Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 491 insertions, 0 deletions

diff --git a/REORG.TODO/hurd/hurdselect.c b/REORG.TODO/hurd/hurdselect.c
new file mode 100644
index 0000000000..8dc7c76995
--- /dev/null
+++ b/REORG.TODO/hurd/hurdselect.c
@@ -0,0 +1,491 @@
+/* Guts of both `select' and `poll' for Hurd.
+   Copyright (C) 1991-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/types.h>
+#include <sys/poll.h>
+#include <hurd.h>
+#include <hurd/fd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <stdint.h>
+
+/* All user select types.  */
+#define SELECT_ALL (SELECT_READ | SELECT_WRITE | SELECT_URG)
+
+/* Used to record that a particular select rpc returned.  Must be distinct
+   from SELECT_ALL (which better not have the high bit set).  */
+#define SELECT_RETURNED ((SELECT_ALL << 1) & ~SELECT_ALL)
+
+/* Check the first NFDS descriptors either in POLLFDS (if nonnnull) or in
+   each of READFDS, WRITEFDS, EXCEPTFDS that is nonnull.  If TIMEOUT is not
+   NULL, time out after waiting the interval specified therein.  Returns
+   the number of ready descriptors, or -1 for errors.  */
+int
+_hurd_select (int nfds,
+	      struct pollfd *pollfds,
+	      fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
+	      const struct timespec *timeout, const sigset_t *sigmask)
+{
+  int i;
+  mach_port_t portset;
+  int got;
+  error_t err;
+  fd_set rfds, wfds, xfds;
+  int firstfd, lastfd;
+  mach_msg_timeout_t to = 0;
+  struct
+    {
+      struct hurd_userlink ulink;
+      struct hurd_fd *cell;
+      mach_port_t io_port;
+      int type;
+      mach_port_t reply_port;
+    } d[nfds];
+  sigset_t oset;
+
+  union typeword		/* Use this to avoid unkosher casts.  */
+    {
+      mach_msg_type_t type;
+      uint32_t word;
+    };
+  assert (sizeof (union typeword) == sizeof (mach_msg_type_t));
+  assert (sizeof (uint32_t) == sizeof (mach_msg_type_t));
+
+  if (nfds < 0 || (pollfds == NULL && nfds > FD_SETSIZE))
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
+  if (timeout != NULL)
+    {
+      if (timeout->tv_sec < 0 || timeout->tv_nsec < 0)
+	{
+	  errno = EINVAL;
+	  return -1;
+	}
+
+      to = (timeout->tv_sec * 1000 +
+            (timeout->tv_nsec + 999999) / 1000000);
+    }
+
+  if (sigmask && __sigprocmask (SIG_SETMASK, sigmask, &oset))
+    return -1;
+
+  if (pollfds)
+    {
+      /* Collect interesting descriptors from the user's `pollfd' array.
+	 We do a first pass that reads the user's array before taking
+	 any locks.  The second pass then only touches our own stack,
+	 and gets the port references.  */
+
+      for (i = 0; i < nfds; ++i)
+	if (pollfds[i].fd >= 0)
+	  {
+	    int type = 0;
+	    if (pollfds[i].events & POLLIN)
+	      type |= SELECT_READ;
+	    if (pollfds[i].events & POLLOUT)
+	      type |= SELECT_WRITE;
+	    if (pollfds[i].events & POLLPRI)
+	      type |= SELECT_URG;
+
+	    d[i].io_port = pollfds[i].fd;
+	    d[i].type = type;
+	  }
+	else
+	  d[i].type = 0;
+
+      HURD_CRITICAL_BEGIN;
+      __mutex_lock (&_hurd_dtable_lock);
+
+      for (i = 0; i < nfds; ++i)
+	if (d[i].type != 0)
+	  {
+	    const int fd = (int) d[i].io_port;
+
+	    if (fd < _hurd_dtablesize)
+	      {
+		d[i].cell = _hurd_dtable[fd];
+		d[i].io_port = _hurd_port_get (&d[i].cell->port, &d[i].ulink);
+		if (d[i].io_port != MACH_PORT_NULL)
+		  continue;
+	      }
+
+	    /* If one descriptor is bogus, we fail completely.  */
+	    while (i-- > 0)
+	      if (d[i].type != 0)
+		_hurd_port_free (&d[i].cell->port,
+				 &d[i].ulink, d[i].io_port);
+	    break;
+	  }
+
+      __mutex_unlock (&_hurd_dtable_lock);
+      HURD_CRITICAL_END;
+
+      if (i < nfds)
+	{
+	  if (sigmask)
+	    __sigprocmask (SIG_SETMASK, &oset, NULL);
+	  errno = EBADF;
+	  return -1;
+	}
+
+      lastfd = i - 1;
+      firstfd = i == 0 ? lastfd : 0;
+    }
+  else
+    {
+      /* Collect interested descriptors from the user's fd_set arguments.
