Merge branch 'minac_write_lines_with_semaphore' into 'master'

Synchronize writing CSV lines with semaphore

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/160596



Merged-by: Brian Williams <bwilliams@gitlab.com>
Approved-by: Subashis Chakraborty <schakraborty@gitlab.com>
Approved-by: Brian Williams <bwilliams@gitlab.com>
Co-authored-by: Mehmet Emin INAC <minac@gitlab.com>

ee/app/services/vulnerability_exports/export_service.rb

@@ -67,6 +67,7 @@ def finalise_segmented_export
 
       Async do
         semaphore = Async::Semaphore.new(NUMBER_OF_CONCURRENT_TASKS)
+        write_semaphore = Async::Semaphore.new
 
         tasks = vulnerability_export.export_parts.map do |part|
           semaphore.async do
@@ -74,13 +75,15 @@ def finalise_segmented_export
               stream.readline if export_header.present? # Moves the cursor to next line
 
               stream.each_line do |line|
-                # The encoding of the parts is read as ASCI-8BIT.
-                # We need to force the encoding to utf-8 to avoid a write failure due to
-                # wide-chars used in place like group names.
-                # See:
-                # https://github.com/carrierwaveuploader/carrierwave/issues/1583
-                # https://gitlab.com/gitlab-org/gitlab/-/blob/0aa846a1baa08b1f6f11b2711f8f6bf880542a46/lib/gitlab/http_io.rb
-                tempfile << line.force_encoding(Encoding::UTF_8)
+                write_semaphore.acquire do
+                  # The encoding of the parts is read as ASCI-8BIT.
+                  # We need to force the encoding to utf-8 to avoid a write failure due to
+                  # wide-chars used in place like group names.
+                  # See:
+                  # https://github.com/carrierwaveuploader/carrierwave/issues/1583
+                  # https://gitlab.com/gitlab-org/gitlab/-/blob/0aa846a1baa08b1f6f11b2711f8f6bf880542a46/lib/gitlab/http_io.rb
+                  tempfile << line.force_encoding(Encoding::UTF_8)
+                end
               end
             end
           end