @@
* See the License for the specific language governing permissions and
* limitations under the License.
*/
+
package model
import (
@@ -22,29 +23,60 @@
"time"
)
-type _singletonProxyAccessControl struct {
- Cache sync.Map
+type singletonProxyAccessControl struct {
+ sync.RWMutex
+ cache map[string]ProxyAccessControl
}
-var _instanceProxyAccessControl *_singletonProxyAccessControl
-var _onceProxyAccessControl sync.Once
+var instanceProxyAccessControl *singletonProxyAccessControl
+var onceProxyAccessControl sync.Once
-func GetProxyAccessControl() *_singletonProxyAccessControl {
- _onceProxyAccessControl.Do(func() {
- _instanceProxyAccessControl = &_singletonProxyAccessControl{}
+// PAC provides access to the proxy access control singleton instance
+func PAC() *singletonProxyAccessControl {
+ onceProxyAccessControl.Do(func() {
+ instanceProxyAccessControl = &singletonProxyAccessControl{cache: make(map[string]ProxyAccessControl)}
})
- return _instanceProxyAccessControl
+ return instanceProxyAccessControl
}
+// ReservePath will apply access control for a specific path within the model
+func (singleton *singletonProxyAccessControl) ReservePath(path string, proxy *Proxy, pathLock string) ProxyAccessControl {
+ singleton.Lock()
+ defer singleton.Unlock()
+ var pac ProxyAccessControl
+ var exists bool
+ if pac, exists = singleton.cache[path]; !exists {
+ pac = NewProxyAccessControl(proxy, pathLock)
+ singleton.cache[path] = pac
+ }
+
+ if exists {
+ log.Debugf("PAC exists for path: %s... re-using", path)
+ } else {
+ log.Debugf("PAC does not exists for path: %s... creating", path)
+ }
+ return pac
+}
+
+// ReleasePath will remove access control for a specific path within the model
+func (singleton *singletonProxyAccessControl) ReleasePath(pathLock string) {
+ singleton.Lock()
+ defer singleton.Unlock()
+ delete(singleton.cache, pathLock)
+}
+
+// ProxyAccessControl is the abstraction interface to the base proxyAccessControl structure
type ProxyAccessControl interface {
Get(path string, depth int, deep bool, txid string, control bool) interface{}
Update(path string, data interface{}, strict bool, txid string, control bool) interface{}
Add(path string, data interface{}, txid string, control bool) interface{}
Remove(path string, txid string, control bool) interface{}
+ SetProxy(proxy *Proxy)
}
+// proxyAccessControl holds details of the path and proxy that requires access control
type proxyAccessControl struct {
- //sync.Mutex
+ sync.RWMutex
Proxy *Proxy
PathLock chan struct{}
Path string
@@ -53,6 +85,7 @@
stop time.Time
}
+// NewProxyAccessControl creates a new instance of an access control structure
func NewProxyAccessControl(proxy *Proxy, path string) ProxyAccessControl {
return &proxyAccessControl{
Proxy: proxy,
@@ -61,58 +94,109 @@
}
}
+// lock will prevent access to a model path
func (pac *proxyAccessControl) lock() {
- log.CleanUp()
- log.Debugf("Before lock ... pac: %+v, stack = %s", pac, string(debug.Stack()))
pac.PathLock <- struct{}{}
- pac.start = time.Now()
- log.Debugf("Got lock ... pac: %+v, stack = %s", pac, string(debug.Stack()))
- //time.Sleep(1 * time.Second)
- log.Debugf("<<<<< %s >>>>>> locked, stack=%s", pac.Path, string(debug.Stack()))
-}
-func (pac *proxyAccessControl) unlock() {
- log.CleanUp()
- log.Debugf("Before unlock ... pac: %+v, stack = %s", pac, string(debug.Stack()))
- <-pac.PathLock
- pac.stop = time.Now()
- GetProfiling().AddToInMemoryLockTime(pac.stop.Sub(pac.start).Seconds())
- log.Debugf("Got unlock ... pac: %+v, stack = %s", pac, string(debug.Stack()))
- log.Debugf("<<<<< %s >>>>>> unlocked, stack=%s", pac.Path, string(debug.Stack()))
