gnulib: lib/fclose.c annotate

annotate lib/fclose.c @ 40057:b06060465f09

maint: Run 'make update-copyright'

author	Paul Eggert <eggert@cs.ucla.edu>
date	Tue, 01 Jan 2019 00:25:11 +0100
parents	10eb9086bea0
children

rev	line source
10623 cce8e54214d5 * lib/fclose.c: Fix typo in comment: s/close/fclose/. Jim Meyering <meyering@redhat.com> parents: 10622 diff changeset	1 /* fclose replacement.
40057 b06060465f09 maint: Run 'make update-copyright' Paul Eggert <eggert@cs.ucla.edu> parents: 19484 diff changeset	2 Copyright (C) 2008-2019 Free Software Foundation, Inc.
10622 ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	3
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	4 This program is free software: you can redistribute it and/or modify
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	5 it under the terms of the GNU General Public License as published by
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	6 the Free Software Foundation; either version 3 of the License, or
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	7 (at your option) any later version.
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	8
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	9 This program is distributed in the hope that it will be useful,
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	10 but WITHOUT ANY WARRANTY; without even the implied warranty of
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	12 GNU General Public License for more details.
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	13
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	14 You should have received a copy of the GNU General Public License
19190 9759915b2aca all: prefer https: URLs Paul Eggert <eggert@cs.ucla.edu> parents: 18883 diff changeset	15 along with this program. If not, see <https://www.gnu.org/licenses/>. */
10622 ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	16
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	17 #include <config.h>
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	18
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	19 /* Specification. */
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	20 #include <stdio.h>
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	21
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	22 #include <errno.h>
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	23 #include <unistd.h>
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	24
14667 1f6b1f7275d0 fclose: don't fail on non-seekable input stream Eric Blake <eblake@redhat.com> parents: 14079 diff changeset	25 #include "freading.h"
18883 19886582ca8d Implement a way to opt out from MSVC support. Bruno Haible <bruno@clisp.org> parents: 18626 diff changeset	26 #if HAVE_MSVC_INVALID_PARAMETER_HANDLER
19886582ca8d Implement a way to opt out from MSVC support. Bruno Haible <bruno@clisp.org> parents: 18626 diff changeset	27 # include "msvc-inval.h"
19886582ca8d Implement a way to opt out from MSVC support. Bruno Haible <bruno@clisp.org> parents: 18626 diff changeset	28 #endif
15779 fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	29
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	30 #undef fclose
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	31
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	32 #if HAVE_MSVC_INVALID_PARAMETER_HANDLER
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	33 static int
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	34 fclose_nothrow (FILE *fp)
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	35 {
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	36 int result;
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	37
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	38 TRY_MSVC_INVAL
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	39 {
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	40 result = fclose (fp);
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	41 }
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	42 CATCH_MSVC_INVAL
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	43 {
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	44 result = EOF;
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	45 errno = EBADF;
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	46 }
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	47 DONE_MSVC_INVAL;
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	48
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	49 return result;
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	50 }
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	51 #else
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	52 # define fclose_nothrow fclose
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	53 #endif
14667 1f6b1f7275d0 fclose: don't fail on non-seekable input stream Eric Blake <eblake@redhat.com> parents: 14079 diff changeset	54
14678 68c96ae4be1a fflush: also replace fclose when fixing fflush Eric Blake <eblake@redhat.com> parents: 14676 diff changeset	55 /* Override fclose() to call the overridden fflush() or close(). */
10622 ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	56
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	57 int
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	58 rpl_fclose (FILE *fp)
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	59 {
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	60 int saved_errno = 0;
14678 68c96ae4be1a fflush: also replace fclose when fixing fflush Eric Blake <eblake@redhat.com> parents: 14676 diff changeset	61 int fd;
14723 890d9b0fe421 fclose: avoid double close race when possible Eric Blake <eblake@redhat.com> parents: 14678 diff changeset	62 int result = 0;
14678 68c96ae4be1a fflush: also replace fclose when fixing fflush Eric Blake <eblake@redhat.com> parents: 14676 diff changeset	63
68c96ae4be1a fflush: also replace fclose when fixing fflush Eric Blake <eblake@redhat.com> parents: 14676 diff changeset	64 /* Don't change behavior on memstreams. */
68c96ae4be1a fflush: also replace fclose when fixing fflush Eric Blake <eblake@redhat.com> parents: 14676 diff changeset	65 fd = fileno (fp);
