realfps

app/src/fps_counter.c

@@ -1,60 +1,141 @@
 #include "fps_counter.h"
 
 #include <SDL2/SDL_timer.h>
+#include <SDL2/SDL_assert.h>
 
+#include "lock_util.h"
 #include "log.h"
 
-void
-fps_counter_init(struct fps_counter *counter) {
-    counter->started = false;
-    // no need to initialize the other fields, they are meaningful only when
-    // started is true
-}
+#define FPS_COUNTER_INTERVAL 1000
 
-void
-fps_counter_start(struct fps_counter *counter) {
-    counter->started = true;
-    counter->slice_start = SDL_GetTicks();
+bool
+fps_counter_init(struct fps_counter *counter) {
+    counter->mutex = SDL_CreateMutex();
+    if (!counter->mutex) {
+        return false;
+    }
+
+    counter->state_cond = SDL_CreateCond();
+    if (!counter->state_cond) {
+        SDL_DestroyMutex(counter->mutex);
+        return false;
+    }
+
+    counter->thread = NULL;
+    counter->started = false;
+    counter->interrupted = false;
     counter->nr_rendered = 0;
     counter->nr_skipped = 0;
+    // no need to initialize slice_start, it is meaningful only when started
+
+    return true;
 }
 
 void
-fps_counter_stop(struct fps_counter *counter) {
-    counter->started = false;
+fps_counter_destroy(struct fps_counter *counter) {
+    SDL_DestroyCond(counter->state_cond);
+    SDL_DestroyMutex(counter->mutex);
 }
 
 static void
 display_fps(struct fps_counter *counter) {
+    unsigned rendered_per_second =
+        counter->nr_rendered * 1000 / FPS_COUNTER_INTERVAL;
     if (counter->nr_skipped) {
-        LOGI("%d fps (+%d frames skipped)", counter->nr_rendered,
-                                            counter->nr_skipped);
+        unsigned skipped_per_second =
+            counter->nr_skipped * 1000 / FPS_COUNTER_INTERVAL;
+        LOGI("%u fps (+%u frames skipped)", rendered_per_second,
+                                            skipped_per_second);
     } else {
-        LOGI("%d fps", counter->nr_rendered);
+        LOGI("%u fps", rendered_per_second);
     }
 }
 
-static void
-check_expired(struct fps_counter *counter) {
-    uint32_t now = SDL_GetTicks();
-    if (now - counter->slice_start >= 1000) {
-        display_fps(counter);
-        // add a multiple of one second
-        uint32_t elapsed_slices = (now - counter->slice_start) / 1000;
-        counter->slice_start += 1000 * elapsed_slices;
-        counter->nr_rendered = 0;
-        counter->nr_skipped = 0;
+static int
+run_fps_counter(void *data) {
+    struct fps_counter *counter = data;
+
+    mutex_lock(counter->mutex);
+    while (!counter->interrupted) {
+        while (!counter->interrupted && !counter->started) {
+            cond_wait(counter->state_cond, counter->mutex);
+        }
+        while (!counter->interrupted && counter->started) {
+            uint32_t now = SDL_GetTicks();
+            if (now >= counter->next_timestamp) {
+                display_fps(counter);
+                counter->nr_rendered = 0;
+                counter->nr_skipped = 0;
+                // add a multiple of the interval
+                uint32_t elapsed_slices =
+                    (now - counter->next_timestamp) / FPS_COUNTER_INTERVAL + 1;
+                counter->next_timestamp += FPS_COUNTER_INTERVAL * elapsed_slices;
+            }
+            SDL_assert(counter->next_timestamp > now);
+            uint32_t remaining = counter->next_timestamp - now;
+
+            // ignore the reason (timeout or signaled), we just loop anyway
+            cond_wait_timeout(counter->state_cond, counter->mutex, remaining);
+        }
+    }
+    mutex_unlock(counter->mutex);
+    return 0;
+}
+
+bool
+fps_counter_start(struct fps_counter *counter) {
+    if (!counter->thread) {
+        counter->thread =
+            SDL_CreateThread(run_fps_counter, "fps counter", counter);
+        if (!counter->thread) {
+            LOGE("Could not start FPS counter thread");
+            return false;
+        }
+    }
+
+    mutex_lock(counter->mutex);
+    counter->started = true;
+    counter->next_timestamp = SDL_GetTicks() + FPS_COUNTER_INTERVAL;
+    counter->nr_rendered = 0;
+    counter->nr_skipped = 0;
+    mutex_unlock(counter->mutex);
+
+    cond_signal(counter->state_cond);
+    return true;
+}
+
+void
+fps_counter_stop(struct fps_counter *counter) {
+    mutex_lock(counter->mutex);
+    counter->started = false;
+    mutex_unlock(counter->mutex);
+    cond_signal(counter->state_cond);
+}
+
+void
+fps_counter_interrupt(struct fps_counter *counter) {
+    if (counter->thread) {
+        mutex_lock(counter->mutex);
+        counter->interrupted = true;
+        mutex_unlock(counter->mutex);
+        // wake up blocking wait
+        cond_signal(counter->state_cond);
+    }
+}
+
+void
+fps_counter_join(struct fps_counter *counter) {
+    if (counter->thread) {
+        SDL_WaitThread(counter->thread, NULL);
     }
 }
 
