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/* Abstract base class inherited by all process_stratum targets
Copyright (C) 2018-2021 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef PROCESS_STRATUM_TARGET_H
#define PROCESS_STRATUM_TARGET_H
#include "target.h"
#include <set>
#include "gdbsupport/intrusive_list.h"
#include "gdbthread.h"
/* Abstract base class inherited by all process_stratum targets. */
class process_stratum_target : public target_ops
{
public:
~process_stratum_target () override = 0;
strata stratum () const final override { return process_stratum; }
/* Return a string representation of this target's open connection.
This string is used to distinguish different instances of a given
target type. For example, when remote debugging, the target is
called "remote", but since we may have more than one remote
target open, connection_string() returns the connection serial
connection name, e.g., "localhost:10001", "192.168.0.1:20000",
etc. This string is shown in several places, e.g., in "info
connections" and "info inferiors". */
virtual const char *connection_string () { return nullptr; }
/* We must default these because they must be implemented by any
target that can run. */
bool can_async_p () override { return false; }
bool supports_non_stop () override { return false; }
bool supports_disable_randomization () override { return false; }
/* This default implementation returns the inferior's address
space. */
struct address_space *thread_address_space (ptid_t ptid) override;
/* This default implementation always returns target_gdbarch (). */
struct gdbarch *thread_architecture (ptid_t ptid) override;
/* Default implementations for process_stratum targets. Return true
if there's a selected inferior, false otherwise. */
bool has_all_memory () override;
bool has_memory () override;
bool has_stack () override;
bool has_registers () override;
bool has_execution (inferior *inf) override;
/* Default implementation of follow_exec.
If the current inferior and FOLLOW_INF are different (execution continues
in a new inferior), push this process target to FOLLOW_INF's target stack
and add an initial thread to FOLLOW_INF. */
void follow_exec (inferior *follow_inf, ptid_t ptid,
const char *execd_pathname) override;
/* Default implementation of follow_fork.
If a child inferior was created by infrun while following the fork
(CHILD_INF is non-nullptr), push this target on CHILD_INF's target stack
and add an initial thread with ptid CHILD_PTID. */
void follow_fork (inferior *child_inf, ptid_t child_ptid,
target_waitkind fork_kind, bool follow_child,
bool detach_on_fork) override;
/* True if any thread is, or may be executing. We need to track
this separately because until we fully sync the thread list, we
won't know whether the target is fully stopped, even if we see
stop events for all known threads, because any of those threads
may have spawned new threads we haven't heard of yet. */
bool threads_executing = false;
/* If THREAD is resumed and has a pending wait status, add it to the
target's "resumed with pending wait status" list. */
void maybe_add_resumed_with_pending_wait_status (thread_info *thread);
/* If THREAD is resumed and has a pending wait status, remove it from the
target's "resumed with pending wait status" list. */
void maybe_remove_resumed_with_pending_wait_status (thread_info *thread);
/* Return true if this target has at least one resumed thread with a pending
wait status. */
bool has_resumed_with_pending_wait_status () const
{ return !m_resumed_with_pending_wait_status.empty (); }
/* Return a random resumed thread with pending wait status belonging to INF
and matching FILTER_PTID. */
thread_info *random_resumed_with_pending_wait_status
(inferior *inf, ptid_t filter_ptid);
/* The connection number. Visible in "info connections". */
int connection_number = 0;
/* Whether resumed threads must be committed to the target.
When true, resumed threads must be committed to the execution
target.
When false, the target may leave resumed threads stopped when
it's convenient or efficient to do so. When the core requires
resumed threads to be committed again, this is set back to true
and calls the `commit_resumed` method to allow the target to do
so.
To simplify the implementation of targets, the following methods
are guaranteed to be called with COMMIT_RESUMED_STATE set to
false:
- resume
- stop
- wait
Knowing this, the target doesn't need to implement different
behaviors depending on the COMMIT_RESUMED_STATE, and can simply
assume that it is false.
Targets can take advantage of this to batch resumption requests,
for example. In that case, the target doesn't actually resume in
its `resume` implementation. Instead, it takes note of the
resumption intent in `resume` and defers the actual resumption to
`commit_resumed`. For example, the remote target uses this to
coalesce multiple resumption requests in a single vCont
packet. */
bool commit_resumed_state = false;
private:
/* List of threads managed by this target which simultaneously are resumed
and have a pending wait status.
This is done for optimization reasons, it would be possible to walk the
inferior thread lists to find these threads. But since this is something
we need to do quite frequently in the hot path, maintaining this list
avoids walking the thread lists repeatedly. */
thread_info_resumed_with_pending_wait_status_list
m_resumed_with_pending_wait_status;
};
/* Downcast TARGET to process_stratum_target. */
static inline process_stratum_target *
as_process_stratum_target (target_ops *target)
{
gdb_assert (target->stratum () == process_stratum);
return static_cast<process_stratum_target *> (target);
}
/* Return a collection of targets that have non-exited inferiors. */
extern std::set<process_stratum_target *> all_non_exited_process_targets ();
/* Switch to the first inferior (and program space) of TARGET, and
switch to no thread selected. */
extern void switch_to_target_no_thread (process_stratum_target *target);
#endif /* !defined (PROCESS_STRATUM_TARGET_H) */