$ gdb /usr/bin/emacs-w32.exe GNU gdb (GDB) 7.6.50.20130728-cvs (cygwin-special) [...] Reading symbols from /usr/bin/emacs-w32.exe...Reading symbols from /usr/lib/debug/usr/bin/emacs-w32.exe.dbg...done. done. (gdb) b run_timers Breakpoint 1 at 0x5e625e: file /usr/src/debug/emacs-24.3.93-4/src/atimer.c, line 343. (gdb) r -Q Starting program: /usr/bin/emacs-w32.exe -Q [New Thread 3820.0x1594] [New Thread 3820.0x1540] [New Thread 3820.0x1a54] [New Thread 3820.0x1bcc] [New Thread 3820.0x1bdc] Breakpoint 1, run_timers () at /usr/src/debug/emacs-24.3.93-4/src/atimer.c:343 343 struct timespec now = current_timespec (); (gdb) thread apply all bt Thread 5 (Thread 3820.0x1bdc): #0 0x756d78d7 in USER32!DispatchMessageW () from /c/windows/syswow64/USER32.dll #1 0x005ffd9c in w32_msg_pump (msg_buf=0x3b3acd8) at /usr/src/debug/emacs-24.3.93-4/src/w32fns.c:2450 #2 0x005fffdf in w32_msg_worker@4 (arg=0x0) at /usr/src/debug/emacs-24.3.93-4/src/w32fns.c:2676 #3 0x61005f04 in _cygtls::call2(unsigned long (*)(void*, void*), void*, void*)@16 (this=, func=func@entry=0x5fff3f , arg=0x3b3ac70, arg@entry=0x0, buf=buf@entry=0x3b3cdc4) at /home/cygnus/vinschen/mknetrel/src/cygwin-snapshot-20140905-1/winsup/cygwin/cygtls.cc:100 #4 0x61006076 in _cygtls::call (func=0x5fff3f , arg=0x0) at /home/cygnus/vinschen/mknetrel/src/cygwin-snapshot-20140905-1/winsup/cygwin/cygtls.cc:30 #5 0x6107f1f8 in threadfunc_fe (arg=) at /home/cygnus/vinschen/mknetrel/src/cygwin-snapshot-20140905-1/winsup/cygwin/init.cc:30 #6 0x753e338a in KERNEL32!BaseThreadInitThunk () from /c/windows/syswow64/kernel32.dll #7 0x77759f72 in ntdll!RtlInitializeExceptionChain () from /c/windows/system32/ntdll.dll #8 0x77759f45 in ntdll!RtlInitializeExceptionChain () from /c/windows/system32/ntdll.dll #9 0x00000000 in ?? () Thread 4 (Thread 3820.0x1bcc): #0 0x7773f8d1 in ntdll!ZwWaitForSingleObject () from /c/windows/system32/ntdll.dll #1 0x7773f8d1 in ntdll!ZwWaitForSingleObject () from /c/windows/system32/ntdll.dll #2 0x758c14ab in WaitForSingleObjectEx () from /c/windows/syswow64/KERNELBASE.dll #3 0x00000318 in ?? () #4 0x00000000 in ?? () Thread 3 (Thread 3820.0x1a54): #0 0x7774015d in ntdll!ZwWaitForMultipleObjects () from /c/windows/system32/ntdll.dll #1 0x7774015d in ntdll!ZwWaitForMultipleObjects () from /c/windows/system32/ntdll.dll #2 0x77772f91 in ntdll!RtlMoveMemory () from /c/windows/system32/ntdll.dll #3 0x00000001 in ?? () #4 0x00000001 in ?? () #5 0x00000000 in ?? () Thread 2 (Thread 3820.0x1540): #0 0x7773f905 in ntdll!ZwReadFile () from /c/windows/system32/ntdll.dll #1 0x7773f905 in ntdll!ZwReadFile () from /c/windows/system32/ntdll.dll #2 0x758bdd62 in ReadFile () from /c/windows/syswow64/KERNELBASE.dll #3 0x00000090 in ?? () ---Type to continue, or q to quit--- #4 0x753e3ee7 in ReadFile () from /c/windows/syswow64/kernel32.dll #5 0x00000090 in ?? () #6 0x610e1b8c in wait_sig () at /home/cygnus/vinschen/mknetrel/src/cygwin-snapshot-20140905-1/winsup/cygwin/sigproc.cc:1239 #7 0x61004cc7 in cygthread::callfunc(bool)@8 ( this=this@entry=0x6119b840 , issimplestub=issimplestub@entry=false) at /home/cygnus/vinschen/mknetrel/src/cygwin-snapshot-20140905-1/winsup/cygwin/cygthread.cc:51 #8 0x6100523a in cygthread::stub(void*)@4 (arg=0x6119b840 ) at /home/cygnus/vinschen/mknetrel/src/cygwin-snapshot-20140905-1/winsup/cygwin/cygthread.cc:93 #9 0x61005f04 in _cygtls::call2(unsigned long (*)(void*, void*), void*, void*)@16 (this=, func=func@entry=0x610051f0 , arg=arg@entry=0x6119b840 , buf=buf@entry=0x2b6cdc4) at /home/cygnus/vinschen/mknetrel/src/cygwin-snapshot-20140905-1/winsup/cygwin/cygtls.cc:100 #10 0x61006076 in _cygtls::call (func=0x610051f0 , arg=0x6119b840 ) at /home/cygnus/vinschen/mknetrel/src/cygwin-snapshot-20140905-1/winsup/cygwin/cygtls.cc:30 #11 0x6107f1f8 in threadfunc_fe (arg=) at /home/cygnus/vinschen/mknetrel/src/cygwin-snapshot-20140905-1/winsup/cygwin/init.cc:30 #12 0x753e338a in KERNEL32!BaseThreadInitThunk () from /c/windows/syswow64/kernel32.dll #13 0x77759f72 in ntdll!RtlInitializeExceptionChain () from /c/windows/system32/ntdll.dll #14 0x77759f45 in ntdll!RtlInitializeExceptionChain () from /c/windows/system32/ntdll.dll #15 0x00000000 in ?? () Thread 1 (Thread 3820.0x1594): #0 run_timers () at /usr/src/debug/emacs-24.3.93-4/src/atimer.c:343 #1 0x005e634c in do_pending_atimers () at /usr/src/debug/emacs-24.3.93-4/src/atimer.c:385 #2 0x0050d946 in process_pending_signals () at /usr/src/debug/emacs-24.3.93-4/src/keyboard.c:7105 #3 0x0056c13e in Fmake_list (length=0, init=9555994) at /usr/src/debug/emacs-24.3.93-4/src/alloc.c:2644 #4 0x00594cba in concat (nargs=1, args=0x28a030, target_type=Lisp_Cons, last_special=false) at /usr/src/debug/emacs-24.3.93-4/src/fns.c:588 #5 0x005947cf in Fcopy_sequence (arg=11843918) at /usr/src/debug/emacs-24.3.93-4/src/fns.c:456 #6 0x00508e74 in timer_check () at /usr/src/debug/emacs-24.3.93-4/src/keyboard.c:4568 #7 0x00506f54 in readable_events (flags=1) at /usr/src/debug/emacs-24.3.93-4/src/keyboard.c:3447 #8 0x0050d473 in get_input_pending (flags=1) at /usr/src/debug/emacs-24.3.93-4/src/keyboard.c:6765 #9 0x00513b17 in detect_input_pending_run_timers (do_display=true) ---Type to continue, or q to quit--- at /usr/src/debug/emacs-24.3.93-4/src/keyboard.c:9894 #10 0x005dafca in wait_reading_process_output (time_limit=0, nsecs=0, read_kbd=-1, do_display=true, wait_for_cell=9555994, wait_proc=0x0, just_wait_proc=0) at /usr/src/debug/emacs-24.3.93-4/src/process.c:4699 #11 0x00507c76 in kbd_buffer_get_event (kbp=0x28a2e4, used_mouse_menu=0x28a7e3, end_time=0x0) at /usr/src/debug/emacs-24.3.93-4/src/keyboard.c:3906 #12 0x00503c64 in read_event_from_main_queue (end_time=0x0, local_getcjmp=0x28a5ac, used_mouse_menu=0x28a7e3) at /usr/src/debug/emacs-24.3.93-4/src/keyboard.c:2246 #13 0x00503ec0 in read_decoded_event_from_main_queue (end_time=0x0, local_getcjmp=0x28a5ac, prev_event=9555994, used_mouse_menu=0x28a7e3) at /usr/src/debug/emacs-24.3.93-4/src/keyboard.c:2309 #14 0x005056af in read_char (commandflag=1, map=11275222, prev_event=9555994, used_mouse_menu=0x28a7e3, end_time=0x0) at /usr/src/debug/emacs-24.3.93-4/src/keyboard.c:2895 #15 0x00512218 in read_key_sequence (keybuf=0x28a900, bufsize=30, prompt=9555994, dont_downcase_last=false, can_return_switch_frame=true, fix_current_buffer=true, prevent_redisplay=false) at /usr/src/debug/emacs-24.3.93-4/src/keyboard.c:9088 #16 0x00502184 in command_loop_1 () at /usr/src/debug/emacs-24.3.93-4/src/keyboard.c:1452 #17 0x0058d2bd in internal_condition_case (bfun=0x501e06 , handlers=9606530, hfun=0x501633 ) at /usr/src/debug/emacs-24.3.93-4/src/eval.c:1354 #18 0x00501ab0 in command_loop_2 (ignore=9555994) at /usr/src/debug/emacs-24.3.93-4/src/keyboard.c:1177 #19 0x0058c82a in internal_catch (tag=9608722, func=0x501a8c , arg=9555994) at /usr/src/debug/emacs-24.3.93-4/src/eval.c:1118 #20 0x00501a66 in command_loop () at /usr/src/debug/emacs-24.3.93-4/src/keyboard.c:1156 #21 0x005011c7 in recursive_edit_1 () at /usr/src/debug/emacs-24.3.93-4/src/keyboard.c:777 #22 0x00501387 in Frecursive_edit () at /usr/src/debug/emacs-24.3.93-4/src/keyboard.c:848 #23 0x004ff777 in main (argc=2, argv=0x28ac3c) at /usr/src/debug/emacs-24.3.93-4/src/emacs.c:1647