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2021-07-12gdb: optimize all_matching_threads_iteratorSimon Marchi1-48/+90
all_matching_threads_iterator is used extensively in some pretty fast paths, often under the all_non_exited_threads function. If a filter target and thread-specific ptid are given, it iterates on all threads of all inferiors of that target, to ultimately yield exactly on thread. And this happens quite often, which means we unnecessarily spend time iterating on threads to find the one we are looking for. The same thing happens if an inferior-specific ptid is given, although there the iterator yields all the threads of that inferior. In those cases, the callers of all_non_exited_threads could have different behaviors depending on the kind of ptid, to avoid this inefficiency, but that would be very tedious. Using all_non_exited_threads has the advantage that one simple implementation can work seamlessly on multiple threads or on one specific thread, just by playing with the ptid. Instead, optimize all_matching_threads_iterator directly to detect these different cases and limiting what we iterate on to just what we need. - if filter_ptid is minus_one_ptid, do as we do now: filter inferiors based on filter_target, iterate on all of the matching inferiors' threads - if filter_ptid is a pid-only ptid (then a filter_target must necessarily be given), look up that inferior and iterate on all its threads - otherwise, filter_ptid is a thread-specific ptid, so look up that specific thread and "iterate" only on it For the last case, what was an iteration on all threads of the filter target now becomes a call to find_thread_ptid, which is quite efficient now thanks to inferior::ptid_thread_map. gdb/ChangeLog: * thread-iter.h (class all_matching_threads_iterator) <all_matching_threads_iterator>: Use default. <enum class mode>: New. <m_inf, m_thr>: Initialize. <m_filter_ptid>: Remove. * thread-iter.c (all_matching_threads_iterator::m_inf_matches): Don't filter on m_filter_ptid. (all_matching_threads_iterator::all_matching_threads_iterator): Choose path based on filter_ptid (all threads, all threads of inferior, single thread). (all_matching_threads_iterator::advance): Likewise. Change-Id: Ic6a19845f5f760fa1b8eac8145793c0ff431bbc9
2021-07-12gdb: make inferior_list use intrusive_listPedro Alves1-27/+41
Change inferior_list, the global list of inferiors, to use intrusive_list. I think most other changes are somewhat obvious fallouts from this change. There is a small change in behavior in scoped_mock_context. Before this patch, constructing a scoped_mock_context would replace the whole inferior list with only the new mock inferior. Tests using two scoped_mock_contexts therefore needed to manually link the two inferiors together, as the second scoped_mock_context would bump the first mock inferior from the thread list. With this patch, a scoped_mock_context adds its mock inferior to the inferior list on construction, and removes it on destruction. This means that tests run with mock inferiors in the inferior list in addition to any pre-existing inferiors (there is always at least one). There is no possible pid clash problem, since each scoped mock inferior uses its own process target, and pids are per process target. Co-Authored-By: Simon Marchi <simon.marchi@efficios.com> Change-Id: I7eb6a8f867d4dcf8b8cd2dcffd118f7270756018
2021-07-12gdb: introduce intrusive_list, make thread_info use itPedro Alves1-14/+39
GDB currently has several objects that are put in a singly linked list, by having the object's type have a "next" pointer directly. For example, struct thread_info and struct inferior. Because these are simply-linked lists, and we don't keep track of a "tail" pointer, when we want to append a new element on the list, we need to walk the whole list to find the current tail. It would be nice to get rid of that walk. Removing elements from such lists also requires a walk, to find the "previous" position relative to the element being removed. To eliminate the need for that walk, we could make those lists doubly-linked, by adding a "prev" pointer alongside "next". It would be nice to avoid the boilerplate associated with maintaining such a list manually, though. That is what the new intrusive_list type addresses. With an intrusive list, it's also possible to move items out of the list without destroying them, which is interesting in our case for example for threads, when we exit them, but can't destroy them immediately. We currently keep exited threads on the thread list, but we could change that which would simplify some things. Note that with std::list, element removal is O(N). I.e., with std::list, we need to walk the list to find the iterator pointing to the position to remove. However, we could store a list iterator inside the object as soon as we put the object in the list, to address it, because std::list iterators are not invalidated when other