pollset.c

#ifndef _WIN32
#include <errno.h>
 
#include "pollset.h"
#include <winpr/handle.h>
#include <winpr/sysinfo.h>
#include <winpr/assert.h>
#include "../log.h"
 
#define TAG WINPR_TAG("sync.pollset")
 
#if defined(__EMSCRIPTEN__)
/* in pollset_emscripten.js: returns once the browser's event loop has run the tasks that were
 * waiting, without the 4 ms that emscripten_sleep(0) (setTimeout) costs there */
extern void winpr_pollset_js_yield(void);
#endif
 
#ifdef WINPR_HAVE_POLL_H
static INT16 handle_mode_to_pollevent(ULONG mode)
{
  INT16 event = 0;
 
  if (mode & WINPR_FD_READ)
    event |= POLLIN;
 
  if (mode & WINPR_FD_WRITE)
    event |= POLLOUT;
 
  return event;
}
#endif
 
BOOL pollset_init(WINPR_POLL_SET* set, size_t nhandles)
{
  WINPR_ASSERT(set);
#ifdef WINPR_HAVE_POLL_H
  if (nhandles > MAXIMUM_WAIT_OBJECTS)
  {
    set->isStatic = FALSE;
    set->pollset = calloc(nhandles, sizeof(*set->pollset));
    if (!set->pollset)
      return FALSE;
  }
  else
  {
    set->pollset = set->staticSet;
    set->isStatic = TRUE;
  }
#else
  set->fdIndex = calloc(nhandles, sizeof(*set->fdIndex));
  if (!set->fdIndex)
    return FALSE;
 
  FD_ZERO(&set->rset_base);
  FD_ZERO(&set->rset);
  FD_ZERO(&set->wset_base);
  FD_ZERO(&set->wset);
  set->maxFd = 0;
  set->nread = set->nwrite = 0;
#endif
 
  set->size = nhandles;
  set->fillIndex = 0;
  return TRUE;
}
 
void pollset_uninit(WINPR_POLL_SET* set)
{
  WINPR_ASSERT(set);
#ifdef WINPR_HAVE_POLL_H
  if (!set->isStatic)
    free(set->pollset);
#else
  free(set->fdIndex);
#endif
}
 
void pollset_reset(WINPR_POLL_SET* set)
{
  WINPR_ASSERT(set);
#ifndef WINPR_HAVE_POLL_H
  FD_ZERO(&set->rset_base);
  FD_ZERO(&set->wset_base);
  set->maxFd = 0;
  set->nread = set->nwrite = 0;
#endif
  set->fillIndex = 0;
}
 
BOOL pollset_add(WINPR_POLL_SET* set, int fd, ULONG mode)
{
  WINPR_ASSERT(set);
#ifdef WINPR_HAVE_POLL_H
  struct pollfd* item = nullptr;
  if (set->fillIndex == set->size)
    return FALSE;
 
  item = &set->pollset[set->fillIndex];
  item->fd = fd;
  item->revents = 0;
  item->events = handle_mode_to_pollevent(mode);
#else
  FdIndex* fdIndex = &set->fdIndex[set->fillIndex];
  if (mode & WINPR_FD_READ)
  {
    FD_SET(fd, &set->rset_base);
    set->nread++;
  }
 
  if (mode & WINPR_FD_WRITE)
  {
    FD_SET(fd, &set->wset_base);
    set->nwrite++;
  }
 
  if (fd > set->maxFd)
    set->maxFd = fd;
 
  fdIndex->fd = fd;
  fdIndex->mode = mode;
#endif
  set->fillIndex++;
  return TRUE;
}
 
int pollset_poll(WINPR_POLL_SET* set, DWORD dwMilliseconds)
{
  WINPR_ASSERT(set);
  int ret = 0;
  UINT64 dueTime = 0;
  UINT64 now = 0;
 
  now = GetTickCount64();
  if (dwMilliseconds == INFINITE)
    dueTime = 0xFFFFFFFFFFFFFFFF;
  else
    dueTime = now + dwMilliseconds;
 
