Do not warn on terminating the server

If the server is already dead, terminating it fails. This is expected.

app/src/fps_counter.c

@@ -23,7 +23,7 @@ fps_counter_init(struct fps_counter *counter) {
     }
 
     counter->thread = NULL;
-    atomic_init(&counter->started, 0);
+    SDL_AtomicSet(&counter->started, 0);
     // no need to initialize the other fields, they are unused until started
 
     return true;
@@ -35,16 +35,6 @@ fps_counter_destroy(struct fps_counter *counter) {
     SDL_DestroyMutex(counter->mutex);
 }
 
-static inline bool
-is_started(struct fps_counter *counter) {
-    return atomic_load_explicit(&counter->started, memory_order_acquire);
-}
-
-static inline void
-set_started(struct fps_counter *counter, bool started) {
-    atomic_store_explicit(&counter->started, started, memory_order_release);
-}
-
 // must be called with mutex locked
 static void
 display_fps(struct fps_counter *counter) {
@@ -80,10 +70,10 @@ run_fps_counter(void *data) {
 
     mutex_lock(counter->mutex);
     while (!counter->interrupted) {
-        while (!counter->interrupted && !is_started(counter)) {
+        while (!counter->interrupted && !SDL_AtomicGet(&counter->started)) {
             cond_wait(counter->state_cond, counter->mutex);
         }
-        while (!counter->interrupted && is_started(counter)) {
+        while (!counter->interrupted && SDL_AtomicGet(&counter->started)) {
             uint32_t now = SDL_GetTicks();
             check_interval_expired(counter, now);
 
@@ -106,7 +96,7 @@ fps_counter_start(struct fps_counter *counter) {
     counter->nr_skipped = 0;
     mutex_unlock(counter->mutex);
 
-    set_started(counter, true);
+    SDL_AtomicSet(&counter->started, 1);
     cond_signal(counter->state_cond);
 
     // counter->thread is always accessed from the same thread, no need to lock
@@ -124,13 +114,13 @@ fps_counter_start(struct fps_counter *counter) {
 
 void
 fps_counter_stop(struct fps_counter *counter) {
-    set_started(counter, false);
+    SDL_AtomicSet(&counter->started, 0);
     cond_signal(counter->state_cond);
 }
 
 bool
 fps_counter_is_started(struct fps_counter *counter) {
-    return is_started(counter);
+    return SDL_AtomicGet(&counter->started);
 }
 
 void
@@ -155,7 +145,7 @@ fps_counter_join(struct fps_counter *counter) {
 
 void
 fps_counter_add_rendered_frame(struct fps_counter *counter) {
-    if (!is_started(counter)) {
+    if (!SDL_AtomicGet(&counter->started)) {
         return;
     }
 
@@ -168,7 +158,7 @@ fps_counter_add_rendered_frame(struct fps_counter *counter) {
 
 void
 fps_counter_add_skipped_frame(struct fps_counter *counter) {
-    if (!is_started(counter)) {
+    if (!SDL_AtomicGet(&counter->started)) {
         return;
     }
 

app/src/fps_counter.h

@@ -1,9 +1,9 @@
 #ifndef FPSCOUNTER_H
 #define FPSCOUNTER_H
 
-#include <stdatomic.h>
 #include <stdbool.h>
 #include <stdint.h>
+#include <SDL2/SDL_atomic.h>
 #include <SDL2/SDL_mutex.h>
 #include <SDL2/SDL_thread.h>
 
@@ -16,7 +16,7 @@ struct fps_counter {
 
     // atomic so that we can check without locking the mutex
     // if the FPS counter is disabled, we don't want to lock unnecessarily
-    atomic_bool started;
+    SDL_atomic_t started;
 
     // the following fields are protected by the mutex
     bool interrupted;

app/src/server.c

@@ -5,6 +5,7 @@
 #include <inttypes.h>
 #include <libgen.h>
 #include <stdio.h>
+#include <unistd.h>
 #include <SDL2/SDL_thread.h>
 #include <SDL2/SDL_timer.h>
 #include <SDL2/SDL_platform.h>
@@ -318,12 +319,14 @@ connect_to_server(uint16_t port, uint32_t attempts, uint32_t delay) {
 }
 
 static void
-close_socket(socket_t socket) {
-    assert(socket != INVALID_SOCKET);
-    net_shutdown(socket, SHUT_RDWR);
-    if (!net_close(socket)) {
+close_socket(socket_t *socket) {
+    assert(*socket != INVALID_SOCKET);
+    net_shutdown(*socket, SHUT_RDWR);
+    if (!net_close(*socket)) {
         LOGW("Could not close socket");
+        return;
     }
+    *socket = INVALID_SOCKET;
 }
 
