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persist.c
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Created
Thu, Sep 26, 15:22
Size
8 KB
Mime Type
text/x-c
Expires
Sat, Sep 28, 15:22 (2 d)
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blob
Format
Raw Data
Handle
21035007
Attached To
R10977 RADIANCE Photon Map
persist.c
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#ifndef lint
static
const
char
RCSid
[]
=
"$Id: persist.c,v 2.44 2016/03/06 01:13:18 schorsch Exp $"
;
#endif
/*
* Routines for persistent rtrace and rpict processes.
*
* External symbols declared in ray.h
*/
#include "copyright.h"
#include <string.h>
#include <signal.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "platform.h"
#ifndef NON_POSIX
/* XXX need abstraction for process management */
#include <sys/wait.h>
#endif
#include "rtprocess.h"
/* getpid() */
#include "standard.h"
#include "random.h"
#include "ray.h"
#ifdef F_SETLKW
#include "paths.h"
#include "selcall.h"
#ifndef TIMELIM
#define TIMELIM (8*3600)
/* time limit for holding pattern */
#endif
extern
int
headismine
;
/* boolean true if header belongs to me */
extern
char
*
progname
;
/* global program name */
extern
char
*
errfile
;
/* global error file name */
static
char
*
persistfname
=
NULL
;
/* persist file name */
static
int
persistfd
=
-
1
;
/* persist file descriptor */
static
char
inpname
[
TEMPLEN
+
1
],
outpname
[
TEMPLEN
+
1
],
errname
[
TEMPLEN
+
1
];
typedef
void
(
rsighandler_t
)(
int
);
static
rsighandler_t
sig_io
;
static
rsighandler_t
sig_alrm
;
void
pfdetach
(
void
)
/* release persist (and header) resources */
{
if
(
persistfd
>=
0
)
close
(
persistfd
);
persistfd
=
-
1
;
persistfname
=
NULL
;
inpname
[
0
]
=
'\0'
;
outpname
[
0
]
=
'\0'
;
errname
[
0
]
=
'\0'
;
headismine
=
0
;
}
void
pfclean
(
void
)
/* clean up persist files */
{
if
(
persistfd
>=
0
)
close
(
persistfd
);
if
(
persistfname
!=
NULL
)
unlink
(
persistfname
);
if
(
inpname
[
0
])
unlink
(
inpname
);
if
(
outpname
[
0
])
unlink
(
outpname
);
if
(
errname
[
0
])
unlink
(
errname
);
}
void
pflock
(
/* place or release exclusive lock on file */
int
lf
)
{
struct
flock
fls
;
fls
.
l_type
=
lf
?
F_WRLCK
:
F_UNLCK
;
fls
.
l_whence
=
0
;
fls
.
l_start
=
0L
;
fls
.
l_len
=
0L
;
if
(
fcntl
(
persistfd
,
F_SETLKW
,
&
fls
)
<
0
)
error
(
SYSTEM
,
"cannot (un)lock persist file"
);
}
void
persistfile
(
/* open persist file and lock it */
char
*
pfn
)
{
persistfd
=
open
(
pfn
,
O_WRONLY
|
O_CREAT
|
O_EXCL
,
0644
);
if
(
persistfd
>=
0
)
{
persistfname
=
pfn
;
pflock
(
1
);
return
;
}
/* file exists -- switch to i/o process */
persistfd
=
open
(
pfn
,
O_RDWR
);
if
(
persistfd
<
0
)
{
sprintf
(
errmsg
,
"cannot open persist file
\"
%s
\"
"
,
pfn
);
error
(
SYSTEM
,
errmsg
);
}
pflock
(
1
);
io_process
();
/* never returns */
}
static
int
got_io
;
static
void
sig_io
(
int
i
)
{
got_io
++
;
}
static
void
sig_alrm
(
int
i
)
{
quit
(
0
);
}
void
pfhold
(
void
)
/* holding pattern for idle rendering process */
{
rsighandler_t
*
oldalrm
;
char
buf
[
512
];
int
n
;
/* close input and output descriptors */
close
(
0
);
close
(
1
);
if
(
errfile
==
NULL
)
close
(
2
);
/* create named pipes for input and output */
if
(
mkfifo
(
mktemp
(
strcpy
(
inpname
,
TEMPLATE
)),
0600
)
<
0
)
goto
createrr
;
if
(
mkfifo
(
mktemp
(
strcpy
(
outpname
,
TEMPLATE
)),
0600
)
<
0
)
goto
createrr
;
if
(
errfile
==
NULL
&&
mkfifo
(
mktemp
(
strcpy
(
errname
,
TEMPLATE
)),
0600
)
<
0
)
goto
createrr
;
sprintf
(
buf
,
"%s %d
\n
%s
\n
%s
\n
%s
\n
"
,
progname
,
getpid
(),
inpname
,
outpname
,
errname
);
n
=
strlen
(
buf
);
if
(
write
(
persistfd
,
buf
,
n
)
<
n
)
error
(
SYSTEM
,
"error writing persist file"
);
lseek
(
persistfd
,
(
off_t
)
0
,
SEEK_SET
);
/* wait TIMELIM for someone to signal us */
got_io
=
0
;
signal
(
SIGIO
,
sig_io
);
oldalrm
=
signal
(
SIGALRM
,
sig_alrm
);
alarm
(
TIMELIM
);
pflock
(
0
);
/* unlock persist file for attach */
while
(
!