+ pac.setStart(time.Now())
}
+// unlock will release control of a model path
+func (pac *proxyAccessControl) unlock() {
+ <-pac.PathLock
+ pac.setStop(time.Now())
+ GetProfiling().AddToInMemoryLockTime(pac.getStop().Sub(pac.getStart()).Seconds())
+}
+
+// getStart is used for profiling purposes and returns the time at which access control was applied
+func (pac *proxyAccessControl) getStart() time.Time {
+ pac.Lock()
+ defer pac.Unlock()
+ return pac.start
+}
+
+// getStart is used for profiling purposes and returns the time at which access control was removed
+func (pac *proxyAccessControl) getStop() time.Time {
+ pac.Lock()
+ defer pac.Unlock()
+ return pac.stop
+}
+
+// getPath returns the access controlled path
+func (pac *proxyAccessControl) getPath() string {
+ pac.Lock()
+ defer pac.Unlock()
+ return pac.Path
+}
+
+// getProxy returns the proxy used to reach a specific location in the data model
+func (pac *proxyAccessControl) getProxy() *Proxy {
+ pac.Lock()
+ defer pac.Unlock()
+ return pac.Proxy
+}
+
+// setStart is for profiling purposes and applies a start time value at which access control was started
+func (pac *proxyAccessControl) setStart(time time.Time) {
+ pac.Lock()
+ defer pac.Unlock()
+ pac.start = time
+}
+
+// setStop is for profiling purposes and applies a stop time value at which access control was stopped
+func (pac *proxyAccessControl) setStop(time time.Time) {
+ pac.Lock()
+ defer pac.Unlock()
+ pac.stop = time
+}
+
+// SetProxy is used to changed the proxy object of an access controlled path
+func (pac *proxyAccessControl) SetProxy(proxy *Proxy) {
+ pac.Lock()
+ defer pac.Unlock()
+ pac.Proxy = proxy
+}
+
+// Get retrieves data linked to a data model path
func (pac *proxyAccessControl) Get(path string, depth int, deep bool, txid string, control bool) interface{} {
if control {
pac.lock()
defer pac.unlock()
log.Debugf("controlling get, stack = %s", string(debug.Stack()))
}
- pac.Proxy.Root.Proxy = pac.Proxy
- return pac.Proxy.Root.Get(path, "", depth, deep, txid)
+
+ // FIXME: Forcing depth to 0 for now due to problems deep copying the data structure
+ // The data traversal through reflection currently corrupts the content
+
+ return pac.getProxy().GetRoot().Get(path, "", 0, deep, txid)
}
+
+// Update changes the content of the data model at the specified location with the provided data
func (pac *proxyAccessControl) Update(path string, data interface{}, strict bool, txid string, control bool) interface{} {
if control {
pac.lock()
defer pac.unlock()
log.Debugf("controlling update, stack = %s", string(debug.Stack()))
}
- pac.Proxy.Root.Proxy = pac.Proxy
- return pac.Proxy.Root.Update(path, data, strict, txid, nil)
+ return pac.getProxy().GetRoot().Update(path, data, strict, txid, nil).GetData()
}
+
+// Add creates a new data model entry at the specified location with the provided data
func (pac *proxyAccessControl) Add(path string, data interface{}, txid string, control bool) interface{} {
if control {
pac.lock()
defer pac.unlock()
log.Debugf("controlling add, stack = %s", string(debug.Stack()))
}
- pac.Proxy.Root.Proxy = pac.Proxy
- return pac.Proxy.Root.Add(path, data, txid, nil)
+ return pac.getProxy().GetRoot().Add(path, data, txid, nil).GetData()
+
}
+
+// Remove discards information linked to the data model path
func (pac *proxyAccessControl) Remove(path string, txid string, control bool) interface{} {
if control {
pac.lock()
defer pac.unlock()
log.Debugf("controlling remove, stack = %s", string(debug.Stack()))
}
- pac.Proxy.Root.Proxy = pac.Proxy
- return pac.Proxy.Root.Remove(path, txid, nil)
+ return pac.getProxy().GetRoot().Remove(path, txid, nil)
}