68c96ae4be1a fflush: also replace fclose when fixing fflush Eric Blake <eblake@redhat.com> parents: 14676 diff changeset	66 if (fd < 0)
15779 fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	67 return fclose_nothrow (fp);
10622 ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	68
14667 1f6b1f7275d0 fclose: don't fail on non-seekable input stream Eric Blake <eblake@redhat.com> parents: 14079 diff changeset	69 /* We only need to flush the file if it is not reading or if it is
14676 ead32d10a3f0 fclose: reduce dependencies Eric Blake <eblake@redhat.com> parents: 14667 diff changeset	70 seekable. This only guarantees the file position of input files
ead32d10a3f0 fclose: reduce dependencies Eric Blake <eblake@redhat.com> parents: 14667 diff changeset	71 if the fflush module is also in use. */
ead32d10a3f0 fclose: reduce dependencies Eric Blake <eblake@redhat.com> parents: 14667 diff changeset	72 if ((!freading (fp) \|\| lseek (fileno (fp), 0, SEEK_CUR) != -1)
ead32d10a3f0 fclose: reduce dependencies Eric Blake <eblake@redhat.com> parents: 14667 diff changeset	73 && fflush (fp))
10622 ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	74 saved_errno = errno;
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	75
14726 3e7ea0014c67 fclose: Fix possible link error. Bruno Haible <bruno@clisp.org> parents: 14723 diff changeset	76 /* fclose() calls close(), but we need to also invoke all hooks that our
3e7ea0014c67 fclose: Fix possible link error. Bruno Haible <bruno@clisp.org> parents: 14723 diff changeset	77 overridden close() function invokes. See lib/close.c. */
14723 890d9b0fe421 fclose: avoid double close race when possible Eric Blake <eblake@redhat.com> parents: 14678 diff changeset	78 #if WINDOWS_SOCKETS
14726 3e7ea0014c67 fclose: Fix possible link error. Bruno Haible <bruno@clisp.org> parents: 14723 diff changeset	79 /* Call the overridden close(), then the original fclose().
3e7ea0014c67 fclose: Fix possible link error. Bruno Haible <bruno@clisp.org> parents: 14723 diff changeset	80 Note about multithread-safety: There is a race condition where some
3e7ea0014c67 fclose: Fix possible link error. Bruno Haible <bruno@clisp.org> parents: 14723 diff changeset	81 other thread could open fd between our close and fclose. */
14678 68c96ae4be1a fflush: also replace fclose when fixing fflush Eric Blake <eblake@redhat.com> parents: 14676 diff changeset	82 if (close (fd) < 0 && saved_errno == 0)
10622 ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	83 saved_errno = errno;
ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	84
15779 fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	85 fclose_nothrow (fp); /* will fail with errno = EBADF,
fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	86 if we did not lose a race */
10622 ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	87
14723 890d9b0fe421 fclose: avoid double close race when possible Eric Blake <eblake@redhat.com> parents: 14678 diff changeset	88 #else /* !WINDOWS_SOCKETS */
14726 3e7ea0014c67 fclose: Fix possible link error. Bruno Haible <bruno@clisp.org> parents: 14723 diff changeset	89 /* Call fclose() and invoke all hooks of the overridden close(). */
14723 890d9b0fe421 fclose: avoid double close race when possible Eric Blake <eblake@redhat.com> parents: 14678 diff changeset	90
890d9b0fe421 fclose: avoid double close race when possible Eric Blake <eblake@redhat.com> parents: 14678 diff changeset	91 # if REPLACE_FCHDIR
14726 3e7ea0014c67 fclose: Fix possible link error. Bruno Haible <bruno@clisp.org> parents: 14723 diff changeset	92 /* Note about multithread-safety: There is a race condition here as well.
3e7ea0014c67 fclose: Fix possible link error. Bruno Haible <bruno@clisp.org> parents: 14723 diff changeset	93 Some other thread could open fd between our calls to fclose and
3e7ea0014c67 fclose: Fix possible link error. Bruno Haible <bruno@clisp.org> parents: 14723 diff changeset	94 _gl_unregister_fd. */
15779 fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	95 result = fclose_nothrow (fp);
14731 687d9ec4a38c fclose: Fix mistake earlier today. Bruno Haible <bruno@clisp.org> parents: 14730 diff changeset	96 if (result == 0)
14726 3e7ea0014c67 fclose: Fix possible link error. Bruno Haible <bruno@clisp.org> parents: 14723 diff changeset	97 _gl_unregister_fd (fd);
3e7ea0014c67 fclose: Fix possible link error. Bruno Haible <bruno@clisp.org> parents: 14723 diff changeset	98 # else
3e7ea0014c67 fclose: Fix possible link error. Bruno Haible <bruno@clisp.org> parents: 14723 diff changeset	99 /* No race condition here. */
15779 fb3ece2324db fclose: Support for MSVC 9. Bruno Haible <bruno@clisp.org> parents: 14731 diff changeset	100 result = fclose_nothrow (fp);
14723 890d9b0fe421 fclose: avoid double close race when possible Eric Blake <eblake@redhat.com> parents: 14678 diff changeset	101 # endif
14726 3e7ea0014c67 fclose: Fix possible link error. Bruno Haible <bruno@clisp.org> parents: 14723 diff changeset	102
14723 890d9b0fe421 fclose: avoid double close race when possible Eric Blake <eblake@redhat.com> parents: 14678 diff changeset	103 #endif /* !WINDOWS_SOCKETS */
890d9b0fe421 fclose: avoid double close race when possible Eric Blake <eblake@redhat.com> parents: 14678 diff changeset	104
14730 f0a9a2cd267c fclose: preserve fflush errors Eric Blake <eblake@redhat.com> parents: 14726 diff changeset	105 if (saved_errno != 0)
f0a9a2cd267c fclose: preserve fflush errors Eric Blake <eblake@redhat.com> parents: 14726 diff changeset	106 {
f0a9a2cd267c fclose: preserve fflush errors Eric Blake <eblake@redhat.com> parents: 14726 diff changeset	107 errno = saved_errno;
f0a9a2cd267c fclose: preserve fflush errors Eric Blake <eblake@redhat.com> parents: 14726 diff changeset	108 result = EOF;
f0a9a2cd267c fclose: preserve fflush errors Eric Blake <eblake@redhat.com> parents: 14726 diff changeset	109 }
f0a9a2cd267c fclose: preserve fflush errors Eric Blake <eblake@redhat.com> parents: 14726 diff changeset	110
14723 890d9b0fe421 fclose: avoid double close race when possible Eric Blake <eblake@redhat.com> parents: 14678 diff changeset	111 return result;
10622 ac6f431cc95d New module 'fclose'. Bruno Haible <bruno@clisp.org> parents: diff changeset	112 }

Mercurial > gnulib

annotate lib/fclose.c @ 40057:b06060465f09