[binutils-gdb] gdb: make thread_info::m_thread_fsm a std::unique_ptr
Lancelot SIX
lsix@sourceware.org
Mon Feb 7 11:13:25 GMT 2022
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=573269a87c89ae866db556428fe9ea63d6c4db5f
commit 573269a87c89ae866db556428fe9ea63d6c4db5f
Author: Lancelot SIX <lancelot.six@amd.com>
Date: Tue Jan 11 10:10:11 2022 -0500
gdb: make thread_info::m_thread_fsm a std::unique_ptr
While working on function calls, I realized that the thread_fsm member
of struct thread_info is a raw pointer to a resource it owns. This
commit changes the type of the thread_fsm member to a std::unique_ptr in
order to signify this ownership relationship and slightly ease resource
management (no need to manually call delete).
To ensure consistent use, the field is made a private member
(m_thread_fsm). The setter method (set_thread_fsm) can then check
that it is incorrect to associate a FSM to a thread_info object if
another one is already in place. This is ensured by an assertion.
The function run_inferior_call takes an argument as a pointer to a
call_thread_fsm and installs it in it in a thread_info instance. Also
change this function's signature to accept a unique_ptr in order to
signify that the ownership of the call_thread_fsm is transferred during
the call.
No user visible change expected after this commit.
Tested on x86_64-linux with no regression observed.
Change-Id: Ia1224f72a4afa247801ce6650ce82f90224a9ae8
Diff:
---
gdb/breakpoint.c | 6 ++++--
gdb/cli/cli-interp.c | 6 +++---
gdb/gdbthread.h | 37 ++++++++++++++++++++++++++++++++-----
gdb/infcall.c | 49 ++++++++++++++++++++++++++++---------------------
gdb/infcmd.c | 8 ++++----
gdb/infrun.c | 44 +++++++++++++++++++-------------------------
gdb/mi/mi-interp.c | 6 +++---
gdb/thread.c | 7 +++----
8 files changed, 96 insertions(+), 67 deletions(-)
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index b1130acbab2..9ff2bf82374 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -10830,8 +10830,10 @@ until_break_command (const char *arg, int from_tty, int anywhere)
breakpoints.emplace_back (std::move (location_breakpoint));
}
- tp->thread_fsm = new until_break_fsm (command_interp (), tp->global_num,
- std::move (breakpoints));
+ tp->set_thread_fsm
+ (std::unique_ptr<thread_fsm>
+ (new until_break_fsm (command_interp (), tp->global_num,
+ std::move (breakpoints))));
if (lj_deleter)
lj_deleter->release ();
diff --git a/gdb/cli/cli-interp.c b/gdb/cli/cli-interp.c
index dd56e12e696..0190b4d32bc 100644
--- a/gdb/cli/cli-interp.c
+++ b/gdb/cli/cli-interp.c
@@ -108,9 +108,9 @@ should_print_stop_to_console (struct interp *console_interp,
{
if ((bpstat_what (tp->control.stop_bpstat).main_action
== BPSTAT_WHAT_STOP_NOISY)
- || tp->thread_fsm == NULL
- || tp->thread_fsm->command_interp == console_interp
- || !tp->thread_fsm->finished_p ())
+ || tp->thread_fsm () == nullptr
+ || tp->thread_fsm ()->command_interp == console_interp
+ || !tp->thread_fsm ()->finished_p ())
return 1;
return 0;
}
diff --git a/gdb/gdbthread.h b/gdb/gdbthread.h
index 9921dae7a71..1a33eb61221 100644
--- a/gdb/gdbthread.h
+++ b/gdb/gdbthread.h
@@ -34,6 +34,7 @@ struct symtab;
#include "gdbsupport/forward-scope-exit.h"
#include "displaced-stepping.h"
#include "gdbsupport/intrusive_list.h"
+#include "thread-fsm.h"
struct inferior;
struct process_stratum_target;
@@ -443,6 +444,32 @@ public:
m_suspend.stop_reason = reason;
}
+ /* Get the FSM associated with the thread. */
+
+ struct thread_fsm *thread_fsm () const
+ {
+ return m_thread_fsm.get ();
+ }
+
+ /* Get the owning reference to the FSM associated with the thread.
+
+ After a call to this method, "thread_fsm () == nullptr". */
+
+ std::unique_ptr<struct thread_fsm> release_thread_fsm ()
+ {
+ return std::move (m_thread_fsm);
+ }
+
+ /* Set the FSM associated with the current thread.
