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gdb: Coalesce/aggregate (async) vCont packets/actions

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Currently, with "maint set target-non-stop on", that is, when gdb
connects with the non-stop/asynchronous variant of the remote
protocol, even with "set non-stop off", GDB always sends one vCont
packet per thread resumed.  This patch makes GDB aggregate and
coalesce vCont packets, so we send vCont packets like "vCont;s:p1.1;c"
in non-stop mode too.

Basically, this is done by:

  - Adding a new target method target_commit_resume that is called
    after calling target_resume one or more times.  When resuming a
    batch of threads, we'll only call target_commit_resume once after
    calling target_resume for all threads.

  - Making the remote target defer sending the actual vCont packet to
    target_commit_resume.

Special care must be taken to avoid sending a vCont action with a
"wildcard" thread-id (all threads of process / all threads) when that
would resume threads/processes that should not be resumed.  See
remote_commit_resume comments for details.

Unlike all-stop's remote_resume implementation, this handles the case
of too many actions resulting in a too-big vCont packet, by flushing
the vCont packet and starting a new one.

E.g., imagining that the "c" action in:

  vCont;s:1;c

overflows the packet buffer, we split the actions like:

  vCont;s:1
  vCont;c

Tested on x86_64 Fedora 20, with and without "maint set
target-non-stop on".

Also tested with a hack that makes remote_commit_resume flush the vCont
packet after every action appended (which caught a few bugs).

gdb/ChangeLog:
2016-10-26  Pedro Alves  <palves@redhat.com>

	* inferior.h (ALL_NON_EXITED_INFERIORS): New macro.
	* infrun.c (do_target_resume): Call target_commit_resume.
	(proceed): Defer target_commit_resume while looping over threads,
	resuming them.  Call target_commit_resume at the end.
	* record-btrace.c (record_btrace_commit_resume): New function.
	(init_record_btrace_ops): Install it as to_commit_resume method.
	* record-full.c (record_full_commit_resume): New function.
	(record_full_wait_1): Call the beneath target's to_commit_resume
	method.
	(init_record_full_ops): Install record_full_commit_resume as
	to_commit_resume method.
	* remote.c (struct private_thread_info) <last_resume_step,
	last_resume_sig, vcont_resumed>: New fields.
	(remote_add_thread): Set the new thread's vcont_resumed flag.
	(demand_private_info): Delete.
	(get_private_info_thread, get_private_info_ptid): New functions.
	(remote_update_thread_list): Adjust.
	(process_initial_stop_replies): Clear the thread's vcont_resumed
	flag.
	(remote_resume): If connected in non-stop mode, record the resume
	request and return early.
	(struct private_inferior): New.
	(struct vcont_builder): New.
	(vcont_builder_restart, vcont_builder_flush)
	(vcont_builder_push_action): New functions.
	(MAX_ACTION_SIZE): New macro.
	(remote_commit_resume): New function.
	(thread_pending_fork_status, is_pending_fork_parent_thread): New
	functions.
	(check_pending_event_prevents_wildcard_vcont_callback)
	(check_pending_events_prevent_wildcard_vcont): New functions.
	(process_stop_reply): Adjust.  Clear the thread's vcont_resumed
	flag.
	(init_remote_ops): Install remote_commit_resume.
	* target-delegates.c: Regenerate.
	* target.c (defer_target_commit_resume): New global.
	(target_commit_resume, make_cleanup_defer_target_commit_resume):
	New functions.
	* target.h (struct target_ops) <to_commit_resume>: New field.
	(target_resume): Update comments.
	(target_commit_resume): New declaration.
This commit is contained in:
Pedro Alves 2016-10-26 11:08:28 +01:00
parent 5a04c4cf5d
commit 85ad3aaf40
9 changed files with 600 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
gdb/ChangeLog
View File

