adb: initialize mDNS asynchronously.
Use fdevent_run_on_main_thread to initialize mDNS in a thread and
register an fdevent from the main thread upon success.
This reduces the startup time of `adb server` by ~3 seconds when mDNS
can't be successfully started. With an already running adb server,
`time adb server nodaemon` goes from:
adb server nodaemon 0.00s user 0.16s system 4% cpu 3.817 total
to:
adb server nodaemon 0.00s user 0.01s system 1% cpu 0.665 total
Bug: http://b/37869663
Test: `adb server nodaemon` with an existing adb server
Change-Id: Ia5a1a2a138610f3bf6792400050ca68f95ae3734
diff --git a/adb/transport_mdns.cpp b/adb/transport_mdns.cpp
index e49b1c6..3603f09 100644
--- a/adb/transport_mdns.cpp
+++ b/adb/transport_mdns.cpp
@@ -24,6 +24,8 @@
#include <arpa/inet.h>
#endif
+#include <thread>
+
#include <android-base/stringprintf.h>
#include <dns_sd.h>
@@ -262,19 +264,22 @@
}
}
-void init_mdns_transport_discovery(void) {
- DNSServiceErrorType errorCode =
- DNSServiceBrowse(&service_ref, 0, 0, kADBServiceType, nullptr,
- register_mdns_transport, nullptr);
+void init_mdns_transport_discovery_thread(void) {
+ DNSServiceErrorType errorCode = DNSServiceBrowse(&service_ref, 0, 0, kADBServiceType, nullptr,
+ register_mdns_transport, nullptr);
if (errorCode != kDNSServiceErr_NoError) {
D("Got %d initiating mDNS browse.", errorCode);
return;
}
- fdevent_install(&service_ref_fde,
- adb_DNSServiceRefSockFD(service_ref),
- pump_service_ref,
- &service_ref);
- fdevent_set(&service_ref_fde, FDE_READ);
+ fdevent_run_on_main_thread([]() {
+ fdevent_install(&service_ref_fde, adb_DNSServiceRefSockFD(service_ref), pump_service_ref,
+ &service_ref);
+ fdevent_set(&service_ref_fde, FDE_READ);
+ });
+}
+
+void init_mdns_transport_discovery(void) {
+ std::thread(init_mdns_transport_discovery_thread).detach();
}