+	 Use local copies so we can't crash from user bogosity.  */
+
+      if (readfds == NULL)
+	FD_ZERO (&rfds);
+      else
+	rfds = *readfds;
+      if (writefds == NULL)
+	FD_ZERO (&wfds);
+      else
+	wfds = *writefds;
+      if (exceptfds == NULL)
+	FD_ZERO (&xfds);
+      else
+	xfds = *exceptfds;
+
+      HURD_CRITICAL_BEGIN;
+      __mutex_lock (&_hurd_dtable_lock);
+
+      if (nfds > _hurd_dtablesize)
+	nfds = _hurd_dtablesize;
+
+      /* Collect the ports for interesting FDs.  */
+      firstfd = lastfd = -1;
+      for (i = 0; i < nfds; ++i)
+	{
+	  int type = 0;
+	  if (readfds != NULL && FD_ISSET (i, &rfds))
+	    type |= SELECT_READ;
+	  if (writefds != NULL && FD_ISSET (i, &wfds))
+	    type |= SELECT_WRITE;
+	  if (exceptfds != NULL && FD_ISSET (i, &xfds))
+	    type |= SELECT_URG;
+	  d[i].type = type;
+	  if (type)
+	    {
+	      d[i].cell = _hurd_dtable[i];
+	      d[i].io_port = _hurd_port_get (&d[i].cell->port, &d[i].ulink);
+	      if (d[i].io_port == MACH_PORT_NULL)
+		{
+		  /* If one descriptor is bogus, we fail completely.  */
+		  while (i-- > 0)
+		    if (d[i].type != 0)
+		      _hurd_port_free (&d[i].cell->port, &d[i].ulink,
+				       d[i].io_port);
+		  break;
+		}
+	      lastfd = i;
+	      if (firstfd == -1)
+		firstfd = i;
+	    }
+	}
+
+      __mutex_unlock (&_hurd_dtable_lock);
+      HURD_CRITICAL_END;
+
+      if (i < nfds)
+	{
+	  if (sigmask)
+	    __sigprocmask (SIG_SETMASK, &oset, NULL);
+	  errno = EBADF;
+	  return -1;
+	}
+    }
+
+
+  err = 0;
+  got = 0;
+
+  /* Send them all io_select request messages.  */
+
+  if (firstfd == -1)
+    /* But not if there were no ports to deal with at all.
