Test on solib load and unload

This patch is to add a test case to on the performance of GDB handling
load and unload of shared library.

In V4:

 - Handle malloc and dlopen failure,
 - Document test parameters.

In V3, there are some changes,

 - Adapt to perf test framework changes.
 - Measure load and unload separately.

In V2, there are some changes,

 - A new proc gdb_produce_source to produce source files.  I tried to
   move all source file generation code out of solib.exp, but
   compilation step still needs to know the generated file names.  I
   have to hard-code the file names in compilation step, which is not
   good to me, so I give up on this moving.
 - SOLIB_NUMBER -> SOLIB_COUNT
 - New variable SOLIB_DLCLOSE_REVERSED_ORDER to control the order of
   iterating a list of shared libs to dlclose them.
 - New variable GDB_PERFORMANCE to enable these perf test cases.
 - Remove dlsym call in solib.c.
 - Update solib.py for the updated framework.

gdb/testsuite/

	* lib/gdb.exp (gdb_produce_source): New procedure.
	* gdb.perf/solib.c: New.
	* gdb.perf/solib.exp: New.
	* gdb.perf/solib.py: New.

1 files changed, 87 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.perf/solib.exp b/gdb/testsuite/gdb.perf/solib.exp
new file mode 100644
index 0000000..c1b00b0
--- /dev/null
+++ b/gdb/testsuite/gdb.perf/solib.exp
@@ -0,0 +1,87 @@
+# Copyright (C) 2013 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 3 of the License, 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/>.
+
+# This test case is to test the performance of GDB when it is handling
+# the shared libraries of inferior are loaded and unloaded.
+# There are two parameters in this test:
+#  - SOLIB_COUNT is the number of shared libraries program will load
+#    and unload
+#  - SOLIB_DLCLOSE_REVERSED_ORDER controls the order of dlclose shared
+#    libraries.  If it is set, program dlclose shared libraries in a
+#    reversed order of loading.
+
+load_lib perftest.exp
+
+if [skip_perf_tests] {
+    return 0
+}
+
+standard_testfile .c
+set executable $testfile
+set expfile $testfile.exp
+
+# make check-perf RUNTESTFLAGS='solib.exp SOLIB_COUNT=1024'
+if ![info exists SOLIB_COUNT] {
+    set SOLIB_COUNT 128
+}
+
+PerfTest::assemble {
+    global SOLIB_COUNT
+    global srcdir subdir srcfile binfile
+
+    for {set i 0} {$i < $SOLIB_COUNT} {incr i} {
+
+	# Produce source files.
+	set libname "solib-lib$i"
+	set src [standard_output_file $libname.c]
+	set exe [standard_output_file $libname]
+
+	gdb_produce_source $src "int shr$i (void) {return 0;}"
+
+	# Compile.
+	if { [gdb_compile_shlib $src $exe {debug}] != "" } {
+	    return -1
+	}
+
+	# Delete object files to save some space.
+	file delete [standard_output_file  "solib-lib$i.c.o"]
+    }
+
+    set compile_flags {debug shlib_load}
+    global SOLIB_DLCLOSE_REVERSED_ORDER
+
+    if [info exists SOLIB_DLCLOSE_REVERSED_ORDER] {
+	lappend compile_flags "additional_flags=-DSOLIB_DLCLOSE_REVERSED_ORDER"
+    }
+
+    if { [gdb_compile "$srcdir/$subdir/$srcfile" ${binfile} executable  $compile_flags] != "" } {
+	return -1
+    }
+
+    return 0
+} {
+    global binfile
+
+    clean_restart $binfile
+
+    if ![runto_main] {
+	fail "Can't run to main"
+	return -1
+    }
+} {
+    global SOLIB_COUNT
+
+    gdb_test_no_output "python SolibLoadUnload\($SOLIB_COUNT\).run()"
+}