[PATCH v3 01/29] Remove the "next" field from windows_thread_info

Tom Tromey
2020-03-13T19:08:57Z

This changes windows_thread_info to remove the "next" field, replacing
the linked list of threads with a vector. This is a prerequisite to
sharing this structure with gdbserver, which manages threads
differently.

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

* windows-nat.c (struct windows_thread_info): Remove typedef.
(thread_head): Remove.
(thread_list): New global.
(thread_rec, windows_add_thread, windows_init_thread_list)
(windows_delete_thread, windows_continue): Update.
---
gdb/ChangeLog | 8 ++++++++
gdb/windows-nat.c | 52 +++++++++++++++++++----------------------------
2 files changed, 29 insertions(+), 31 deletions(-)

diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index 614b235edea..8b993912713 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -43,6 +43,7 @@
#include <cygwin/version.h>
#endif
#include <algorithm>
+#include <vector>

#include "filenames.h"
#include "symfile.h"
@@ -245,9 +246,8 @@ static enum gdb_signal last_sig = GDB_SIGNAL_0;

/* Thread information structure used to track information that is
not available in gdb's thread structure. */
-typedef struct windows_thread_info_struct
+struct windows_thread_info
{
- struct windows_thread_info_struct *next;
DWORD id;
HANDLE h;
CORE_ADDR thread_local_base;
@@ -261,10 +261,9 @@ typedef struct windows_thread_info_struct
WOW64_CONTEXT wow64_context;
#endif
};
- }
-windows_thread_info;
+ };

-static windows_thread_info thread_head;
+static std::vector<windows_thread_info *> thread_list;

/* The process and thread handles for the above context. */

@@ -429,9 +428,7 @@ check (BOOL ok, const char *file, int line)
static windows_thread_info *
thread_rec (DWORD id, int get_context)
{
- windows_thread_info *th;
-
- for (th = &thread_head; (th = th->next) != NULL;)
+ for (windows_thread_info *th : thread_list)
if (th->id == id)
{
if (!th->suspended && get_context)
@@ -499,8 +496,7 @@ windows_add_thread (ptid_t ptid, HANDLE h, void *tlb, bool main_thread_p)
if (wow64_process)
th->thread_local_base += 0x2000;
#endif
- th->next = thread_head.next;
- thread_head.next = th;
+ thread_list.push_back (th);

/* Add this new thread to the list of threads.

@@ -554,17 +550,13 @@ windows_add_thread (ptid_t ptid, HANDLE h, void *tlb, bool main_thread_p)
static void
windows_init_thread_list (void)
{
- windows_thread_info *th = &thread_head;
-
DEBUG_EVENTS (("gdb: windows_init_thread_list\n"));
init_thread_list ();
- while (th->next != NULL)
- {
- windows_thread_info *here = th->next;
- th->next = here->next;
- xfree (here);
- }
- thread_head.next = NULL;
+
+ for (windows_thread_info *here : thread_list)
+ xfree (here);
+
+ thread_list.clear ();
}

/* Delete a thread from the list of threads.
@@ -577,7 +569,6 @@ windows_init_thread_list (void)
static void
windows_delete_thread (ptid_t ptid, DWORD exit_code, bool main_thread_p)
{
- windows_thread_info *th;
DWORD id;

gdb_assert (ptid.tid () != 0);
@@ -600,17 +591,17 @@ windows_delete_thread (ptid_t ptid, DWORD exit_code, bool main_thread_p)

delete_thread (find_thread_ptid (&the_windows_nat_target, ptid));

- for (th = &thread_head;
- th->next != NULL && th->next->id != id;
- th = th->next)
- continue;
+ auto iter = std::find_if (thread_list.begin (), thread_list.end (),
+ [=] (windows_thread_info *th)
+ {
+ return th->id == id;
+ });

- if (th->next != NULL)
+ if (iter != thread_list.end ())
{
- windows_thread_info *here = th->next;
- th->next = here->next;
- xfree (here->name);
- xfree (here);
+ xfree ((*iter)->name);
+ xfree (*iter);
+ thread_list.erase (iter);
}
}

@@ -1477,7 +1468,6 @@ handle_exception (struct target_waitstatus *ourstatus)
static BOOL
windows_continue (DWORD continue_status, int id, int killed)
{
- windows_thread_info *th;
BOOL res;

DEBUG_EVENTS (("ContinueDebugEvent (cpid=%d, ctid=0x%x, %s);\n",
@@ -1486,7 +1476,7 @@ windows_continue (DWORD continue_status, int id, int killed)
continue_status == DBG_CONTINUE ?
"DBG_CONTINUE" : "DBG_EXCEPTION_NOT_HANDLED"));

- for (th = &thread_head; (th = th->next) != NULL;)
+ for (windows_thread_info *th : thread_list)
if ((id == -1 || id == (int) th->id)
&& th->suspended)
{
--
2.21.1