[PATCH 3/3] parallel-tests: optimize global log creation

[Stefano Lattarini]

With this change, the time required to execute the test case
'testsuite-summary-speed.sh' has dropped as follows:

  + Slow Debian i686 system, 1 core x 1.5 GHz, 768 MB of RAM,
    GNU make 3.81:
      - 1 run: 4 minutes => 30/40 seconds

  + Fast Solaris 10 i686 system, 4 cores x 3 GHz, 20 GB of RAM,
    Solaris CCS make:
     - 2 runs: 6 minutes => 30 seconds

  + Very fast Fedora ppc64 system, 64 cores x 3.5 GHz, 64 GB of RAM,
    GNU make 3.82:
     - 5 runs: 7 minutes => 1 minute and 10 seconds

* lib/am/check.am ($(TEST_SUITE_LOG)): Optimize for speed, by avoiding
lots of forks with the help of ...
(am__create_global_log): ... this new internal variable, basically
defining a smart awk program, and ...
(am__global_test_result_rx, am__copy_in_global_log_rx): ... these new
internal variables, used by the one above.
(am__rst_section): Remove as obsolete
* t/rst-formatting.trs: Remove.
* t/list-of-tests.mk: Update.
* t/testsuite-summary-count-many.sh: Improve its stress testing by
using 1 million tests rather than just 5 thousands: we can afford
this with our new optimization, and still have the test completed
in a reasonable time.

Signed-off-by: Stefano Lattarini <address@hidden>
---
 lib/am/check.am                   |   82 ++++++++++++++++++++++----------
 t/list-of-tests.mk                |    1 -
 t/rst-formatting.sh               |   93 -------------------------------------
 t/testsuite-summary-count-many.sh |    4 +-
 4 files changed, 58 insertions(+), 122 deletions(-)
 delete mode 100755 t/rst-formatting.sh

diff --git a/lib/am/check.am b/lib/am/check.am
index f2bfb6a..a65fef9 100644
--- a/lib/am/check.am
+++ b/lib/am/check.am
@@ -56,6 +56,8 @@ include inst-vars.am
 ## (among them, TAP).
 
 am__recheck_rx = ^[    ]*:recheck:[    ]*
+am__global_test_result_rx = ^[         ]*:global-test-result:[         ]*
+am__copy_in_global_log_rx = ^[         ]*:copy-in-global-log:[         ]*
 
 # A command that, given a newline-separated list of test names on the
 # standard input, print the name of the tests that are to be re-run
@@ -106,9 +108,59 @@ am__list_recheck_tests = $(AWK) '{ \
   close ($$0 ".log"); \
 }'
 
-# Restructured Text title and section.
+# A command that, given a newline-separated list of test names on the
+# standard input, create the global log from their .trs and .log files.
+am__create_global_log = $(AWK) ' \
+function fatal(msg) \
+{ \
+  print "fatal: making $@: " msg | "cat >&2"; \
+  exit 1; \
+} \
+function rst_section(header) \
+{ \
+  print header; \
+  len = length(header); \
+  for (i = 1; i <= len; i = i + 1) \
+    printf "="; \
+  printf "\n\n"; \
+} \
+{ \
+## By default, we assume the test log is to be copied in the global log,
+## and that its result is simply "RUN" (i.e., we still don't know what
+## it outcome was, but we know that at least it has run).
+  copy_in_global_log = 1; \
+  global_test_result = "RUN"; \
+  while ((rc = (getline line < ($$0 ".trs"))) != 0) \
+    { \
+      if (rc < 0) \
+         fatal("failed to read from " $$0 ".trs"); \
+      if (line ~ /$(am__global_test_result_rx)/) \
+        { \
+          sub("$(am__global_test_result_rx)", "", line); \
+          sub("[       ]*$$", "", line); \
+          global_test_result = line; \
+        } \
+      else if (line ~ /$(am__copy_in_global_log_rx)[nN][oO]/) \
+        copy_in_global_log = 0; \
+    }; \
+  if (copy_in_global_log) \
+    { \
+      rst_section(global_test_result ": " $$0); \
+      while ((rc = (getline line < ($$0 ".log"))) != 0) \
+      { \
+        if (rc < 0) \
+          fatal("failed to read from " $$0 ".log"); \
+        print line; \
+      }; \
+    }; \
+## Don't leak open file descriptors, as this could cause serious
+## problems when there are many tests (yes, even on Linux).
+  close ($$0 ".trs"); \
+  close ($$0 ".log"); \
+}'
+
+# Restructured Text title.
 am__rst_title = { sed 's/.*/   &   /;h;s/./=/g;p;x;s/ *$$//;p;g' && echo; }
-am__rst_section = { sed 'p;s/./=/g;' && echo; }
 
