[EventEngine] Use new thread pool for all builds (#34155)

This turns on the `work_stealing` experiment everywhere, enabling the
work-stealing thread pool in Posix & Windows EventEngine
implementations. This only really has an effect when EventEngine is used
for I/O (currently flag-guarded).

src/core/lib/experiments/experiments.cc

@@ -101,11 +101,6 @@ const char* const description_keepalive_server_fix =
     "Allows overriding keepalive_permit_without_calls for servers. Refer "
     "https://github.com/grpc/grpc/pull/33917 for more information.";
 const char* const additional_constraints_keepalive_server_fix = "{}";
-#ifdef NDEBUG
-const bool kDefaultForDebugOnly = false;
-#else
-const bool kDefaultForDebugOnly = true;
-#endif
 }  // namespace
 
 namespace grpc_core {
@@ -145,7 +140,7 @@ const ExperimentMetadata g_experiment_metadata[] = {
     {"event_engine_dns", description_event_engine_dns,
      additional_constraints_event_engine_dns, false, false},
     {"work_stealing", description_work_stealing,
-     additional_constraints_work_stealing, kDefaultForDebugOnly, false},
+     additional_constraints_work_stealing, true, false},
     {"client_privacy", description_client_privacy,
      additional_constraints_client_privacy, false, false},
     {"canary_client_privacy", description_canary_client_privacy,
@@ -243,11 +238,6 @@ const char* const description_keepalive_server_fix =
     "Allows overriding keepalive_permit_without_calls for servers. Refer "
     "https://github.com/grpc/grpc/pull/33917 for more information.";
 const char* const additional_constraints_keepalive_server_fix = "{}";
-#ifdef NDEBUG
-const bool kDefaultForDebugOnly = false;
-#else
-const bool kDefaultForDebugOnly = true;
-#endif
 }  // namespace
 
 namespace grpc_core {
@@ -287,7 +277,7 @@ const ExperimentMetadata g_experiment_metadata[] = {
     {"event_engine_dns", description_event_engine_dns,
      additional_constraints_event_engine_dns, false, false},
     {"work_stealing", description_work_stealing,
-     additional_constraints_work_stealing, kDefaultForDebugOnly, false},
+     additional_constraints_work_stealing, true, false},
     {"client_privacy", description_client_privacy,
      additional_constraints_client_privacy, false, false},
     {"canary_client_privacy", description_canary_client_privacy,
@@ -385,11 +375,6 @@ const char* const description_keepalive_server_fix =
     "Allows overriding keepalive_permit_without_calls for servers. Refer "
     "https://github.com/grpc/grpc/pull/33917 for more information.";
 const char* const additional_constraints_keepalive_server_fix = "{}";
-#ifdef NDEBUG
-const bool kDefaultForDebugOnly = false;
-#else
-const bool kDefaultForDebugOnly = true;
-#endif
 }  // namespace
 
 namespace grpc_core {
@@ -429,7 +414,7 @@ const ExperimentMetadata g_experiment_metadata[] = {
     {"event_engine_dns", description_event_engine_dns,
      additional_constraints_event_engine_dns, false, false},
     {"work_stealing", description_work_stealing,
-     additional_constraints_work_stealing, kDefaultForDebugOnly, false},
+     additional_constraints_work_stealing, true, false},
     {"client_privacy", description_client_privacy,
      additional_constraints_client_privacy, false, false},
     {"canary_client_privacy", description_canary_client_privacy,

src/core/lib/experiments/experiments.h

@@ -75,16 +75,8 @@ inline bool IsEventEngineListenerEnabled() { return false; }
 inline bool IsScheduleCancellationOverWriteEnabled() { return false; }
 inline bool IsTraceRecordCallopsEnabled() { return false; }
 inline bool IsEventEngineDnsEnabled() { return false; }
-#ifndef NDEBUG
 #define GRPC_EXPERIMENT_IS_INCLUDED_WORK_STEALING
-#endif
-inline bool IsWorkStealingEnabled() {
-#ifdef NDEBUG
-  return false;
-#else
-  return true;
-#endif
-}
+inline bool IsWorkStealingEnabled() { return true; }
 inline bool IsClientPrivacyEnabled() { return false; }
 inline bool IsCanaryClientPrivacyEnabled() { return false; }
 inline bool IsServerPrivacyEnabled() { return false; }
@@ -110,16 +102,8 @@ inline bool IsEventEngineListenerEnabled() { return false; }
 inline bool IsScheduleCancellationOverWriteEnabled() { return false; }
 inline bool IsTraceRecordCallopsEnabled() { return false; }
 inline bool IsEventEngineDnsEnabled() { return false; }
-#ifndef NDEBUG
 #define GRPC_EXPERIMENT_IS_INCLUDED_WORK_STEALING
-#endif
-inline bool IsWorkStealingEnabled() {
-#ifdef NDEBUG
-  return false;
-#else
-  return true;
-#endif
-}
+inline bool IsWorkStealingEnabled() { return true; }
 inline bool IsClientPrivacyEnabled() { return false; }
 inline bool IsCanaryClientPrivacyEnabled() { return false; }
 inline bool IsServerPrivacyEnabled() { return false; }
@@ -145,16 +129,8 @@ inline bool IsEventEngineListenerEnabled() { return false; }
 inline bool IsScheduleCancellationOverWriteEnabled() { return false; }
 inline bool IsTraceRecordCallopsEnabled() { return false; }
 inline bool IsEventEngineDnsEnabled() { return false; }
-#ifndef NDEBUG
 #define GRPC_EXPERIMENT_IS_INCLUDED_WORK_STEALING
-#endif
-inline bool IsWorkStealingEnabled() {
-#ifdef NDEBUG
-  return false;
-#else
-  return true;
-#endif
-}
+inline bool IsWorkStealingEnabled() { return true; }
 inline bool IsClientPrivacyEnabled() { return false; }
 inline bool IsCanaryClientPrivacyEnabled() { return false; }
 inline bool IsServerPrivacyEnabled() { return false; }

src/core/lib/experiments/rollouts.yaml

@@ -79,7 +79,7 @@
     # implemented
     windows: broken
 - name: work_stealing
-  default: debug
+  default: true
 - name: client_privacy
   default: false
 - name: canary_client_privacy