/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
 * This file implements _PR_MD_PR_POLL for Win32.
 */

/* The default value of FD_SETSIZE is 64. */
#define FD_SETSIZE 1024

#include "primpl.h"

#if !defined(_PR_GLOBAL_THREADS_ONLY)

struct select_data_s {
  PRInt32 status;
  PRInt32 error;
  fd_set *rd, *wt, *ex;
  const struct timeval* tv;
};

static void _PR_MD_select_thread(void* cdata) {
  struct select_data_s* cd = (struct select_data_s*)cdata;

  cd->status = select(0, cd->rd, cd->wt, cd->ex, cd->tv);

  if (cd->status == SOCKET_ERROR) {
    cd->error = WSAGetLastError();
  }
}

int _PR_NTFiberSafeSelect(int nfds, fd_set* readfds, fd_set* writefds,
                          fd_set* exceptfds, const struct timeval* timeout) {
  PRThread* me = _PR_MD_CURRENT_THREAD();
  int ready;

  if (_PR_IS_NATIVE_THREAD(me)) {
    ready = _MD_SELECT(nfds, readfds, writefds, exceptfds, timeout);
  } else {
    /*
    ** Creating a new thread on each call!!
    ** I guess web server doesn't use non-block I/O.
    */
    PRThread* selectThread;
    struct select_data_s data;
    data.status = 0;
    data.error = 0;
    data.rd = readfds;
    data.wt = writefds;
    data.ex = exceptfds;
    data.tv = timeout;

    selectThread = PR_CreateThread(PR_USER_THREAD, _PR_MD_select_thread, &data,
                                   PR_PRIORITY_NORMAL, PR_GLOBAL_THREAD,
                                   PR_JOINABLE_THREAD, 0);
    if (selectThread == NULL) {
      return -1;
    }

    PR_JoinThread(selectThread);
    ready = data.status;
    if (ready == SOCKET_ERROR) {
      WSASetLastError(data.error);
    }
  }
  return ready;
}

#endif /* !defined(_PR_GLOBAL_THREADS_ONLY) */

PRInt32 _PR_MD_PR_POLL(PRPollDesc* pds, PRIntn npds, PRIntervalTime timeout) {
  int ready, err;
  fd_set rd, wt, ex;
  fd_set *rdp, *wtp, *exp;
  int nrd, nwt, nex;
  PRFileDesc* bottom;
  PRPollDesc *pd, *epd;
  PRThread* me = _PR_MD_CURRENT_THREAD();

  struct timeval tv, *tvp = NULL;

  if (_PR_PENDING_INTERRUPT(me)) {
    me->flags &= ~_PR_INTERRUPT;
    PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0);
    return -1;
  }

  /*
  ** Is it an empty set? If so, just sleep for the timeout and return
  */
  if (0 == npds) {
    PR_Sleep(timeout);
    return 0;
  }

  nrd = nwt = nex = 0;
  FD_ZERO(&rd);
  FD_ZERO(&wt);
  FD_ZERO(&ex);

  ready = 0;
  for (pd = pds, epd = pd + npds; pd < epd; pd++) {
    SOCKET osfd;
    PRInt16 in_flags_read = 0, in_flags_write = 0;
    PRInt16 out_flags_read = 0, out_flags_write = 0;

    if ((NULL != pd->fd) && (0 != pd->in_flags)) {
      if (pd->in_flags & PR_POLL_READ) {
        in_flags_read = (pd->fd->methods->poll)(
            pd->fd, (PRInt16)(pd->in_flags & ~PR_POLL_WRITE), &out_flags_read);
      }
      if (pd->in_flags & PR_POLL_WRITE) {
        in_flags_write = (pd->fd->methods->poll)(
            pd->fd, (PRInt16)(pd->in_flags & ~PR_POLL_READ), &out_flags_write);
      }
      if ((0 != (in_flags_read & out_flags_read)) ||
          (0 != (in_flags_write & out_flags_write))) {
        /* this one's ready right now (buffered input) */
        if (0 == ready) {
          /*
           * We will have to return without calling the
           * system poll/select function.  So zero the
           * out_flags fields of all the poll descriptors
           * before this one.
           */
          PRPollDesc* prev;
          for (prev = pds; prev < pd; prev++) {
            prev->out_flags = 0;
          }
        }
        ready += 1;
        pd->out_flags = out_flags_read | out_flags_write;
      } else {
        pd->out_flags = 0; /* pre-condition */
        /* make sure this is an NSPR supported stack */
        bottom = PR_GetIdentitiesLayer(pd->fd, PR_NSPR_IO_LAYER);
        /* ignore a socket without PR_NSPR_IO_LAYER available */