+
+ It is invalid to set the FSM if another FSM is already installed. */
+
+ void set_thread_fsm (std::unique_ptr<struct thread_fsm> fsm)
+ {
+ gdb_assert (m_thread_fsm == nullptr);
+ m_thread_fsm = std::move (fsm);
+ }
+
int current_line = 0;
struct symtab *current_symtab = NULL;
@@ -480,11 +507,6 @@ public:
when GDB gets back SIGTRAP from step_resume_breakpoint. */
int step_after_step_resume_breakpoint = 0;
- /* Pointer to the state machine manager object that handles what is
- left to do for the thread's execution command after the target
- stops. Several execution commands use it. */
- struct thread_fsm *thread_fsm = NULL;
-
/* This is used to remember when a fork or vfork event was caught by
a catchpoint, and thus the event is to be followed at the next
resume of the thread, and not immediately. */
@@ -550,6 +572,11 @@ private:
Nullptr if the thread does not have a user-given name. */
gdb::unique_xmalloc_ptr<char> m_name;
+
+ /* Pointer to the state machine manager object that handles what is
+ left to do for the thread's execution command after the target
+ stops. Several execution commands use it. */
+ std::unique_ptr<struct thread_fsm> m_thread_fsm;
};
using thread_info_resumed_with_pending_wait_status_node
diff --git a/gdb/infcall.c b/gdb/infcall.c
index 05cf18f0a7f..8e896296b96 100644
--- a/gdb/infcall.c
+++ b/gdb/infcall.c
@@ -574,7 +574,7 @@ call_thread_fsm::should_notify_stop ()
thrown errors. The caller should rethrow if there's an error. */
static struct gdb_exception
-run_inferior_call (struct call_thread_fsm *sm,
+run_inferior_call (std::unique_ptr<call_thread_fsm> sm,
struct thread_info *call_thread, CORE_ADDR real_pc)
{
struct gdb_exception caught_error;
@@ -597,9 +597,8 @@ run_inferior_call (struct call_thread_fsm *sm,
clear_proceed_status (0);
/* Associate the FSM with the thread after clear_proceed_status
- (otherwise it'd clear this FSM), and before anything throws, so
- we don't leak it (and any resources it manages). */
- call_thread->thread_fsm = sm;
+ (otherwise it'd clear this FSM). */
+ call_thread->set_thread_fsm (std::move (sm));
disable_watchpoints_before_interactive_call_start ();
@@ -1251,12 +1250,9 @@ call_function_by_hand_dummy (struct value *function,
just below is the place to chop this function in two.. */
{
- struct thread_fsm *saved_sm;
- struct call_thread_fsm *sm;
-
/* Save the current FSM. We'll override it. */
- saved_sm = call_thread->thread_fsm;
- call_thread->thread_fsm = NULL;
+ std::unique_ptr<thread_fsm> saved_sm = call_thread->release_thread_fsm ();
+ struct call_thread_fsm *sm;
/* Save this thread's ptid, we need it later but the thread
may have exited. */
@@ -1273,17 +1269,19 @@ call_function_by_hand_dummy (struct value *function,
values_type,
return_method != return_method_normal,
struct_addr);
-
- e = run_inferior_call (sm, call_thread.get (), real_pc);
+ {
+ std::unique_ptr<call_thread_fsm> sm_up (sm);
+ e = run_inferior_call (std::move (sm_up), call_thread.get (), real_pc);
+ }
gdb::observers::inferior_call_post.notify (call_thread_ptid, funaddr);
if (call_thread->state != THREAD_EXITED)
{
/* The FSM should still be the same. */
- gdb_assert (call_thread->thread_fsm == sm);
+ gdb_assert (call_thread->thread_fsm () == sm);
- if (call_thread->thread_fsm->finished_p ())
+ if (call_thread->thread_fsm ()->finished_p ())
{
struct value *retval;
@@ -1297,11 +1295,16 @@ call_function_by_hand_dummy (struct value *function,
/* Get the return value. */
retval = sm->return_value;
- /* Clean up / destroy the call FSM, and restore the
- original one. */
- call_thread->thread_fsm->clean_up (call_thread.get ());
- delete call_thread->thread_fsm;
- call_thread->thread_fsm = saved_sm;
+ /* Restore the original FSM and clean up / destroh the call FSM.
