commit b43ad44f4ce49cf77a0fcff1585261751ee5c3b1
author Josh Gao <jmgao@google.com> Thu Jul 11 13:47:44 2019 -0700
committer Josh Gao <jmgao@google.com> Wed Aug 14 13:56:08 2019 -0700
tree d811544e4c715745a6c0dfa90c2e983250e38dab
parent e22cb9f30617d925d1d3232d7f1954c62c56da1b

adb: fdevent: add fdevent_context_epoll.

Implement an epoll-backed fdevent_context, that reduces overhead when
we're polling many file descriptors. FdeventTest.smoke goes from ~5.2s
to ~3.3s when run on the host (after this patch's modification to change
it from chaining 10 file descriptors together to 512).

Test: adb_test on host
Test: adbd_test on blueline
Test: test_adb.py
Test: test_device.py
Change-Id: Iacf0093aa7bebea31e447c2cb012af72d8c3297e

adb/fdevent/fdevent.cpp

diff --git a/adb/fdevent/fdevent.cpp b/adb/fdevent/fdevent.cpp
index d215217..562f587 100644
--- a/adb/fdevent/fdevent.cpp
+++ b/adb/fdevent/fdevent.cpp
@@ -26,6 +26,7 @@
 
 #include "adb_utils.h"
 #include "fdevent.h"
+#include "fdevent_epoll.h"
 #include "fdevent_poll.h"
 
 using namespace std::chrono_literals;
@@ -185,8 +186,16 @@
     Interrupt();
 }
 
+static std::unique_ptr<fdevent_context> fdevent_create_context() {
+#if defined(__linux__)
+    return std::make_unique<fdevent_context_epoll>();
+#else
+    return std::make_unique<fdevent_context_poll>();
+#endif
+}
+
 static auto& g_ambient_fdevent_context =
-        *new std::unique_ptr<fdevent_context>(new fdevent_context_poll());
+        *new std::unique_ptr<fdevent_context>(fdevent_create_context());
 
 static fdevent_context* fdevent_get_ambient() {
     return g_ambient_fdevent_context.get();
@@ -247,5 +256,5 @@
 }
 
 void fdevent_reset() {
-    g_ambient_fdevent_context.reset(new fdevent_context_poll());
+    g_ambient_fdevent_context = fdevent_create_context();
 }