+       We are just a pure timeout.  */
+    portset = __mach_reply_port ();
+  else
+    {
+      portset = MACH_PORT_NULL;
+
+      for (i = firstfd; i <= lastfd; ++i)
+	if (d[i].type)
+	  {
+	    int type = d[i].type;
+	    d[i].reply_port = __mach_reply_port ();
+	    err = __io_select (d[i].io_port, d[i].reply_port,
+			       /* Poll only if there's a single descriptor.  */
+			       (firstfd == lastfd) ? to : 0,
+			       &type);
+	    switch (err)
+	      {
+	      case MACH_RCV_TIMED_OUT:
+		/* No immediate response.  This is normal.  */
+		err = 0;
+		if (firstfd == lastfd)
+		  /* When there's a single descriptor, we don't need a
+		     portset, so just pretend we have one, but really
+		     use the single reply port.  */
+		  portset = d[i].reply_port;
+		else if (got == 0)
+		  /* We've got multiple reply ports, so we need a port set to
+		     multiplex them.  */
+		  {
+		    /* We will wait again for a reply later.  */
+		    if (portset == MACH_PORT_NULL)
+		      /* Create the portset to receive all the replies on.  */
+		      err = __mach_port_allocate (__mach_task_self (),
+						  MACH_PORT_RIGHT_PORT_SET,
+						  &portset);
+		    if (! err)
+		      /* Put this reply port in the port set.  */
+		      __mach_port_move_member (__mach_task_self (),
+					       d[i].reply_port, portset);
+		  }
+		break;
+
+	      default:
+		/* No other error should happen.  Callers of select
+		   don't expect to see errors, so we simulate
+		   readiness of the erring object and the next call
+		   hopefully will get the error again.  */
+		type = SELECT_ALL;
+		/* FALLTHROUGH */
+
+	      case 0:
+		/* We got an answer.  */
+		if ((type & SELECT_ALL) == 0)
+		  /* Bogus answer; treat like an error, as a fake positive.  */
+		  type = SELECT_ALL;
+
+		/* This port is already ready already.  */
+		d[i].type &= type;
+		d[i].type |= SELECT_RETURNED;
+		++got;
+		break;
+	      }
+	    _hurd_port_free (&d[i].cell->port, &d[i].ulink, d[i].io_port);
+	  }
+    }
+
+  /* Now wait for reply messages.  */
+  if (!err && got == 0)
+    {
+      /* Now wait for io_select_reply messages on PORT,
+	 timing out as appropriate.  */
+
+      union
+	{
+	  mach_msg_header_t head;
+#ifdef MACH_MSG_TRAILER_MINIMUM_SIZE
+	  struct
+	    {
+	      mach_msg_header_t head;
+	      NDR_record_t ndr;
+	      error_t err;
+	    } error;
+	  struct
+	    {
+	      mach_msg_header_t head;
+	      NDR_record_t ndr;
+	      error_t err;
+	      int result;
+	      mach_msg_trailer_t trailer;
+	    } success;
+#else
+	  struct
+	    {
+	      mach_msg_header_t head;
+	      union typeword err_type;
+	      error_t err;
+	    } error;
+	  struct
+	    {
+	      mach_msg_header_t head;
+	      union typeword err_type;
+	      error_t err;
+	      union typeword result_type;
+	      int result;
+	    } success;
+#endif
+	} msg;
+      mach_msg_option_t options = (timeout == NULL ? 0 : MACH_RCV_TIMEOUT);
+      error_t msgerr;
+      while ((msgerr = __mach_msg (&msg.head,
+				   MACH_RCV_MSG | MACH_RCV_INTERRUPT | options,
+				   0, sizeof msg, portset, to,
+				   MACH_PORT_NULL)) == MACH_MSG_SUCCESS)
+	{
+	  /* We got a message.  Decode it.  */
+#define IO_SELECT_REPLY_MSGID (21012 + 100) /* XXX */
+#ifdef MACH_MSG_TYPE_BIT
+	  const union typeword inttype =
+	  { type:
+	    { MACH_MSG_TYPE_INTEGER_T, sizeof (integer_t) * 8, 1, 1, 0, 0 }
+	  };
+#endif
+	  if (msg.head.msgh_id == IO_SELECT_REPLY_MSGID &&
+	      msg.head.msgh_size >= sizeof msg.error &&
+	      !(msg.head.msgh_bits & MACH_MSGH_BITS_COMPLEX) &&
+#ifdef MACH_MSG_TYPE_BIT
+	      msg.error.err_type.word == inttype.word
+#endif
+	      )
+	    {
+	      /* This is a properly formatted message so far.
