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Merge branch 'sverker/unsafe_CancelIoEx/OTP-8937' into dev
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* sverker/unsafe_CancelIoEx/OTP-8937:
  Remove use of unreliable CancelIoEx on Windows.
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@sverker
sverker committed Nov 26, 2010
2 parents 8339345 + c5b7477 commit e643069
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Showing 3 changed files with 105 additions and 41 deletions.
116 changes: 80 additions & 36 deletions erts/emulator/sys/win32/sys.c
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Original file line number Diff line number Diff line change
Expand Up @@ -97,7 +97,7 @@ static int driver_write(long, HANDLE, byte*, int);
static void common_stop(int);
static int create_file_thread(struct async_io* aio, int mode);
#ifdef ERTS_SMP
static void close_active_handles(ErlDrvPort, const HANDLE* handles, int cnt);
static void close_active_handle(ErlDrvPort, HANDLE handle);
static DWORD WINAPI threaded_handle_closer(LPVOID param);
#endif
static DWORD WINAPI threaded_reader(LPVOID param);
Expand Down Expand Up @@ -137,7 +137,11 @@ static BOOL win_console = FALSE;

static OSVERSIONINFO int_os_version; /* Version information for Win32. */

#ifdef ERTS_SMP
/*#define USE_CANCELIOEX
Disabled the use of CancelIoEx as its been seen to cause problem with some
drivers. Not sure what to blame; faulty drivers or some form of invalid use.
*/
#if defined(ERTS_SMP) && defined(USE_CANCELIOEX)
static BOOL (WINAPI *fpCancelIoEx)(HANDLE,LPOVERLAPPED);
#endif

Expand Down Expand Up @@ -684,6 +688,7 @@ release_driver_data(DriverData* dp)
erts_smp_mtx_lock(&sys_driver_data_lock);

#ifdef ERTS_SMP
#ifdef USE_CANCELIOEX
if (fpCancelIoEx != NULL) {
if (dp->in.thread == (HANDLE) -1 && dp->in.fd != INVALID_HANDLE_VALUE) {
(*fpCancelIoEx)(dp->in.fd, NULL);
Expand All @@ -692,10 +697,12 @@ release_driver_data(DriverData* dp)
(*fpCancelIoEx)(dp->out.fd, NULL);
}
}
else {
else
#endif
{
/* This is a workaround for the fact that CancelIo cant cancel
requests issued by another thread and that we cant use
CancelIoEx as that's only availabele in Vista etc.
CancelIoEx as that's only available in Vista etc.
R14: Avoid scheduler deadlock by only wait for 10ms, and then spawn
a thread that will keep waiting in in order to close handles. */
HANDLE handles[2];
Expand All @@ -706,7 +713,7 @@ release_driver_data(DriverData* dp)
dp->in.fd = INVALID_HANDLE_VALUE;
DEBUGF(("Waiting for the in event thingie"));
if (WaitForSingleObject(dp->in.ov.hEvent,timeout) == WAIT_TIMEOUT) {
handles[i++] = dp->in.ov.hEvent;
close_active_handle(dp->port_num, dp->in.ov.hEvent);
dp->in.ov.hEvent = NULL;
timeout = 0;
}
Expand All @@ -717,14 +724,11 @@ release_driver_data(DriverData* dp)
dp->out.fd = INVALID_HANDLE_VALUE;
DEBUGF(("Waiting for the out event thingie"));
if (WaitForSingleObject(dp->out.ov.hEvent,timeout) == WAIT_TIMEOUT) {
handles[i++] = dp->out.ov.hEvent;
close_active_handle(dp->port_num, dp->out.ov.hEvent);
dp->out.ov.hEvent = NULL;
}
DEBUGF(("...done\n"));
}
if (i > 0) {
close_active_handles(dp->port_num, handles, i);
}
}
#else
if (dp->in.thread == (HANDLE) -1 && dp->in.fd != INVALID_HANDLE_VALUE) {
Expand Down Expand Up @@ -772,42 +776,82 @@ release_driver_data(DriverData* dp)

#ifdef ERTS_SMP

struct handles_to_be_closed
{
int cnt;
HANDLE handles[2];
struct handles_to_be_closed {
HANDLE handles[MAXIMUM_WAIT_OBJECTS];
unsigned cnt;
};
static struct handles_to_be_closed* htbc_curr = NULL;
CRITICAL_SECTION htbc_lock;

static void close_active_handles(ErlDrvPort port_num, const HANDLE* handles, int cnt)
static void close_active_handle(ErlDrvPort port_num, HANDLE handle)
{
DWORD tid;
HANDLE thread;
struct handles_to_be_closed* htbc;
int i;
struct handles_to_be_closed* htbc = erts_alloc(ERTS_ALC_T_DRV_TAB,
sizeof(struct handles_to_be_closed));
htbc->cnt = cnt;
for (i=0; i < cnt; ++i) {
htbc->handles[i] = handles[i];
(void) driver_select(port_num, (ErlDrvEvent)handles[i],
ERL_DRV_USE_NO_CALLBACK, 0);
EnterCriticalSection(&htbc_lock);
htbc = htbc_curr;
if (htbc == NULL || htbc->cnt >= MAXIMUM_WAIT_OBJECTS) {
DWORD tid;
HANDLE thread;

htbc = (struct handles_to_be_closed*) erts_alloc(ERTS_ALC_T_DRV_TAB,
sizeof(*htbc));
htbc->handles[0] = CreateAutoEvent(FALSE);
htbc->cnt = 1;
thread = (HANDLE *) _beginthreadex(NULL, 0, threaded_handle_closer, htbc, 0, &tid);
CloseHandle(thread);
}
thread = (HANDLE *) _beginthreadex(NULL, 0, threaded_handle_closer, htbc, 0, &tid);
CloseHandle(thread);
htbc->handles[htbc->cnt++] = handle;
driver_select(port_num, (ErlDrvEvent)handle, ERL_DRV_USE_NO_CALLBACK, 0);
SetEvent(htbc->handles[0]);
htbc_curr = htbc;
LeaveCriticalSection(&htbc_lock);
}


