macFD.c
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- /* ***** BEGIN LICENSE BLOCK *****
- * Source last modified: $Id: macFD.c,v 1.3.36.3 2004/07/09 01:44:14 hubbe Exp $
- *
- * Portions Copyright (c) 1995-2004 RealNetworks, Inc. All Rights Reserved.
- *
- * The contents of this file, and the files included with this file,
- * are subject to the current version of the RealNetworks Public
- * Source License (the "RPSL") available at
- * http://www.helixcommunity.org/content/rpsl unless you have licensed
- * the file under the current version of the RealNetworks Community
- * Source License (the "RCSL") available at
- * http://www.helixcommunity.org/content/rcsl, in which case the RCSL
- * will apply. You may also obtain the license terms directly from
- * RealNetworks. You may not use this file except in compliance with
- * the RPSL or, if you have a valid RCSL with RealNetworks applicable
- * to this file, the RCSL. Please see the applicable RPSL or RCSL for
- * the rights, obligations and limitations governing use of the
- * contents of the file.
- *
- * Alternatively, the contents of this file may be used under the
- * terms of the GNU General Public License Version 2 or later (the
- * "GPL") in which case the provisions of the GPL are applicable
- * instead of those above. If you wish to allow use of your version of
- * this file only under the terms of the GPL, and not to allow others
- * to use your version of this file under the terms of either the RPSL
- * or RCSL, indicate your decision by deleting the provisions above
- * and replace them with the notice and other provisions required by
- * the GPL. If you do not delete the provisions above, a recipient may
- * use your version of this file under the terms of any one of the
- * RPSL, the RCSL or the GPL.
- *
- * This file is part of the Helix DNA Technology. RealNetworks is the
- * developer of the Original Code and owns the copyrights in the
- * portions it created.
- *
- * This file, and the files included with this file, is distributed
- * and made available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY
- * KIND, EITHER EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS
- * ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES
- * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET
- * ENJOYMENT OR NON-INFRINGEMENT.
- *
- * Technology Compatibility Kit Test Suite(s) Location:
- * http://www.helixcommunity.org/content/tck
- *
- * Contributor(s):
- *
- * ***** END LICENSE BLOCK ***** */
- // if we're building mach-o we already have honest implementations of all this.
- #ifndef _MAC_MACHO
- #include <assert.h>
- #include "macFD.h"
- #include "platform/mac/socketerrors.h"
- FD gFDs[FD_SETSIZE];
- Boolean gFDInitialized = FALSE;
- // init_fds initializes the FD array. This MUST be called at program startup
- void init_fds(void)
- {
- int i;
-
- if(gFDInitialized)
- return;
-
- for(i = 0; i < FD_SETSIZE; i++)
- {
- FD *temp = &gFDs[i];
- temp->index = i;
- temp->owner = NULL;
- temp->available = TRUE;
- temp->readReady = FALSE;
- temp->writeReady = FALSE;
- temp->error = 0;
- temp->type = 0;
- }
-
- gFDInitialized = TRUE;
- }
- // fd_get_owner returns the FD object's owner
- void *fd_get_owner(int fd)
- {
- FD *temp;
- // validate fd
- assert(gFDInitialized);
- if(!FD_VALID(fd))
- {
- errno = EBADF;
- return NULL;
- }
-
- temp = &gFDs[fd];
-
- return (temp->owner);
- }
- // free_fd marks the FD object referenced by fd as free
- int free_fd(int fd)
- {
- FD *temp;
-
- // validate fd
- assert(gFDInitialized);
- if(!FD_VALID(fd))
- {
- errno = EBADF;
- return - 1;
- }
-
- temp = &gFDs[fd];
-
- // if(temp->owner)
- // delete temp->owner;
-
- temp->owner = NULL;
- temp->readReady = FALSE;
- temp->writeReady = FALSE;
- temp->error = 0;
- temp->available = TRUE;
- temp->type = 0;
-
- return 0;
- }
- void fd_register(int fd, void *owner, int type)
- {
- FD *theFD = get_fd_object(fd);
- if(theFD)
- {
- theFD->owner = owner;
- theFD->type = type;
- }
- }
- // get_fd_object returns a pointer to the actual FD object referenced by
- // fd. returns NULL if fd is not a valid file descriptor
- FD *get_fd_object(int fd)
- {
- assert(gFDInitialized);
-
- // validate fd
- if(!FD_VALID(fd))
- {
- errno = EBADF;
- return NULL;
- }
-
- return &gFDs[fd];
- }
- // get_free_fd returns a file descriptor (fd) reference if there is a
- // free FD object in the FD array
- int get_free_fd(void)
- {
- int i;
- Boolean found = FALSE;
- assert(gFDInitialized);
-
- for(i = 0; i < FD_SETSIZE; i++)
- {
- if(gFDs[i].available)
- {
- gFDs[i].available = 0; // mark FD as not available
- found = TRUE;
- break;
- }
- }
-
- if(!found)
- {
- errno = EMFILE;
- return -1;
- }
- else
- return i;
- }
- int close(int fd)
- {
- return free_fd(fd);
- }
- // select scans the requested file descriptors to check if they are ready for
- // reading and/or writing. NOTE: timeout is ignored. This version of select is
- // only for polling the fds.
