[libpng16] Fixed race conditions in parallel make builds. With higher degrees

of parallelism during 'make' the use of the same temporary file names such
as 'dfn*' can result in a race where a temporary file from one arm of the
build is deleted or overwritten in another arm.  This changes the
temporary files for suffix rules to always use $* and ensures that the
non-suffix rules use unique file names.
This commit is contained in:
John Bowler 2011-12-08 09:37:24 -06:00 committed by Glenn Randers-Pehrson
parent 90a87c8853
commit eb26ee6602
4 changed files with 46 additions and 30 deletions

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@ -1,5 +1,5 @@
Libpng 1.6.0alpha01 - December 5, 2011
Libpng 1.6.0alpha01 - December 8, 2011
This is not intended to be a public release. It will be replaced
within a few weeks by a public version or by another test version.
@ -107,7 +107,7 @@ Version 1.5.7beta05 [(PENDING RELEASE)]
Added MINGW support to CMakeLists.txt
Reject invalid compression flag or method when reading the iTXt chunk.
Version 1.6.0alpha01 [December 5, 2011]
Version 1.6.0alpha01 [December 8, 2011]
Removed machine-generated configure files from the GIT repository (they will
continue to appear in the tarball distributions).
Restored the new 'simplified' API, which was deleted from libpng-1.5.7.
@ -135,6 +135,12 @@ Version 1.6.0alpha01 [December 5, 2011]
as in libpng-1.5.4.
Put CRLF line endings in the owatcom project files.
Fixed minor memset/sizeof errors in pngvalid.c.
Fixed race conditions in parallel make builds. With higher degress of
parallelism during 'make' the use of the same temporary file names such
as 'dfn*' can result in a race where a temporary file from one arm of the
build is deleted or overwritten in another arm. This changes the
temporary files for suffix rules to always use $* and ensures that the
non-suffix rules use unique file names.
Send comments/corrections/commendations to png-mng-implement at lists.sf.net:
(subscription required; visit

View File

@ -3752,7 +3752,7 @@ Version 1.5.7beta05 [(PENDING RELEASE)]
Added MINGW support to CMakeLists.txt
Reject invalid compression flag or method when reading the iTXt chunk.
Version 1.6.0alpha01 [December 5, 2011]
Version 1.6.0alpha01 [December 8, 2011]
Removed machine-generated configure files from the GIT repository (they will
continue to appear in the tarball distributions).
Restored the new 'simplified' API, which was deleted from libpng-1.5.7.
@ -3780,6 +3780,12 @@ Version 1.6.0alpha01 [December 5, 2011]
as in libpng-1.5.4.
Put CRLF line endings in the owatcom project files.
Fixed minor memset/sizeof errors in pngvalid.c.
Fixed race conditions in parallel make builds. With higher degress of
parallelism during 'make' the use of the same temporary file names such
as 'dfn*' can result in a race where a temporary file from one arm of the
build is deleted or overwritten in another arm. This changes the
temporary files for suffix rules to always use $* and ensures that the
non-suffix rules use unique file names.
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit

View File

@ -88,7 +88,7 @@ EXTRA_DIST= \
SCRIPT_CLEANFILES=scripts/*.out scripts/*.chk scripts/pnglibconf.dfn
CLEANFILES= dfn.c dfn?.out pngout.png libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc \
CLEANFILES= *.tf? pngout.png libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc \
libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config libpng.vers libpng.sym \
check.new pnglibconf.* symbols.new pngtest-log.txt \
$(SCRIPT_CLEANFILES)
@ -143,47 +143,49 @@ SYMBOL_CFLAGS = -DPNGLIB_LIBNAME='PNG@PNGLIB_MAJOR@@PNGLIB_MINOR@_0'\
-DPNG_NO_USE_READ_MACROS -DPNG_BUILDING_SYMBOL_TABLE
.dfn.out:
rm -f $@ dfn.c dfn?.out
rm -f $@ $*.c $*.tf[123]
test -d scripts || mkdir scripts
echo '#include "$<"' >dfn.c
echo '#include "$<"' >$*.c
$(DFNCPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) @LIBPNG_DEFINES@\
$(CPPFLAGS) $(SYMBOL_CFLAGS) dfn.c > dfn1.out
$(CPPFLAGS) $(SYMBOL_CFLAGS) $*.c > $*.tf1
$(SED) -n -e 's|^.*PNG_DEFN_MAGIC *-\(.*\)- *PNG_DEFN_END.*$$|\1|p'\
dfn1.out >dfn2.out
$(SED) -e 's| *PNG_JOIN *||g' -e 's| *$$||' dfn2.out >dfn3.out
rm -f dfn.c dfn[12].out
mv dfn3.out $@
$*.tf1 >$*.tf2
$(SED) -e 's| *PNG_JOIN *||g' -e 's| *$$||' $*.tf2 >$*.tf3
rm -f $*.c $*.tf[12]
mv $*.tf3 $@
# The .dfn file for pnglibconf.h is machine generated
pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk pngconf.h
rm -f $@ dfn?.out
$(AWK) -f ${srcdir}/scripts/options.awk out=dfn1.out version=search\
rm -f $@ $*.tf[45]
$(AWK) -f ${srcdir}/scripts/options.awk out=$*.tf4 version=search\
${srcdir}/pngconf.h ${srcdir}/scripts/pnglibconf.dfa\
$(DFA_XTRA) 1>&2
$(AWK) -f ${srcdir}/scripts/options.awk out=dfn2.out dfn1.out 1>&2
rm dfn1.out
mv dfn2.out $@
$(AWK) -f ${srcdir}/scripts/options.awk out=$*.tf5 $*.tf4 1>&2
rm $*.tf4
mv $*.tf5 $@
# Symbol checks (.def and .out files should match)
scripts/symbols.chk: scripts/checksym.awk scripts/symbols.def scripts/symbols.out
.out.chk:
rm -f $@ symbols.new
rm -f $@ $*.new
$(AWK) -f ${srcdir}/scripts/checksym.awk ${srcdir}/scripts/${*F}.def\
$< >&2
mv symbols.new $@
of="$*.new" $< >&2
mv $*.new $@
# used on demand to regenerate the standard header, CPPFLAGS should
# be empty - no non-standard defines
scripts/pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk pngconf.h
rm -f $@ dfn?.out
rm -f $@ pnglibconf.tf[67]
test -z "$(CPPFLAGS)"
echo "com @PNGLIB_VERSION@ STANDARD API DEFINITION" |\
$(AWK) -f ${srcdir}/scripts/options.awk out=dfn1.out logunsupported=1
version=search ${srcdir}/pngconf.h -\
${srcdir}/scripts/pnglibconf.dfa 1>&2
$(AWK) -f ${srcdir}/scripts/options.awk out=dfn2.out dfn1.out 1>&2
rm dfn1.out
mv dfn2.out $@
$(AWK) -f ${srcdir}/scripts/options.awk out=pnglibconf.tf6\
logunsupported=1 version=search ${srcdir}/pngconf.h -\
${srcdir}/scripts/pnglibconf.dfa 1>&2
$(AWK) -f ${srcdir}/scripts/options.awk out=pnglibconf.tf7\
pnglibconf.tf6 1>&2
rm pnglibconf.tf6
mv pnglibconf.tf7 $@
$(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS): png.h pngconf.h \
pnglibconf.h pngpriv.h pngdebug.h pnginfo.h pngstruct.h

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@ -5,8 +5,9 @@
# awk -f checksym.awk official-def list-to-check
#
# Output is a file in the current directory called 'symbols.new',
# stdout holds error messages. Error code indicates success or
# failure.
# the value of the awk variable "of" (which can be changed on the
# command line if required.) stdout holds error messages. Error
# code indicates success or failure.
#
# NOTE: this is a pure, old fashioned, awk script. It will
# work with any awk
@ -21,6 +22,7 @@ BEGIN{
mastero = 0 # highest ordinal in master file
symbolo = 0 # highest ordinal in png.h
missing = "error"# log an error on missing symbols
of="symbols.new" # default to a fixed name
}
# Read existing definitions from the master file (the first
@ -151,11 +153,11 @@ END{
# Finally generate symbols.new
if (symbol[o] != "")
print " " symbol[o], "@" o > "symbols.new"
print " " symbol[o], "@" o > of
}
if (err != 0) {
print "*** A new list is in symbols.new ***"
print "*** A new list is in", of, "***"
exit 1
}
}