@ -1,3 +1,47 @@
2016-10-26 Pedro Alves <palves@redhat.com>
* inferior.h (ALL_NON_EXITED_INFERIORS): New macro.
* infrun.c (do_target_resume): Call target_commit_resume.
(proceed): Defer target_commit_resume while looping over threads,
resuming them. Call target_commit_resume at the end.
* record-btrace.c (record_btrace_commit_resume): New function.
(init_record_btrace_ops): Install it as to_commit_resume method.
* record-full.c (record_full_commit_resume): New function.
(record_full_wait_1): Call the beneath target's to_commit_resume
method.
(init_record_full_ops): Install record_full_commit_resume as
to_commit_resume method.
* remote.c (struct private_thread_info) <last_resume_step,
last_resume_sig, vcont_resumed>: New fields.
(remote_add_thread): Set the new thread's vcont_resumed flag.
(demand_private_info): Delete.
(get_private_info_thread, get_private_info_ptid): New functions.
(remote_update_thread_list): Adjust.
(process_initial_stop_replies): Clear the thread's vcont_resumed
flag.
(remote_resume): If connected in non-stop mode, record the resume
request and return early.
(struct private_inferior): New.
(struct vcont_builder): New.
(vcont_builder_restart, vcont_builder_flush)
(vcont_builder_push_action): New functions.
(MAX_ACTION_SIZE): New macro.
(remote_commit_resume): New function.
(thread_pending_fork_status, is_pending_fork_parent_thread): New
functions.
(check_pending_event_prevents_wildcard_vcont_callback)
(check_pending_events_prevent_wildcard_vcont): New functions.
(process_stop_reply): Adjust. Clear the thread's vcont_resumed
flag.
(init_remote_ops): Install remote_commit_resume.
* target-delegates.c: Regenerate.
* target.c (defer_target_commit_resume): New global.
(target_commit_resume, make_cleanup_defer_target_commit_resume):
New functions.
* target.h (struct target_ops) <to_commit_resume>: New field.
(target_resume): Update comments.
(target_commit_resume): New declaration.
2016-10-26 Pedro Alves <palves@redhat.com>
* inferior.c (exit_inferior_1): Free 'priv'.

6
gdb/inferior.h
View File

@ -513,6 +513,12 @@ extern struct cleanup *save_current_inferior (void);
#define ALL_INFERIORS(I) \
for ((I) = inferior_list; (I); (I) = (I)->next)
/* Traverse all non-exited inferiors. */
#define ALL_NON_EXITED_INFERIORS(I) \
ALL_INFERIORS (I) \
if ((I)->pid != 0)
extern struct inferior *inferior_list;
/* Prune away automatically added inferiors that aren't required

8
gdb/infrun.c
View File

@ -2366,6 +2366,8 @@ do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
target_resume (resume_ptid, step, sig);
target_commit_resume ();
}
/* Resume the inferior, but allow a QUIT. This is useful if the user
@ -2984,6 +2986,7 @@ proceed (CORE_ADDR addr, enum gdb_signal siggnal)
struct execution_control_state ecss;
struct execution_control_state *ecs = &ecss;
struct cleanup *old_chain;
struct cleanup *defer_resume_cleanup;
int started;
/* If we're stopped at a fork/vfork, follow the branch set by the
@ -3125,6 +3128,8 @@ proceed (CORE_ADDR addr, enum gdb_signal siggnal)
until the target stops again. */
tp->prev_pc = regcache_read_pc (regcache);
defer_resume_cleanup = make_cleanup_defer_target_commit_resume ();
started = start_step_over ();
if (step_over_info_valid_p ())
@ -3189,6 +3194,9 @@ proceed (CORE_ADDR addr, enum gdb_signal siggnal)
error (_("Command aborted."));
}
do_cleanups (defer_resume_cleanup);
target_commit_resume ();
discard_cleanups (old_chain);
/* Tell the event loop to wait for it to stop. If the target

11
gdb/record-btrace.c
View File

@ -2150,6 +2150,16 @@ record_btrace_resume (struct target_ops *ops, ptid_t ptid, int step,
}
}
/* The to_commit_resume method of target record-btrace. */
static void
record_btrace_commit_resume (struct target_ops *ops)
{
if ((execution_direction != EXEC_REVERSE)
&& !record_btrace_is_replaying (ops, minus_one_ptid))
ops->beneath->to_commit_resume (ops->beneath);
}
/* Cancel resuming TP. */
static void
@ -2875,6 +2885,7 @@ init_record_btrace_ops (void)
ops->to_get_unwinder = &record_btrace_to_get_unwinder;
ops->to_get_tailcall_unwinder = &record_btrace_to_get_tailcall_unwinder;
ops->to_resume = record_btrace_resume;
ops->to_commit_resume = record_btrace_commit_resume;
ops->to_wait = record_btrace_wait;
ops->to_stop = record_btrace_stop;
ops->to_update_thread_list = record_btrace_update_thread_list;

