mirror of
https://gitlab.gnome.org/GNOME/glib.git
synced 2024-11-10 11:26:16 +01:00
win32 gpoll: overcome the 64 handles limit
This is a new polling method allowing to poll more than 64 handles based on the glib one. When we reach the limit of 64 we create a thread and we poll on that thread for a batch of handles this way we overcome the limit. https://gitlab.gnome.org/GNOME/glib/issues/1071
This commit is contained in:
Ignacio Casal Quinteiro
parent
0d2f7074ea
commit
24714b50df
280
glib/gpoll.c
280
glib/gpoll.c
@ -72,6 +72,7 @@
|
||||
#ifdef G_OS_WIN32
|
||||
#define STRICT
|
||||
#include <windows.h>
|
||||
#include <process.h>
|
||||
#endif /* G_OS_WIN32 */
|
||||
|
||||
#include "gpoll.h"
|
||||
@ -130,6 +131,7 @@ g_poll (GPollFD *fds,
|
||||
|
||||
static int
|
||||
poll_rest (GPollFD *msg_fd,
|
||||
GPollFD *stop_fd,
|
||||
HANDLE *handles,
|
||||
GPollFD *handle_to_fd[],
|
||||
gint nhandles,
|
||||
@ -211,113 +213,279 @@ poll_rest (GPollFD *msg_fd,
|
||||
/* If no timeout and handles to poll, recurse to poll them,
|
||||
* too.
|
||||
*/
|
||||
recursed_result = poll_rest (NULL, handles, handle_to_fd, nhandles, 0);
|
||||
recursed_result = poll_rest (NULL, stop_fd, handles, handle_to_fd, nhandles, 0);
|
||||
return (recursed_result == -1) ? -1 : 1 + recursed_result;
|
||||
}
|
||||
else if (ready >= WAIT_OBJECT_0 && ready < WAIT_OBJECT_0 + nhandles)
|
||||
{
|
||||
int retval;
|
||||
|
||||
f = handle_to_fd[ready - WAIT_OBJECT_0];
|
||||
f->revents = f->events;
|
||||
if (_g_main_poll_debug)
|
||||
g_print (" got event %p\n", (HANDLE) f->fd);
|
||||
|
||||
/* Do not count the stop_fd */
|
||||
retval = (f != stop_fd) ? 1 : 0;
|
||||
|
||||
/* If no timeout and polling several handles, recurse to poll
|
||||
* the rest of them.
|
||||
*/
|
||||
if (timeout_ms == 0 && nhandles > 1)
|
||||
{
|
||||
/* Poll the handles with index > ready */
|
||||
HANDLE *shorter_handles;
|
||||
{
|
||||
/* Poll the handles with index > ready */
|
||||
HANDLE *shorter_handles;
|
||||
GPollFD **shorter_handle_to_fd;
|
||||
gint shorter_nhandles;
|
||||
gint shorter_nhandles;
|
||||
|
||||
shorter_handles = &handles[ready - WAIT_OBJECT_0 + 1];
|
||||
shorter_handle_to_fd = &handle_to_fd[ready - WAIT_OBJECT_0 + 1];
|
||||
shorter_nhandles = nhandles - (ready - WAIT_OBJECT_0 + 1);
|
||||
|
||||
recursed_result = poll_rest (NULL, shorter_handles, shorter_handle_to_fd, shorter_nhandles, 0);
