[newlib-cygwin] Cygwin: timerfd: implement TFD_TIMER_CANCEL_ON_SET
Corinna Vinschen
corinna@sourceware.org
Sun Jan 20 21:49:00 GMT 2019
https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=2993057a94fa0f3954c327d8430943c7f71642ba
commit 2993057a94fa0f3954c327d8430943c7f71642ba
Author: Corinna Vinschen <corinna@vinschen.de>
Date: Sun Jan 20 22:47:52 2019 +0100
Cygwin: timerfd: implement TFD_TIMER_CANCEL_ON_SET
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Diff:
---
winsup/cygwin/autoload.cc | 2 ++
winsup/cygwin/timerfd.cc | 90 +++++++++++++++++++++++++++++++++++++++++++++--
winsup/cygwin/timerfd.h | 28 ++++++++++-----
3 files changed, 109 insertions(+), 11 deletions(-)
diff --git a/winsup/cygwin/autoload.cc b/winsup/cygwin/autoload.cc
index 7978287..b4dc773 100644
--- a/winsup/cygwin/autoload.cc
+++ b/winsup/cygwin/autoload.cc
@@ -663,6 +663,7 @@ LoadDLLfunc (CreateDesktopW, 24, user32)
LoadDLLfunc (CreateWindowExW, 48, user32)
LoadDLLfunc (CreateWindowStationW, 16, user32)
LoadDLLfunc (DefWindowProcW, 16, user32)
+LoadDLLfunc (DestroyWindow, 4, user32)
LoadDLLfunc (DispatchMessageW, 4, user32)
LoadDLLfunc (EmptyClipboard, 0, user32)
LoadDLLfunc (EnumWindows, 8, user32)
@@ -690,6 +691,7 @@ LoadDLLfunc (SetClipboardData, 8, user32)
LoadDLLfunc (SetParent, 8, user32)
LoadDLLfunc (SetProcessWindowStation, 4, user32)
LoadDLLfunc (SetThreadDesktop, 4, user32)
+LoadDLLfunc (UnregisterClassW, 8, user32)
LoadDLLfuncEx (CreateEnvironmentBlock, 12, userenv, 1)
LoadDLLfuncEx2 (CreateProfile, 16, userenv, 1, 1)
diff --git a/winsup/cygwin/timerfd.cc b/winsup/cygwin/timerfd.cc
index dbb63e6..cebb002 100644
--- a/winsup/cygwin/timerfd.cc
+++ b/winsup/cygwin/timerfd.cc
@@ -16,6 +16,70 @@ details. */
#include <sys/timerfd.h>
#include "timerfd.h"
+#define TFD_CANCEL_FLAGS (TFD_TIMER_ABSTIME | TFD_TIMER_CANCEL_ON_SET)
+
+/* Unfortunately MsgWaitForMultipleObjectsEx does not receive WM_TIMECHANGED
+ messages without a window defined in this process. Create a hidden window
+ for that purpose. */
+
+void
+timerfd_tracker::create_timechange_window ()
+{
+ WNDCLASSW wclass = { 0 };
+ WCHAR cname[NAME_MAX];
+
+ __small_swprintf (cname, L"Cygwin.timerfd.%u", winpid);
+ wclass.lpfnWndProc = DefWindowProcW;
+ wclass.hInstance = GetModuleHandle (NULL);
+ wclass.hbrBackground = (HBRUSH) (COLOR_WINDOW + 1);
+ wclass.lpszClassName = cname;
+ atom = RegisterClassW (&wclass);
+ if (!atom)
+ debug_printf ("RegisterClass %E");
+ else
+ {
+ window = CreateWindowExW (0, cname, cname, WS_POPUP, 0, 0, 0, 0,
+ NULL, NULL, NULL, NULL);
+ if (!window)
+ debug_printf ("RegisterClass %E");
+ }
+}
+
+void
+timerfd_tracker::delete_timechange_window ()
+{
+ if (window)
+ DestroyWindow (window);
+ if (atom)
+ UnregisterClassW ((LPWSTR) (uintptr_t) atom, GetModuleHandle (NULL));
+}
+
+void
+timerfd_tracker::handle_timechange_window ()
+{
+ MSG msg;
+
+ if (PeekMessageW(&msg, NULL, 0, 0, PM_REMOVE) && msg.message != WM_QUIT)
+ {
+ DispatchMessageW(&msg);
+ if (msg.message == WM_TIMECHANGE
