Rename 'uid' to 'scid'

A random identifier is generated to differentiate multiple running
scrcpy instances. Rename it from 'uid' to 'scid' (scrcpy id) not to
confuse it with Linux UID.

Fixes #3729 <https://github.com/Genymobile/scrcpy/issues/3729>
Refs 4315be1648

app/src/scrcpy.c

@@ -273,8 +273,9 @@ sc_server_on_disconnected(struct sc_server *server, void *userdata) {
     // event
 }
 
+// Generate a scrcpy id to differentiate multiple running scrcpy instances
 static uint32_t
-scrcpy_generate_uid() {
+scrcpy_generate_scid() {
     struct sc_rand rand;
     sc_rand_init(&rand);
     // Only use 31 bits to avoid issues with signed values on the Java-side
@@ -314,10 +315,10 @@ scrcpy(struct scrcpy_options *options) {
 
     struct sc_acksync *acksync = NULL;
 
-    uint32_t uid = scrcpy_generate_uid();
+    uint32_t scid = scrcpy_generate_scid();
 
     struct sc_server_params params = {
-        .uid = uid,
+        .scid = scid,
         .req_serial = options->serial,
         .select_usb = options->select_usb,
         .select_tcpip = options->select_tcpip,

app/src/server.c

@@ -213,7 +213,7 @@ execute_server(struct sc_server *server,
         cmd[count++] = p; \
     }
 
-    ADD_PARAM("uid=%08x", params->uid);
+    ADD_PARAM("scid=%08x", params->scid);
     ADD_PARAM("log_level=%s", log_level_to_server_string(params->log_level));
     ADD_PARAM("bit_rate=%" PRIu32, params->bit_rate);
 
@@ -787,7 +787,7 @@ run_server(void *data) {
     LOGD("Device serial: %s", serial);
 
     int r = asprintf(&server->device_socket_name, SC_SOCKET_NAME_PREFIX "%08x",
-                     params->uid);
+                     params->scid);
     if (r == -1) {
         LOG_OOM();
         goto error_connection_failed;

app/src/server.h

@@ -22,7 +22,7 @@ struct sc_server_info {
 };
 
 struct sc_server_params {
-    uint32_t uid;
+    uint32_t scid;
     const char *req_serial;
     enum sc_log_level log_level;
     enum sc_codec codec;

server/src/main/java/com/genymobile/scrcpy/DesktopConnection.java

@@ -46,17 +46,17 @@ public final class DesktopConnection implements Closeable {
         return localSocket;
     }
 
-    private static String getSocketName(int uid) {
+    private static String getSocketName(int scid) {
-        if (uid == -1) {
+        if (scid == -1) {
-            // If no UID is set, use "scrcpy" to simplify using scrcpy-server alone
+            // If no SCID is set, use "scrcpy" to simplify using scrcpy-server alone
             return SOCKET_NAME_PREFIX;
         }
 
-        return SOCKET_NAME_PREFIX + String.format("_%08x", uid);
+        return SOCKET_NAME_PREFIX + String.format("_%08x", scid);
     }
 
-    public static DesktopConnection open(int uid, boolean tunnelForward, boolean control, boolean sendDummyByte) throws IOException {
+    public static DesktopConnection open(int scid, boolean tunnelForward, boolean control, boolean sendDummyByte) throws IOException {
-        String socketName = getSocketName(uid);
+        String socketName = getSocketName(scid);
 
         LocalSocket videoSocket;
         LocalSocket controlSocket = null;

server/src/main/java/com/genymobile/scrcpy/Options.java

@@ -7,7 +7,7 @@ import java.util.List;
 public class Options {
 
     private Ln.Level logLevel = Ln.Level.DEBUG;
-    private int uid = -1; // 31-bit non-negative value, or -1
+    private int scid = -1; // 31-bit non-negative value, or -1
     private int maxSize;
     private VideoCodec codec = VideoCodec.H264;
     private int bitRate = 8000000;
@@ -41,12 +41,12 @@ public class Options {
         this.logLevel = logLevel;
     }
 
-    public int getUid() {
+    public int getScid() {
-        return uid;
+        return scid;
     }
 
-    public void setUid(int uid) {
+    public void setScid(int scid) {
-        this.uid = uid;
+        this.scid = scid;
     }
 
     public int getMaxSize() {

server/src/main/java/com/genymobile/scrcpy/Server.java

@@ -66,7 +66,7 @@ public final class Server {
 
         Thread initThread = startInitThread(options);
 
-        int uid = options.getUid();
+        int scid = options.getScid();
         boolean tunnelForward = options.isTunnelForward();
         boolean control = options.getControl();
         boolean sendDummyByte = options.getSendDummyByte();
@@ -84,7 +84,7 @@ public final class Server {
             Workarounds.fillAppInfo();
         }
 
-        try (DesktopConnection connection = DesktopConnection.open(uid, tunnelForward, control, sendDummyByte)) {
+        try (DesktopConnection connection = DesktopConnection.open(scid, tunnelForward, control, sendDummyByte)) {
             VideoCodec codec = options.getCodec();
             if (options.getSendDeviceMeta()) {
                 Size videoSize = device.getScreenInfo().getVideoSize();
@@ -158,12 +158,12 @@ public final class Server {
             String key = arg.substring(0, equalIndex);
             String value = arg.substring(equalIndex + 1);
             switch (key) {
-                case "uid":
+                case "scid":
-                    int uid = Integer.parseInt(value, 0x10);
+                    int scid = Integer.parseInt(value, 0x10);
-                    if (uid < -1) {
+                    if (scid < -1) {
-                        throw new IllegalArgumentException("uid may not be negative (except -1 for 'none'): " + uid);
+                        throw new IllegalArgumentException("scid may not be negative (except -1 for 'none'): " + scid);
                     }
-                    options.setUid(uid);
+                    options.setScid(scid);
                     break;
                 case "log_level":
                     Ln.Level level = Ln.Level.valueOf(value.toUpperCase(Locale.ENGLISH));