 void
 fps_counter_add_rendered_frame(struct fps_counter *counter) {
-    check_expired(counter);
     ++counter->nr_rendered;
 }
 
 void
 fps_counter_add_skipped_frame(struct fps_counter *counter) {
-    check_expired(counter);
     ++counter->nr_skipped;
 }

app/src/fps_counter.h

@@ -3,23 +3,41 @@
 
 #include <stdbool.h>
 #include <stdint.h>
+#include <SDL2/SDL_atomic.h>
+#include <SDL2/SDL_mutex.h>
+#include <SDL2/SDL_thread.h>
 
 struct fps_counter {
+    SDL_Thread *thread;
+    SDL_mutex *mutex;
+    SDL_cond *state_cond;
     bool started;
-    uint32_t slice_start; // initialized by SDL_GetTicks()
-    int nr_rendered;
-    int nr_skipped;
+    bool interrupted;
+    unsigned nr_rendered;
+    unsigned nr_skipped;
+    uint32_t next_timestamp;
 };
 
-void
+bool
 fps_counter_init(struct fps_counter *counter);
 
 void
+fps_counter_destroy(struct fps_counter *counter);
+
+bool
 fps_counter_start(struct fps_counter *counter);
 
 void
 fps_counter_stop(struct fps_counter *counter);
 
+// request to stop the thread (on quit)
+// must be called before fps_counter_join()
+void
+fps_counter_interrupt(struct fps_counter *counter);
+
+void
+fps_counter_join(struct fps_counter *counter);
+
 void
 fps_counter_add_rendered_frame(struct fps_counter *counter);
 

app/src/input_manager.c

@@ -172,16 +172,19 @@ set_screen_power_mode(struct controller *controller,
 }
 
 static void
-switch_fps_counter_state(struct video_buffer *vb) {
-    mutex_lock(vb->mutex);
-    if (vb->fps_counter.started) {
+switch_fps_counter_state(struct fps_counter *fps_counter) {
+    mutex_lock(fps_counter->mutex);
+    if (fps_counter->started) {
+        fps_counter_stop(fps_counter);
         LOGI("FPS counter stopped");
-        fps_counter_stop(&vb->fps_counter);
     } else {
-        LOGI("FPS counter started");
-        fps_counter_start(&vb->fps_counter);
+        if (fps_counter_start(fps_counter)) {
+            LOGI("FPS counter started");
+        } else {
+            LOGE("FPS counter starting failed");
+        }
     }
-    mutex_unlock(vb->mutex);
+    mutex_unlock(fps_counter->mutex);
 }
 
 static void
@@ -339,7 +342,9 @@ input_manager_process_key(struct input_manager *input_manager,
                 return;
             case SDLK_i:
                 if (ctrl && !meta && !shift && !repeat && down) {
-                    switch_fps_counter_state(input_manager->video_buffer);
+                    struct fps_counter *fps_counter =
+                        input_manager->video_buffer->fps_counter;
+                    switch_fps_counter_state(fps_counter);
                 }
                 return;
             case SDLK_n:

app/src/lock_util.c

@@ -28,6 +28,16 @@ cond_wait(SDL_cond *cond, SDL_mutex *mutex) {
     }
 }
 
+int
+cond_wait_timeout(SDL_cond *cond, SDL_mutex *mutex, uint32_t ms) {
+    int r = SDL_CondWaitTimeout(cond, mutex, ms);
+    if (r < 0) {
+        LOGC("Could not wait on condition with timeout");
+        abort();
+    }
+    return r;
+}
+
 void
 cond_signal(SDL_cond *cond) {
     if (SDL_CondSignal(cond)) {

app/src/lock_util.h

@@ -1,6 +1,8 @@
 #ifndef LOCKUTIL_H
 #define LOCKUTIL_H
 
+#include <stdint.h>
+
 // forward declarations
 typedef struct SDL_mutex SDL_mutex;
 typedef struct SDL_cond SDL_cond;
@@ -14,6 +16,10 @@ mutex_unlock(SDL_mutex *mutex);
 void
 cond_wait(SDL_cond *cond, SDL_mutex *mutex);
 