elements are added/removed. However, if you need to put the same object in more than one list, then std::list<object> doesn't work. You need to instead use std::list<object *>, which is less efficient for requiring extra memory allocations. For an example of an object in multiple lists, see the step_over_next/step_over_prev fields in thread_info: /* Step-over chain. A thread is in the step-over queue if these are non-NULL. If only a single thread is in the chain, then these fields point to self. */ struct thread_info *step_over_prev = NULL; struct thread_info *step_over_next = NULL; The new intrusive_list type gives us the advantages of an intrusive linked list, while avoiding the boilerplate associated with manually maintaining it. intrusive_list's API follows the standard container interface, and thus std::list's interface. It is based the API of Boost's intrusive list, here: https://www.boost.org/doc/libs/1_73_0/doc/html/boost/intrusive/list.html Our implementation is relatively simple, while Boost's is complicated and intertwined due to a lot of customization options, which our version doesn't have. The easiest way to use an intrusive_list is to make the list's element type inherit from intrusive_node. This adds a prev/next pointers to the element type. However, to support putting the same object in more than one list, intrusive_list supports putting the "node" info as a field member, so you can have more than one such nodes, one per list. As a first guinea pig, this patch makes the per-inferior thread list use intrusive_list using the base class method. Unlike Boost's implementation, ours is not a circular list. An earlier version of the patch was circular: the intrusive_list type included an intrusive_list_node "head". In this design, a node contained pointers to the previous and next nodes, not the previous and next elements. This wasn't great for when debugging GDB with GDB, as it was difficult to get from a pointer to the node to a pointer to the element. With the design proposed in this patch, nodes contain pointers to the previous and next elements, making it easy to traverse the list by hand and inspect each element. The intrusive_list object contains pointers to the first and last elements of the list. They are nullptr if the list is empty. Each element's node contains a pointer to the previous and next elements. The first element's previous pointer is nullptr and the last element's next pointer is nullptr. Therefore, if there's a single element in the list, both its previous and next pointers are nullptr. To differentiate such an element from an element that is not linked into a list, the previous and next pointers contain a special value (-1) when the node is not linked. This is necessary to be able to reliably tell if a given node is currently linked or not. A begin() iterator points to the first item in the list. An end() iterator contains nullptr. This makes iteration until end naturally work, as advancing past the last element will make the iterator contain nullptr, making it equal to the end iterator. If the list is empty, a begin() iterator will contain nullptr from the start, and therefore be immediately equal to the end. Iterating on an intrusive_list yields references to objects (e.g. `thread_info&`). The rest of GDB currently expects iterators and ranges to yield pointers (e.g. `thread_info*`). To bridge the gap, add the reference_to_pointer_iterator type. It is used to define inf_threads_iterator. Add a Python pretty-printer, to help inspecting intrusive lists when debugging GDB with GDB. Here's an example of the output: (top-gdb) p current_inferior_.m_obj.thread_list $1 = intrusive list of thread_info = {0x61700002c000, 0x617000069080, 0x617000069400, 0x61700006d680, 0x61700006eb80} It's not possible with current master, but with this patch [1] that I hope will be merged eventually, it's possible to index the list and access the pretty-printed value's children: (top-gdb) p current_inferior_.m_obj.thread_list[1] $2 = (thread_info *) 0x617000069080 (top-gdb) p current_inferior_.m_obj.thread_list[1].ptid $3 = { m_pid = 406499, m_lwp = 406503, m_tid = 0 } Even though iterating the list in C++ yields references, the Python pretty-printer yields pointers. The reason for this is that the output of printing the thread list above would be unreadable, IMO, if each thread_info object was printed in-line, since they contain so much information. I think it's more useful to print pointers, and let the user drill down as needed. [1] https://sourceware.org/pipermail/gdb-patches/2021-April/178050.html Co-Authored-By: Simon Marchi <simon.marchi@efficios.com> Change-Id: I3412a14dc77f25876d742dab8f44e0ba7c7586c0
2021-01-01Update copyright year range in all GDB filesJoel Brobecker1-1/+1
This commits the result of running gdb/copyright.py as per our Start of New Year procedure... gdb/ChangeLog Update copyright year range in copyright header of all GDB files.