11
gdb/record-full.c
View File

@ -1002,6 +1002,15 @@ record_full_resume (struct target_ops *ops, ptid_t ptid, int step,
target_async (1);
}
/* "to_commit_resume" method for process record target. */
static void
record_full_commit_resume (struct target_ops *ops)
{
if (!RECORD_FULL_IS_REPLAY)
ops->beneath->to_commit_resume (ops->beneath);
}
static int record_full_get_sig = 0;
/* SIGINT signal handler, registered by "to_wait" method. */
@ -1172,6 +1181,7 @@ record_full_wait_1 (struct target_ops *ops,
"target beneath\n");
ops->beneath->to_resume (ops->beneath, ptid, step,
GDB_SIGNAL_0);
ops->beneath->to_commit_resume (ops->beneath);
continue;
}
}
@ -1975,6 +1985,7 @@ init_record_full_ops (void)
record_full_ops.to_close = record_full_close;
record_full_ops.to_async = record_full_async;
record_full_ops.to_resume = record_full_resume;
record_full_ops.to_commit_resume = record_full_commit_resume;
record_full_ops.to_wait = record_full_wait;
record_full_ops.to_disconnect = record_disconnect;
record_full_ops.to_detach = record_detach;

456
gdb/remote.c
View File

@ -452,6 +452,24 @@ struct private_thread_info
/* This is set to the data address of the access causing the target
to stop for a watchpoint. */
CORE_ADDR watch_data_address;
/* Fields used by the vCont action coalescing implemented in
remote_resume / remote_commit_resume. remote_resume stores each
thread's last resume request in these fields, so that a later
remote_commit_resume knows which is the proper action for this
thread to include in the vCont packet. */
/* True if the last target_resume call for this thread was a step
request, false if a continue request. */
int last_resume_step;
/* The signal specified in the last target_resume call for this
thread. */
enum gdb_signal last_resume_sig;
/* Whether this thread was already vCont-resumed on the remote
side. */
int vcont_resumed;
};
static void
@ -1805,6 +1823,9 @@ remote_add_inferior (int fake_pid_p, int pid, int attached,
return inf;
}
static struct private_thread_info *
get_private_info_thread (struct thread_info *info);
/* Add thread PTID to GDB's thread list. Tag it as executing/running
according to RUNNING. */
@ -1812,6 +1833,7 @@ static void
remote_add_thread (ptid_t ptid, int running, int executing)
{
struct remote_state *rs = get_remote_state ();
struct thread_info *thread;
/* GDB historically didn't pull threads in the initial connection
setup. If the remote target doesn't even have a concept of
@ -1820,10 +1842,11 @@ remote_add_thread (ptid_t ptid, int running, int executing)
might be confusing to the user. Be silent then, preserving the
age old behavior. */
if (rs->starting_up)
add_thread_silent (ptid);
thread = add_thread_silent (ptid);
else
add_thread (ptid);
thread = add_thread (ptid);
get_private_info_thread (thread)->vcont_resumed = executing;
set_executing (ptid, executing);
set_running (ptid, running);
}
@ -1918,25 +1941,40 @@ remote_notice_new_inferior (ptid_t currthread, int executing)
}
}
/* Return the private thread data, creating it if necessary. */
/* Return THREAD's private thread data, creating it if necessary. */
static struct private_thread_info *
demand_private_info (ptid_t ptid)
get_private_info_thread (struct thread_info *thread)
{
gdb_assert (thread != NULL);
if (thread->priv == NULL)
{
struct private_thread_info *priv = XNEW (struct private_thread_info);
thread->private_dtor = free_private_thread_info;
thread->priv = priv;
priv->core = -1;
priv->extra = NULL;
priv->name = NULL;
priv->name = NULL;
priv->last_resume_step = 0;
priv->last_resume_sig = GDB_SIGNAL_0;
priv->vcont_resumed = 0;
}
return thread->priv;
}
/* Return PTID's private thread data, creating it if necessary. */
static struct private_thread_info *
get_private_info_ptid (ptid_t ptid)
{
struct thread_info *info = find_thread_ptid (ptid);
gdb_assert (info);
if (!info->priv)
{
info->priv = XNEW (struct private_thread_info);
info->private_dtor = free_private_thread_info;
info->priv->core = -1;
info->priv->extra = NULL;
info->priv->name = NULL;
}
return info->priv;
return get_private_info_thread (info);
}
/* Call this function as a result of
@ -3280,7 +3318,7 @@ remote_update_thread_list (struct target_ops *ops)
remote_notice_new_inferior (item->ptid, executing);
info = demand_private_info (item->ptid);
info = get_private_info_ptid (item->ptid);
info->core = item->core;
info->extra = item->extra;
item->extra = NULL;
