Rate limit the unimplemented syscall event handler.

This introduces two new types of Emitters:
1. MultiEmitter, which will forward events to other registered Emitters, and
2. RateLimitedEmitter, which will forward events to a wrapped Emitter, subject
	to given rate limits.

The methods in the eventchannel package itself act like a multiEmitter, but is
not actually an Emitter. Now we have a DefaultEmitter, and the methods in
eventchannel simply forward calls to the DefaultEmitter.

The unimplemented syscall handler now uses a RateLimetedEmitter that wraps the
DefaultEmitter.

PiperOrigin-RevId: 260612770

1 files changed, 12 insertions, 1 deletions

diff --git a/pkg/eventchannel/BUILD b/pkg/eventchannel/BUILD
index 4c336ea84..9961baaa9 100644
--- a/pkg/eventchannel/BUILD
+++ b/pkg/eventchannel/BUILD
@@ -1,4 +1,4 @@
-load("//tools/go_stateify:defs.bzl", "go_library")
+load("//tools/go_stateify:defs.bzl", "go_library", "go_test")
 load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
 
 package(licenses = ["notice"])
@@ -7,6 +7,7 @@ go_library(
     name = "eventchannel",
     srcs = [
         "event.go",
+        "rate.go",
     ],
     importpath = "gvisor.dev/gvisor/pkg/eventchannel",
     visibility = ["//:sandbox"],
@@ -16,6 +17,7 @@ go_library(
         "//pkg/unet",
         "@com_github_golang_protobuf//proto:go_default_library",
         "@com_github_golang_protobuf//ptypes:go_default_library_gen",
+        "@org_golang_x_time//rate:go_default_library",
     ],
 )
 
@@ -30,3 +32,12 @@ go_proto_library(
     proto = ":eventchannel_proto",
     visibility = ["//:sandbox"],
 )
+
+go_test(
+    name = "eventchannel_test",
+    srcs = ["event_test.go"],
+    embed = [":eventchannel"],
+    deps = [
+        "@com_github_golang_protobuf//proto:go_default_library",
+    ],
+)