|
||||
return (recursed_result == -1) ? -1 : 1 + recursed_result;
|
||||
}
|
||||
return 1;
|
||||
recursed_result = poll_rest (NULL, stop_fd, shorter_handles, shorter_handle_to_fd, shorter_nhandles, 0);
|
||||
return (recursed_result == -1) ? -1 : retval + recursed_result;
|
||||
}
|
||||
return retval;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
gint
|
||||
g_poll (GPollFD *fds,
|
||||
guint nfds,
|
||||
gint timeout)
|
||||
typedef struct
|
||||
{
|
||||
HANDLE handles[MAXIMUM_WAIT_OBJECTS];
|
||||
GPollFD *handle_to_fd[MAXIMUM_WAIT_OBJECTS];
|
||||
GPollFD *msg_fd = NULL;
|
||||
GPollFD *f;
|
||||
gint nhandles = 0;
|
||||
GPollFD *msg_fd;
|
||||
GPollFD *stop_fd;
|
||||
gint nhandles;
|
||||
gint timeout_ms;
|
||||
} GWin32PollThreadData;
|
||||
|
||||
static gint
|
||||
poll_single_thread (GWin32PollThreadData *data)
|
||||
{
|
||||
int retval;
|
||||
|
||||
if (_g_main_poll_debug)
|
||||
g_print ("g_poll: waiting for");
|
||||
|
||||
for (f = fds; f < &fds[nfds]; ++f)
|
||||
{
|
||||
if (f->fd == G_WIN32_MSG_HANDLE && (f->events & G_IO_IN))
|
||||
{
|
||||
if (_g_main_poll_debug && msg_fd == NULL)
|
||||
g_print (" MSG");
|
||||
msg_fd = f;
|
||||
}
|
||||
else if (f->fd > 0)
|
||||
{
|
||||
if (nhandles == MAXIMUM_WAIT_OBJECTS)
|
||||
{
|
||||
g_warning ("Too many handles to wait for!");
|
||||
break;
|
||||
}
|
||||
else
|
||||
{
|
||||
if (_g_main_poll_debug)
|
||||
g_print (" %p", (HANDLE) f->fd);
|
||||
handle_to_fd[nhandles] = f;
|
||||
handles[nhandles++] = (HANDLE) f->fd;
|
||||
}
|
||||
}
|
||||
f->revents = 0;
|
||||
}
|
||||
|
||||
if (_g_main_poll_debug)
|
||||
g_print ("\n");
|
||||
|
||||
if (timeout == -1)
|
||||
timeout = INFINITE;
|
||||
|
||||
/* Polling for several things? */
|
||||
if (nhandles > 1 || (nhandles > 0 && msg_fd != NULL))
|
||||
if (data->nhandles > 1 || (data->nhandles > 0 && data->msg_fd != NULL))
|
||||
{
|
||||
/* First check if one or several of them are immediately
|
||||
* available
|
||||
*/
|
||||
retval = poll_rest (msg_fd, handles, handle_to_fd, nhandles, 0);
|
||||
retval = poll_rest (data->msg_fd, data->stop_fd, data->handles, data->handle_to_fd, data->nhandles, 0);
|
||||
|
||||
/* If not, and we have a significant timeout, poll again with
|
||||
* timeout then. Note that this will return indication for only
|
||||
* one event, or only for messages.