@ -3913,6 +3951,7 @@ process_initial_stop_replies (int from_tty)
set_executing (event_ptid, 0);
set_running (event_ptid, 0);
thread->priv->vcont_resumed = 0;
}
/* "Notice" the new inferiors before anything related to
@ -5701,6 +5740,26 @@ remote_resume (struct target_ops *ops,
{
struct remote_state *rs = get_remote_state ();
/* When connected in non-stop mode, the core resumes threads
individually. Resuming remote threads directly in target_resume
would thus result in sending one packet per thread. Instead, to
minimize roundtrip latency, here we just store the resume
request; the actual remote resumption will be done in
target_commit_resume / remote_commit_resume, where we'll be able
to do vCont action coalescing. */
if (target_is_non_stop_p () && execution_direction != EXEC_REVERSE)
{
struct private_thread_info *remote_thr;
if (ptid_equal (minus_one_ptid, ptid) || ptid_is_pid (ptid))
remote_thr = get_private_info_ptid (inferior_ptid);
else
remote_thr = get_private_info_ptid (ptid);
remote_thr->last_resume_step = step;
remote_thr->last_resume_sig = siggnal;
return;
}
/* In all-stop, we can't mark REMOTE_ASYNC_GET_PENDING_EVENTS_TOKEN
(explained in remote-notif.c:handle_notification) so
remote_notif_process is not called. We need find a place where
@ -5736,6 +5795,283 @@ remote_resume (struct target_ops *ops,
if (!target_is_non_stop_p ())
rs->waiting_for_stop_reply = 1;
}
static void check_pending_events_prevent_wildcard_vcont
(int *may_global_wildcard_vcont);
static int is_pending_fork_parent_thread (struct thread_info *thread);
/* Private per-inferior info for target remote processes. */
struct private_inferior
{
/* Whether we can send a wildcard vCont for this process. */
int may_wildcard_vcont;
};
/* Structure used to track the construction of a vCont packet in the
outgoing packet buffer. This is used to send multiple vCont
packets if we have more actions than would fit a single packet. */
struct vcont_builder
{
/* Pointer to the first action. P points here if no action has been
appended yet. */
char *first_action;
/* Where the next action will be appended. */
char *p;
/* The end of the buffer. Must never write past this. */
char *endp;
};
/* Prepare the outgoing buffer for a new vCont packet. */
static void
vcont_builder_restart (struct vcont_builder *builder)
{
struct remote_state *rs = get_remote_state ();
builder->p = rs->buf;
builder->endp = rs->buf + get_remote_packet_size ();
builder->p += xsnprintf (builder->p, builder->endp - builder->p, "vCont");
builder->first_action = builder->p;
}
/* If the vCont packet being built has any action, send it to the
remote end. */
static void
vcont_builder_flush (struct vcont_builder *builder)
{
struct remote_state *rs;
if (builder->p == builder->first_action)
return;
rs = get_remote_state ();
putpkt (rs->buf);
getpkt (&rs->buf, &rs->buf_size, 0);
if (strcmp (rs->buf, "OK") != 0)
error (_("Unexpected vCont reply in non-stop mode: %s"), rs->buf);
}
/* The largest action is range-stepping, with its two addresses. This
is more than sufficient. If a new, bigger action is created, it'll
quickly trigger a failed assertion in append_resumption (and we'll
just bump this). */
#define MAX_ACTION_SIZE 200
/* Append a new vCont action in the outgoing packet being built. If
the action doesn't fit the packet along with previous actions, push
what we've got so far to the remote end and start over a new vCont
packet (with the new action). */
static void
vcont_builder_push_action (struct vcont_builder *builder,
ptid_t ptid, int step, enum gdb_signal siggnal)
{
char buf[MAX_ACTION_SIZE + 1];
char *endp;
size_t rsize;
endp = append_resumption (buf, buf + sizeof (buf),
ptid, step, siggnal);
/* Check whether this new action would fit in the vCont packet along
with previous actions. If not, send what we've got so far and
start a new vCont packet. */
rsize = endp - buf;
if (rsize > builder->endp - builder->p)
{
vcont_builder_flush (builder);
vcont_builder_restart (builder);
/* Should now fit. */
gdb_assert (rsize <= builder->endp - builder->p);
}
memcpy (builder->p, buf, rsize);
builder->p += rsize;
*builder->p = '\0';
}
/* to_commit_resume implementation. */
static void
remote_commit_resume (struct target_ops *ops)
{
struct remote_state *rs = get_remote_state ();
struct inferior *inf;
struct thread_info *tp;
int any_process_wildcard;
int may_global_wildcard_vcont;
struct vcont_builder vcont_builder;
