gdb/testsuite/gdb.threads/watchthreads2.exp

# This testcase is part of GDB, the GNU debugger.

# Copyright 2009-2024 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/>.

# Check that watchpoints get propagated to all existing threads when the
# watchpoint is created.

set NR_THREADS 4
set X_INCR_COUNT 10


# This test verifies that a watchpoint is detected in the proper thread
# so the test is only meaningful on a system with hardware watchpoints.
require allow_hw_watchpoint_tests

standard_testfile
if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable [list debug "additional_flags=-DNR_THREADS=$NR_THREADS -DX_INCR_COUNT=$X_INCR_COUNT"]] != "" } {
    return -1
}

clean_restart ${binfile}

gdb_test_no_output "set can-use-hw-watchpoints 1" ""

#
# Run to `main' where we begin our tests.
#

if {![runto_main]} {
    return 0
}

gdb_test "break thread_started" \
         "Breakpoint 2 at .*: file .*${srcfile}, line .*" \
         "breakpoint on thread_started"

# Run the program until all threads have hit thread_started.
# We use this as the vehicle to determine when gdb is aware
# of all threads (i.e. "info threads" would show all threads).

set nr_started 0
set message "run to thread_started"
for { set i 0 } { $i < $NR_THREADS } { incr i } {
    gdb_test_multiple "continue" $message {
	-re ".*Breakpoint 2, thread_started ().*$gdb_prompt $" {
	    incr nr_started
	}
	timeout {
	    set i $NR_THREADS
	}
    }
}
if { $nr_started == $NR_THREADS } {
    pass "all threads started"
} else {
    fail "all threads started"
    # No point in continuing.
    return -1
}

# Check that multiple uses of the 'thread' keyword will give an error.
gdb_test "watch x thread 1 thread 2" "You can specify only one thread\\."

# Watch X, it will be modified by all threads.
# We want this watchpoint to be set *after* all threads are running.
gdb_test "watch x" "Hardware watchpoint 3: x"

# Now that the watchpoint is set, we can let the threads increment X.
gdb_test_no_output "set var test_ready = 1"

# While debugging.
#gdb_test_no_output "set debug infrun 1"

set x_inc_line [gdb_get_line_number "X increment"]
set x_thread_loc "thread_function \\\(arg=.*\\\) at .*watchthreads.c:$x_inc_line"

# X is incremented under a mutex, so we should get NR_THREADS * X_INCR_COUNT
# hits.
set limit [expr $NR_THREADS*$X_INCR_COUNT]
set x_count 0
set done 0

set message "x watch loop"

for {set i 0} {!$done && $i < $limit} {incr i} {
    set test_flag 0

    gdb_test_multiple "continue" $message {
	-re "(.*Hardware watchpoint.*)$gdb_prompt $" {
	    set string $expect_out(1,string)

	    if [regexp "Hardware watchpoint 3: x\[^\r\]*\r\[^\r\]*\r\[^\r\]*Old value = $x_count\[^\r\]*\r\[^\r\]*New value = [expr $x_count+1]\r" $string] {
		incr x_count
		set test_flag 1
	    } else {
		# We test for new value = old value + 1 each iteration.
		# This can fail due to gdb/10116.
		# This is caught after the loop exits.
	    }
	}
	-re "The program is not being run.*$gdb_prompt $" {
	    fail "$message (program terminated)"
	}
    }

    # If we fail above, don't bother continuing loop.
    if { $test_flag == 0 } {
	set done 1
    }
}

if { $i == $limit } {
    pass "all threads incremented x"
} else {
    kfail "gdb/10116" "gdb can drop watchpoints in multithreaded app"
}