+ Doing it in this order ensures that if the call to clean_up
+ throws, the original FSM is properly restored. */
+ {
+ std::unique_ptr<thread_fsm> finalizing
+ = call_thread->release_thread_fsm ();
+ call_thread->set_thread_fsm (std::move (saved_sm));
+
+ finalizing->clean_up (call_thread.get ());
+ }
maybe_remove_breakpoints ();
@@ -1315,9 +1318,13 @@ call_function_by_hand_dummy (struct value *function,
/* Didn't complete. Clean up / destroy the call FSM, and restore the
previous state machine, and handle the error. */
- call_thread->thread_fsm->clean_up (call_thread.get ());
- delete call_thread->thread_fsm;
- call_thread->thread_fsm = saved_sm;
+ {
+ std::unique_ptr<thread_fsm> finalizing
+ = call_thread->release_thread_fsm ();
+ call_thread->set_thread_fsm (std::move (saved_sm));
+
+ finalizing->clean_up (call_thread.get ());
+ }
}
}
diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index b9fb121dbbe..48dda9b23ee 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -848,7 +848,7 @@ step_1 (int skip_subroutines, int single_inst, const char *count_string)
steps. */
thr = inferior_thread ();
step_sm = new step_command_fsm (command_interp ());
- thr->thread_fsm = step_sm;
+ thr->set_thread_fsm (std::unique_ptr<thread_fsm> (step_sm));
step_command_fsm_prepare (step_sm, skip_subroutines,
single_inst, count, thr);
@@ -865,7 +865,7 @@ step_1 (int skip_subroutines, int single_inst, const char *count_string)
/* Stepped into an inline frame. Pretend that we've
stopped. */
- thr->thread_fsm->clean_up (thr);
+ thr->thread_fsm ()->clean_up (thr);
proceeded = normal_stop ();
if (!proceeded)
inferior_event_handler (INF_EXEC_COMPLETE);
@@ -1355,7 +1355,7 @@ until_next_command (int from_tty)
delete_longjmp_breakpoint_cleanup lj_deleter (thread);
sm = new until_next_fsm (command_interp (), tp->global_num);
- tp->thread_fsm = sm;
+ tp->set_thread_fsm (std::unique_ptr<thread_fsm> (sm));
lj_deleter.release ();
proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
@@ -1762,7 +1762,7 @@ finish_command (const char *arg, int from_tty)
sm = new finish_command_fsm (command_interp ());
- tp->thread_fsm = sm;
+ tp->set_thread_fsm (std::unique_ptr<thread_fsm> (sm));
/* Finishing from an inline frame is completely different. We don't
try to show the "return value" - no way to locate it. */
diff --git a/gdb/infrun.c b/gdb/infrun.c
index f9420d54990..61af16238de 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -698,7 +698,6 @@ follow_fork ()
int current_line = 0;
symtab *current_symtab = NULL;
struct frame_id step_frame_id = { 0 };
- struct thread_fsm *thread_fsm = NULL;
if (!non_stop)
{
@@ -741,6 +740,7 @@ follow_fork ()
case TARGET_WAITKIND_VFORKED:
{
ptid_t parent, child;
+ std::unique_ptr<struct thread_fsm> thread_fsm;
/* If the user did a next/step, etc, over a fork call,
preserve the stepping state in the fork child. */
@@ -755,7 +755,7 @@ follow_fork ()
step_frame_id = tp->control.step_frame_id;
exception_resume_breakpoint
= clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
- thread_fsm = tp->thread_fsm;
+ thread_fsm = tp->release_thread_fsm ();
/* For now, delete the parent's sr breakpoint, otherwise,
parent/child sr breakpoints are considered duplicates,
@@ -767,7 +767,6 @@ follow_fork ()
tp->control.step_range_end = 0;
tp->control.step_frame_id = null_frame_id;
delete_exception_resume_breakpoint (tp);
- tp->thread_fsm = NULL;
}
parent = inferior_ptid;
@@ -809,7 +808,7 @@ follow_fork ()
tp->control.step_frame_id = step_frame_id;
tp->control.exception_resume_breakpoint
= exception_resume_breakpoint;