+// return 0 or SDL_MUTEX_TIMEDOUT
+int
+cond_wait_timeout(SDL_cond *cond, SDL_mutex *mutex, uint32_t ms);
+
 void
 cond_signal(SDL_cond *cond);
 

app/src/scrcpy.c

@@ -29,6 +29,7 @@
 
 static struct server server = SERVER_INITIALIZER;
 static struct screen screen = SCREEN_INITIALIZER;
+static struct fps_counter fps_counter;
 static struct video_buffer video_buffer;
 static struct stream stream;
 static struct decoder decoder;
@@ -293,6 +294,7 @@ scrcpy(const struct scrcpy_options *options) {
 
     bool ret = false;
 
+    bool fps_counter_initialized = false;
     bool video_buffer_initialized = false;
     bool file_handler_initialized = false;
     bool recorder_initialized = false;
@@ -320,7 +322,13 @@ scrcpy(const struct scrcpy_options *options) {
 
     struct decoder *dec = NULL;
     if (options->display) {
-        if (!video_buffer_init(&video_buffer, options->render_expired_frames)) {
+        if (!fps_counter_init(&fps_counter)) {
+            goto end;
+        }
+        fps_counter_initialized = true;
+
+        if (!video_buffer_init(&video_buffer, &fps_counter,
+                               options->render_expired_frames)) {
             goto end;
         }
         video_buffer_initialized = true;
@@ -414,6 +422,9 @@ end:
     if (file_handler_initialized) {
         file_handler_stop(&file_handler);
     }
+    if (fps_counter_initialized) {
+        fps_counter_interrupt(&fps_counter);
+    }
 
     // shutdown the sockets and kill the server
     server_stop(&server);
@@ -443,6 +454,11 @@ end:
         video_buffer_destroy(&video_buffer);
     }
 
+    if (fps_counter_initialized) {
+        fps_counter_join(&fps_counter);
+        fps_counter_destroy(&fps_counter);
+    }
+
     if (options->show_touches) {
         if (!show_touches_waited) {
             // wait the process which enabled "show touches"

app/src/video_buffer.c

@@ -10,7 +10,10 @@
 #include "log.h"
 
 bool
-video_buffer_init(struct video_buffer *vb, bool render_expired_frames) {
+video_buffer_init(struct video_buffer *vb, struct fps_counter *fps_counter,
+                  bool render_expired_frames) {
+    vb->fps_counter = fps_counter;
+
     if (!(vb->decoding_frame = av_frame_alloc())) {
         goto error_0;
     }
@@ -37,7 +40,6 @@ video_buffer_init(struct video_buffer *vb, bool render_expired_frames) {
     // there is initially no rendering frame, so consider it has already been
     // consumed
     vb->rendering_frame_consumed = true;
-    fps_counter_init(&vb->fps_counter);
 
     return true;
 
@@ -76,8 +78,8 @@ video_buffer_offer_decoded_frame(struct video_buffer *vb,
             cond_wait(vb->rendering_frame_consumed_cond, vb->mutex);
         }
     } else {
-        if (vb->fps_counter.started && !vb->rendering_frame_consumed) {
-            fps_counter_add_skipped_frame(&vb->fps_counter);
+        if (vb->fps_counter->started && !vb->rendering_frame_consumed) {
+            fps_counter_add_skipped_frame(vb->fps_counter);
         }
     }
 
@@ -93,8 +95,8 @@ const AVFrame *
 video_buffer_consume_rendered_frame(struct video_buffer *vb) {
     SDL_assert(!vb->rendering_frame_consumed);
     vb->rendering_frame_consumed = true;
-    if (vb->fps_counter.started) {
-        fps_counter_add_rendered_frame(&vb->fps_counter);
+    if (vb->fps_counter->started) {
+        fps_counter_add_rendered_frame(vb->fps_counter);
     }
     if (vb->render_expired_frames) {
         // unblock video_buffer_offer_decoded_frame()

app/src/video_buffer.h

@@ -17,11 +17,12 @@ struct video_buffer {
     bool interrupted;
     SDL_cond *rendering_frame_consumed_cond;
     bool rendering_frame_consumed;
-    struct fps_counter fps_counter;
+    struct fps_counter *fps_counter;
 };
 
 bool
-video_buffer_init(struct video_buffer *vb, bool render_expired_frames);
+video_buffer_init(struct video_buffer *vb, struct fps_counter *fps_counter,
+                  bool render_expired_frames);
 
 void
 video_buffer_destroy(struct video_buffer *vb);