gdb/testsuite/gdb.threads/inf-thr-count.exp

   1 # Copyright 2023 Free Software Foundation, Inc.
   2
   3 # This program is free software; you can redistribute it and/or modify
   4 # it under the terms of the GNU General Public License as published by
   5 # the Free Software Foundation; either version 3 of the License, or
   6 # (at your option) any later version.
   7 #
   8 # This program is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 # GNU General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU General Public License
  14 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15
  16 # Check that the $_inferior_thread_count convenience variable will
  17 # correctly update its value without passing through a normal stop
  18 # event.
  19 #
  20 # When GDB is using a remote (or extended-remote) target, GDB only
  21 # learns about changes to the thread list be explicitly querying the
  22 # target.  This is done as part of a normal stop, but there are some
  23 # situations where the thread list can change, but GDB doesn't pass
  24 # through a normal stop.
  25 #
  26 # For example, when the target is running asynchronously in non-stop
  27 # mode; in this case GDB can query the thread list without the target
  28 # ever stopping.
  29 #
  30 # Or after an inferior function call.
  31 #
  32 # The solution is to ensure that $_inferior_thread_count explicitly
  33 # queries the target to update the thread list.  This test checks that
  34 # this is done.
  35
  36 standard_testfile
  37
  38 if {[build_executable "failed to prepare" $testfile $srcfile \
  39          {debug pthreads}] == -1} {
  40     return -1
  41 }
  42
  43 # Start GDB.  Ensure we are in non-stop mode as we need to read from
  44 # the inferior while it is running.
  45 save_vars {GDBFLAGS} {
  46     append GDBFLAGS " -ex \"set non-stop on\""
  47     clean_restart $binfile
  48 }
  49
  50 if ![runto_main] {
  51     return -1
  52 }
  53
  54 gdb_breakpoint breakpt
  55 gdb_continue_to_breakpoint "first breakpt call"
  56
  57 # Check we can see a single thread to begin with.
  58 gdb_test "p \$_inferior_thread_count" \
  59     "^\\\$$::decimal = 1" \
  60     "only one thread in \$_inferior_thread_count"
  61
  62 # We don't want thread events, it makes it harder to match GDB's
  63 # output.
  64 gdb_test_no_output "set print thread-events off"
  65
  66 # Continue the program in the background.
  67 set test "continue&"
  68 gdb_test_multiple "continue&" $test {
  69     -re "Continuing\\.\r\n$gdb_prompt " {
  70         pass $test
  71     }
  72 }
  73
  74 # Read the 'stage' flag from the inferior.  This is initially 0, but
  75 # will be set to 1 once the extra thread has been created, and then 2
  76 # once the extra thread has exited.
  77 #
  78 # We catch the case where we can't read from the inferior while the
  79 # inferior is running, this happens if the target hasn't entered
  80 # non-stop mode like we asked.  In this case we interrupt the inferior
  81 # and bail.
  82 #
  83 # Otherwise, if we can read from the inferior we try at most 10 times
  84 # to read the flag (with a 1 second delay after each read).  If the
  85 # flag isn't set after this then we bail.  The inferior is either very
  86 # slow, or the thread hasn't started for some reason.
  87 proc wait_for_stage { num } {
  88     set failure_count 0
  89     set cmd "print /d stage"
  90     set stage_flag 0
  91     gdb_test_multiple "$cmd" "wait for 'stage' flag to be $num" {
  92         -re -wrap "^Cannot execute this command while the target is running\\.\r\nUse the \"interrupt\" command to stop the target\r\nand then try again\\." {
  93             fail "$gdb_test_name (can't read asynchronously)"
  94             gdb_test_no_output "interrupt"
  95
  96             gdb_test_multiple "" "wait for thread to stop" {
  97                 -re "Thread .* received signal .*" {
  98                     pass $gdb_test_name
  99                     gdb_test "p 1 + 2" " = 3"
 100                 }
 101             }
 102         }
 103
 104         -re -wrap "^\\$\[0-9\]* = (\[-\]*\[0-9\]*).*" {
 105             set stage_flag $expect_out(1,string)
 106             if {$stage_flag != $num} {
 107                 set stage_flag 0
 108                 incr failure_count
 109                 if { $failure_count < 10 } {
 110                     sleep 1
 111                     send_gdb "$cmd\n"
 112                     exp_continue
 113                 }
 114                 fail $gdb_test_name
 115             } else {
 116                 pass $gdb_test_name
 117             }
 118         }
 119     }
 120
 121     return $stage_flag
 122 }
 123
 124 # Wait until we can see that the extra thread has been created.
 125 if {![wait_for_stage 1]} {
 126     unresolved "failed to see thread start"
 127     return -1
 128 }
 129
 130
 131 if {[target_info exists gdb_protocol]
 132     && ([target_info gdb_protocol] == "remote"
 133         || [target_info gdb_protocol] == "extended-remote")} {
 134     set new_thread_re "\\\[New Thread \[^\r\n\]+\\\]\r\n"
 135     set exit_thread_re "\\\[Thread \[^\r\n\]+ exited\\\]\r\n"
 136 } else {
 137     set new_thread_re ""
 138     set exit_thread_re ""
 139 }
 140
 141 # This is the test we actually care about.  Check that the
 142 # $_inferior_thread_count convenience variable shows the correct
 143 # thread count; the new thread should be visible.
 144 gdb_test "with print thread-events on -- p \$_inferior_thread_count" \
 145     "^${new_thread_re}\\\$$::decimal = 2" \
 146     "second thread visible in \$_inferior_thread_count"
 147
 148 # Set a variable in the inferior, this will cause the second thread to
 149 # exit.
 150 gdb_test_no_output "set variable spin = 0" \
 151     "set 'spin' flag to allow worker thread to exit"
 152
 153 # Wait until the extra thread has exited.
 154 if {![wait_for_stage 2]} {
 155     unresolved "failed to see thread start"
 156     return -1
 157 }
 158
 159 # Check that the second thread has gone away.
 160 gdb_test "with print thread-events on -- p \$_inferior_thread_count" \
 161     "^${exit_thread_re}\\\$$::decimal = 1" \
 162     "back to one thread visible in \$_inferior_thread_count"
 163
 164 # Set a variable in the inferior, this will cause the second thread to
 165 # exit.
 166 gdb_test_no_output "set variable spin = 0" \
 167     "set 'spin' flag to allow main thread to exit"
 168
 169 # When the second thread exits, the main thread joins with it, and
 170 # then proceeds to hit the breakpt function again.
 171 gdb_test_multiple "" "wait for main thread to stop" {
 172     -re "Thread 1 \[^\r\n\]+ hit Breakpoint $decimal, breakpt \\(\\)\[^\r\n\]+\r\n\[^\r\n\]+\r\n" {
 173         pass $gdb_test_name
 174     }
 175 }