poll_loop.hxx

// dawn/include/dawn/common/poll_loop.hxx
//
// SPDX-License-Identifier: Apache-2.0
//
 
#pragma once
 
#include <poll.h>
 
#include "dawn/common/thread.hxx"
 
namespace dawn
{
static constexpr int DAWN_POLL_TIMEOUT_MS = 1000;
 
struct SPollLoopCallbacks
{
  int (*beforePoll)(void *priv, struct pollfd *pfds, nfds_t nfds);
 
  void (*afterPoll)(void *priv, struct pollfd *pfds, nfds_t nfds, int ret);
 
  int (*onPollReady)(void *priv, struct pollfd *pfds, nfds_t nfds, int pollRet);
};
 
class CPollLoopRunner
{
public:
  static int run(CThreadedObject &threadCtl,
                 struct pollfd *pfds,
                 nfds_t nfds,
                 int timeoutMs,
                 const SPollLoopCallbacks &callbacks,
                 void *priv)
  {
    int ret;
 
    do
      {
        if (callbacks.beforePoll)
          {
            ret = callbacks.beforePoll(priv, pfds, nfds);
            if (ret < 0)
              {
                continue;
              }
          }
 
        ret = poll(pfds, nfds, timeoutMs);
 
        if (callbacks.afterPoll)
          {
            callbacks.afterPoll(priv, pfds, nfds, ret);
          }
 
        if (ret > 0 && callbacks.onPollReady)
          {
            callbacks.onPollReady(priv, pfds, nfds, ret);
          }
      }
    while (!threadCtl.shouldQuit());
 
    threadCtl.markThreadFinished();
    return 0;
  }
};
 
} // Namespace dawn