2020-01-10Multi-target supportPedro Alves1-4/+10
This commit adds multi-target support to GDB. What this means is that with this commit, GDB can now be connected to different targets at the same time. E.g., you can debug a live native process and a core dump at the same time, connect to multiple gdbservers, etc. Actually, the word "target" is overloaded in gdb. We already have a target stack, with pushes several target_ops instances on top of one another. We also have "info target" already, which means something completely different to what this patch does. So from here on, I'll be using the "target connections" term, to mean an open process_stratum target, pushed on a target stack. This patch makes gdb have multiple target stacks, and multiple process_stratum targets open simultaneously. The user-visible changes / commands will also use this terminology, but of course it's all open to debate. User-interface-wise, not that much changes. The main difference is that each inferior may have its own target connection. A target connection (e.g., a target extended-remote connection) may support debugging multiple processes, just as before. Say you're debugging against gdbserver in extended-remote mode, and you do "add-inferior" to prepare to spawn a new process, like: (gdb) target extended-remote :9999 ... (gdb) start ... (gdb) add-inferior Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) file a.out ... (gdb) start ... At this point, you have two inferiors connected to the same gdbserver. With this commit, GDB will maintain a target stack per inferior, instead of a global target stack. To preserve the behavior above, by default, "add-inferior" makes the new inferior inherit a copy of the target stack of the current inferior. Same across a fork - the child inherits a copy of the target stack of the parent. While the target stacks are copied, the targets themselves are not. Instead, target_ops is made a refcounted_object, which means that target_ops instances are refcounted, which each inferior counting for a reference. What if you want to create an inferior and connect it to some _other_ target? For that, this commit introduces a new "add-inferior -no-connection" option that makes the new inferior not share the current inferior's target. So you could do: (gdb) target extended-remote :9999 Remote debugging using :9999 ... (gdb) add-inferior -no-connection [New inferior 2] Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 <null> (gdb) tar extended-remote :10000 Remote debugging using :10000 ... (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 process 18450 target:/home/pedro/tmp/main (gdb) A following patch will extended "info inferiors" to include a column indicating which connection an inferior is bound to, along with a couple other UI tweaks. Other than that, debugging is the same as before. Users interact with inferiors and threads as before. The only difference is that inferiors may be bound to processes running in different machines. That's pretty much all there is to it in terms of noticeable UI changes. On to implementation. Since we can be connected to different systems at the same time, a ptid_t is no longer a unique identifier. Instead a thread can be identified by a pair of ptid_t and 'process_stratum_target *', the later being the instance of the process_stratum target that owns the process/thread. Note that process_stratum_target inherits from target_ops, and all process_stratum targets inherit from process_stratum_target. In earlier patches, many places in gdb were converted to refer to threads by thread_info pointer instead of ptid_t, but there are still places in gdb where we start with a pid/tid and need to find the corresponding inferior or thread_info objects. So you'll see in the patch many places adding a process_stratum_target parameter to functions that used to take only a ptid_t. Since each inferior has its own target stack now, we can always find the process_stratum target for an inferior. That is done via a inf->process_target() convenience method. Since each inferior has its own target stack, we need to handle the "beneath" calls when servicing target calls. The solution I settled with is just to make sure to switch the current inferior to the inferior you want before making a target call. Not relying on global context is just not feasible in current GDB. Fortunately, there aren't that many places that need to do that, because generally most code that calls target methods already has the current context pointing to the right inferior/thread. Note, to emphasize -- there's no method to "switch to this target stack". Instead, you switch the current inferior, and that implicitly switches the target stack. In some spots, we need to iterate over all inferiors so that we reach all target stacks. Native targets are still singletons. There's always only a single instance of such targets. Remote targets however, we'll have one instance per remote connection. The exec target is still a singleton. There's only one instance. I did not