/* If connected in all-stop mode, we'd send the remote resume
request directly from remote_resume. Likewise if
reverse-debugging, as there are no defined vCont actions for
reverse execution. */
if (!target_is_non_stop_p () || execution_direction == EXEC_REVERSE)
return;
/* Try to send wildcard actions ("vCont;c" or "vCont;c:pPID.-1")
instead of resuming all threads of each process individually.
However, if any thread of a process must remain halted, we can't
send wildcard resumes and must send one action per thread.
Care must be taken to not resume threads/processes the server
side already told us are stopped, but the core doesn't know about
yet, because the events are still in the vStopped notification
queue. For example:
#1 => vCont s:p1.1;c
#2 <= OK
#3 <= %Stopped T05 p1.1
#4 => vStopped
#5 <= T05 p1.2
#6 => vStopped
#7 <= OK
#8 (infrun handles the stop for p1.1 and continues stepping)
#9 => vCont s:p1.1;c
The last vCont above would resume thread p1.2 by mistake, because
the server has no idea that the event for p1.2 had not been
handled yet.
The server side must similarly ignore resume actions for the
thread that has a pending %Stopped notification (and any other
threads with events pending), until GDB acks the notification
with vStopped. Otherwise, e.g., the following case is
mishandled:
#1 => g (or any other packet)
#2 <= [registers]
#3 <= %Stopped T05 p1.2
#4 => vCont s:p1.1;c
#5 <= OK
Above, the server must not resume thread p1.2. GDB can't know
that p1.2 stopped until it acks the %Stopped notification, and
since from GDB's perspective all threads should be running, it
sends a "c" action.
Finally, special care must also be given to handling fork/vfork
events. A (v)fork event actually tells us that two processes
stopped -- the parent and the child. Until we follow the fork,
we must not resume the child. Therefore, if we have a pending
fork follow, we must not send a global wildcard resume action
(vCont;c). We can still send process-wide wildcards though. */
/* Start by assuming a global wildcard (vCont;c) is possible. */
may_global_wildcard_vcont = 1;
/* And assume every process is individually wildcard-able too. */
ALL_NON_EXITED_INFERIORS (inf)
{
if (inf->priv == NULL)
inf->priv = XNEW (struct private_inferior);
inf->priv->may_wildcard_vcont = 1;
}
/* Check for any pending events (not reported or processed yet) and
disable process and global wildcard resumes appropriately. */
check_pending_events_prevent_wildcard_vcont (&may_global_wildcard_vcont);
ALL_NON_EXITED_THREADS (tp)
{
/* If a thread of a process is not meant to be resumed, then we
can't wildcard that process. */
if (!tp->executing)
{
tp->inf->priv->may_wildcard_vcont = 0;
/* And if we can't wildcard a process, we can't wildcard
everything either. */
may_global_wildcard_vcont = 0;
continue;
}
/* If a thread is the parent of an unfollowed fork, then we
can't do a global wildcard, as that would resume the fork
child. */
if (is_pending_fork_parent_thread (tp))
may_global_wildcard_vcont = 0;
}
/* Now let's build the vCont packet(s). Actions must be appended
from narrower to wider scopes (thread -> process -> global). If
we end up with too many actions for a single packet vcont_builder
flushes the current vCont packet to the remote side and starts a
new one. */
vcont_builder_restart (&vcont_builder);
/* Threads first. */
ALL_NON_EXITED_THREADS (tp)
{
struct private_thread_info *remote_thr = tp->priv;
if (!tp->executing || remote_thr->vcont_resumed)
continue;
gdb_assert (!thread_is_in_step_over_chain (tp));
if (!remote_thr->last_resume_step
&& remote_thr->last_resume_sig == GDB_SIGNAL_0
&& tp->inf->priv->may_wildcard_vcont)
{
/* We'll send a wildcard resume instead. */
remote_thr->vcont_resumed = 1;
continue;
}
vcont_builder_push_action (&vcont_builder, tp->ptid,
remote_thr->last_resume_step,
remote_thr->last_resume_sig);
remote_thr->vcont_resumed = 1;
}
/* Now check whether we can send any process-wide wildcard. This is
to avoid sending a global wildcard in the case nothing is
supposed to be resumed. */
any_process_wildcard = 0;
ALL_NON_EXITED_INFERIORS (inf)
{
if (inf->priv->may_wildcard_vcont)
{
any_process_wildcard = 1;
break;
}
}
if (any_process_wildcard)
{
/* If all processes are wildcard-able, then send a single "c"
action, otherwise, send an "all (-1) threads of process"
continue action for each running process, if any. */
if (may_global_wildcard_vcont)
