7993 2015-07-14 12:43:15 +0000 pseudo: select returns immediately on FIFO 2015-09-22 15:13:11 +0000 1 1 6 Yocto Project Subprojects Pseudo pseudo unspecified All Multiple VERIFIED FIXED Medium+ normal 1.9 M2 1 bluelightning seebs alexandru.c.georgescu ross.burton seebs yp.pseudo.watcher yp.watcher daniel.alexandrux.istrate --- --- No (bug/feature does not impact docs) oldest_to_newest 52341 0 2588 bluelightning 2015-07-14 12:43:15 +0000 Created attachment 2588 Test script to demonstrate the issue With a recent change in BitBake we are creating a FIFO for each shell task and then writing to it when bbnote/bbwarn/bberror etc. are called (see bug 5275 for details). Unfortunately this has exposed a bug in pseudo: calling select() on a FIFO created with mkfifo() under pseudo returns immediately instead of waiting until there is some data to read, even when the FIFO is opened read/write. This has led to a performance regression. A test case is attached - run it outside of pseudo and it behaves correctly, only printing what is echoed into the FIFO; run it under pseudo and it will print out empty strings repeatedly. Richard also has a patch which does appear to fix the issue but needs work: http://git.yoctoproject.org/cgit.cgi/poky-contrib/patch/?id=ef004bfbad695dcd7c9001b7529181ae72d45162 52566 1 ross.burton 2015-07-23 20:41:44 +0000 Fixed in pseudo 1.6.7, merged in oe-core 0295947a2ccc66037f9c20f06b4b69a781a046bd. 54463 2 daniel.alexandrux.istrate 2015-09-22 15:13:11 +0000 Verified on master: 7b86c771c80d0759c2ca0e57c46c4c966f89c49e Steps to verify: 1. Download the attached script and run it 2. In another terminal run: echo test > /tmp/testfifo --> You should see the echoed message in the first terminal where the script is running. Now to test for pseudo: 1. Start the pseudo env with: bitbake m4 -c devshell 2. In the shell that pops up copy the attached script and run it 3. In another terminal run: echo test > /tmp/testfifo --> You should see the echoed message in the pseudo env where the script is running. 2588 2015-07-14 12:43:15 +0000 2015-07-14 12:43:15 +0000 Test script to demonstrate the issue testpipe2.py text/x-python 700 bluelightning aW1wb3J0IHN5cwppbXBvcnQgb3MKaW1wb3J0IGZjbnRsCmltcG9ydCBlcnJubwppbXBvcnQgc2Vs ZWN0CgpkZWYgbm9uYmxvY2tpbmdmZChmZCk6CiAgICBmY250bC5mY250bChmZCwgZmNudGwuRl9T RVRGTCwgZmNudGwuZmNudGwoZmQsIGZjbnRsLkZfR0VURkwpIHwgb3MuT19OT05CTE9DSykKCmZp Zm9wYXRoID0gIi90bXAvdGVzdGZpZm8iCgppZiBvcy5wYXRoLmV4aXN0cyhmaWZvcGF0aCk6CiAg ICBvcy51bmxpbmsoZmlmb3BhdGgpCgpvcy5ta2ZpZm8oZmlmb3BhdGgpCgp3aXRoIG9wZW4oZmlm b3BhdGgsICdyKycpIGFzIGZpZm86CiAgICBybGlzdCA9IFtdCiAgICBub25ibG9ja2luZ2ZkKGZp Zm8uZmlsZW5vKCkpCiAgICBybGlzdC5hcHBlbmQoZmlmbykKICAgIHdoaWxlIFRydWU6CiAgICAg ICAgcix3LGUgPSBzZWxlY3Quc2VsZWN0IChybGlzdCwgW10sIFtdLCAxKQogICAgICAgIGlmIGZp Zm8gaW4gcjoKICAgICAgICAgICAgdHJ5OgogICAgICAgICAgICAgICAgZGF0YSA9IGZpZm8ucmVh ZCgpCiAgICAgICAgICAgIGV4Y2VwdCBJT0Vycm9yIGFzIGVycjoKICAgICAgICAgICAgICAgIGlm IGVyci5lcnJubyA9PSBlcnJuby5FQUdBSU4gb3IgZXJyLmVycm5vID09IGVycm5vLkVXT1VMREJM T0NLOgogICAgICAgICAgICAgICAgICAgIGRhdGEgPSBOb25lCgogICAgICAgICAgICBwcmludCAn IicgKyBkYXRhICsgJyInCg==