see the point of instanciating more than one exec_target object. After vfork, we need to make sure to push the exec target on the new inferior. See exec_on_vfork. For type safety, functions that need a {target, ptid} pair to identify a thread, take a process_stratum_target pointer for target parameter instead of target_ops *. Some shared code in gdb/nat/ also need to gain a target pointer parameter. This poses an issue, since gdbserver doesn't have process_stratum_target, only target_ops. To fix this, this commit renames gdbserver's target_ops to process_stratum_target. I think this makes sense. There's no concept of target stack in gdbserver, and gdbserver's target_ops really implements a process_stratum-like target. The thread and inferior iterator functions also gain process_stratum_target parameters. These are used to be able to iterate over threads and inferiors of a given target. Following usual conventions, if the target pointer is null, then we iterate over threads and inferiors of all targets. I tried converting "add-inferior" to the gdb::option framework, as a preparatory patch, but that stumbled on the fact that gdb::option does not support file options yet, for "add-inferior -exec". I have a WIP patchset that adds that, but it's not a trivial patch, mainly due to need to integrate readline's filename completion, so I deferred that to some other time. In infrun.c/infcmd.c, the main change is that we need to poll events out of all targets. See do_target_wait. Right after collecting an event, we switch the current inferior to an inferior bound to the target that reported the event, so that target methods can be used while handling the event. This makes most of the code transparent to multi-targets. See fetch_inferior_event. infrun.c:stop_all_threads is interesting -- in this function we need to stop all threads of all targets. What the function does is send an asynchronous stop request to all threads, and then synchronously waits for events, with target_wait, rinse repeat, until all it finds are stopped threads. Now that we have multiple targets, it's not efficient to synchronously block in target_wait waiting for events out of one target. Instead, we implement a mini event loop, with interruptible_select, select'ing on one file descriptor per target. For this to work, we need to be able to ask the target for a waitable file descriptor. Such file descriptors already exist, they are the descriptors registered in the main event loop with add_file_handler, inside the target_async implementations. This commit adds a new target_async_wait_fd target method that just returns the file descriptor in question. See wait_one / stop_all_threads in infrun.c. The 'threads_executing' global is made a per-target variable. Since it is only relevant to process_stratum_target targets, this is where it is put, instead of in target_ops. You'll notice that remote.c includes some FIXME notes. These refer to the fact that the global arrays that hold data for the remote packets supported are still globals. For example, if we connect to two different servers/stubs, then each might support different remote protocol features. They might even be different architectures, like e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a host/controller scenario as a single program. That isn't going to work correctly today, because of said globals. I'm leaving fixing that for another pass, since it does not appear to be trivial, and I'd rather land the base work first. It's already useful to be able to debug multiple instances of the same server (e.g., a distributed cluster, where you have full control over the servers installed), so I think as is it's already reasonable incremental progress. Current limitations: - You can only resume more that one target at the same time if all targets support asynchronous debugging, and support non-stop mode. It should be possible to support mixed all-stop + non-stop backends, but that is left for another time. This means that currently in order to do multi-target with gdbserver you need to issue "maint set target-non-stop on". I would like to make that mode be the default, but we're not there yet. Note that I'm talking about how the target backend works, only. User-visible all-stop mode works just fine. - As explained above, connecting to different remote servers at the same time is likely to produce bad results if they don't support the exact set of RSP features. FreeBSD updates courtesy of John Baldwin. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> John Baldwin <jhb@FreeBSD.org> * aarch64-linux-nat.c (aarch64_linux_nat_target::thread_architecture): Adjust. * ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call. (task_command_1): Likewise. * aix-thread.c (sync_threadlists, aix_thread_target::resume) (aix_thread_target::wait, aix_thread_target::fetch_registers) (aix_thread_target::store_registers) (aix_thread_target::thread_alive): Adjust. * amd64-fbsd-tdep.c: Include "inferior.h". (amd64fbsd_get_thread_local_address): Pass down target. * amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle thread's gdbarch instead of target_gdbarch. * break-catch-sig.c (signal_catchpoint_print_it): Adjust call to get_last_target_status. * break-catch-syscall.c (print_it_catch_syscall): Likewise. * breakpoint.c (breakpoints_should_be_inserted_now): Consider all inferiors. (update_inserted_breakpoint_locations): Skip if inferiors with no execution. (update_global_location_list): When handling moribund locations, find representative inferior for location's pspace, and use thread count of its process_stratum target. * bsd-kvm.c (bsd_kvm_target_open): Pass target down. * bsd-uthread.c (bsd_uthread_target::wait): Use as_process_stratum_target and adjust thread_change_ptid and add_thread calls. (bsd_uthread_target::update_thread_list): Use as_process_stratum_target and adjust find_thread_ptid, thread_change_ptid and add_thread calls. * btrace.c (maint_btrace_packet_history_cmd): Adjust find_thread_ptid call. * corelow.c (add_to_thread_list): Adjust add_thread call. (core_target_open): Adjust add_thread_silent and thread_count calls. (core_target::pid_to_str): Adjust find_inferior_ptid call. * ctf.c (ctf_target_open): Adjust add_thread_silent call. * event-top.c (async_disconnect): Pop targets from all inferiors. * exec.c (add_target_sections): Push exec target on all inferiors sharing the program space. (remove_target_sections): Remove the exec target from all inferiors sharing the program space. (exec_on_vfork): New. * exec.h (exec_on_vfork): Declare. * fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::update_thread_list): Adjust. (fbsd_nat_target::resume): Adjust. (fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust. * fbsd-tdep.c (fbsd_corefile_thread): Adjust get_thread_arch_regcache call. * fork-child.c (gdb_startup_inferior): Pass target down to startup_inferior and set_executing. * gdbthread.h (struct process_stratum_target): Forward declare. (add_thread, add_thread_silent, add_thread_with_info) (in_thread_list): Add process_stratum_target parameter. (find_thread_ptid(inferior*, ptid_t)): New overload. (find_thread_ptid, thread_change_ptid): Add process_stratum_target parameter. (all_threads()): Delete overload. (all_threads, all_non_exited_threads): Add process_stratum_target parameter. (all_threads_safe): Use brace initialization. (thread_count): Add process_stratum_target parameter. (set_resumed, set_running, set_stop_requested, set_executing) (threads_are_executing, finish_thread_state): Add process_stratum_target parameter. (switch_to_thread): Use is_current_thread. * i386-fbsd-tdep.c: Include "inferior.h". (i386fbsd_get_thread_local_address): Pass down target. * i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust. * inf-child.c (inf_child_target::maybe_unpush_target): Remove have_inferiors check. * inf-ptrace.c (inf_ptrace_target::create_inferior) (inf_ptrace_target::attach): Adjust. * infcall.c (run_inferior_call): Adjust. * infcmd.c (run_command_1): Pass target to scoped_finish_thread_state. (proceed_thread_callback): Skip inferiors with no execution. (continue_command): Rename 'all_threads' local to avoid hiding 'all_threads' function. Adjust get_last_target_status call. (prepare_one_step): Adjust set_running call. (signal_command): Use user_visible_resume_target. Compare thread pointers instead of inferior_ptid. (info_program_command): Adjust to pass down target. (attach_command): Mark target's 'thread_executing' flag. (stop_current_target_threads_ns): New, factored out from ... (interrupt_target_1): ... this. Switch inferior before making target calls. * inferior-iter.h (struct all_inferiors_iterator, struct all_inferiors_range) (struct all_inferiors_safe_range) (struct all_non_exited_inferiors_range): Filter on process_stratum_target too. Remove explicit. * inferior.c (inferior::inferior): Push dummy target on target stack. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors): Add process_stratum_target parameter, and pass it down. (have_live_inferiors): Adjust. (switch_to_inferior_and_push_target): New. (add_inferior_command, clone_inferior_command): Handle "-no-connection" parameter. Use switch_to_inferior_and_push_target. (_initialize_inferior): Mention "-no-connection" option in the help of "add-inferior" and "clone-inferior" commands. * inferior.h: Include "process-stratum-target.h". (interrupt_target_1): Use bool. (struct inferior) <push_target, unpush_target, target_is_pushed, find_target_beneath, top_target, process_target, target_at, m_stack>: New. (discard_all_inferiors): Delete. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors) (all_inferiors, all_non_exited_inferiors): Add process_stratum_target parameter. * infrun.c: Include "gdb_select.h" and <unordered_map>. (target_last_proc_target): New global. (follow_fork_inferior): Push target on new inferior. Pass target to add_thread_silent. Call exec_on_vfork. Handle target's reference count. (follow_fork): Adjust get_last_target_status call. Also consider target. (follow_exec): Push target on new inferior. (struct execution_control_state) <target>: New field. (user_visible_resume_target): New. (do_target_resume): Call target_async. (resume_1): Set target's threads_executing flag. Consider resume target. (commit_resume_all_targets): New. (proceed): Also consider resume target. Skip threads of inferiors with no execution. Commit resumtion in all targets. (start_remote): Pass current inferior to wait_for_inferior. (infrun_thread_stop_requested): Consider target as well. Pass thread_info pointer to clear_inline_frame_state instead of ptid. (infrun_thread_thread_exit): Consider target as well. (random_pending_event_thread): New inferior parameter. Use it. (do_target_wait): Rename to ... (do_target_wait_1): ... this. Add inferior parameter, and pass it down. (threads_are_resumed_pending_p, do_target_wait): New. (prepare_for_detach): Adjust calls. (wait_for_inferior): New inferior parameter. Handle it. Use do_target_wait_1 instead of do_target_wait. (fetch_inferior_event): Adjust. Switch to representative inferior. Pass target down. (set_last_target_status): Add process_stratum_target parameter. Save target in global. (get_last_target_status): Add process_stratum_target parameter and handle it. (nullify_last_target_wait_ptid): Clear 'target_last_proc_target'. (context_switch): Check inferior_ptid == null_ptid before calling inferior_thread(). (get_inferior_stop_soon): Pass down target. (wait_one): Rename to ... (poll_one_curr_target): ... this. (struct wait_one_event): New. (wait_one): New. (stop_all_threads): Adjust. (handle_no_resumed, handle_inferior_event): Adjust to consider the event's target. (switch_back_to_stepped_thread): Also consider target. (print_stop_event): Update. (normal_stop): Update. Also consider the resume target. * infrun.h (wait_for_inferior): Remove declaration. (user_visible_resume_target): New declaration. (get_last_target_status, set_last_target_status): New process_stratum_target parameter. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter, and use it. (clear_inline_frame_state (thread_info*)): New. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter. (clear_inline_frame_state (thread_info*)): Declare. * linux-fork.c (delete_checkpoint_command): Pass target down to find_thread_ptid. (checkpoint_command): Adjust. * linux-nat.c (linux_nat_target::follow_fork): Switch to thread instead of just tweaking inferior_ptid. (linux_nat_switch_fork): Pass target down to thread_change_ptid. (exit_lwp): Pass target down to find_thread_ptid. (attach_proc_task_lwp_callback): Pass target down to add_thread/set_running/set_executing. (linux_nat_target::attach): Pass target down to thread_change_ptid. (get_detach_signal): Pass target down to find_thread_ptid. Consider last target status's target. (linux_resume_one_lwp_throw, resume_lwp) (linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp) (stop_wait_callback, save_stop_reason, linux_nat_filter_event) (linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down. (linux_nat_target::async_wait_fd): New. (linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass target down. * linux-nat.h (linux_nat_target::async_wait_fd): Declare. * linux-tdep.c (get_thread_arch_regcache): Pass target down. * linux-thread-db.c (struct thread_db_info::process_target): New field. (add_thread_db_info): Save target. (get_thread_db_info): New process_stratum_target parameter. Also match target. (delete_thread_db_info): New process_stratum_target parameter. Also match target. (thread_from_lwp): Adjust to pass down target. (thread_db_notice_clone): Pass down target. (check_thread_db_callback): Pass down target. (try_thread_db_load_1): Always push the thread_db target. (try_thread_db_load, record_thread): Pass target down. (thread_db_target::detach): Pass target down. Always unpush the thread_db target. (thread_db_target::wait, thread_db_target::mourn_inferior): Pass target down. Always unpush the thread_db target. (find_new_threads_callback, thread_db_find_new_threads_2) (thread_db_target::update_thread_list): Pass target down. (thread_db_target::pid_to_str): Pass current inferior down. (thread_db_target::get_thread_local_address): Pass target down. (thread_db_target::resume, maintenance_check_libthread_db): Pass target down. * nto-procfs.c (nto_procfs_target::update_thread_list): Adjust. * procfs.c (procfs_target::procfs_init_inferior): Declare. (proc_set_current_signal, do_attach, procfs_target::wait): Adjust. (procfs_init_inferior): Rename to ... (procfs_target::procfs_init_inferior): ... this and adjust. (procfs_target::create_inferior, procfs_notice_thread) (procfs_do_thread_registers): Adjust. * ppc-fbsd-tdep.c: Include "inferior.h". (ppcfbsd_get_thread_local_address): Pass down target. * proc-service.c (ps_xfer_memory): Switch current inferior and program space as well. (get_ps_regcache): Pass target down. * process-stratum-target.c (process_stratum_target::thread_address_space) (process_stratum_target::thread_architecture): Pass target down. * process-stratum-target.h (process_stratum_target::threads_executing): New field. (as_process_stratum_target): New. * ravenscar-thread.c (ravenscar_thread_target::update_inferior_ptid): Pass target down. (ravenscar_thread_target::wait, ravenscar_add_thread): Pass target down. * record-btrace.c (record_btrace_target::info_record): Adjust. (record_btrace_target::record_method) (record_btrace_target::record_is_replaying) (record_btrace_target::fetch_registers) (get_thread_current_frame_id, record_btrace_target::resume) (record_btrace_target::wait, record_btrace_target::stop): Pass target down. * record-full.c (record_full_wait_1): Switch to event thread. Pass target down. * regcache.c (regcache::regcache) (get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add process_stratum_target parameter and handle it. (current_thread_target): New global. (get_thread_regcache): Add process_stratum_target parameter and handle it. Switch inferior before calling target method. (get_thread_regcache): Pass target down. (get_thread_regcache_for_ptid): Pass target down. (registers_changed_ptid): Add process_stratum_target parameter and handle it. (registers_changed_thread, registers_changed): Pass target down. (test_get_thread_arch_aspace_regcache): New. (current_regcache_test): Define a couple local test_target_ops instances and use them for testing. (readwrite_regcache): Pass process_stratum_target parameter. (cooked_read_test, cooked_write_test): Pass mock_target down. * regcache.h (get_thread_regcache, get_thread_arch_regcache) (get_thread_arch_aspace_regcache): Add process_stratum_target parameter. (regcache::target): New method. (regcache::regcache, regcache::get_thread_arch_aspace_regcache) (regcache::registers_changed_ptid): Add process_stratum_target parameter. (regcache::m_target): New field. (registers_changed_ptid): Add process_stratum_target parameter. * remote.c (remote_state::supports_vCont_probed): New field. (remote_target::async_wait_fd): New method. (remote_unpush_and_throw): Add remote_target parameter. (get_current_remote_target): Adjust. (remote_target::remote_add_inferior): Push target. (remote_target::remote_add_thread) (remote_target::remote_notice_new_inferior) (get_remote_thread_info): Pass target down. (remote_target::update_thread_list): Skip threads of inferiors bound to other targets. (remote_target::close): Don't discard inferiors. (remote_target::add_current_inferior_and_thread) (remote_target::process_initial_stop_replies) (remote_target::start_remote) (remote_target::remote_serial_quit_handler): Pass down target. (remote_target::remote_unpush_target): New remote_target parameter. Unpush the target from all inferiors. (remote_target::remote_unpush_and_throw): New remote_target parameter. Pass it down. (remote_target::open_1): Check whether the current inferior has execution instead of checking whether any inferior is live. Pass target down. (remote_target::remote_detach_1): Pass down target. Use remote_unpush_target. (extended_remote_target::attach): Pass down target. (remote_target::remote_vcont_probe): Set supports_vCont_probed. (remote_target::append_resumption): Pass down target. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc, remote_target::resume) (remote_target::commit_resume): Pass down target. (remote_target::remote_stop_ns): Check supports_vCont_probed. (remote_target::interrupt_query) (remote_target::remove_new_fork_children) (remote_target::check_pending_events_prevent_wildcard_vcont) (remote_target::remote_parse_stop_reply) (remote_target::process_stop_reply): Pass down target. (first_remote_resumed_thread): New remote_target parameter. Pass it down. (remote_target::wait_as): Pass down target. (unpush_and_perror): New remote_target parameter. Pass it down. (remote_target::readchar, remote_target::remote_serial_write) (remote_target::getpkt_or_notif_sane_1) (remote_target::kill_new_fork_children, remote_target::kill): Pass down target. (remote_target::mourn_inferior): Pass down target. Use remote_unpush_target. (remote_target::core_of_thread) (remote_target::remote_btrace_maybe_reopen): Pass down target. (remote_target::pid_to_exec_file) (remote_target::thread_handle_to_thread_info): Pass down target. (remote_target::async_wait_fd): New. * riscv-fbsd-tdep.c: Include "inferior.h". (riscv_fbsd_get_thread_local_address): Pass down target. * sol2-tdep.c (sol2_core_pid_to_str): Pass down target. * sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs) (ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback): Adjust. * solib-spu.c (spu_skip_standalone_loader): Pass down target. * solib-svr4.c (enable_break): Pass down target. * spu-multiarch.c (parse_spufs_run): Pass down target. * spu-tdep.c (spu2ppu_sniffer): Pass down target. * target-delegates.c: Regenerate. * target.c (g_target_stack): Delete. (current_top_target): Return the current inferior's top target. (target_has_execution_1): Refer to the passed-in inferior's top target. (target_supports_terminal_ours): Check whether the initial inferior was already created. (decref_target): New. (target_stack::push): Incref/decref