binman: Support multithreading for building images

Some images may take a while to build, e.g. if they are large and use slow
compression. Support compiling sections in parallel to speed things up.

Signed-off-by: Simon Glass <sjg@chromium.org>
(fixed to use a separate test file to fix flakiness)

1 files changed, 33 insertions, 3 deletions

diff --git a/tools/binman/etype/section.py b/tools/binman/etype/section.py
index c3bac026c1..92d3f3add4 100644
--- a/tools/binman/etype/section.py
+++ b/tools/binman/etype/section.py
@@ -9,10 +9,12 @@ images to be created.
 """
 
 from collections import OrderedDict
+import concurrent.futures
 import re
 import sys
 
 from binman.entry import Entry
+from binman import state
 from dtoc import fdt_util
 from patman import tools
 from patman import tout
@@ -525,15 +527,43 @@ class Entry_section(Entry):
     def GetEntryContents(self):
         """Call ObtainContents() for each entry in the section
         """
+        def _CheckDone(entry):
+            if not entry.ObtainContents():
+                next_todo.append(entry)
+            return entry
+
         todo = self._entries.values()
         for passnum in range(3):
+            threads = state.GetThreads()
             next_todo = []
-            for entry in todo:
-                if not entry.ObtainContents():
-                    next_todo.append(entry)
+
+            if threads == 0:
+                for entry in todo:
+                    _CheckDone(entry)
+            else:
+                with concurrent.futures.ThreadPoolExecutor(
+                        max_workers=threads) as executor:
+                    future_to_data = {
+                        entry: executor.submit(_CheckDone, entry)
+                        for entry in todo}
+                    timeout = 60
+                    if self.GetImage().test_section_timeout:
+                        timeout = 0
+                    done, not_done = concurrent.futures.wait(
+                        future_to_data.values(), timeout=timeout)
+                    # Make sure we check the result, so any exceptions are
+                    # generated. Check the results in entry order, since tests
+                    # may expect earlier entries to fail first.
+                    for entry in todo:
+                        job = future_to_data[entry]
+                        job.result()
+                    if not_done:
+                        self.Raise('Timed out obtaining contents')
+
             todo = next_todo
             if not todo:
                 break
+
         if todo:
             self.Raise('Internal error: Could not complete processing of contents: remaining %s' %
                        todo)