|
||||
*/
|
||||
if (retval == 0 && (timeout == INFINITE || timeout > 0))
|
||||
retval = poll_rest (msg_fd, handles, handle_to_fd, nhandles, timeout);
|
||||
if (retval == 0 && (data->timeout_ms == INFINITE || data->timeout_ms > 0))
|
||||
retval = poll_rest (data->msg_fd, data->stop_fd, data->handles, data->handle_to_fd, data->nhandles, data->timeout_ms);
|
||||
}
|
||||
else
|
||||
{
|
||||
/* Just polling for one thing, so no need to check first if
|
||||
* available immediately
|
||||
*/
|
||||
retval = poll_rest (msg_fd, handles, handle_to_fd, nhandles, timeout);
|
||||
retval = poll_rest (data->msg_fd, data->stop_fd, data->handles, data->handle_to_fd, data->nhandles, data->timeout_ms);
|
||||
}
|
||||
|
||||
return retval;
|
||||
}
|
||||
|
||||
static void
|
||||
fill_poll_thread_data (GPollFD *fds,
|
||||
guint nfds,
|
||||
gint timeout_ms,
|
||||
GPollFD *stop_fd,
|
||||
GWin32PollThreadData *data)
|
||||
{
|
||||
GPollFD *f;
|
||||
|
||||
data->timeout_ms = timeout_ms;
|
||||
|
||||
if (stop_fd != NULL)
|
||||
{
|
||||
if (_g_main_poll_debug)
|
||||
g_print (" Stop FD: %p", (HANDLE) stop_fd->fd);
|
||||
|
||||
g_assert (data->nhandles < MAXIMUM_WAIT_OBJECTS);
|
||||
|
||||
data->stop_fd = stop_fd;
|
||||
data->handle_to_fd[data->nhandles] = stop_fd;
|
||||
data->handles[data->nhandles++] = (HANDLE) stop_fd->fd;
|
||||
}
|
||||
|
||||
for (f = fds; f < &fds[nfds]; ++f)
|
||||
{
|
||||
if ((data->nhandles == MAXIMUM_WAIT_OBJECTS) ||
|
||||
(data->msg_fd != NULL && (data->nhandles == MAXIMUM_WAIT_OBJECTS - 1)))
|
||||
{
|
||||
g_warning ("Too many handles to wait for!");
|
||||
break;
|
||||
}
|
||||
|
||||
if (f->fd == G_WIN32_MSG_HANDLE && (f->events & G_IO_IN))
|
||||
{
|
||||
if (_g_main_poll_debug && data->msg_fd == NULL)
|
||||
g_print (" MSG");
|
||||
data->msg_fd = f;
|
||||
}
|
||||
else if (f->fd > 0)
|
||||
{
|
||||
if (_g_main_poll_debug)
|
||||
g_print (" %p", (HANDLE) f->fd);
|
||||
data->handle_to_fd[data->nhandles] = f;
|
||||
data->handles[data->nhandles++] = (HANDLE) f->fd;
|
||||
}
|
||||
|
||||
f->revents = 0;
|
||||
}
|
||||
}
|
||||
|
||||
static guint __stdcall
|
||||
poll_thread_run (gpointer user_data)
|
||||
{
|
||||
GWin32PollThreadData *data = user_data;
|
||||
|
||||
/* Docs say that it is safer to call _endthreadex by our own:
|
||||
* https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/endthread-endthreadex
|
||||
*/
|
||||
_endthreadex (poll_single_thread (data));
|
||||
|
||||
g_assert_not_reached ();
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* One slot for a possible msg object or the stop event */
|
||||
#define MAXIMUM_WAIT_OBJECTS_PER_THREAD (MAXIMUM_WAIT_OBJECTS - 1)
|
||||
|
||||
gint
|
||||
g_poll (GPollFD *fds,
|
||||
guint nfds,
|
||||
gint timeout)
|
||||
{
|
||||
guint nthreads, threads_remain;
|
||||
HANDLE thread_handles[MAXIMUM_WAIT_OBJECTS];
|
||||
GWin32PollThreadData *threads_data;
|
||||
GPollFD stop_event = { 0, };
|
||||
GPollFD *f;
|
||||
guint i, fds_idx = 0;
|
||||
DWORD ready;
|
||||
DWORD thread_retval;
|
||||
int retval;
|
||||
GPollFD *msg_fd = NULL;
|
||||
|
||||
if (timeout == -1)
|
||||
