text: /*
   * Copyright (C) 2012 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #define LOG_TAG "Fence"
  #define ATRACE_TAG ATRACE_TAG_GRAPHICS
  //#define LOG_NDEBUG 0
  
  #include <sync/sync.h>
  #include <ui/Fence.h>
  #include <unistd.h>
  #include <utils/Log.h>
  #include <utils/Trace.h>
  
  namespace android {
  
  const sp<Fence> Fence::NO_FENCE = sp<Fence>();
  
  Fence::Fence() :
      mFenceFd(-1) {
  }
  
  Fence::Fence(int fenceFd) :
      mFenceFd(fenceFd) {
  }
  
  Fence::~Fence() {
      if (mFenceFd != -1) {
          close(mFenceFd);
      }
  }
  
  status_t Fence::wait(unsigned int timeout) {
      ATRACE_CALL();
      if (mFenceFd == -1) {
          return NO_ERROR;
      }
      int err = sync_wait(mFenceFd, timeout);
      return err < 0 ? -errno : status_t(NO_ERROR);
  }
  
  status_t Fence::waitForever(unsigned int warningTimeout, const char* logname) {
      ATRACE_CALL();
      if (mFenceFd == -1) {
          return NO_ERROR;
      }
      int err = sync_wait(mFenceFd, warningTimeout);
      if (err < 0 && errno == ETIME) {
          ALOGE("%s: fence %d didn't signal in %u ms", logname, mFenceFd,
                  warningTimeout);
          err = sync_wait(mFenceFd, TIMEOUT_NEVER);
      }
      return err < 0 ? -errno : status_t(NO_ERROR);
  }
  
  sp<Fence> Fence::merge(const String8& name, const sp<Fence>& f1,
          const sp<Fence>& f2) {
      ATRACE_CALL();
      int result = sync_merge(name.string(), f1->mFenceFd, f2->mFenceFd);
      if (result == -1) {
          status_t err = -errno;
          ALOGE("merge: sync_merge(\"%s\", %d, %d) returned an error: %s (%d)",
                  name.string(), f1->mFenceFd, f2->mFenceFd,
                  strerror(-err), err);
          return NO_FENCE;
      }
      return sp<Fence>(new Fence(result));
  }
  
  int Fence::dup() const {
      if (mFenceFd == -1) {
          return -1;
      }
      return ::dup(mFenceFd);
  }
  
  size_t Fence::getFlattenedSize() const {
      return 0;
  }
  
  size_t Fence::getFdCount() const {
      return 1;
  }
  
  status_t Fence::flatten(void* buffer, size_t size, int fds[],
          size_t count) const {
      if (size != 0 || count != 1) {
          return BAD_VALUE;
      }
  
      fds[0] = mFenceFd;
      return NO_ERROR;
  }
  
  status_t Fence::unflatten(void const* buffer, size_t size, int fds[],
          size_t count) {
      if (size != 0 || count != 1) {
          return BAD_VALUE;
      }
      if (mFenceFd != -1) {
          // Don't unflatten if we already have a valid fd.
          return INVALID_OPERATION;
      }
  
      mFenceFd = fds[0];
      return NO_ERROR;
  }
  
  } // namespace android
  