diff --git a/adb/Android.bp b/adb/Android.bp
index 19e921f..8779c0a 100644
--- a/adb/Android.bp
+++ b/adb/Android.bp
@@ -165,7 +165,6 @@
     "adb_unique_fd.cpp",
     "adb_utils.cpp",
     "fdevent/fdevent.cpp",
-    "fdevent/fdevent_poll.cpp",
     "services.cpp",
     "sockets.cpp",
     "socket_spec.cpp",
@@ -176,6 +175,17 @@
     "types.cpp",
 ]
 
+libadb_darwin_srcs = [
+    "fdevent/fdevent_poll.cpp",
+]
+
+libadb_windows_srcs = [
+    "fdevent/fdevent_poll.cpp",
+    "sysdeps_win32.cpp",
+    "sysdeps/win32/errno.cpp",
+    "sysdeps/win32/stat.cpp",
+]
+
 libadb_posix_srcs = [
     "sysdeps_unix.cpp",
     "sysdeps/posix/network.cpp",
@@ -219,7 +229,7 @@
             srcs: ["client/usb_linux.cpp"] + libadb_linux_srcs,
         },
         darwin: {
-            srcs: ["client/usb_osx.cpp"],
+            srcs: ["client/usb_osx.cpp"] + libadb_darwin_srcs,
         },
         not_windows: {
             srcs: libadb_posix_srcs,
@@ -228,10 +238,7 @@
             enabled: true,
             srcs: [
                 "client/usb_windows.cpp",
-                "sysdeps_win32.cpp",
-                "sysdeps/win32/errno.cpp",
-                "sysdeps/win32/stat.cpp",
-            ],
+            ] + libadb_windows_srcs,
             shared_libs: ["AdbWinApi"],
         },
     },
diff --git a/adb/adb_trace.cpp b/adb/adb_trace.cpp
index cea24fe..c579dde 100644
--- a/adb/adb_trace.cpp
+++ b/adb/adb_trace.cpp
@@ -89,18 +89,13 @@
 
 int adb_trace_mask;
 
