diff options
Diffstat (limited to 'source4/lib/util')
| -rw-r--r-- | source4/lib/util/config.mk | 1 | ||||
| -rw-r--r-- | source4/lib/util/select.c | 169 |
2 files changed, 0 insertions, 170 deletions
diff --git a/source4/lib/util/config.mk b/source4/lib/util/config.mk index 4e00e2d7e2..312653c19f 100644 --- a/source4/lib/util/config.mk +++ b/source4/lib/util/config.mk @@ -25,7 +25,6 @@ OBJ_FILES = xfile.o \ substitute.o \ fsusage.o \ ms_fnmatch.o \ - select.o \ mutex.o \ idtree.o \ module.o diff --git a/source4/lib/util/select.c b/source4/lib/util/select.c deleted file mode 100644 index 4f906f2454..0000000000 --- a/source4/lib/util/select.c +++ /dev/null @@ -1,169 +0,0 @@ -/* - Unix SMB/Netbios implementation. - Version 3.0 - Samba select/poll implementation - Copyright (C) Andrew Tridgell 1992-1998 - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. - - This program 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 General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. -*/ - -#include "includes.h" -#include "system/filesys.h" - -/* This is here because it allows us to avoid a nasty race in signal handling. - We need to guarantee that when we get a signal we get out of a select immediately - but doing that involves a race condition. We can avoid the race by getting the - signal handler to write to a pipe that is in the select/poll list - - This means all Samba signal handlers should call sys_select_signal(). -*/ - -static pid_t initialised; -static int select_pipe[2]; -static volatile unsigned pipe_written, pipe_read; - -/******************************************************************* - Call this from all Samba signal handlers if you want to avoid a - nasty signal race condition. -********************************************************************/ - -void sys_select_signal(void) -{ - char c = 1; - if (!initialised) return; - - if (pipe_written > pipe_read+256) return; - - if (write(select_pipe[1], &c, 1) == 1) pipe_written++; -} - -/******************************************************************* - Like select() but avoids the signal race using a pipe - it also guarantees that fds on return only ever contains bits set - for file descriptors that were readable. -********************************************************************/ - -int sys_select(int maxfd, fd_set *readfds, fd_set *writefds, fd_set *errorfds, struct timeval *tval) -{ - int ret, saved_errno; - fd_set *readfds2, readfds_buf; - - if (initialised != getpid()) { - pipe(select_pipe); - - /* - * These next two lines seem to fix a bug with the Linux - * 2.0.x kernel (and probably other UNIXes as well) where - * the one byte read below can block even though the - * select returned that there is data in the pipe and - * the pipe_written variable was incremented. Thanks to - * HP for finding this one. JRA. - */ - - if(set_blocking(select_pipe[0],0)==-1) - smb_panic("select_pipe[0]: O_NONBLOCK failed.\n"); - if(set_blocking(select_pipe[1],0)==-1) - smb_panic("select_pipe[1]: O_NONBLOCK failed.\n"); - - initialised = getpid(); - } - - maxfd = MAX(select_pipe[0]+1, maxfd); - - /* If readfds is NULL we need to provide our own set. */ - if (readfds) { - readfds2 = readfds; - } else { - readfds2 = &readfds_buf; - FD_ZERO(readfds2); - } - FD_SET(select_pipe[0], readfds2); - - errno = 0; - ret = select(maxfd,readfds2,writefds,errorfds,tval); - - if (ret <= 0) { - FD_ZERO(readfds2); - if (writefds) - FD_ZERO(writefds); - if (errorfds) - FD_ZERO(errorfds); - } else if (FD_ISSET(select_pipe[0], readfds2)) { - char c; - saved_errno = errno; - if (read(select_pipe[0], &c, 1) == 1) { - pipe_read++; - /* Mark Weaver <mark-clist@npsl.co.uk> pointed out a critical - fix to ensure we don't lose signals. We must always - return -1 when the select pipe is set, otherwise if another - fd is also ready (so ret == 2) then we used to eat the - byte in the pipe and lose the signal. JRA. - */ - ret = -1; - errno = EINTR; - } else { - FD_CLR(select_pipe[0], readfds2); - ret--; - errno = saved_errno; - } - } - - return ret; -} - -/******************************************************************* - Similar to sys_select() but catch EINTR and continue. - This is what sys_select() used to do in Samba. -********************************************************************/ - -int sys_select_intr(int maxfd, fd_set *readfds, fd_set *writefds, fd_set *errorfds, struct timeval *tval) -{ - int ret; - fd_set *readfds2, readfds_buf, *writefds2, writefds_buf, *errorfds2, errorfds_buf; - struct timeval tval2, *ptval; - - readfds2 = (readfds ? &readfds_buf : NULL); - writefds2 = (writefds ? &writefds_buf : NULL); - errorfds2 = (errorfds ? &errorfds_buf : NULL); - ptval = (tval ? &tval2 : NULL); - - do { - if (readfds) - readfds_buf = *readfds; - if (writefds) - writefds_buf = *writefds; - if (errorfds) - errorfds_buf = *errorfds; - if (tval) - tval2 = *tval; - - /* We must use select and not sys_select here. If we use - sys_select we'd lose the fact a signal occurred when sys_select - read a byte from the pipe. Fix from Mark Weaver - <mark-clist@npsl.co.uk> - */ - - ret = select(maxfd, readfds2, writefds2, errorfds2, ptval); - } while (ret == -1 && errno == EINTR); - - if (readfds) - *readfds = readfds_buf; - if (writefds) - *writefds = writefds_buf; - if (errorfds) - *errorfds = errorfds_buf; - - return ret; -} |