view tests/test-patchbomb-tls.t @ 38732:be4984261611

merge: mark file gets as not thread safe (issue5933)

In default installs, this has the effect of disabling the thread-based
worker on Windows when manifesting files in the working directory. My
measurements have shown that with revlog-based repositories, Mercurial
spends a lot of CPU time in revlog code resolving file data. This ends
up incurring a lot of context switching across threads and slows down
`hg update` operations when going from an empty working directory to
the tip of the repo.

On mozilla-unified (246,351 files) on an i7-6700K (4+4 CPUs):

before: 487s wall
after:  360s wall (equivalent to worker.enabled=false)
cpus=2: 379s wall

Even with only 2 threads, the thread pool is still slower.

The introduction of the thread-based worker (02b36e860e0b) states that
it resulted in a "~50%" speedup for `hg sparse --enable-profile` and
`hg sparse --disable-profile`. This disagrees with my measurement
above. I theorize a few reasons for this:

1) Removal of files from the working directory is I/O - not CPU - bound
   and should benefit from a thread pool (unless I/O is insanely fast
   and the GIL release is near instantaneous). So tests like `hg sparse
   --enable-profile` may exercise deletion throughput and aren't good
   benchmarks for worker tasks that are CPU heavy.
2) The patch was authored by someone at Facebook. The results were
   likely measured against a repository using remotefilelog. And I
   believe that revision retrieval during working directory updates with
   remotefilelog will often use a remote store, thus being I/O and not
   CPU bound. This probably resulted in an overstated performance gain.

Since there appears to be a need to enable the thread-based worker with
some stores, I've made the flagging of file gets as thread safe
configurable. I've made it experimental because I don't want to formalize
a boolean flag for this option and because this attribute is best
captured against the store implementation. But we don't have a proper
store API for this yet. I'd rather cross this bridge later.

It is possible there are revlog-based repositories that do benefit from
a thread-based worker. I didn't do very comprehensive testing. If there
are, we may want to devise a more proper algorithm for whether to use
the thread-based worker, including possibly config options to limit the
number of threads to use. But until I see evidence that justifies
complexity, simplicity wins.

Differential Revision: https://phab.mercurial-scm.org/D3963

#require serve ssl

Set up SMTP server:

  $ CERTSDIR="$TESTDIR/sslcerts"
  $ cat "$CERTSDIR/priv.pem" "$CERTSDIR/pub.pem" >> server.pem

  $ $PYTHON "$TESTDIR/dummysmtpd.py" -p $HGPORT --pid-file a.pid -d \
  > --tls smtps --certificate `pwd`/server.pem
  listening at localhost:$HGPORT (?)
  $ cat a.pid >> $DAEMON_PIDS

Set up repository:

  $ hg init t
  $ cd t
  $ cat <<EOF >> .hg/hgrc
  > [extensions]
  > patchbomb =
  > [email]
  > method = smtp
  > [smtp]
  > host = localhost
  > port = $HGPORT
  > tls = smtps
  > EOF

  $ echo a > a
  $ hg commit -Ama -d '1 0'
  adding a

Utility functions:

  $ DISABLECACERTS=
  $ try () {
  >   hg email $DISABLECACERTS -f quux -t foo -c bar -r tip "$@"
  > }

Our test cert is not signed by a trusted CA. It should fail to verify if
we are able to load CA certs:

#if sslcontext defaultcacerts no-defaultcacertsloaded
  $ try
  this patch series consists of 1 patches.
  
  
  (an attempt was made to load CA certificates but none were loaded; see https://mercurial-scm.org/wiki/SecureConnections for how to configure Mercurial to avoid this error)
  (?i)abort: .*?certificate.verify.failed.* (re)
  [255]
#endif

#if no-sslcontext defaultcacerts
  $ try
  this patch series consists of 1 patches.
  
  
  warning: connecting to localhost using legacy security technology (TLS 1.0); see https://mercurial-scm.org/wiki/SecureConnections for more info
  (using CA certificates from *; if you see this message, your Mercurial install is not properly configured; see https://mercurial-scm.org/wiki/SecureConnections for how to configure Mercurial to avoid this message) (glob) (?)
  (?i)abort: .*?certificate.verify.failed.* (re)
  [255]
#endif

#if defaultcacertsloaded
  $ try
  this patch series consists of 1 patches.
  
  
  warning: connecting to localhost using legacy security technology (TLS 1.0); see https://mercurial-scm.org/wiki/SecureConnections for more info (?)
  (using CA certificates from *; if you see this message, your Mercurial install is not properly configured; see https://mercurial-scm.org/wiki/SecureConnections for how to configure Mercurial to avoid this message) (glob) (?)
  (the full certificate chain may not be available locally; see "hg help debugssl") (windows !)
  (?i)abort: .*?certificate.verify.failed.* (re)
  [255]

#endif

#if no-defaultcacerts
  $ try
  this patch series consists of 1 patches.
  
  
  (unable to load * certificates; see https://mercurial-scm.org/wiki/SecureConnections for how to configure Mercurial to avoid this message) (glob) (?)
  abort: localhost certificate error: no certificate received
  (set hostsecurity.localhost:certfingerprints=sha256:62:09:97:2f:97:60:e3:65:8f:12:5d:78:9e:35:a1:36:7a:65:4b:0e:9f:ac:db:c3:bc:6e:b6:a3:c0:16:e0:30 config setting or use --insecure to connect insecurely)
  [255]
#endif

  $ DISABLECACERTS="--config devel.disableloaddefaultcerts=true"

Without certificates:

  $ try --debug
  this patch series consists of 1 patches.
  
  
  (using smtps)
  sending mail: smtp host localhost, port * (glob)
  warning: connecting to localhost using legacy security technology (TLS 1.0); see https://mercurial-scm.org/wiki/SecureConnections for more info (?)
  (verifying remote certificate)
  abort: unable to verify security of localhost (no loaded CA certificates); refusing to connect
  (see https://mercurial-scm.org/wiki/SecureConnections for how to configure Mercurial to avoid this error or set hostsecurity.localhost:fingerprints=sha256:20:de:b3:ad:b4:cd:a5:42:f0:74:41:1c:a2:70:1e:da:6e:c0:5c:16:9e:e7:22:0f:f1:b7:e5:6e:e4:92:af:7e to trust this server)
  [255]

With global certificates:

  $ try --debug --config web.cacerts="$CERTSDIR/pub.pem"
  this patch series consists of 1 patches.
  
  
  (using smtps)
  sending mail: smtp host localhost, port * (glob)
  warning: connecting to localhost using legacy security technology (TLS 1.0); see https://mercurial-scm.org/wiki/SecureConnections for more info (?)
  (verifying remote certificate)
  sending [PATCH] a ...

With invalid certificates:

  $ try --config web.cacerts="$CERTSDIR/pub-other.pem"
  this patch series consists of 1 patches.
  
  
  warning: connecting to localhost using legacy security technology (TLS 1.0); see https://mercurial-scm.org/wiki/SecureConnections for more info (?)
  (the full certificate chain may not be available locally; see "hg help debugssl") (windows !)
  (?i)abort: .*?certificate.verify.failed.* (re)
  [255]

  $ cd ..