 void
@@ -335,14 +338,10 @@ static int
 run_wait_server(void *data) {
     struct server *server = data;
     cmd_simple_wait(server->process, NULL); // ignore exit code
-    // no need for synchronization, server_socket is initialized before this
-    // thread was created
-    if (server->server_socket != INVALID_SOCKET
-            && !atomic_flag_test_and_set(&server->server_socket_closed)) {
-        // On Linux, accept() is unblocked by shutdown(), but on Windows, it is
-        // unblocked by closesocket(). Therefore, call both (close_socket()).
-        close_socket(server->server_socket);
-    }
+
+    // wake up any net_select_interruptible()
+    close(server->pipe_intr[1]);
+
     LOGD("Server terminated");
     return 0;
 }
@@ -367,37 +366,36 @@ server_start(struct server *server, const char *serial,
         goto error1;
     }
 
-    // server will connect to our server socket
-    server->process = execute_server(server, params);
-    if (server->process == PROCESS_NONE) {
+    bool ok = net_pipe(server->pipe_intr);
+    if (!ok) {
+        perror("pipe");
         goto error2;
     }
 
-    // If the server process dies before connecting to the server socket, then
-    // the client will be stuck forever on accept(). To avoid the problem, we
-    // must be able to wake up the accept() call when the server dies. To keep
-    // things simple and multiplatform, just spawn a new thread waiting for the
-    // server process and calling shutdown()/close() on the server socket if
-    // necessary to wake up any accept() blocking call.
+    // server will connect to our server socket
+    server->process = execute_server(server, params);
+    if (server->process == PROCESS_NONE) {
+        goto error3;
+    }
+
     server->wait_server_thread =
         SDL_CreateThread(run_wait_server, "wait-server", server);
     if (!server->wait_server_thread) {
         cmd_terminate(server->process);
         cmd_simple_wait(server->process, NULL); // ignore exit code
-        goto error2;
+        goto error3;
     }
 
     server->tunnel_enabled = true;
 
     return true;
 
+error3:
+    close(server->pipe_intr[0]);
+    close(server->pipe_intr[1]);
 error2:
     if (!server->tunnel_forward) {
-        bool was_closed =
-            atomic_flag_test_and_set(&server->server_socket_closed);
-        // the thread is not started, the flag could not be already set
-        assert(!was_closed);
-        close_socket(server->server_socket);
+        close_socket(&server->server_socket);
     }
     disable_tunnel(server);
 error1:
@@ -408,23 +406,34 @@ error1:
 bool
 server_connect_to(struct server *server) {
     if (!server->tunnel_forward) {
+        bool acceptable = net_select_interruptible(server->server_socket,
+                                                   server->pipe_intr[0]);
+        if (!acceptable) {
+            // the process died, accept() would never succeed
+            return false;
+        }
+
         server->video_socket = net_accept(server->server_socket);
         if (server->video_socket == INVALID_SOCKET) {
             return false;
         }
 
+        acceptable = net_select_interruptible(server->server_socket,
+                                              server->pipe_intr[0]);
+        if (!acceptable) {
+            // the process died, accept() would never succeed
+            return false;
+        }
         server->control_socket = net_accept(server->server_socket);
         if (server->control_socket == INVALID_SOCKET) {
             // the video_socket will be cleaned up on destroy
             return false;
         }
 
+        close(server->pipe_intr[0]);
+
         // we don't need the server socket anymore
-        if (!atomic_flag_test_and_set(&server->server_socket_closed)) {
-            // close it from here
-            close_socket(server->server_socket);
-            // otherwise, it is closed by run_wait_server()
-        }
+        close_socket(&server->server_socket);
     } else {
         uint32_t attempts = 100;
         uint32_t delay = 100; // ms
@@ -451,15 +460,14 @@ server_connect_to(struct server *server) {
 
 void
 server_stop(struct server *server) {
-    if (server->server_socket != INVALID_SOCKET
-            && !atomic_flag_test_and_set(&server->server_socket_closed)) {
-        close_socket(server->server_socket);
+    if (server->server_socket != INVALID_SOCKET) {
+        close_socket(&server->server_socket);
     }
     if (server->video_socket != INVALID_SOCKET) {
-        close_socket(server->video_socket);
+        close_socket(&server->video_socket);
     }
     if (server->control_socket != INVALID_SOCKET) {
-        close_socket(server->control_socket);
+        close_socket(&server->control_socket);
     }
 
     assert(server->process != PROCESS_NONE);

app/src/server.h

@@ -1,7 +1,6 @@
 #ifndef SERVER_H
 #define SERVER_H
 
-#include <stdatomic.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <SDL2/SDL_thread.h>
@@ -15,7 +14,7 @@ struct server {
     char *serial;
     process_t process;
     SDL_Thread *wait_server_thread;
-    atomic_flag server_socket_closed;
+    int pipe_intr[2]; // to wake up blocking accept() on process exit
     socket_t server_socket; // only used if !tunnel_forward
     socket_t video_socket;
     socket_t control_socket;
@@ -28,8 +27,6 @@ struct server {
 #define SERVER_INITIALIZER { \
     .serial = NULL, \
     .process = PROCESS_NONE, \
-    .wait_server_thread = NULL, \
-    .server_socket_closed = ATOMIC_FLAG_INIT, \
     .server_socket = INVALID_SOCKET, \
     .video_socket = INVALID_SOCKET, \
     .control_socket = INVALID_SOCKET, \

app/src/util/net.c

@@ -1,16 +1,22 @@
 #include "net.h"
 