- /*
- int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout)
- select - synchronous I/O multiplexing
- DESCRIPTION
- Select() examines the I/O descriptor sets whose addresses are passed in
- readfds, writefds, and exceptfds to see if some of their descriptors are
- ready for reading, are ready for writing, or have an exceptional condi-
- tion pending, respectively. The first nfds descriptors are checked in
- each set; i.e., the descriptors from 0 through nfds-1 in the descriptor
- sets are examined. On return, select() replaces the given descriptor
- sets with subsets consisting of those descriptors that are ready for the
- requested operation. Select() returns the total number of ready descrip-
- tors in all the sets.
- The descriptor sets are stored as bit fields in arrays of integers. The
- following macros are provided for manipulating such descriptor sets:
- FD_ZERO(&fdsetx) initializes a descriptor set fdset to the null set.
- FD_SET(fd, &fdset) includes a particular descriptor fd in fdset.
- FD_CLR(fd, &fdset) removes fd from fdset. FD_ISSET(fd, &fdset) is non-
- zero if fd is a member of fdset, zero otherwise. The behavior of these
- macros is undefined if a descriptor value is less than zero or greater
- than or equal to FD_SETSIZE, which is normally at least equal to the max-
- imum number of descriptors supported by the system.
- If timeout is a non-nil pointer, it specifies a maximum interval to wait
- for the selection to complete. If timeout is a nil pointer, the select
- blocks indefinitely. To affect a poll, the timeout argument should be
- non-nil, pointing to a zero-valued timeval structure.
- Any of readfds, writefds, and exceptfds may be given as nil pointers if
- no descriptors are of interest.
- RETURN VALUES
- Select() returns the number of ready descriptors that are contained in
- the descriptor sets, or -1 if an error occurred. If the time limit ex-
- pires, select() returns 0. If select() returns with an error, including
- one due to an interrupted call, the descriptor sets will be unmodified.
- ERRORS
- An error return from select() indicates:
- [EBADF] One of the descriptor sets specified an invalid descriptor.
- [EINTR] A signal was delivered before the time limit expired and
- before any of the selected events occurred.
- [EINVAL] The specified time limit is invalid. One of its components
- is negative or too large.
- SEE ALSO
- accept(2), connect(2), getdtablesize(2), gettimeofday(2), read(2),
- recv(2), send(2), write(2)
- BUGS
- Although the provision of getdtablesize(2) was intended to allow user
- programs to be written independent of the kernel limit on the number of
- open files, the dimension of a sufficiently large bit field for select
- remains a problem. The default size FD_SETSIZE (currently 256) is some-
- what larger than the current kernel limit to the number of open files.
- However, in order to accommodate programs which might potentially use a
- larger number of open files with select, it is possible to increase this
- size within a kernel by providing a larger definition of FD_SETSIZE in
- kernel configuration file and rebuilding a kernel. To increase default
- limit user program must define its own FD_SETSIZE which is less or equal
- new kernel FD_SETSIZE before the inclusion of any header which includes
- <sys/types.h>.
- Select() should probably return the time remaining from the original
- timeout, if any, by modifying the time value in place. This may be im-
- plemented in future versions of the system. Thus, it is unwise to assume
- that the timeout value will be unmodified by the select() call.
- */
- int select(int width, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout)
- {
- int count = 0;
- int s;
- assert(gFDInitialized);
-
- // check for valid fds
- for (s = 0; s < width ; s++)
- {
- if ((readfds && FD_ISSET(s,readfds)) ||(writefds && FD_ISSET(s,writefds)) || (exceptfds && FD_ISSET(s,exceptfds)))
- {
- if (gFDs[s].owner == NULL)
- return EBADF;
- }
- }
- // check for read/write/exception ready
- for (s = 0; s < width ; s++)
- {
- Boolean ready = FALSE;
-
- if(readfds)
- {
- if (gFDs[s].readReady && FD_ISSET(s,readfds))
- ready = TRUE;
- else
- FD_CLR(s,readfds);
- }
- if(writefds)
- {
- if (gFDs[s].writeReady && FD_ISSET(s,writefds))
- ready = TRUE;
- else
- FD_CLR(s,writefds);
- }
- if(exceptfds)
- {
- if (gFDs[s].error && FD_ISSET(s,exceptfds))
- ready = TRUE;
- else
- FD_CLR(s,exceptfds);
- }
-
- if(ready)
- count++;
- }
- return count;
- }
- #endif