        if ((NULL != bottom) && (_PR_FILEDESC_OPEN == bottom->secret->state)) {
          if (0 == ready) {
            osfd = (SOCKET)bottom->secret->md.osfd;
            if (in_flags_read & PR_POLL_READ) {
              pd->out_flags |= _PR_POLL_READ_SYS_READ;
              FD_SET(osfd, &rd);
              nrd++;
            }
            if (in_flags_read & PR_POLL_WRITE) {
              pd->out_flags |= _PR_POLL_READ_SYS_WRITE;
              FD_SET(osfd, &wt);
              nwt++;
            }
            if (in_flags_write & PR_POLL_READ) {
              pd->out_flags |= _PR_POLL_WRITE_SYS_READ;
              FD_SET(osfd, &rd);
              nrd++;
            }
            if (in_flags_write & PR_POLL_WRITE) {
              pd->out_flags |= _PR_POLL_WRITE_SYS_WRITE;
              FD_SET(osfd, &wt);
              nwt++;
            }
            if (pd->in_flags & PR_POLL_EXCEPT) {
              FD_SET(osfd, &ex);
              nex++;
            }
          }
        } else {
          if (0 == ready) {
            PRPollDesc* prev;
            for (prev = pds; prev < pd; prev++) {
              prev->out_flags = 0;
            }
          }
          ready += 1;                   /* this will cause an abrupt return */
          pd->out_flags = PR_POLL_NVAL; /* bogii */
        }
      }
    } else {
      pd->out_flags = 0;
    }
  }

  if (0 != ready) {
    return ready; /* no need to block */
  }

  /*
   * FD_SET does nothing if the fd_set's internal fd_array is full.  If
   * nrd, nwt, or nex is greater than FD_SETSIZE, we know FD_SET must
   * have failed to insert an osfd into the corresponding fd_set, and
   * therefore we should fail.
   */
  if ((nrd > FD_SETSIZE) || (nwt > FD_SETSIZE) || (nex > FD_SETSIZE)) {
    PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
    return -1;
  }

  rdp = (0 == nrd) ? NULL : &rd;
  wtp = (0 == nwt) ? NULL : &wt;
  exp = (0 == nex) ? NULL : &ex;

  if ((NULL == rdp) && (NULL == wtp) && (NULL == exp)) {
    PR_Sleep(timeout);
    return 0;
  }

  if (timeout != PR_INTERVAL_NO_TIMEOUT) {
    PRInt32 ticksPerSecond = PR_TicksPerSecond();
    tv.tv_sec = timeout / ticksPerSecond;
    tv.tv_usec = PR_IntervalToMicroseconds(timeout % ticksPerSecond);
    tvp = &tv;
  }

#if defined(_PR_GLOBAL_THREADS_ONLY)
  ready = _MD_SELECT(0, rdp, wtp, exp, tvp);
#else
  ready = _PR_NTFiberSafeSelect(0, rdp, wtp, exp, tvp);
#endif

  /*
  ** Now to unravel the select sets back into the client's poll
  ** descriptor list. Is this possibly an area for pissing away
  ** a few cycles or what?
  */
  if (ready > 0) {
    ready = 0;
    for (pd = pds, epd = pd + npds; pd < epd; pd++) {
      PRInt16 out_flags = 0;
      if ((NULL != pd->fd) && (0 != pd->in_flags)) {
        SOCKET osfd;
        bottom = PR_GetIdentitiesLayer(pd->fd, PR_NSPR_IO_LAYER);
        PR_ASSERT(NULL != bottom);

        osfd = (SOCKET)bottom->secret->md.osfd;

        if (FD_ISSET(osfd, &rd)) {
          if (pd->out_flags & _PR_POLL_READ_SYS_READ) {
            out_flags |= PR_POLL_READ;
          }
          if (pd->out_flags & _PR_POLL_WRITE_SYS_READ) {
            out_flags |= PR_POLL_WRITE;
          }
        }
        if (FD_ISSET(osfd, &wt)) {
          if (pd->out_flags & _PR_POLL_READ_SYS_WRITE) {
            out_flags |= PR_POLL_READ;
          }
          if (pd->out_flags & _PR_POLL_WRITE_SYS_WRITE) {
            out_flags |= PR_POLL_WRITE;
          }
        }
        if (FD_ISSET(osfd, &ex)) {
          out_flags |= PR_POLL_EXCEPT;
        }
      }
      pd->out_flags = out_flags;
      if (out_flags) {
        ready++;
      }
    }
    PR_ASSERT(ready > 0);
  } else if (ready == SOCKET_ERROR) {
    err = WSAGetLastError();
    if (err == WSAENOTSOCK) {
      /* Find the bad fds */
      int optval;
      int optlen = sizeof(optval);
      ready = 0;
      for (pd = pds, epd = pd + npds; pd < epd; pd++) {
        pd->out_flags = 0;
        if ((NULL != pd->fd) && (0 != pd->in_flags)) {
          bottom = PR_GetIdentitiesLayer(pd->fd, PR_NSPR_IO_LAYER);
          if (getsockopt(bottom->secret->md.osfd, SOL_SOCKET, SO_TYPE,
                         (char*)&optval, &optlen) == -1) {
            PR_ASSERT(WSAGetLastError() == WSAENOTSOCK);
            if (WSAGetLastError() == WSAENOTSOCK) {
              pd->out_flags = PR_POLL_NVAL;
              ready++;
            }
          }
        }
      }
      PR_ASSERT(ready > 0);
    } else {
      _PR_MD_MAP_SELECT_ERROR(err);
    }
  }

  return ready;
}