{
vcont_builder_push_action (&vcont_builder, minus_one_ptid,
0, GDB_SIGNAL_0);
}
else
{
ALL_NON_EXITED_INFERIORS (inf)
{
if (inf->priv->may_wildcard_vcont)
{
vcont_builder_push_action (&vcont_builder,
pid_to_ptid (inf->pid),
0, GDB_SIGNAL_0);
}
}
}
}
vcont_builder_flush (&vcont_builder);
}
/* Non-stop version of target_stop. Uses `vCont;t' to stop a remote
@ -6102,7 +6438,7 @@ struct queue_iter_param
struct stop_reply *output;
};
/* Determine if THREAD is a pending fork parent thread. ARG contains
/* Determine if THREAD_PTID is a pending fork parent thread. ARG contains
the pid of the process that owns the threads we want to check, or
-1 if we want to check all threads. */
@ -6120,6 +6456,29 @@ is_pending_fork_parent (struct target_waitstatus *ws, int event_pid,
return 0;
}
/* Return the thread's pending status used to determine whether the
thread is a fork parent stopped at a fork event. */
static struct target_waitstatus *
thread_pending_fork_status (struct thread_info *thread)
{
if (thread->suspend.waitstatus_pending_p)
return &thread->suspend.waitstatus;
else
return &thread->pending_follow;
}
/* Determine if THREAD is a pending fork parent thread. */
static int
is_pending_fork_parent_thread (struct thread_info *thread)
{
struct target_waitstatus *ws = thread_pending_fork_status (thread);
int pid = -1;
return is_pending_fork_parent (ws, pid, thread->ptid);
}
/* Check whether EVENT is a fork event, and if it is, remove the
fork child from the context list passed in DATA. */
@ -6159,12 +6518,7 @@ remove_new_fork_children (struct threads_listing_context *context)
fork child threads from the CONTEXT list. */
ALL_NON_EXITED_THREADS (thread)
{
struct target_waitstatus *ws;
if (thread->suspend.waitstatus_pending_p)
ws = &thread->suspend.waitstatus;
else
ws = &thread->pending_follow;
struct target_waitstatus *ws = thread_pending_fork_status (thread);
if (is_pending_fork_parent (ws, pid, thread->ptid))
{
@ -6182,6 +6536,56 @@ remove_new_fork_children (struct threads_listing_context *context)
remove_child_of_pending_fork, &param);
}
/* Check whether EVENT would prevent a global or process wildcard
vCont action. */
static int
check_pending_event_prevents_wildcard_vcont_callback
(QUEUE (stop_reply_p) *q,
QUEUE_ITER (stop_reply_p) *iter,
stop_reply_p event,
void *data)
{
struct inferior *inf;
int *may_global_wildcard_vcont = (int *) data;
if (event->ws.kind == TARGET_WAITKIND_NO_RESUMED
|| event->ws.kind == TARGET_WAITKIND_NO_HISTORY)
return 1;
if (event->ws.kind == TARGET_WAITKIND_FORKED
|| event->ws.kind == TARGET_WAITKIND_VFORKED)
*may_global_wildcard_vcont = 0;
inf = find_inferior_ptid (event->ptid);
/* This may be the first time we heard about this process.
Regardless, we must not do a global wildcard resume, otherwise
we'd resume this process too. */
*may_global_wildcard_vcont = 0;
if (inf != NULL)
inf->priv->may_wildcard_vcont = 0;
return 1;
}
/* Check whether any event pending in the vStopped queue would prevent
a global or process wildcard vCont action. Clear
*may_global_wildcard if we can't do a global wildcard (vCont;c),
and clear the event inferior's may_wildcard_vcont flag if we can't
do a process-wide wildcard resume (vCont;c:pPID.-1). */
static void
check_pending_events_prevent_wildcard_vcont (int *may_global_wildcard)
{
struct notif_client *notif = &notif_client_stop;
remote_notif_get_pending_events (notif);
QUEUE_iterate (stop_reply_p, stop_reply_queue,
check_pending_event_prevents_wildcard_vcont_callback,
may_global_wildcard);
}
/* Remove stop replies in the queue if its pid is equal to the given
inferior's pid. */
@ -6812,10 +7216,11 @@ process_stop_reply (struct stop_reply *stop_reply,
}
remote_notice_new_inferior (ptid, 0);
remote_thr = demand_private_info (ptid);
remote_thr = get_private_info_ptid (ptid);
remote_thr->core = stop_reply->core;
remote_thr->stop_reason = stop_reply->stop_reason;
remote_thr->watch_data_address = stop_reply->watch_data_address;
remote_thr->vcont_resumed = 0;
}
stop_reply_xfree (stop_reply);
@ -13114,6 +13519,7 @@ Specify the serial device it is connected to\n\
remote_ops.to_detach = remote_detach;
remote_ops.to_disconnect = remote_disconnect;
remote_ops.to_resume = remote_resume;
remote_ops.to_commit_resume = remote_commit_resume;
remote_ops.to_wait = remote_wait;
remote_ops.to_fetch_registers = remote_fetch_registers;
remote_ops.to_store_registers = remote_store_registers;