+ && get_clockid () == CLOCK_REALTIME
+ && (flags () & TFD_CANCEL_FLAGS) == TFD_CANCEL_FLAGS
+ && enter_critical_section ())
+ {
+ /* make sure to handle each WM_TIMECHANGE only once! */
+ if (msg.time != tc_time ())
+ {
+ set_overrun_count (-1LL);
+ disarm_timer ();
+ timer_expired ();
+ set_tc_time (msg.time);
+ }
+ leave_critical_section ();
+ }
+ }
+}
+
DWORD
timerfd_tracker::thread_func ()
{
@@ -23,14 +87,19 @@ timerfd_tracker::thread_func ()
HANDLE armed[2] = { tfd_shared->arm_evt (),
cancel_evt };
+ create_timechange_window ();
while (1)
{
- switch (WaitForMultipleObjects (2, armed, FALSE, INFINITE))
+ switch (MsgWaitForMultipleObjectsEx (2, armed, INFINITE, QS_POSTMESSAGE,
+ MWMO_INPUTAVAILABLE))
{
case WAIT_OBJECT_0:
break;
case WAIT_OBJECT_0 + 1:
goto canceled;
+ case WAIT_OBJECT_0 + 2:
+ handle_timechange_window ();
+ continue;
default:
continue;
}
@@ -40,9 +109,12 @@ timerfd_tracker::thread_func ()
HANDLE expired[3] = { tfd_shared->timer (),
tfd_shared->disarm_evt (),
cancel_evt };
+
while (1)
{
- switch (WaitForMultipleObjects (3, expired, FALSE, INFINITE))
+ switch (MsgWaitForMultipleObjectsEx (3, expired, INFINITE,
+ QS_POSTMESSAGE,
+ MWMO_INPUTAVAILABLE))
{
case WAIT_OBJECT_0:
break;
@@ -50,12 +122,23 @@ timerfd_tracker::thread_func ()
goto disarmed;
case WAIT_OBJECT_0 + 2:
goto canceled;
+ case WAIT_OBJECT_0 + 3:
+ handle_timechange_window ();
+ continue;
default:
continue;
}
if (!enter_critical_section ())
continue;
+ /* Make sure we haven't been abandoned and/or disarmed
+ in the meantime */
+ if (overrun_count () == -1LL
+ || IsEventSignalled (tfd_shared->disarm_evt ()))
+ {
+ leave_critical_section ();
+ goto disarmed;
+ }
/* One-shot timer? */
if (!get_interval ())
{
@@ -93,7 +176,7 @@ timerfd_tracker::thread_func ()
NtSetTimer (tfd_shared->timer (), &DueTime, NULL, NULL,
Resume, 0, NULL);
}
- }
+ }
/* Arm the expiry object */
timer_expired ();
leave_critical_section ();
@@ -103,6 +186,7 @@ disarmed:
}
canceled:
+ delete_timechange_window ();
_my_tls._ctinfo->auto_release (); /* automatically return the cygthread to the cygthread pool */
return 0;
}
diff --git a/winsup/cygwin/timerfd.h b/winsup/cygwin/timerfd.h
index 543fad1..cebd1d9 100644
--- a/winsup/cygwin/timerfd.h
+++ b/winsup/cygwin/timerfd.h
@@ -31,6 +31,7 @@ class timerfd_shared
LONG64 _interval; /* timer interval in 100ns */
LONG64 _overrun_count; /* expiry counter */
int _flags; /* settime flags */
+ DWORD _tc_time; /* timestamp of the last WM_TIMECHANGE msg */
int create (clockid_t);
bool dtor ();
@@ -43,7 +44,8 @@ class timerfd_shared
LONG64 get_clock_now () const { return get_clock (_clockid)->n100secs (); }
struct itimerspec &time_spec () { return _time_spec; }
int flags () const { return _flags; }
- LONG64 overrun_count () const { return _overrun_count; }
+
+ /* write access methods */
void increment_overrun_count (LONG64 add)
{ InterlockedAdd64 (&_overrun_count, add); }
void set_overrun_count (LONG64 newval)
@@ -55,8 +57,6 @@ class timerfd_shared
ResetEvent (_expired_evt);