-std::string get_trace_setting_from_env() {
+std::string get_trace_setting() {
+#if ADB_HOST
     const char* setting = getenv("ADB_TRACE");
     if (setting == nullptr) {
         setting = "";
     }
-
-    return std::string(setting);
-}
-
-std::string get_trace_setting() {
-#if ADB_HOST
-    return get_trace_setting_from_env();
+    return setting;
 #else
     return android::base::GetProperty("persist.adb.trace_mask", "");
 #endif
diff --git a/adb/coverage.sh b/adb/coverage.sh
deleted file mode 100755
index 50ccdf5..0000000
--- a/adb/coverage.sh
+++ /dev/null
@@ -1,63 +0,0 @@
-#!/bin/bash
-# Copyright (C) 2020 The Android Open Source Project
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-set -euxo pipefail
-
-adb root
-adb shell logcat -c -G128M
-adb shell setprop persist.adb.trace_mask 1
-adb shell killall adbd
-
-# TODO: Add `adb transport-id` and wait-for-offline on it.
-sleep 5
-
-adb wait-for-device shell rm "/data/misc/trace/*"
-
-./test_device.py
-
-# Dump traces from the currently running adbd.
-adb shell killall -37 adbd
-
-echo Waiting for adbd to finish dumping traces
-sleep 5
-
-TRACEDIR=`mktemp -d`
-adb pull /data/misc/trace "$TRACEDIR"/
-echo Pulled traces to $TRACEDIR
-
-
-# Identify which of the trace files are actually adbd, in case something else exited simultaneously.
-ADBD_PIDS=$(adb shell "logcat -d -s adbd --format=process | grep 'adbd started' | cut -c 3-7 | tr -d ' ' | sort | uniq")
-mkdir "$TRACEDIR"/adbd_traces
-
-adb shell 'setprop persist.adb.trace_mask 0; killall adbd'
-
-IFS=$'\n'
-for PID in $ADBD_PIDS; do
-  cp "$TRACEDIR"/trace/clang-$PID-*.profraw "$TRACEDIR"/adbd_traces 2>/dev/null || true
-done
-
-llvm-profdata merge --output="$TRACEDIR"/adbd.profdata "$TRACEDIR"/adbd_traces/*
-
-cd $ANDROID_BUILD_TOP
-llvm-cov report --instr-profile="$TRACEDIR"/adbd.profdata \
-  $ANDROID_PRODUCT_OUT/apex/com.android.adbd/bin/adbd \
-  --show-region-summary=false \
-  /proc/self/cwd/system/core/adb
-
-llvm-cov show --instr-profile="$TRACEDIR"/adbd.profdata \
-  $ANDROID_PRODUCT_OUT/apex/com.android.adbd/bin/adbd \
-  --format=html \
-  /proc/self/cwd/system/core/adb > $TRACEDIR/report.html
diff --git a/adb/coverage/.gitignore b/adb/coverage/.gitignore
new file mode 100644
index 0000000..b6a2582
--- /dev/null
+++ b/adb/coverage/.gitignore
@@ -0,0 +1,2 @@
+/adbd.profdata
+/report
diff --git a/adb/coverage/gen_coverage.sh b/adb/coverage/gen_coverage.sh
new file mode 100755
index 0000000..cced62a
--- /dev/null
+++ b/adb/coverage/gen_coverage.sh
@@ -0,0 +1,114 @@
+#!/bin/bash
+
+set -euxo pipefail
+
+OUTPUT_DIR=$(dirname "$0")
+. "$OUTPUT_DIR"/include.sh
+
+TRACEDIR=`mktemp -d`
+
+### Make sure we can connect to the device.
+
+# Get the device's wlan0 address.
+IP_ADDR=$(adb shell ip route get 0.0.0.0 oif wlan0 | sed -En -e 's/.*src (\S+)\s.*/\1/p')
+REMOTE_PORT=5555
+REMOTE=$IP_ADDR:$REMOTE_PORT
+LOCAL_SERIAL=$(adb shell getprop ro.serialno)
+
+# Check that we can connect to it.
+adb disconnect
+adb tcpip $REMOTE_PORT
+
+# TODO: Add `adb transport-id` and wait-for-offline on it.
+sleep 5
+
+adb connect $REMOTE
+
+REMOTE_FETCHED_SERIAL=$(adb -s $REMOTE shell getprop ro.serialno)
+
+if [[ "$LOCAL_SERIAL" != "$REMOTE_FETCHED_SERIAL" ]]; then
+  echo "Mismatch: local serial = $LOCAL_SERIAL, remote serial = $REMOTE_FETCHED_SERIAL"
+  exit 1
+fi
+
+# Back to USB, and make sure adbd is root.
+adb disconnect $REMOTE
+
+adb root
+adb wait-for-device usb
+
+# TODO: Add `adb transport-id` and wait-for-offline on it.
+sleep 5
+
+adb wait-for-device
+
+### Run the adb unit tests and fetch traces from them.
+mkdir "$TRACEDIR"/test_traces
+adb shell rm -rf /data/local/tmp/adb_coverage
+adb shell mkdir /data/local/tmp/adb_coverage
+
+for TEST in $ADB_TESTS; do
+  adb shell LLVM_PROFILE_FILE=/data/local/tmp/adb_coverage/$TEST.profraw /data/nativetest64/$TEST/$TEST
+  adb pull /data/local/tmp/adb_coverage/$TEST.profraw "$TRACEDIR"/test_traces/
+done
+
+adb pull /data/local/tmp/adb_coverage "$TRACEDIR"/test_traces
+
+# Clear logcat and increase the buffer to something ridiculous so we can fetch the pids of adbd later.
+adb shell logcat -c -G128M
+
+# Turn on extremely verbose logging so as to not count debug logging against us.
+adb shell setprop persist.adb.trace_mask 1
+
+### Run test_device.py over USB.
+adb shell killall adbd
+
+# TODO: Add `adb transport-id` and wait-for-offline on it.
+sleep 5
+
+adb wait-for-device shell rm -rf "/data/misc/trace/*" /data/local/tmp/adb_coverage/
+"$OUTPUT_DIR"/../test_device.py
+
+# Do a usb reset to exercise the disconnect code.
+adb_usbreset
