[Buildroot] [PATCH 3/6] infra: fix 'packages-file-list.txt' with TLP

["Jérôme Pouiller" <jezz@sysmic.org>]

Until now, `$(BUILD_DIR)/packages-file-list.txt' was not filled properly when
top level parallelization is enabled. Therefore, all scripts that rely on
packages-file-list.txt did not work.

In order to fix it,this patch place target installation task in a critical
section.

Signed-off-by: J?r?me Pouiller <jezz@sysmic.org>
---
 package/pkg-generic.mk | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/package/pkg-generic.mk b/package/pkg-generic.mk
index 987efa6..c5f70e0 100644
--- a/package/pkg-generic.mk
+++ b/package/pkg-generic.mk
@@ -62,6 +62,9 @@ GLOBAL_INSTRUMENTATION_HOOKS += step_time
 # files currently installed in the target. Note that the MD5 is also
 # stored, in order to identify if the files are overwritten.
 define step_pkg_size_start
+	while ! flock $(BUILD_DIR) -c "[ ! -e $(BUILD_DIR)/.target_lock ] && touch $(BUILD_DIR)/.target_lock"; do \
+		sleep 0.5; \
+	done
 	(cd $(TARGET_DIR) ; find . -type f -print0 | xargs -0 md5sum) | sort > \
 		$($(PKG)_DIR)/.br_filelist_before
 endef
@@ -78,6 +81,7 @@ define step_pkg_size_end
 		while read hash file ; do \
 			echo "$(1),$${file}" >> $(BUILD_DIR)/packages-file-list.txt ; \
 		done
+	rm $(BUILD_DIR)/.target_lock
 endef
 
 define step_pkg_size
-- 
2.9.3