26
gdb/target-delegates.c
View File

@ -109,6 +109,28 @@ debug_resume (struct target_ops *self, ptid_t arg1, int arg2, enum gdb_signal ar
fputs_unfiltered (")\n", gdb_stdlog);
}
static void
delegate_commit_resume (struct target_ops *self)
{
self = self->beneath;
self->to_commit_resume (self);
}
static void
tdefault_commit_resume (struct target_ops *self)
{
}
static void
debug_commit_resume (struct target_ops *self)
{
fprintf_unfiltered (gdb_stdlog, "-> %s->to_commit_resume (...)\n", debug_target.to_shortname);
debug_target.to_commit_resume (&debug_target);
fprintf_unfiltered (gdb_stdlog, "<- %s->to_commit_resume (", debug_target.to_shortname);
target_debug_print_struct_target_ops_p (&debug_target);
fputs_unfiltered (")\n", gdb_stdlog);
}
static ptid_t
delegate_wait (struct target_ops *self, ptid_t arg1, struct target_waitstatus *arg2, int arg3)
{
@ -4108,6 +4130,8 @@ install_delegators (struct target_ops *ops)
ops->to_disconnect = delegate_disconnect;
if (ops->to_resume == NULL)
ops->to_resume = delegate_resume;
if (ops->to_commit_resume == NULL)
ops->to_commit_resume = delegate_commit_resume;
if (ops->to_wait == NULL)
ops->to_wait = delegate_wait;
if (ops->to_fetch_registers == NULL)
@ -4413,6 +4437,7 @@ install_dummy_methods (struct target_ops *ops)
ops->to_detach = tdefault_detach;
ops->to_disconnect = tdefault_disconnect;
ops->to_resume = tdefault_resume;
ops->to_commit_resume = tdefault_commit_resume;
ops->to_wait = default_target_wait;
ops->to_fetch_registers = tdefault_fetch_registers;
ops->to_store_registers = tdefault_store_registers;
@ -4570,6 +4595,7 @@ init_debug_target (struct target_ops *ops)
ops->to_detach = debug_detach;
ops->to_disconnect = debug_disconnect;
ops->to_resume = debug_resume;
ops->to_commit_resume = debug_commit_resume;
ops->to_wait = debug_wait;
ops->to_fetch_registers = debug_fetch_registers;
ops->to_store_registers = debug_store_registers;

