Merge "adb: fix deadlock between transport_unref and usb_close." am: 6f61a6d9c4 am: 2a8ce10cd8 am: 64523c01bd
am: 7ff1e56f59
Change-Id: Ibac1c6c001b40fc8d0563bbcbecd7e8a2f367e28
diff --git a/adb/transport.cpp b/adb/transport.cpp
index 308ee8d..2bbbefd 100644
--- a/adb/transport.cpp
+++ b/adb/transport.cpp
@@ -603,15 +603,15 @@
static void transport_unref(atransport* t) {
CHECK(t != nullptr);
- std::lock_guard<std::mutex> lock(transport_lock);
- CHECK_GT(t->ref_count, 0u);
- t->ref_count--;
- if (t->ref_count == 0) {
+ size_t old_refcount = t->ref_count--;
+ CHECK_GT(old_refcount, 0u);
+
+ if (old_refcount == 1u) {
D("transport: %s unref (kicking and closing)", t->serial);
t->close(t);
remove_transport(t);
} else {
- D("transport: %s unref (count=%zu)", t->serial, t->ref_count);
+ D("transport: %s unref (count=%zu)", t->serial, old_refcount - 1);
}
}
diff --git a/adb/transport.h b/adb/transport.h
index 57fc988..4a89ed9 100644
--- a/adb/transport.h
+++ b/adb/transport.h
@@ -61,7 +61,7 @@
// class in one go is a very large change. Given how bad our testing is,
// it's better to do this piece by piece.
- atransport(ConnectionState state = kCsOffline) : connection_state_(state) {
+ atransport(ConnectionState state = kCsOffline) : ref_count(0), connection_state_(state) {
transport_fde = {};
protocol_version = A_VERSION;
max_payload = MAX_PAYLOAD;
@@ -88,7 +88,7 @@
int fd = -1;
int transport_socket = -1;
fdevent transport_fde;
- size_t ref_count = 0;
+ std::atomic<size_t> ref_count;
uint32_t sync_token = 0;
bool online = false;
TransportType type = kTransportAny;