FileImage: make thread-safe
FileImage needs to be thread-safe because multiple
threads gets data from it when an incremental OTA
package is created.
Test: apply incremental OTA on cuttlefish
Bug: 113175337
Change-Id: I31637fce0fbd66f3fa6c5c478da09bae65a52229
diff --git a/tools/releasetools/blockimgdiff.py b/tools/releasetools/blockimgdiff.py
index 2e5f804..b23eef1 100644
--- a/tools/releasetools/blockimgdiff.py
+++ b/tools/releasetools/blockimgdiff.py
@@ -205,6 +205,8 @@
self.clobbered_blocks = RangeSet()
self.extended = RangeSet()
+ self.generator_lock = threading.Lock()
+
self.hashtree_info = None
if hashtree_info_generator:
self.hashtree_info = hashtree_info_generator.Generate(self)
@@ -236,10 +238,13 @@
self._file.close()
def _GetRangeData(self, ranges):
- for s, e in ranges:
- self._file.seek(s * self.blocksize)
- for _ in range(s, e):
- yield self._file.read(self.blocksize)
+ # Use a lock to protect the generator so that we will not run two
+ # instances of this generator on the same object simultaneously.
+ with self.generator_lock:
+ for s, e in ranges:
+ self._file.seek(s * self.blocksize)
+ for _ in range(s, e):
+ yield self._file.read(self.blocksize)
def RangeSha1(self, ranges):
h = sha1()