the target. (push_target, push_target, unpush_target): Adjust. (target_stack::unpush): Defref target. (target_is_pushed): Return bool. Adjust to refer to the current inferior's target stack. (dispose_inferior): Delete, and inline parts ... (target_preopen): ... here. Only dispose of the current inferior. (target_detach): Hold strong target reference while detaching. Pass target down. (target_thread_name): Add assertion. (target_resume): Pass down target. (target_ops::beneath, find_target_at): Adjust to refer to the current inferior's target stack. (get_dummy_target): New. (target_pass_ctrlc): Pass the Ctrl-C to the first inferior that has a thread running. (initialize_targets): Rename to ... (_initialize_target): ... this. * target.h: Include "gdbsupport/refcounted-object.h". (struct target_ops): Inherit refcounted_object. (target_ops::shortname, target_ops::longname): Make const. (target_ops::async_wait_fd): New method. (decref_target): Declare. (struct target_ops_ref_policy): New. (target_ops_ref): New typedef. (get_dummy_target): Declare function. (target_is_pushed): Return bool. * thread-iter.c (all_matching_threads_iterator::m_inf_matches) (all_matching_threads_iterator::all_matching_threads_iterator): Handle filter target. * thread-iter.h (struct all_matching_threads_iterator, struct all_matching_threads_range, class all_non_exited_threads_range): Filter by target too. Remove explicit. * thread.c (threads_executing): Delete. (inferior_thread): Pass down current inferior. (clear_thread_inferior_resources): Pass down thread pointer instead of ptid_t. (add_thread_silent, add_thread_with_info, add_thread): Add process_stratum_target parameter. Use it for thread and inferior searches. (is_current_thread): New. (thread_info::deletable): Use it. (find_thread_ptid, thread_count, in_thread_list) (thread_change_ptid, set_resumed, set_running): New process_stratum_target parameter. Pass it down. (set_executing): New process_stratum_target parameter. Pass it down. Adjust reference to 'threads_executing'. (threads_are_executing): New process_stratum_target parameter. Adjust reference to 'threads_executing'. (set_stop_requested, finish_thread_state): New process_stratum_target parameter. Pass it down. (switch_to_thread): Also match inferior. (switch_to_thread): New process_stratum_target parameter. Pass it down. (update_threads_executing): Reimplement. * top.c (quit_force): Pop targets from all inferior. (gdb_init): Don't call initialize_targets. * windows-nat.c (windows_nat_target) <get_windows_debug_event>: Declare. (windows_add_thread, windows_delete_thread): Adjust. (get_windows_debug_event): Rename to ... (windows_nat_target::get_windows_debug_event): ... this. Adjust. * tracefile-tfile.c (tfile_target_open): Pass down target. * gdbsupport/common-gdbthread.h (struct process_stratum_target): Forward declare. (switch_to_thread): Add process_stratum_target parameter. * mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target parameter. Use it. (mi_on_resume): Pass target down. * nat/fork-inferior.c (startup_inferior): Add process_stratum_target parameter. Pass it down. * nat/fork-inferior.h (startup_inferior): Add process_stratum_target parameter. * python/py-threadevent.c (py_get_event_thread): Pass target down. gdb/gdbserver/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * fork-child.c (post_fork_inferior): Pass target down to startup_inferior. * inferiors.c (switch_to_thread): Add process_stratum_target parameter. * lynx-low.c (lynx_target_ops): Now a process_stratum_target. * nto-low.c (nto_target_ops): Now a process_stratum_target. * linux-low.c (linux_target_ops): Now a process_stratum_target. * remote-utils.c (prepare_resume_reply): Pass the target to switch_to_thread. * target.c (the_target): Now a process_stratum_target. (done_accessing_memory): Pass the target to switch_to_thread. (set_target_ops): Ajust to use process_stratum_target. * target.h (struct target_ops): Rename to ... (struct process_stratum_target): ... this. (the_target, set_target_ops): Adjust. (prepare_to_access_memory): Adjust comment. * win32-low.c (child_xfer_memory): Adjust to use process_stratum_target. (win32_target_ops): Now a process_stratum_target.
2020-01-01Update copyright year range in all GDB files.Joel Brobecker1-1/+1
gdb/ChangeLog: Update copyright year range in all GDB files.
2019-01-01Update copyright year range in all GDB files.Joel Brobecker1-1/+1
This commit applies all changes made after running the gdb/copyright.py script. Note that one file was flagged by the script, due to an invalid copyright header (gdb/unittests/basic_string_view/element_access/char/empty.cc). As the file was copied from GCC's libstdc++-v3 testsuite, this commit leaves this file untouched for the time being; a patch to fix the header was sent to gcc-patches first. gdb/ChangeLog: Update copyright year range in all GDB files.
2018-11-22Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc.Pedro Alves1-0/+101
As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().