+#include <assert.h>
+#include <errno.h>
 #include <stdio.h>
 #include <SDL2/SDL_platform.h>
 
 #include "config.h"
+#include "common.h"
 #include "log.h"
 
 #ifdef __WINDOWS__
+# include <io.h>
+# include <winsock2.h>
   typedef int socklen_t;
 #else
-# include <sys/types.h>
+# include <sys/select.h>
 # include <sys/socket.h>
+# include <sys/types.h>
 # include <netinet/in.h>
 # include <arpa/inet.h>
 # include <unistd.h>
@@ -145,3 +151,38 @@ net_close(socket_t socket) {
     return !close(socket);
 #endif
 }
+
+bool
+net_select_interruptible(int fd, int fd_intr) {
+    fd_set rfds;
+
+    FD_ZERO(&rfds);
+    FD_SET(fd, &rfds);
+    FD_SET(fd_intr, &rfds);
+
+    int nfds = MAX(fd, fd_intr) + 1;
+
+    // use select() because it's available on supported platforms
+    int r = select(nfds, &rfds, NULL, NULL, NULL);
+    if (r == -1) {
+        // failure
+        return false;
+    }
+    assert(r > 0);
+    if (FD_ISSET(fd_intr, &rfds)) {
+        // interrupted is set
+        return false;
+    }
+
+    assert(FD_ISSET(fd, &rfds));
+    return true;
+}
+
+bool
+net_pipe(int fds[static 2]) {
+#ifdef __WINDOWS__
+    return !_pipe(fds, 4096, 0);
+#else
+    return !pipe(fds);
+#endif
+}

app/src/util/net.h

@@ -54,4 +54,12 @@ net_shutdown(socket_t socket, int how);
 bool
 net_close(socket_t socket);
 
+// wait for fd or fd_intr to be readable
+// return true if fd is readable and fd_intr is not
+bool
+net_select_interruptible(int fd, int fd_intr);
+
+bool
+net_pipe(int fd[static 2]);
+
 #endif

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

@@ -163,10 +163,8 @@ public final class Device {
     }
 
     public void setClipboardText(String text) {
-        boolean ok = serviceManager.getClipboardManager().setText(text);
-        if (ok) {
-            Ln.i("Device clipboard set");
-        }
+        serviceManager.getClipboardManager().setText(text);
+        Ln.i("Device clipboard set");
     }
 
     /**
@@ -178,10 +176,8 @@ public final class Device {
             Ln.e("Could not get built-in display");
             return;
         }
-        boolean ok = SurfaceControl.setDisplayPowerMode(d, mode);
-        if (ok) {
-            Ln.i("Device screen turned " + (mode == Device.POWER_MODE_OFF ? "off" : "on"));
-        }
+        SurfaceControl.setDisplayPowerMode(d, mode);
+        Ln.i("Device screen turned " + (mode == Device.POWER_MODE_OFF ? "off" : "on"));
     }
 
     /**

server/src/main/java/com/genymobile/scrcpy/wrappers/ClipboardManager.java

@@ -74,15 +74,13 @@ public class ClipboardManager {
         }
     }
 
-    public boolean setText(CharSequence text) {
+    public void setText(CharSequence text) {
         try {
             Method method = getSetPrimaryClipMethod();
             ClipData clipData = ClipData.newPlainText(null, text);
             setPrimaryClip(method, manager, clipData);
-            return true;
         } catch (InvocationTargetException | IllegalAccessException | NoSuchMethodException e) {
             Ln.e("Could not invoke method", e);
-            return false;
         }
     }
 }

server/src/main/java/com/genymobile/scrcpy/wrappers/SurfaceControl.java

@@ -121,14 +121,12 @@ public final class SurfaceControl {
         return setDisplayPowerModeMethod;
     }
 
-    public static boolean setDisplayPowerMode(IBinder displayToken, int mode) {
+    public static void setDisplayPowerMode(IBinder displayToken, int mode) {
         try {
             Method method = getSetDisplayPowerModeMethod();
             method.invoke(null, displayToken, mode);
-            return true;
         } catch (InvocationTargetException | IllegalAccessException | NoSuchMethodException e) {
             Ln.e("Could not invoke method", e);
-            return false;
         }
     }