Kill adb daemon in OTG mode on Windows

On Windows, it is not possible to open a USB device from several
process, so HID events may only work if no adb daemon is running.

PR #3011 <https://github.com/Genymobile/scrcpy/pull/3011>

app/src/adb/adb.c

@@ -204,6 +204,14 @@ sc_adb_start_server(struct sc_intr *intr, unsigned flags) {
     return process_check_success_intr(intr, pid, "adb start-server", flags);
 }
 
+bool
+sc_adb_kill_server(struct sc_intr *intr, unsigned flags) {
+    const char *const argv[] = SC_ADB_COMMAND("kill-server");
+
+    sc_pid pid = sc_adb_execute(argv, flags);
+    return process_check_success_intr(intr, pid, "adb kill-server", flags);
+}
+
 bool
 sc_adb_forward(struct sc_intr *intr, const char *serial, uint16_t local_port,
                const char *device_socket_name, unsigned flags) {

app/src/adb/adb.h

@@ -36,6 +36,9 @@ sc_adb_execute(const char *const argv[], unsigned flags);
 bool
 sc_adb_start_server(struct sc_intr *intr, unsigned flags);
 
+bool
+sc_adb_kill_server(struct sc_intr *intr, unsigned flags);
+
 bool
 sc_adb_forward(struct sc_intr *intr, const char *serial, uint16_t local_port,
                const char *device_socket_name, unsigned flags);

app/src/usb/scrcpy_otg.c

@@ -2,6 +2,7 @@
 
 #include <SDL2/SDL.h>
 
+#include "adb/adb.h"
 #include "events.h"
 #include "screen_otg.h"
 #include "util/log.h"
@@ -75,6 +76,15 @@ scrcpy_otg(struct scrcpy_options *options) {
     bool aoa_started = false;
     bool aoa_initialized = false;
 
+#ifdef _WIN32
+    // On Windows, only one process could open a USB device
+    // <https://github.com/Genymobile/scrcpy/issues/2773>
+    LOGI("Killing adb daemon (if any)...");
+    unsigned flags = SC_ADB_NO_STDOUT | SC_ADB_NO_STDERR | SC_ADB_NO_LOGERR;
+    // uninterruptible (intr == NULL), but in practice it's very quick
+    sc_adb_kill_server(NULL, flags);
+#endif
+
     static const struct sc_usb_callbacks cbs = {
         .on_disconnected = sc_usb_on_disconnected,
     };