+adb wait-for-device
+
+# Dump traces from the currently running adbd.
+adb shell killall -37 adbd
+
+echo Waiting for adbd to finish dumping traces
+sleep 5
+
+# Restart adbd in tcp mode.
+adb tcpip $REMOTE_PORT
+sleep 5
+adb connect $REMOTE
+adb -s $REMOTE wait-for-device
+
+# Run test_device.py again.
+ANDROID_SERIAL=$REMOTE "$OUTPUT_DIR"/../test_device.py
+
+# Dump traces again.
+adb disconnect $REMOTE
+adb shell killall -37 adbd
+
+echo Waiting for adbd to finish dumping traces
+sleep 5
+
+adb pull /data/misc/trace "$TRACEDIR"/
+echo Pulled traces to $TRACEDIR
+
+# Identify which of the trace files are actually adbd, in case something else exited simultaneously.
+ADBD_PIDS=$(adb shell "logcat -d -s adbd --format=process | grep 'adbd started' | cut -c 3-7 | tr -d ' ' | sort | uniq")
+mkdir "$TRACEDIR"/adbd_traces
+
+adb shell 'setprop persist.adb.trace_mask 0; killall adbd'
+
+IFS=$'\n'
+for PID in $ADBD_PIDS; do
+  cp "$TRACEDIR"/trace/clang-$PID-*.profraw "$TRACEDIR"/adbd_traces 2>/dev/null || true
+done
+unset IFS
+
+### Merge the traces.
+llvm-profdata merge --output="$OUTPUT_DIR"/adbd.profdata "$TRACEDIR"/adbd_traces/* "$TRACEDIR"/test_traces/*
diff --git a/adb/coverage/include.sh b/adb/coverage/include.sh
new file mode 100644
index 0000000..45ebc34
--- /dev/null
+++ b/adb/coverage/include.sh
@@ -0,0 +1,5 @@
+ADB_TESTS="adbd_test adb_crypto_test adb_pairing_auth_test adb_pairing_connection_test adb_tls_connection_test"
+ADB_TEST_BINARIES=""
+for TEST in $ADB_TESTS; do
+  ADB_TEST_BINARIES="--object=$ANDROID_PRODUCT_OUT/data/nativetest64/$TEST/$TEST $ADB_TEST_BINARIES"
+done
diff --git a/adb/coverage/report.sh b/adb/coverage/report.sh
new file mode 100755
index 0000000..257310c
--- /dev/null
+++ b/adb/coverage/report.sh
@@ -0,0 +1,22 @@
+#!/bin/bash
+
+set -euxo pipefail
+
+OUTPUT_DIR=$(realpath $(dirname "$0"))
+. "$OUTPUT_DIR"/include.sh
+
+rm -rf "$OUTPUT_DIR"/report
+
+cd $ANDROID_BUILD_TOP
+llvm-cov show --instr-profile="$OUTPUT_DIR"/adbd.profdata \
+  $ANDROID_PRODUCT_OUT/apex/com.android.adbd/bin/adbd \
+  /proc/self/cwd/system/core/adb \
+  $ADB_TEST_BINARIES \
+  --show-region-summary=false \
+  --format=html -o "$OUTPUT_DIR"/report
+
+llvm-cov report --instr-profile="$OUTPUT_DIR"/adbd.profdata \
+  $ANDROID_PRODUCT_OUT/apex/com.android.adbd/bin/adbd \
+  /proc/self/cwd/system/core/adb \
+  $ADB_TEST_BINARIES \
+  --show-region-summary=false
diff --git a/adb/coverage/show.sh b/adb/coverage/show.sh
new file mode 100755
index 0000000..7ea7949
--- /dev/null
+++ b/adb/coverage/show.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+
+set -euxo pipefail
+
+OUTPUT_DIR=$(realpath $(dirname "$0"))
+. "$OUTPUT_DIR"/include.sh
+
+cd $ANDROID_BUILD_TOP
+llvm-cov show --instr-profile="$OUTPUT_DIR"/adbd.profdata \
+  $ANDROID_PRODUCT_OUT/apex/com.android.adbd/bin/adbd \
+  /proc/self/cwd/system/core/adb \
+  $ADB_TEST_BINARIES
diff --git a/adb/fdevent/fdevent.cpp b/adb/fdevent/fdevent.cpp
index fd55020..70cb9b3 100644
--- a/adb/fdevent/fdevent.cpp
+++ b/adb/fdevent/fdevent.cpp
@@ -27,7 +27,10 @@
 #include "adb_utils.h"
 #include "fdevent.h"
 #include "fdevent_epoll.h"
+
+#if !defined(__linux__)
 #include "fdevent_poll.h"
+#endif
 
 using namespace std::chrono_literals;
 using std::chrono::duration_cast;
diff --git a/adb/services.cpp b/adb/services.cpp
index d87948c..19a9030 100644
--- a/adb/services.cpp
+++ b/adb/services.cpp
@@ -202,11 +202,22 @@
                                       transport_id, &is_ambiguous, &error);
 
         for (const auto& state : states) {
-            // wait-for-disconnect uses kCsOffline, we don't actually want to wait for 'offline'.
-            if ((t == nullptr && state == kCsOffline) || (t != nullptr && state == kCsAny) ||
-                (t != nullptr && state == t->GetConnectionState())) {
-                SendOkay(fd);
-                return;
+            if (state == kCsOffline) {
+                // Special case for wait-for-disconnect:
+                // We want to wait for USB devices to completely disappear, but TCP devices can
+                // go into the offline state, since we automatically reconnect.
+                if (!t) {
+                    SendOkay(fd);
+                    return;
+                } else if (!t->GetUsbHandle()) {
+                    SendOkay(fd);
+                    return;
+                }
+            } else {
+                if (t && (state == kCsAny || state == t->GetConnectionState())) {
+                    SendOkay(fd);
+                    return;
+                }
             }
         }