- tp->thread_fsm = thread_fsm;
+ tp->set_thread_fsm (std::move (thread_fsm));
}
else
{
@@ -2651,8 +2650,7 @@ clear_proceed_status_thread (struct thread_info *tp)
if (!signal_pass_state (tp->stop_signal ()))
tp->set_stop_signal (GDB_SIGNAL_0);
- delete tp->thread_fsm;
- tp->thread_fsm = NULL;
+ tp->release_thread_fsm ();
tp->control.trap_expected = 0;
tp->control.step_range_start = 0;
@@ -3935,24 +3933,24 @@ reinstall_readline_callback_handler_cleanup ()
static void
clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
{
- if (ecs->event_thread != NULL
- && ecs->event_thread->thread_fsm != NULL)
- ecs->event_thread->thread_fsm->clean_up (ecs->event_thread);
+ if (ecs->event_thread != nullptr
+ && ecs->event_thread->thread_fsm () != nullptr)
+ ecs->event_thread->thread_fsm ()->clean_up (ecs->event_thread);
if (!non_stop)
{
for (thread_info *thr : all_non_exited_threads ())
{
- if (thr->thread_fsm == NULL)
+ if (thr->thread_fsm () == nullptr)
continue;
if (thr == ecs->event_thread)
continue;
switch_to_thread (thr);
- thr->thread_fsm->clean_up (thr);
+ thr->thread_fsm ()->clean_up (thr);
}
- if (ecs->event_thread != NULL)
+ if (ecs->event_thread != nullptr)
switch_to_thread (ecs->event_thread);
}
}
@@ -4103,13 +4101,8 @@ fetch_inferior_event ()
delete_just_stopped_threads_infrun_breakpoints ();
- if (thr != NULL)
- {
- struct thread_fsm *thread_fsm = thr->thread_fsm;
-
- if (thread_fsm != NULL)
- should_stop = thread_fsm->should_stop (thr);
- }
+ if (thr != nullptr && thr->thread_fsm () != nullptr)
+ should_stop = thr->thread_fsm ()->should_stop (thr);
if (!should_stop)
{
@@ -4122,8 +4115,9 @@ fetch_inferior_event ()
clean_up_just_stopped_threads_fsms (ecs);
- if (thr != NULL && thr->thread_fsm != NULL)
- should_notify_stop = thr->thread_fsm->should_notify_stop ();
+ if (thr != nullptr && thr->thread_fsm () != nullptr)
+ should_notify_stop
+ = thr->thread_fsm ()->should_notify_stop ();
if (should_notify_stop)
{
@@ -8340,13 +8334,13 @@ print_stop_event (struct ui_out *uiout, bool displays)
}
tp = inferior_thread ();
- if (tp->thread_fsm != NULL
- && tp->thread_fsm->finished_p ())
+ if (tp->thread_fsm () != nullptr
+ && tp->thread_fsm ()->finished_p ())
{
struct return_value_info *rv;
- rv = tp->thread_fsm->return_value ();
- if (rv != NULL)
+ rv = tp->thread_fsm ()->return_value ();
+ if (rv != nullptr)
print_return_value (uiout, rv);
}
}
diff --git a/gdb/mi/mi-interp.c b/gdb/mi/mi-interp.c
index e69ad9aff2d..f02a7cf3f10 100644
--- a/gdb/mi/mi-interp.c
+++ b/gdb/mi/mi-interp.c
@@ -630,12 +630,12 @@ mi_on_normal_stop_1 (struct bpstat *bs, int print_frame)
tp = inferior_thread ();
- if (tp->thread_fsm != NULL
- && tp->thread_fsm->finished_p ())
+ if (tp->thread_fsm () != nullptr
+ && tp->thread_fsm ()->finished_p ())
{
enum async_reply_reason reason;
- reason = tp->thread_fsm->async_reply_reason ();
+ reason = tp->thread_fsm ()->async_reply_reason ();
mi_uiout->field_string ("reason", async_reason_lookup (reason));
}
diff --git a/gdb/thread.c b/gdb/thread.c
index 611be3f4633..12f3abd57bd 100644
--- a/gdb/thread.c
+++ b/gdb/thread.c
@@ -160,11 +160,10 @@ thread_has_single_step_breakpoint_here (struct thread_info *tp,
void
thread_cancel_execution_command (struct thread_info *thr)
{
- if (thr->thread_fsm != NULL)
+ if (thr->thread_fsm () != nullptr)
{
- thr->thread_fsm->clean_up (thr);
- delete thr->thread_fsm;
- thr->thread_fsm = NULL;
+ std::unique_ptr<thread_fsm> fsm = thr->release_thread_fsm ();
+ fsm->clean_up (thr);
}
}
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