Home | History | Annotate | Download | only in vsync 
      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include <gui/DisplayEventReceiver.h>
     18 #include <utils/Looper.h>
     19 
     20 using namespace android;
     21 
     22 int receiver(int fd, int events, void* data)
     23 {
     24     DisplayEventReceiver* q = (DisplayEventReceiver*)data;
     25 
     26     ssize_t n;
     27     DisplayEventReceiver::Event buffer[1];
     28 
     29     static nsecs_t oldTimeStamp = 0;
     30 
     31     while ((n = q->getEvents(buffer, 1)) > 0) {
     32         for (int i=0 ; i<n ; i++) {
     33             if (buffer[i].header.type == DisplayEventReceiver::DISPLAY_EVENT_VSYNC) {
     34                 printf("event vsync: count=%d\t", buffer[i].vsync.count);
     35             }
     36             if (oldTimeStamp) {
     37                 float t = float(buffer[i].header.timestamp - oldTimeStamp) / s2ns(1);
     38                 printf("%f ms (%f Hz)\n", t*1000, 1.0/t);
     39             }
     40             oldTimeStamp = buffer[i].header.timestamp;
     41         }
     42     }
     43     if (n<0) {
     44         printf("error reading events (%s)\n", strerror(-n));
     45     }
     46     return 1;
     47 }
     48 
     49 int main(int argc, char** argv)
     50 {
     51     DisplayEventReceiver myDisplayEvent;
     52 
     53 
     54     sp<Looper> loop = new Looper(false);
     55     loop->addFd(myDisplayEvent.getFd(), 0, ALOOPER_EVENT_INPUT, receiver,
     56             &myDisplayEvent);
     57 
     58     myDisplayEvent.setVsyncRate(1);
     59 
     60     do {
     61         //printf("about to poll...\n");
     62         int32_t ret = loop->pollOnce(-1);
     63         switch (ret) {
     64             case ALOOPER_POLL_WAKE:
     65                 //("ALOOPER_POLL_WAKE\n");
     66                 break;
     67             case ALOOPER_POLL_CALLBACK:
     68                 //("ALOOPER_POLL_CALLBACK\n");
     69                 break;
     70             case ALOOPER_POLL_TIMEOUT:
     71                 printf("ALOOPER_POLL_TIMEOUT\n");
     72                 break;
     73             case ALOOPER_POLL_ERROR:
     74                 printf("ALOOPER_POLL_TIMEOUT\n");
     75                 break;
     76             default:
     77                 printf("ugh? poll returned %d\n", ret);
     78                 break;
     79         }
     80     } while (1);
     81 
     82     return 0;
     83 }
     84