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      1 /*
      2 * Copyright (C) 2016 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 "renderControl_enc.h"
     18 #include "qemu_pipe.h"
     19 
     20 #include <cutils/log.h>
     21 #include <pthread.h>
     22 
     23 static int                sProcPipe = 0;
     24 static pthread_once_t     sProcPipeOnce = PTHREAD_ONCE_INIT;
     25 // sProcUID is a unique ID per process assigned by the host.
     26 // It is different from getpid().
     27 static uint64_t           sProcUID = 0;
     28 
     29 // processPipeInitOnce is used to generate a process unique ID (puid).
     30 // processPipeInitOnce will only be called at most once per process.
     31 // Use it with pthread_once for thread safety.
     32 // The host associates resources with process unique ID (puid) for memory cleanup.
     33 // It will fallback to the default path if the host does not support it.
     34 // Processes are identified by acquiring a per-process 64bit unique ID from the
     35 // host.
     36 static void processPipeInitOnce() {
     37     sProcPipe = qemu_pipe_open("GLProcessPipe");
     38     if (sProcPipe < 0) {
     39         sProcPipe = 0;
     40         ALOGW("Process pipe failed");
     41         return;
     42     }
     43     // Send a confirmation int to the host
     44     int32_t confirmInt = 100;
     45     ssize_t stat = 0;
     46     do {
     47         stat = ::write(sProcPipe, (const char*)&confirmInt,
     48                 sizeof(confirmInt));
     49     } while (stat < 0 && errno == EINTR);
     50 
     51     if (stat != sizeof(confirmInt)) { // failed
     52         close(sProcPipe);
     53         sProcPipe = 0;
     54         ALOGW("Process pipe failed");
     55         return;
     56     }
     57 
     58     // Ask the host for per-process unique ID
     59     do {
     60         stat = ::read(sProcPipe, (char*)&sProcUID,
     61                       sizeof(sProcUID));
     62     } while (stat < 0 && errno == EINTR);
     63 
     64     if (stat != sizeof(sProcUID)) {
     65         close(sProcPipe);
     66         sProcPipe = 0;
     67         sProcUID = 0;
     68         ALOGW("Process pipe failed");
     69         return;
     70     }
     71 }
     72 
     73 bool processPipeInit(renderControl_encoder_context_t *rcEnc) {
     74     pthread_once(&sProcPipeOnce, processPipeInitOnce);
     75     if (!sProcPipe) return false;
     76     rcEnc->rcSetPuid(rcEnc, sProcUID);
     77     return true;
     78 }
     79