Commit Graph

3 Commits

Author SHA1 Message Date
Colin Cross
405af07859 Revert "Make lots of tests run in parallel"
This reverts commit 323dc60712.

Reason for revert: Possible cause of test instability
Bug: 170513220
Test: soong tests

Change-Id: Iee168e9fbb4210569e6cffcc23e60d111403abb8
2020-10-09 18:34:24 -07:00
Colin Cross
323dc60712 Make lots of tests run in parallel
Putting t.Parallel() in each test makes them run in parallel.
Additional t.Parallel() could be added to each subtest, although
that requires making a local copy of the loop variable for
table driven tests.

Test: m checkbuild
Change-Id: I5d9869ead441093f4d7c5757f2447385333a95a4
2020-10-06 15:12:22 -07:00
Colin Cross
ae7fd6baf3 Reimplement ioutil.ReadDir with a version that avoids calling lstat
ioutil.ReadDir returns []os.FileInfo, which contains information on
each entry in the directory that is only available by calling
os.Lstat on the entry.  Finder only the name and type (regular,
directory or symlink) of the files, which on Linux kernels >= 2.6.4
is available in the return values of syscall.Getdents.

Replace ioutil.ReadDir with a call that uses syscall.Getdents
directly and collects the type information from the result.

Testing with:
rm -f /tmp/db && strace -fc finder -names Android.mk,Android.bp,Blueprints,CleanSpec.mk,TEST_MAPPING -exclude-dirs .git,.repo -prune-files .out-dir,.find-ignore -db /tmp/db .

Before:
  7.01   52.688304          63    833398         1 lstat
  1.90   14.246644          68    210523           getdents64
  1.25    9.370471          90    104286         1 openat

After:
  3.48   12.201385         117    104286         1 openat
  3.06   10.729138          51    210523           getdents64
  1.70    5.951892          57    104283         1 lstat

Pros:
Avoids 729115 calls to lstat.

Cons:
Requires copying ~200 lines of finicky buffer parsing code.
Puts all getdents calls (and possibly fallback lstat calls) onto
a non-blocking file descriptor, which will cause it to block a
thread and not just a goroutine.
Only works on Linux and Darwin.

Bug: 70897635
Test: m checkbuild
Change-Id: Iab9f82c38c8675d0b73b4e90540bb9e4d2ee52c1
2017-12-22 13:56:17 -08:00