+		 See if it is a success or a failure.  */
+	      if (msg.error.err == EINTR &&
+		  msg.head.msgh_size == sizeof msg.error)
+		{
+		  /* EINTR response; poll for further responses
+		     and then return quickly.  */
+		  err = EINTR;
+		  goto poll;
+		}
+	      if (msg.error.err ||
+		  msg.head.msgh_size != sizeof msg.success ||
+#ifdef MACH_MSG_TYPE_BIT
+		  msg.success.result_type.word != inttype.word ||
+#endif
+		  (msg.success.result & SELECT_ALL) == 0)
+		{
+		  /* Error or bogus reply.  Simulate readiness.  */
+		  __mach_msg_destroy (&msg.head);
+		  msg.success.result = SELECT_ALL;
+		}
+
+	      /* Look up the respondent's reply port and record its
+		 readiness.  */
+	      {
+		int had = got;
+		if (firstfd != -1)
+		  for (i = firstfd; i <= lastfd; ++i)
+		    if (d[i].type
+			&& d[i].reply_port == msg.head.msgh_local_port)
+		      {
+			d[i].type &= msg.success.result;
+			d[i].type |= SELECT_RETURNED;
+			++got;
+		      }
+		assert (got > had);
+	      }
+	    }
+
+	  if (msg.head.msgh_remote_port != MACH_PORT_NULL)
+	    __mach_port_deallocate (__mach_task_self (),
+				    msg.head.msgh_remote_port);
+
+	  if (got)
+	  poll:
+	    {
+	      /* Poll for another message.  */
+	      to = 0;
+	      options |= MACH_RCV_TIMEOUT;
+	    }
+	}
+
+      if (msgerr == MACH_RCV_INTERRUPTED)
+	/* Interruption on our side (e.g. signal reception).  */
+	err = EINTR;
+
+      if (got)
+	/* At least one descriptor is known to be ready now, so we will
+	   return success.  */
+	err = 0;
+    }
+
+  if (firstfd != -1)
+    for (i = firstfd; i <= lastfd; ++i)
+      if (d[i].type)
+	__mach_port_destroy (__mach_task_self (), d[i].reply_port);
+  if (firstfd == -1 || (firstfd != lastfd && portset != MACH_PORT_NULL))
+    /* Destroy PORTSET, but only if it's not actually the reply port for a
+       single descriptor (in which case it's destroyed in the previous loop;
+       not doing it here is just a bit more efficient).  */
+    __mach_port_destroy (__mach_task_self (), portset);
+
+  if (err)
+    {
+      if (sigmask)
+	__sigprocmask (SIG_SETMASK, &oset, NULL);
+      return __hurd_fail (err);
+    }
+
+  if (pollfds)
+    /* Fill in the `revents' members of the user's array.  */
+    for (i = 0; i < nfds; ++i)
+      {
+	int type = d[i].type;
+	int_fast16_t revents = 0;
+
+	if (type & SELECT_RETURNED)
+	  {
+	    if (type & SELECT_READ)
+	      revents |= POLLIN;
+	    if (type & SELECT_WRITE)
+	      revents |= POLLOUT;
+	    if (type & SELECT_URG)
+	      revents |= POLLPRI;
+	  }
+
+	pollfds[i].revents = revents;
+      }
+  else
+    {
+      /* Below we recalculate GOT to include an increment for each operation
+	 allowed on each fd.  */
+      got = 0;
+
+      /* Set the user bitarrays.  We only ever have to clear bits, as all
+	 desired ones are initially set.  */
+      if (firstfd != -1)
+	for (i = firstfd; i <= lastfd; ++i)
+	  {
+	    int type = d[i].type;
+
+	    if ((type & SELECT_RETURNED) == 0)
+	      type = 0;
+
+	    if (type & SELECT_READ)
+	      got++;
+	    else if (readfds)
+	      FD_CLR (i, readfds);
+	    if (type & SELECT_WRITE)
+	      got++;
+	    else if (writefds)
+	      FD_CLR (i, writefds);
+	    if (type & SELECT_URG)
+	      got++;
+	    else if (exceptfds)
+	      FD_CLR (i, exceptfds);
+	  }
+    }
+
+  if (sigmask && __sigprocmask (SIG_SETMASK, &oset, NULL))
+    return -1;
+
+  return got;
+}