diff options
| -rw-r--r-- | GNUmakefile | 26 | ||||
| -rw-r--r-- | doc/HISTORY | 2 |
2 files changed, 19 insertions, 9 deletions
diff --git a/GNUmakefile b/GNUmakefile index f7a87d35..1beebb4c 100644 --- a/GNUmakefile +++ b/GNUmakefile @@ -102,19 +102,27 @@ all: nonmerge .PHONY: nonmerge nonmerge: $(PRODUCT_SUBDIRS:%=%/all) -# Parallel make (make --jobs) is not smart enough to coordinate builds between -# submakes, so a naive parallel make would cause certain targets to be seen as -# existing by one thread while another thread is in the process of creating -# it. Also, multiple threads may build a target simultaneously. So we -# introduce extra dependencies here just to make sure such targets are already -# up to date before the submake starts, for the benefit of parallel make. -# Note that we ensure that parallel make works for 'make all' in the top -# directory, but it may still fail for the aforementioned reason for other -# invocations. +# Completely parallel make (make --jobs) does not work because there are +# multiple targets somewhere in the Netpbm build that depend upon pm_config.h +# and similar targets, and the threads building those multiple targets might +# simultaneously find that pm_config.h needs to be built and proceed to build +# it. After one thread has built pm_config.h, it will proceed to use +# pm_config.h, but the other thread is still building pm_config.h, which is +# not valid while it is in the middle of being built. +# +# But many submakes don't have any such shared dependencies, so build their +# targets in parallel just fine. So we declare this make file ineligible for +# parallel make and have special dependencies to get pm_config.h and like +# targets built before any submakes begin. The submakes will thus never find +# that pm_config.h needs to be built, so we leave them eligible for parallel +# make. + +.NOTPARALLEL: $(SUBDIRS:%=%/all) lib/util/all: pm_config.h inttypes_netpbm.h version.h $(PROG_SUBDIRS:%=%/all): lib/all $(SUPPORT_SUBDIRS:%=%/all) lib/all: lib/util/all +netpbm: lib/all .PHONY: lib/util/all lib/util/all: diff --git a/doc/HISTORY b/doc/HISTORY index e0baf4d8..524fd359 100644 --- a/doc/HISTORY +++ b/doc/HISTORY @@ -39,6 +39,8 @@ not yet BJH Release 10.85.00 pjtoppm, pbmtoppa: fix arithmetic overflow. + Build: fix parallel make. + Build: fix reference to nonexistent getline on Mac OS X 10.6. Build: fix reference to nonexistent strndup on Mac OS X 10.6. |