core: re-organize RealChannel with updateConfigSelector()
As mentioned in https://github.com/grpc/grpc-java/pull/7413#issuecomment-690756200 `RealChannel` did not manage `configSelector`, and therefore `configSelector.get()`, `configSelector.set()` and `drainPendingCalls()` were scattered everywhere in `ManagedChannelImpl`. This PR re-organizes `RealChannel` to manage `configSelector`.
diff --git a/core/src/main/java/io/grpc/internal/ManagedChannelImpl.java b/core/src/main/java/io/grpc/internal/ManagedChannelImpl.java
index 10aa197..494899b 100644
--- a/core/src/main/java/io/grpc/internal/ManagedChannelImpl.java
+++ b/core/src/main/java/io/grpc/internal/ManagedChannelImpl.java
@@ -263,10 +263,6 @@
// Must be mutated and read from constructor or syncContext
// used for channel tracing when value changed
private ManagedChannelServiceConfig lastServiceConfig = EMPTY_SERVICE_CONFIG;
- // Reference to null if no config selector is available from resolution result
- // Reference must be set() from syncContext
- private final AtomicReference<InternalConfigSelector> configSelector =
- new AtomicReference<>(INITIAL_PENDING_SELECTOR);
@Nullable
private final ManagedChannelServiceConfig defaultServiceConfig;
@@ -750,7 +746,7 @@
@VisibleForTesting
InternalConfigSelector getConfigSelector() {
- return configSelector.get();
+ return realChannel.configSelector.get();
}
/**
@@ -891,6 +887,10 @@
}
private class RealChannel extends Channel {
+ // Reference to null if no config selector is available from resolution result
+ // Reference must be set() from syncContext
+ private final AtomicReference<InternalConfigSelector> configSelector =
+ new AtomicReference<>(INITIAL_PENDING_SELECTOR);
// Set when the NameResolver is initially created. When we create a new NameResolver for the
// same target, the new instance must have the same value.
private final String authority;
@@ -954,12 +954,20 @@
}
// Must run in SynchronizationContext.
- private void drainPendingCalls() {
- if (pendingCalls == null) {
- return;
+ void updateConfigSelector(@Nullable InternalConfigSelector config) {
+ InternalConfigSelector prevConfig = configSelector.get();
+ configSelector.set(config);
+ if (prevConfig == INITIAL_PENDING_SELECTOR && pendingCalls != null) {
+ for (RealChannel.PendingCall<?, ?> pendingCall : pendingCalls) {
+ pendingCall.reprocess();
+ }
}
- for (RealChannel.PendingCall<?, ?> pendingCall : pendingCalls) {
- pendingCall.reprocess();
+ }
+
+ // Must run in SynchronizationContext.
+ void onConfigError() {
+ if (configSelector.get() == INITIAL_PENDING_SELECTOR) {
+ updateConfigSelector(null);
}
}
@@ -1568,7 +1576,6 @@
Status serviceConfigError = configOrError != null ? configOrError.getError() : null;
ManagedChannelServiceConfig effectiveServiceConfig;
- InternalConfigSelector prevConfigSelector = configSelector.get();
if (!lookUpServiceConfig) {
if (validServiceConfig != null) {
channelLogger.log(
@@ -1582,14 +1589,14 @@
ChannelLogLevel.INFO,
"Config selector from name resolver discarded by channel settings");
}
- configSelector.set(effectiveServiceConfig.getDefaultConfigSelector());
+ realChannel.updateConfigSelector(effectiveServiceConfig.getDefaultConfigSelector());
} else {
// Try to use config if returned from name resolver
// Otherwise, try to use the default config if available
if (validServiceConfig != null) {
effectiveServiceConfig = validServiceConfig;
if (resolvedConfigSelector != null) {
- configSelector.set(resolvedConfigSelector);
+ realChannel.updateConfigSelector(resolvedConfigSelector);
if (effectiveServiceConfig.getDefaultConfigSelector() != null) {
channelLogger.log(
ChannelLogLevel.DEBUG,
@@ -1597,11 +1604,11 @@
+ "config-selector");
}
} else {
- configSelector.set(effectiveServiceConfig.getDefaultConfigSelector());
+ realChannel.updateConfigSelector(effectiveServiceConfig.getDefaultConfigSelector());
}
} else if (defaultServiceConfig != null) {
effectiveServiceConfig = defaultServiceConfig;
- configSelector.set(effectiveServiceConfig.getDefaultConfigSelector());
+ realChannel.updateConfigSelector(effectiveServiceConfig.getDefaultConfigSelector());
channelLogger.log(
ChannelLogLevel.INFO,
"Received no service config, using default service config");
@@ -1618,7 +1625,7 @@
}
} else {
effectiveServiceConfig = EMPTY_SERVICE_CONFIG;
- configSelector.set(null);
+ realChannel.updateConfigSelector(null);
}
if (!effectiveServiceConfig.equals(lastServiceConfig)) {
channelLogger.log(
@@ -1640,9 +1647,6 @@
re);
}
}
- if (prevConfigSelector == INITIAL_PENDING_SELECTOR) {
- realChannel.drainPendingCalls();
- }
Attributes effectiveAttrs = resolutionResult.getAttributes();
// Call LB only if it's not shutdown. If LB is shutdown, lbHelper won't match.
@@ -1690,10 +1694,7 @@
private void handleErrorInSyncContext(Status error) {
logger.log(Level.WARNING, "[{0}] Failed to resolve name. status={1}",
new Object[] {getLogId(), error});
- if (configSelector.get() == INITIAL_PENDING_SELECTOR) {
- configSelector.set(null);
- realChannel.drainPendingCalls();
- }
+ realChannel.onConfigError();
if (lastResolutionState != ResolutionState.ERROR) {
channelLogger.log(ChannelLogLevel.WARNING, "Failed to resolve name: {0}", error);
lastResolutionState = ResolutionState.ERROR;