got_io
)
pause
();
/* wait for attach */
alarm
(
0
);
/* turn off alarm */
signal
(
SIGALRM
,
oldalrm
);
signal
(
SIGIO
,
SIG_DFL
);
pflock
(
1
);
/* grab persist file back */
/* someone wants us; reopen stdin and stdout */
close
(
0
);
if
(
open
(
inpname
,
O_RDONLY
)
!=
0
)
error
(
INTERNAL
,
"unexpected stdin file number"
);
clearerr
(
stdin
);
close
(
1
);
if
(
open
(
outpname
,
O_WRONLY
)
!=
1
)
error
(
INTERNAL
,
"unexpected stdout file number"
);
sleep
(
3
);
/* give them a chance to open their pipes */
if
(
errname
[
0
])
{
close
(
2
);
if
(
open
(
errname
,
O_WRONLY
)
!=
2
)
error
(
INTERNAL
,
"unexpected stderr file number"
);
unlink
(
errname
);
errname
[
0
]
=
'\0'
;
}
unlink
(
inpname
);
inpname
[
0
]
=
'\0'
;
unlink
(
outpname
);
outpname
[
0
]
=
'\0'
;
return
;
createrr:
error
(
SYSTEM
,
"cannot create named pipes in pfhold"
);
}
void
io_process
(
void
)
/* just act as go-between for actual process */
{
char
*
cp
;
int
nr
,
n
;
char
buf
[
BUFSIZ
],
*
pfin
,
*
pfout
,
*
pferr
;
int
pid
,
nfds
;
int
fdout
,
fderr
=
-
1
;
int
status
=
0
;
fd_set
readfds
,
excepfds
;
/* load persist file */
n
=
40
;
while
((
nr
=
read
(
persistfd
,
buf
,
sizeof
(
buf
)
-
1
))
==
0
)
{
if
(
!
n
--
)
error
(
USER
,
"unattended persist file?"
);
pflock
(
0
);
sleep
(
3
+
(
3
*
getpid
()
+
random
())
%
13
);
/* wait until ready */
pflock
(
1
);
}
if
(
nr
<
0
)
error
(
SYSTEM
,
"error reading persist file"
);
ftruncate
(
persistfd
,
(
off_t
)
0L
);
/* truncate persist file */
pfdetach
();
/* close & release persist file */
buf
[
nr
]
=
'\0'
;
/* parse what we got */
if
((
cp
=
strchr
(
buf
,
' '
))
==
NULL
)
goto
formerr
;
*
cp
++
=
'\0'
;
if
((
pid
=
atoi
(
cp
))
<=
0
)
goto
formerr
;
if
((
cp
=
strchr
(
cp
,
'\n'
))
==
NULL
)
goto
formerr
;
pfin
=
++
cp
;
if
((
cp
=
strchr
(
cp
,
'\n'
))
==
NULL
)
goto
formerr
;
*
cp
++
=
'\0'
;
pfout
=
cp
;
if
((
cp
=
strchr
(
cp
,
'\n'
))
==
NULL
)
goto
formerr
;
*
cp
++
=
'\0'
;
pferr
=
cp
;
if
((
cp
=
strchr
(
cp
,
'\n'
))
==
NULL
)
goto
formerr
;
*
cp
++
=
'\0'
;
if
(
cp
-
buf
!=
nr
)
goto
formerr
;
if
(
strcmp
(
buf
,
progname
))
{
sprintf
(
errmsg
,
"persist file for %s, not %s"
,
buf
,
progname
);
error
(
USER
,
errmsg
);
}
/* wake up rendering process */
if
(
kill
(
pid
,
SIGIO
)
<
0
)
error
(
SYSTEM
,
"cannot signal rendering process in io_process"
);
/* fork child feeder process */
pid
=
fork
();
if
(
pid
<
0
)
error
(
SYSTEM
,
"fork failed in io_process"
);
if
(
pid
==
0
)
{
/* feeder loop */
int
fdin
;
close
(
1
);
/* open input pipe */
if
((
fdin
=
open
(
pfin
,
O_WRONLY
))
<
0