 # Solaris 10 'make', and several other traditional 'make' implementations,
 # pass "-e" to $(SHELL), and POSIX 2008 even requires this.  Work around it
@@ -295,29 +347,9 @@ $(TEST_SUITE_LOG): $(TEST_LOGS)
          echo;                                                         \
          echo ".. contents:: :depth: 2";                               \
          echo;                                                         \
-         for i in $$bases; do                                          \
-## FIXME: one fork per test -- this is horrendously inefficient!
-           if grep "^$$ws*:copy-in-global-log:$$ws*no$$ws*$$" $$i.trs \
-                >/dev/null; then continue; \
-           fi; \
-## Get the declared "global result" of the test.
-## FIXME: yet another one fork per test here!
-           glob_res=`sed -n -e "s/$$ws*$$//" \
-                            -e "s/^$$ws*:global-test-result:$$ws*//p" \
-                       $$i.trs`; \
-## If no global result is explicitly declared, we'll merely mark the
-## test as "RUN" in the global test log.
-           test -n "$$glob_res" || glob_res=RUN; \
-## Write the name and result of the test as an RST section title.
-           echo "$$glob_res: $$i" | $(am__rst_section); \
-## If we should have remade any unreadable '.log', above.
-           if test ! -r $$i.log; then \
-             echo "fatal: making $@: $$i.log is unreadable" >&2; \
-             exit 1; \
-           fi; \
-           cat $$i.log; echo; \
-         done; \
-       } >$(TEST_SUITE_LOG).tmp;                                       \
+         for b in $$bases; do echo $$b; done                           \
+           | $(am__create_global_log);                                 \
+       } >$(TEST_SUITE_LOG).tmp || exit 1;                             \
        mv $(TEST_SUITE_LOG).tmp $(TEST_SUITE_LOG);                     \
 ## Emit the test summary on the console.
        if $$success; then                                              \
diff --git a/t/list-of-tests.mk b/t/list-of-tests.mk
index 2830073..ff6a668 100644
--- a/t/list-of-tests.mk
+++ b/t/list-of-tests.mk
@@ -934,7 +934,6 @@ t/req.sh \
 t/reqd.sh \
 t/reqd2.sh \
 t/repeated-options.sh \
-t/rst-formatting.sh \
 t/rulepat.sh \
 t/self-check-cleanup.tap \
 t/self-check-configure-help.sh \
diff --git a/t/rst-formatting.sh b/t/rst-formatting.sh
deleted file mode 100755
index f23c28c..0000000
--- a/t/rst-formatting.sh
+++ /dev/null
@@ -1,93 +0,0 @@
-#! /bin/sh
-# Copyright (C) 2012 Free Software Foundation, Inc.
-#
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2, or (at your option)
-# any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-# Parallel testsuite harness: check APIs for the registering the
-# "global test result" in '*.trs' files, as documented in the automake
-# manual.
-
-am_create_testdir=empty
-. ./defs || Exit 1
-
-sed -n '/^am__rst_[a-z_][a-z_]* =/p' "$am_amdir"/check.am > Makefile \
-  || framework_failure_ "fetching definitions from check.am"
-
-cat >> Makefile << 'END'
-test:
-       printf '%s\n' "$$in" | $(am__rst_title) > title-got
-       printf '%s\n' "$$in" | $(am__rst_section) > section-got
-       cat title-exp
-       cat title-got
-       diff title-exp title-got
-       cat section-exp
-       cat section-got
-       diff section-exp section-got
-END
-
-# -------------------------------------------------------------------------
-
-cat > title-exp <<'END'
-==============
-   ab cd ef
-==============
-
-END
-
-cat > section-exp <<'END'
-ab cd ef
-========
-
-END
-
-env in='ab cd ef' $MAKE test
-
-# -------------------------------------------------------------------------
-
-cat > title-exp <<'END'
-============================================================================
-   0123456789012345678901234567890123456789012345678901234567890123456789
-============================================================================
-
-END
-
-cat > section-exp <<'END'
-0123456789012345678901234567890123456789012345678901234567890123456789
-======================================================================
-
-END
-
-in=0123456789012345678901234567890123456789012345678901234567890123456789
-env in=$in $MAKE test
-
-# -------------------------------------------------------------------------
-
-cat > title-exp <<'END'
-=======
-   x
-=======
-
-END
-
-cat > section-exp <<'END'
-x
-=
-
-END
-
-env in=x $MAKE test
-
-# -------------------------------------------------------------------------
-
-:
diff --git a/t/testsuite-summary-count-many.sh 
b/t/testsuite-summary-count-many.sh
index 58157ad..ff38097 100755
--- a/t/testsuite-summary-count-many.sh
+++ b/t/testsuite-summary-count-many.sh
@@ -56,9 +56,7 @@ $PERL -w -e '
   use warnings FATAL => "all";
   use strict;
 
-  # FIXME: we would like this to be 1000 or even 10000, but the current
-  # implementation is too slow to handle that :-(
-  my $base = 5;
+  my $base = 1000;
   my %count = (
     TOTAL => $base * 1000,
     PASS  => $base * 700,
-- 
1.7.9.5