#ifdef WINPR_HAVE_POLL_H
  int timeout = 0;
 
  do
  {
    if (dwMilliseconds == INFINITE)
      timeout = -1;
    else
      timeout = (int)(dueTime - now);
 
    ret = poll(set->pollset, WINPR_ASSERTING_INT_CAST(nfds_t, set->fillIndex), timeout);
    if (ret >= 0)
    {
#if defined(__EMSCRIPTEN__)
      /* If we have tried 10 times unsuccessfully we will yield in emscripten so pending event
       * handlers might be run */
      if (ret == 0)
      {
        if (++set->yieldCounter > 10)
        {
          winpr_pollset_js_yield();
          set->yieldCounter = 0;
        }
      }
      else
        set->yieldCounter = 0;
#endif
      return ret;
    }
 
    if (errno != EINTR)
      return -1;
 
    now = GetTickCount64();
  } while (now < dueTime);
 
#else
  do
  {
    struct timeval staticTimeout;
    struct timeval* timeout;
 
    fd_set* rset = nullptr;
    fd_set* wset = nullptr;
 
    if (dwMilliseconds == INFINITE)
    {
      timeout = nullptr;
    }
    else
    {
      long waitTime = (long)(dueTime - now);
 
      timeout = &staticTimeout;
      timeout->tv_sec = waitTime / 1000;
      timeout->tv_usec = (waitTime % 1000) * 1000;
    }
 
    if (set->nread)
    {
      rset = &set->rset;
      memcpy(rset, &set->rset_base, sizeof(*rset));
    }
 
    if (set->nwrite)
    {
      wset = &set->wset;
      memcpy(wset, &set->wset_base, sizeof(*wset));
    }
 
    ret = select(set->maxFd + 1, rset, wset, nullptr, timeout);
    if (ret >= 0)
      return ret;
 
    if (errno != EINTR)
      return -1;
 
    now = GetTickCount64();
 
  } while (now < dueTime);
 
  FD_ZERO(&set->rset);
  FD_ZERO(&set->wset);
#endif
 
  return 0; /* timeout */
}
 
BOOL pollset_isSignaled(WINPR_POLL_SET* set, size_t idx)
{
  WINPR_ASSERT(set);
 
  if (idx > set->fillIndex)
  {
    WLog_ERR(TAG, "index=%" PRIuz " out of pollset(fillIndex=%" PRIuz ")", idx, set->fillIndex);
    return FALSE;
  }
 
#ifdef WINPR_HAVE_POLL_H
  return !!(set->pollset[idx].revents & set->pollset[idx].events);
#else
  FdIndex* fdIndex = &set->fdIndex[idx];
  if (fdIndex->fd < 0)
    return FALSE;
 
  if ((fdIndex->mode & WINPR_FD_READ) && FD_ISSET(fdIndex->fd, &set->rset))
    return TRUE;
 
  if ((fdIndex->mode & WINPR_FD_WRITE) && FD_ISSET(fdIndex->fd, &set->wset))
    return TRUE;
 
  return FALSE;
#endif
}
 
BOOL pollset_isReadSignaled(WINPR_POLL_SET* set, size_t idx)
{
  WINPR_ASSERT(set);
 
  if (idx > set->fillIndex)
  {
    WLog_ERR(TAG, "index=%" PRIuz " out of pollset(fillIndex=%" PRIuz ")", idx, set->fillIndex);
    return FALSE;
  }
 
#ifdef WINPR_HAVE_POLL_H
  return !!(set->pollset[idx].revents & POLLIN);
#else
  FdIndex* fdIndex = &set->fdIndex[idx];
  if (fdIndex->fd < 0)
    return FALSE;
 
  return FD_ISSET(fdIndex->fd, &set->rset);
#endif
}
 
BOOL pollset_isWriteSignaled(WINPR_POLL_SET* set, size_t idx)
{
  WINPR_ASSERT(set);
 
  if (idx > set->fillIndex)
  {
    WLog_ERR(TAG, "index=%" PRIuz " out of pollset(fillIndex=%" PRIuz ")", idx, set->fillIndex);
    return FALSE;
  }
 
#ifdef WINPR_HAVE_POLL_H
  return !!(set->pollset[idx].revents & POLLOUT);
#else
  FdIndex* fdIndex = &set->fdIndex[idx];
  if (fdIndex->fd < 0)
    return FALSE;
 
  return FD_ISSET(fdIndex->fd, &set->wset);
#endif
}
 
#endif