From: Simon Marchi Date: Wed, 4 Dec 2024 20:07:32 +0000 (-0500) Subject: gdbserver: simplify win32 process removal X-Git-Tag: gdb-16-branchpoint~167 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7893943879cedcc6520d0849fa3d10375dda0333;p=thirdparty%2Fbinutils-gdb.git gdbserver: simplify win32 process removal In the spirit of encapsulation, I'm looking to remove the need for external code to access the "ptid -> thread" map of process_info, making it an internal implementation detail. The only remaining use is in function clear_inferiors, and it led me down this rabbit hole: - clear_inferiors is really only used by the Windows port and doesn't really make sense in the grand scheme of things, I think (when would you want to remove all threads of all processes, without removing those processes?) - ok, so let's remove clear_inferiors and inline the code where it's called, in function win32_clear_inferiors - the Windows port does not support multi-process, so it's not really necessary to loop over all processes like this: for_each_process ([] (process_info *process) { process->thread_list ().clear (); process->thread_map ().clear (); }); We could just do: current_process ()->thread_list ().clear (); current_process ()->thread_map ().clear (); (or pass down the process from the caller, but it's not important right now) - so, the code that we've inlined in win32_clear_inferiors does 3 things: - clear the process' thread list and map (which deletes the thread_info objects) - clear the dll list, which just basically frees some objects - switch to no current process / no current thread - let's now look at where this win32_clear_inferiors function is used: - in win32_process_target::kill, where the process is removed just after - in win32_process_target::detach, where the process is removed just after - in win32_process_target::wait, when handling a process exit. After this returns, we could be in handle_target_event (if async) or resume (if sync), both in `server.cc`. In both of these cases, target_mourn_inferior gets called, we end up in win32_process_target::mourn, which removes the process - in all 3 cases above, we end up removing the process, which takes care of the 3 actions listed above: - the thread list and map get cleared when the process gets destroyed - same with the dll list - remove_process switches to no current process / current thread if the process being removed is the current one - I conclude that it's probably unnecessary to do the cleanup in win32_clear_inferiors, because it's going to get done right after anyway. Therefore, this patch does: - remove clear_inferiors, remove the call in win32_clear_inferiors - remove clear_dlls, which is now unused - remove process_info::thread_map, which is now unused - rename win32_clear_inferiors to win32_clear_process, which seems more accurate win32_clear_inferiors also does: for_each_thread (delete_thread_info); which also makes sure to delete all threads, but it also deletes the Windows private data object (windows_thread_info), so I'll leave this one there for now. But if we could make the thread private data destruction automatic, on thread destruction, it could be removed, I think. There should be no user-visible change with this patch. Of course, operations don't happen in the same order as before, so there might be some important detail I'm missing. I'm only able to build-test this, if someone could give it a test run on Windows, it would be appreciated. Change-Id: I4a560affe763a2c965a97754cc02f3083dbe6fbf --- diff --git a/gdbserver/dll.cc b/gdbserver/dll.cc index ff637a03fed..f49aa560aec 100644 --- a/gdbserver/dll.cc +++ b/gdbserver/dll.cc @@ -89,12 +89,3 @@ unloaded_dll (process_info *proc, const char *name, CORE_ADDR base_addr) proc->dlls_changed = true; } } - -void -clear_dlls (void) -{ - for_each_process ([] (process_info *proc) - { - proc->all_dlls.clear (); - }); -} diff --git a/gdbserver/dll.h b/gdbserver/dll.h index 30c6a2c65d0..e603df4be2b 100644 --- a/gdbserver/dll.h +++ b/gdbserver/dll.h @@ -32,7 +32,6 @@ struct dll_info CORE_ADDR base_addr; }; -extern void clear_dlls (void); extern void loaded_dll (const char *name, CORE_ADDR base_addr); extern void loaded_dll (process_info *proc, const char *name, CORE_ADDR base_addr); diff --git a/gdbserver/inferiors.cc b/gdbserver/inferiors.cc index 7a0209b1673..7bb322b0787 100644 --- a/gdbserver/inferiors.cc +++ b/gdbserver/inferiors.cc @@ -112,21 +112,6 @@ process_info::remove_thread (thread_info *thread) m_thread_list.erase (m_thread_list.iterator_to (*thread)); } -void -clear_inferiors (void) -{ - for_each_process ([] (process_info *process) - { - process->thread_list ().clear (); - process->thread_map ().clear (); - }); - - clear_dlls (); - - switch_to_thread (nullptr); - current_process_ = nullptr; -} - struct process_info * add_process (int pid, int attached) { diff --git a/gdbserver/inferiors.h b/gdbserver/inferiors.h index 2f3d42b8308..890e9b92a9c 100644 --- a/gdbserver/inferiors.h +++ b/gdbserver/inferiors.h @@ -92,10 +92,6 @@ struct process_info : public intrusive_list_node owning_intrusive_list &thread_list () { return m_thread_list; } - /* Return a reference to the private thread map. */ - std::unordered_map &thread_map () - { return m_ptid_thread_map; } - /* Return the number of threads in this process. */ unsigned int thread_count () const { return m_ptid_thread_map.size (); } @@ -159,8 +155,6 @@ int have_attached_inferiors_p (void); /* Switch to a thread of PROC. */ void switch_to_process (process_info *proc); -void clear_inferiors (void); - /* Set the inferior current working directory. If CWD is empty, unset the directory. */ void set_inferior_cwd (std::string cwd); diff --git a/gdbserver/win32-low.cc b/gdbserver/win32-low.cc index dab57f7256b..49f0ed3b1f4 100644 --- a/gdbserver/win32-low.cc +++ b/gdbserver/win32-low.cc @@ -660,7 +660,7 @@ gdbserver_windows_process::handle_output_debug_string } static void -win32_clear_inferiors (void) +win32_clear_process () { if (windows_process.open_process_used) { @@ -670,7 +670,6 @@ win32_clear_inferiors (void) for_each_thread (delete_thread_info); windows_process.siginfo_er.ExceptionCode = 0; - clear_inferiors (); } /* Implementation of target_ops::kill. */ @@ -693,9 +692,9 @@ win32_process_target::kill (process_info *process) windows_process.handle_output_debug_string (nullptr); } - win32_clear_inferiors (); - + win32_clear_process (); remove_process (process); + return 0; } @@ -714,7 +713,7 @@ win32_process_target::detach (process_info *process) return -1; DebugSetProcessKillOnExit (FALSE); - win32_clear_inferiors (); + win32_clear_process (); remove_process (process); return 0; @@ -1197,7 +1196,7 @@ win32_process_target::wait (ptid_t ptid, target_waitstatus *ourstatus, case TARGET_WAITKIND_EXITED: OUTMSG2 (("Child exited with retcode = %x\n", ourstatus->exit_status ())); - win32_clear_inferiors (); + win32_clear_process (); return ptid_t (windows_process.current_event.dwProcessId); case TARGET_WAITKIND_STOPPED: case TARGET_WAITKIND_SIGNALLED: