[PATCH v3 23/29] Introduce fetch_pending_stop

Tom Tromey
2020-03-13T19:09:04Z

This introduces a new "fetch_pending_stop" function and changes gdb to
use it. This function removes the first matching pending stop from
the list of such stops.

gdb/ChangeLog
2020-03-13 Tom Tromey <tromey@adacore.com>

* windows-nat.c (get_windows_debug_event): Use
fetch_pending_stop.
* nat/windows-nat.h (fetch_pending_stop): Declare.
* nat/windows-nat.c (fetch_pending_stop): New function.
---
gdb/ChangeLog | 7 +++++++
gdb/nat/windows-nat.c | 28 ++++++++++++++++++++++++++++
gdb/nat/windows-nat.h | 7 +++++++
gdb/windows-nat.c | 29 +++++++++--------------------
4 files changed, 51 insertions(+), 20 deletions(-)

diff --git a/gdb/nat/windows-nat.c b/gdb/nat/windows-nat.c
index 2c2454b6f6f..823471eb4da 100644
--- a/gdb/nat/windows-nat.c
+++ b/gdb/nat/windows-nat.c
@@ -343,6 +343,34 @@ matching_pending_stop (bool debug_events)

/* See nat/windows-nat.h. */

+gdb::optional<pending_stop>
+fetch_pending_stop (bool debug_events)
+{
+ gdb::optional<pending_stop> result;
+ for (auto iter = pending_stops.begin ();
+ iter != pending_stops.end ();
+ ++iter)
+ {
+ if (desired_stop_thread_id == -1
+ || desired_stop_thread_id == iter->thread_id)
+ {
+ result = *iter;
+ current_event = iter->event;
+
+ DEBUG_EVENTS (("get_windows_debug_event - "
+ "pending stop found in 0x%x (desired=0x%x)\n",
+ iter->thread_id, desired_stop_thread_id));
+
+ pending_stops.erase (iter);
+ break;
+ }
+ }
+
+ return result;
+}
+
+/* See nat/windows-nat.h. */
+
BOOL
continue_last_debug_event (DWORD continue_status, bool debug_events)
{
diff --git a/gdb/nat/windows-nat.h b/gdb/nat/windows-nat.h
index 0e9316577ba..68b72d4bbd2 100644
--- a/gdb/nat/windows-nat.h
+++ b/gdb/nat/windows-nat.h
@@ -22,6 +22,7 @@
#include <windows.h>
#include <vector>

+#include "gdbsupport/gdb_optional.h"
#include "target/waitstatus.h"

namespace windows_nat
@@ -231,6 +232,12 @@ extern handle_exception_result handle_exception

extern bool matching_pending_stop (bool debug_events);

+/* See if a pending stop matches DESIRED_STOP_THREAD_ID. If so,
+ remove it from the list of pending stops, set 'current_event', and
+ return it. Otherwise, return an empty optional. */
+
+extern gdb::optional<pending_stop> fetch_pending_stop (bool debug_events);
+
/* A simple wrapper for ContinueDebugEvent that continues the last
waited-for event. If DEBUG_EVENTS is true, logging will be
enabled. */
diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index 67655dc46e4..9a1dd49a42b 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -1522,29 +1522,18 @@ windows_nat_target::get_windows_debug_event (int pid,
/* If there is a relevant pending stop, report it now. See the
comment by the definition of "pending_stops" for details on why
this is needed. */
- for (auto iter = pending_stops.begin ();
- iter != pending_stops.end ();
- ++iter)
+ gdb::optional<pending_stop> stop = fetch_pending_stop (debug_events);
+ if (stop.has_value ())
{
- if (desired_stop_thread_id == -1
- || desired_stop_thread_id == iter->thread_id)
- {
- thread_id = iter->thread_id;
- *ourstatus = iter->status;
- current_event = iter->event;
-
- inferior_ptid = ptid_t (current_event.dwProcessId, thread_id, 0);
- current_windows_thread = thread_rec (inferior_ptid,
- INVALIDATE_CONTEXT);
- current_windows_thread->reload_context = 1;
+ thread_id = stop->thread_id;
+ *ourstatus = stop->status;

- DEBUG_EVENTS (("get_windows_debug_event - "
- "pending stop found in 0x%x (desired=0x%x)\n",
- thread_id, desired_stop_thread_id));
+ inferior_ptid = ptid_t (current_event.dwProcessId, thread_id, 0);
+ current_windows_thread = thread_rec (inferior_ptid,
+ INVALIDATE_CONTEXT);
+ current_windows_thread->reload_context = 1;

- pending_stops.erase (iter);
- return thread_id;
- }
+ return thread_id;
}

last_sig = GDB_SIGNAL_0;
--
2.21.1