)
error
(
SYSTEM
,
"cannot open feed pipe in io_process"
);
/* renderer stdin */
while
((
nr
=
read
(
0
,
cp
=
buf
,
sizeof
(
buf
)))
>
0
)
{
do
{
if
((
n
=
write
(
fdin
,
cp
,
nr
))
<=
0
)
goto
writerr
;
cp
+=
n
;
}
while
((
nr
-=
n
)
>
0
);
}
if
(
nr
<
0
)
goto
readerr
;
_exit
(
0
);
}
close
(
0
);
/* open output pipes, in order */
if
((
fdout
=
open
(
pfout
,
O_RDONLY
))
<
0
)
error
(
SYSTEM
,
"cannot open output pipe in io_process"
);
if
(
pferr
[
0
]
&&
(
fderr
=
open
(
pferr
,
O_RDONLY
))
<
0
)
error
(
SYSTEM
,
"cannot open error pipe in io_process"
);
for
(
;
;
)
{
/* eater loop */
FD_ZERO
(
&
readfds
);
FD_ZERO
(
&
excepfds
);
nfds
=
0
;
if
(
fdout
>=
0
)
{
FD_SET
(
fdout
,
&
readfds
);
FD_SET
(
fdout
,
&
excepfds
);
nfds
=
fdout
+
1
;
}
if
(
fderr
>=
0
)
{
FD_SET
(
fderr
,
&
readfds
);
FD_SET
(
fderr
,
&
excepfds
);
nfds
=
fderr
+
1
;
}
if
(
nfds
==
0
)
break
;
/* all done, exit */
if
(
select
(
nfds
,
&
readfds
,
NULL
,
&
excepfds
,
NULL
)
<
0
)
error
(
SYSTEM
,
"error in select call in io_process"
);
/* renderer stderr */
if
(
fderr
>=
0
&&
(
FD_ISSET
(
fderr
,
&
readfds
)
||
FD_ISSET
(
fderr
,
&
excepfds
)))
{
nr
=
read
(
fderr
,
cp
=
buf
,
sizeof
(
buf
));
if
(
nr
<
0
)
goto
readerr
;
if
(
nr
==
0
)
{
close
(
fderr
);
/* close(2); don't close stderr! */
fderr
=
-
1
;
}
else
{
cp
[
nr
]
=
'\0'
;
/* deduce status if we can */
n
=
strlen
(
progname
);
if
(
!
strncmp
(
cp
,
progname
,
n
)
&&
cp
[
n
++
]
==
':'
&&
cp
[
n
++
]
==
' '
)
{
struct
erract
*
ep
;
for
(
ep
=
erract
;
ep
<
erract
+
NERRS
;
ep
++
)
if
(
ep
->
pre
[
0
]
&&
!
strncmp
(
cp
+
n
,
ep
->
pre
,
strlen
(
ep
->
pre
)))
{
status
=
ep
->
ec
;
break
;
}
}
do
{
/* write message */
if
((
n
=
write
(
2
,
cp
,
nr
))
<=
0
)
goto
writerr
;
cp
+=
n
;
}
while
((
nr
-=
n
)
>
0
);
}
}
/* renderer stdout */
if
(
fdout
>=
0
&&
(
FD_ISSET
(
fdout
,
&
readfds
)
||
FD_ISSET
(
fdout
,
&
excepfds
)))
{
nr
=
read
(
fdout
,
cp
=
buf
,
sizeof
(
buf
));
if
(
nr
<
0
)
goto
readerr
;
if
(
nr
==
0
)
{
/* EOF */
close
(
fdout
);
close
(
1
);
fdout
=
-
1
;
}
else
do
{
/* write it all */
if
((
n
=
write
(
1
,
cp
,
nr
))
<=
0
)
goto
writerr
;
cp
+=
n
;
}
while
((
nr
-=
n
)
>
0
);
}
}
kill
(
pid
,
SIGTERM
);
/* no more process to feed, so... */
waitpid
(
pid
,
0
,
0
);
/* wait for feeder process */
_exit
(
status
);
formerr:
error
(
USER
,
"format error in persist file"
);
readerr:
error
(
SYSTEM
,
"read error in io_process"
);
writerr:
error
(
SYSTEM
,
"write error in io_process"
);
}
#else
void
pfclean
(
void
)
{}
#endif
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