28
gdb/target.c
View File

@ -2329,6 +2329,34 @@ target_resume (ptid_t ptid, int step, enum gdb_signal signal)
clear_inline_frame_state (ptid);
}
/* If true, target_commit_resume is a nop. */
static int defer_target_commit_resume;
/* See target.h. */
void
target_commit_resume (void)
{
struct target_ops *t;
if (defer_target_commit_resume)
return;
current_target.to_commit_resume (&current_target);
}
/* See target.h. */
struct cleanup *
make_cleanup_defer_target_commit_resume (void)
{
struct cleanup *old_chain;
old_chain = make_cleanup_restore_integer (&defer_target_commit_resume);
defer_target_commit_resume = 1;
return old_chain;
}
void
target_pass_signals (int numsigs, unsigned char *pass_signals)
{

45
gdb/target.h
View File

@ -461,6 +461,8 @@ struct target_ops
int TARGET_DEBUG_PRINTER (target_debug_print_step),
enum gdb_signal)
TARGET_DEFAULT_NORETURN (noprocess ());
void (*to_commit_resume) (struct target_ops *)
TARGET_DEFAULT_IGNORE ();
ptid_t (*to_wait) (struct target_ops *,
ptid_t, struct target_waitstatus *,
int TARGET_DEBUG_PRINTER (target_debug_print_options))
@ -1328,19 +1330,42 @@ extern void target_detach (const char *, int);
extern void target_disconnect (const char *, int);
/* Resume execution of the target process PTID (or a group of
threads). STEP says whether to hardware single-step or to run free;
SIGGNAL is the signal to be given to the target, or GDB_SIGNAL_0 for no
signal. The caller may not pass GDB_SIGNAL_DEFAULT. A specific
PTID means `step/resume only this process id'. A wildcard PTID
(all threads, or all threads of process) means `step/resume
INFERIOR_PTID, and let other threads (for which the wildcard PTID
matches) resume with their 'thread->suspend.stop_signal' signal
(usually GDB_SIGNAL_0) if it is in "pass" state, or with no signal
if in "no pass" state. */
/* Resume execution (or prepare for execution) of a target thread,
process or all processes. STEP says whether to hardware
single-step or to run free; SIGGNAL is the signal to be given to
the target, or GDB_SIGNAL_0 for no signal. The caller may not pass
GDB_SIGNAL_DEFAULT. A specific PTID means `step/resume only this
process id'. A wildcard PTID (all threads, or all threads of
process) means `step/resume INFERIOR_PTID, and let other threads
(for which the wildcard PTID matches) resume with their
'thread->suspend.stop_signal' signal (usually GDB_SIGNAL_0) if it
is in "pass" state, or with no signal if in "no pass" state.
In order to efficiently handle batches of resumption requests,
targets may implement this method such that it records the
resumption request, but defers the actual resumption to the
target_commit_resume method implementation. See
target_commit_resume below. */
extern void target_resume (ptid_t ptid, int step, enum gdb_signal signal);
/* Commit a series of resumption requests previously prepared with
target_resume calls.
GDB always calls target_commit_resume after calling target_resume
one or more times. A target may thus use this method in
coordination with the target_resume method to batch target-side
resumption requests. In that case, the target doesn't actually
resume in its target_resume implementation. Instead, it prepares
the resumption in target_resume, and defers the actual resumption
to target_commit_resume. E.g., the remote target uses this to
coalesce multiple resumption requests in a single vCont packet. */
extern void target_commit_resume ();
/* Setup to defer target_commit_resume calls, and return a cleanup
that reactivates target_commit_resume, if it was previously
active. */
struct cleanup *make_cleanup_defer_target_commit_resume ();
/* For target_read_memory see target/target.h. */
/* The default target_ops::to_wait implementation. */