event: bump libevent version to the latest (envoyproxy#12423)

On Windows, configure event-base to use wepoll backend instead of the default win32 backend.

Risk Level: Low
Testing: CI
Docs Changes: N/A
Release Notes: N/A

Signed-off-by: Nick Grifka <[email protected]>

Author: nigriMSFT

bazel/foreign_cc/BUILD

@@ -158,6 +158,7 @@ envoy_cmake_external(
     name = "event",
     cache_entries = {
         "EVENT__DISABLE_OPENSSL": "on",
+        "EVENT__DISABLE_MBEDTLS": "on",
         "EVENT__DISABLE_REGRESS": "on",
         "EVENT__DISABLE_TESTS": "on",
         "EVENT__LIBRARY_TYPE": "STATIC",

bazel/repository_locations.bzl

@@ -233,18 +233,20 @@ DEPENDENCY_REPOSITORIES = dict(
         use_category = ["test"],
     ),
     com_github_libevent_libevent = dict(
-        sha256 = "c64156c24602ab7a5c66937d774cc55868911d5bbbf1650792f5877744b1c2d9",
+        sha256 = "4c80e5fe044ce5f8055b20a2f141ee32ec2614000f3e95d2aa81611a4c8f5213",
         # This SHA includes the new "prepare" and "check" watchers, used for event loop performance
         # stats (see https://github.com/libevent/libevent/pull/793) and the fix for a race condition
         # in the watchers (see https://github.com/libevent/libevent/pull/802).
         # This also includes the fixes for https://github.com/libevent/libevent/issues/806
         # and https://github.com/lyft/envoy-mobile/issues/215.
-        # This also include the fixes for Phantom events with EV_ET (see
+        # This also includes the fixes for Phantom events with EV_ET (see
         # https://github.com/libevent/libevent/issues/984).
+        # This also includes the wepoll backend for Windows (see
+        # https://github.com/libevent/libevent/pull/1006)
         # TODO(adip): Update to v2.2 when it is released.
-        strip_prefix = "libevent-06a11929511bebaaf40c52aaf91de397b1782ba2",
-        # 2020-05-08
-        urls = ["https://github.com/libevent/libevent/archive/06a11929511bebaaf40c52aaf91de397b1782ba2.tar.gz"],
+        strip_prefix = "libevent-62c152d9a7cd264b993dad730c4163c6ede2e0a3",
+        # 2020-07-31
+        urls = ["https://github.com/libevent/libevent/archive/62c152d9a7cd264b993dad730c4163c6ede2e0a3.tar.gz"],
         use_category = ["dataplane"],
         cpe = "cpe:2.3:a:libevent_project:libevent:*",
     ),

source/common/event/libevent_scheduler.cc

@@ -16,7 +16,18 @@ void recordTimeval(Stats::Histogram& histogram, const timeval& tv) {
 } // namespace
 
 LibeventScheduler::LibeventScheduler() {
+#ifdef WIN32
+  event_config* event_config = event_config_new();
+  RELEASE_ASSERT(event_config != nullptr,
+                 "Failed to initialize libevent event_base: event_config_new");
+  // Request wepoll backend by avoiding win32 backend.
+  int error = event_config_avoid_method(event_config, "win32");
+  RELEASE_ASSERT(error == 0, "Failed to initialize libevent event_base: event_config_avoid_method");
+  event_base* event_base = event_base_new_with_config(event_config);
+  event_config_free(event_config);
+#else
   event_base* event_base = event_base_new();
+#endif
   RELEASE_ASSERT(event_base != nullptr, "Failed to initialize libevent event_base");
   libevent_ = Libevent::BasePtr(event_base);
 

tools/spelling/spelling_dictionary.txt

@@ -1172,6 +1172,7 @@ vptr
 wakeup
 wakeups
 websocket
+wepoll
 whitespace
 whitespaces
 wildcard