return ret;
}
-
- /* write access methods */
bool enter_cs ()
{
return (WaitForSingleObject (_access_mtx, INFINITE) & ~WAIT_ABANDONED_0)
@@ -73,7 +73,7 @@ class timerfd_shared
memset (&_time_spec, 0, sizeof _time_spec);
_exp_ts = 0;
_interval = 0;
- _flags = 0;
+ /* _flags = 0; DON'T DO THAT. Required for TFD_TIMER_CANCEL_ON_SET */
NtCancelTimer (timer (), NULL);
SetEvent (_disarm_evt);
return 0;
@@ -86,8 +86,6 @@ class timerfd_shared
class timerfd_tracker /* cygheap! */
{
- DWORD winpid; /* This is used @ fork/exec time to know if
- this tracker already has been fixed up. */
HANDLE tfd_shared_hdl; /* handle auf shared mem */
timerfd_shared *tfd_shared; /* pointer auf shared mem, needs
NtMapViewOfSection in each new process. */
@@ -96,6 +94,14 @@ class timerfd_tracker /* cygheap! */
HANDLE sync_thr; /* cygthread sync object. */
LONG local_instance_count; /* each open fd increments this.
If 0 -> cancel thread. */
+ DWORD winpid; /* This is used @ fork/exec time to know if
+ this tracker already has been fixed up. */
+ HWND window; /* window handle */
+ ATOM atom; /* window class */
+
+ void create_timechange_window ();
+ void delete_timechange_window ();
+ void handle_timechange_window ();
bool dtor ();
@@ -107,9 +113,10 @@ class timerfd_tracker /* cygheap! */
int disarm_timer () const { return tfd_shared->disarm_timer (); }
void timer_expired () const { tfd_shared->timer_expired (); }
+ LONG64 overrun_count () const { return tfd_shared->_overrun_count; }
void increment_overrun_count (LONG64 add) const
{ tfd_shared->increment_overrun_count (add); }
- void set_overrun_count (uint64_t ov_cnt) const
+ void set_overrun_count (LONG64 ov_cnt) const
{ tfd_shared->set_overrun_count ((LONG64) ov_cnt); }
LONG64 read_and_reset_overrun_count () const
{ return tfd_shared->read_and_reset_overrun_count (); }
@@ -119,9 +126,13 @@ class timerfd_tracker /* cygheap! */
struct timespec it_interval () const
{ return tfd_shared->time_spec ().it_interval; }
+ clock_t get_clockid () const { return tfd_shared->_clockid; }
LONG64 get_clock_now () const { return tfd_shared->get_clock_now (); }
LONG64 get_exp_ts () const { return tfd_shared->_exp_ts; }
LONG64 get_interval () const { return tfd_shared->_interval; }
+ int flags () const { return tfd_shared->flags (); }
+ DWORD tc_time () const { return tfd_shared->_tc_time; }
+ void set_tc_time (DWORD new_time) { tfd_shared->_tc_time = new_time; }
void set_exp_ts (LONG64 ts) const { tfd_shared->set_exp_ts (ts); }
@@ -129,7 +140,8 @@ class timerfd_tracker /* cygheap! */
void *operator new (size_t, void *p) __attribute__ ((nothrow)) {return p;}
timerfd_tracker ()
: tfd_shared_hdl (NULL), tfd_shared (NULL), cancel_evt (NULL),
- sync_thr (NULL), local_instance_count (1) {}
+ sync_thr (NULL), local_instance_count (1), winpid (0), window (NULL),
+ atom (0) {}
int create (clockid_t);
int gettime (struct itimerspec *);
int settime (int, const struct itimerspec *, struct itimerspec *);
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