static DWORD WINAPI
threaded_handle_closer(LPVOID param)
{
struct handles_to_be_closed* htbc = (struct handles_to_be_closed*) param;
int i;
DEBUGF(("threaded_handle_closer waiting for %d handles\r\n",htbc->cnt));
WaitForMultipleObjects(htbc->cnt, htbc->handles, TRUE, INFINITE);
for (i=0; i < htbc->cnt; ++i) {
CloseHandle(htbc->handles[i]);
unsigned ix;
DWORD res;
DEBUGF(("threaded_handle_closer %p started\r\n", htbc));
EnterCriticalSection(&htbc_lock);
for (;;) {
{
HANDLE* handles = htbc->handles;
unsigned cnt = htbc->cnt;
DWORD timeout = (htbc == htbc_curr) ? INFINITE : 10*1000;

LeaveCriticalSection(&htbc_lock);
DEBUGF(("threaded_handle_closer %p waiting for %d handles\r\n", htbc, cnt));
res = WaitForMultipleObjects(cnt, handles, FALSE, timeout);
}
EnterCriticalSection(&htbc_lock);
switch (res) {
case WAIT_OBJECT_0:
case WAIT_TIMEOUT:
break; /* got some more handles to wait for maybe */
default:
ix = res - WAIT_OBJECT_0;
if (ix > 0 && ix < htbc->cnt) {
CloseHandle(htbc->handles[ix]);
htbc->handles[ix] = htbc->handles[--htbc->cnt];
}
}
if (htbc != htbc_curr) {
if (htbc->cnt == 1) { /* no real handles left */
break;
}
/* The thread with most free slots will be "current" */
if (htbc->cnt < htbc_curr->cnt) {
htbc_curr = htbc;
DEBUGF(("threaded_handle_closer %p made current\r\n", htbc));
}
}
}
LeaveCriticalSection(&htbc_lock);
CloseHandle(htbc->handles[0]);
erts_free(ERTS_ALC_T_DRV_TAB, htbc);
DEBUGF(("threaded_handle_closer terminating\r\n"));
DEBUGF(("threaded_handle_closer %p terminating\r\n", htbc));
return 0;
}
#endif /* ERTS_SMP */
Expand Down Expand Up @@ -1101,11 +1145,10 @@ static int
spawn_init()
{
int i;
#ifdef ERTS_SMP
#if defined(ERTS_SMP) && defined(USE_CANCELIOEX)
HMODULE module = GetModuleHandle("kernel32");
fpCancelIoEx = (module != NULL) ?
(BOOL (WINAPI *)(HANDLE,LPOVERLAPPED))
GetProcAddress(module,"CancelIoEx") : NULL;
fpCancelIoEx = (BOOL (WINAPI *)(HANDLE,LPOVERLAPPED))
((module != NULL) ? GetProcAddress(module,"CancelIoEx") : NULL);
DEBUGF(("fpCancelIoEx = %p\r\n", fpCancelIoEx));
#endif
driver_data = (struct driver_data *)
Expand Down Expand Up @@ -3068,6 +3111,7 @@ void erl_sys_init(void)

#ifdef ERTS_SMP
erts_smp_tsd_key_create(&win32_errstr_key);
InitializeCriticalSection(&htbc_lock);
#endif
erts_smp_atomic_init(&pipe_creation_counter,0);
/*
Expand Down
24 changes: 22 additions & 2 deletions erts/emulator/test/port_SUITE.erl
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Original file line number Diff line number Diff line change
Expand Up @@ -2308,8 +2308,28 @@ close_deaf_port(Config) when is_list(Config) ->
?line Dog = test_server:timetrap(test_server:seconds(100)),
?line DataDir = ?config(data_dir, Config),
?line DeadPort = os:find_executable("dead_port", DataDir),

?line Port = open_port({spawn,DeadPort++" 60"},[]),
?line erlang:port_command(Port,"Hello, can you hear me!?!?"),
?line port_close(Port),
ok.

close_deaf_port_1(0, DeadPort).

close_deaf_port_1(1000, _) ->
ok;
close_deaf_port_1(N, Cmd) ->
Timeout = integer_to_list(random:uniform(10*1000)),
try open_port({spawn,Cmd++" "++Timeout},[]) of
Port ->
?line erlang:port_command(Port,"Hello, can you hear me!?!?"),
?line port_close(Port),
close_deaf_port_1(N+1, Cmd)
catch
exit:eagain ->
{comment, "Could not spawn more than " ++ integer_to_list(N) ++ " OS processes."}
end.


repeat(0, _) -> ok;
repeat(Cnt, Fun) ->
Fun(),
repeat(Cnt-1, Fun).
6 changes: 3 additions & 3 deletions erts/emulator/test/port_SUITE_data/dead_port.c
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Original file line number Diff line number Diff line change
Expand Up @@ -72,14 +72,14 @@ char *argv[];
{
int x;
if (argc < 2) {
fprintf(stderr,"Usage %s <seconds>\n",argv[0]);
fprintf(stderr,"Usage %s <milliseconds>\n",argv[0]);
return 1;
}
if ((x = atoi(argv[1])) <= 0) {
fprintf(stderr,"Usage %s <seconds>\n",argv[0]);
fprintf(stderr,"Usage %s <milliseconds>\n",argv[0]);
return 1;
}
delay(x*1000);
delay(x);
return 0;
}

Expand Down

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