timeout = INFINITE;
|
||||
|
||||
/* Simple case without extra threads */
|
||||
if (nfds <= MAXIMUM_WAIT_OBJECTS)
|
||||
{
|
||||
GWin32PollThreadData data = { 0, };
|
||||
|
||||
if (_g_main_poll_debug)
|
||||
g_print ("g_poll: waiting for");
|
||||
|
||||
fill_poll_thread_data (fds, nfds, timeout, NULL, &data);
|
||||
|
||||
if (_g_main_poll_debug)
|
||||
g_print ("\n");
|
||||
|
||||
retval = poll_single_thread (&data);
|
||||
if (retval == -1)
|
||||
for (f = fds; f < &fds[nfds]; ++f)
|
||||
f->revents = 0;
|
||||
|
||||
return retval;
|
||||
}
|
||||
|
||||
if (_g_main_poll_debug)
|
||||
g_print ("g_poll: polling with threads\n");
|
||||
|
||||
nthreads = nfds / MAXIMUM_WAIT_OBJECTS_PER_THREAD;
|
||||
threads_remain = nfds % MAXIMUM_WAIT_OBJECTS_PER_THREAD;
|
||||
if (threads_remain > 0)
|
||||
nthreads++;
|
||||
|
||||
if (nthreads > MAXIMUM_WAIT_OBJECTS_PER_THREAD)
|
||||
{
|
||||
g_warning ("Too many handles to wait for in threads!");
|
||||
nthreads = MAXIMUM_WAIT_OBJECTS_PER_THREAD;
|
||||
}
|
||||
|
||||
#if GLIB_SIZEOF_VOID_P == 8
|
||||
stop_event.fd = (gint64)CreateEventW (NULL, TRUE, FALSE, NULL);
|
||||
#else
|
||||
stop_event.fd = (gint)CreateEventW (NULL, TRUE, FALSE, NULL);
|
||||
#endif
|
||||
stop_event.events = G_IO_IN;
|
||||
|
||||
threads_data = g_new0 (GWin32PollThreadData, nthreads);
|
||||
for (i = 0; i < nthreads; i++)
|
||||
{
|
||||
guint thread_fds;
|
||||
guint ignore;
|
||||
|
||||
if (i == (nthreads - 1) && threads_remain > 0)
|
||||
thread_fds = threads_remain;
|
||||
else
|
||||
thread_fds = MAXIMUM_WAIT_OBJECTS_PER_THREAD;
|
||||
|
||||
fill_poll_thread_data (fds + fds_idx, thread_fds, timeout, &stop_event, &threads_data[i]);
|
||||
fds_idx += thread_fds;
|
||||
|
||||
/* We must poll for messages from the same thread, so poll it along with the threads */
|
||||
if (threads_data[i].msg_fd != NULL)
|
||||
{
|
||||
msg_fd = threads_data[i].msg_fd;
|
||||
threads_data[i].msg_fd = NULL;
|
||||
}
|
||||
|
||||
thread_handles[i] = (HANDLE) _beginthreadex (NULL, 0, poll_thread_run, &threads_data[i], 0, &ignore);
|
||||
}
|
||||
|
||||
/* Wait for at least one thread to return */
|
||||
if (msg_fd != NULL)
|
||||
ready = MsgWaitForMultipleObjectsEx (nthreads, thread_handles, timeout,
|
||||
QS_ALLINPUT, MWMO_ALERTABLE);
|
||||
else
|
||||
ready = WaitForMultipleObjects (nthreads, thread_handles, timeout > 0, timeout);
|
||||
|
||||
/* Signal the stop in case any of the threads did not stop yet */
|
||||
if (!SetEvent ((HANDLE)stop_event.fd))
|
||||
{
|
||||
gchar *emsg = g_win32_error_message (GetLastError ());
|
||||
g_warning ("gpoll: failed to signal the stop event: %s", emsg);
|
||||
g_free (emsg);
|
||||
}
|
||||
|
||||
/* Wait for the rest of the threads to finish */
|
||||
WaitForMultipleObjects (nthreads, thread_handles, TRUE, INFINITE);
|
||||
|
||||
/* The return value of all the threads give us all the fds that changed state */
|
||||
retval = 0;
|
||||
if (msg_fd != NULL && ready == WAIT_OBJECT_0 + nthreads)
|
||||
{
|
||||
msg_fd->revents |= G_IO_IN;
|
||||
retval = 1;
|
||||
}
|
||||
|
||||
for (i = 0; i < nthreads; i++)
|
||||
{
|
||||
if (GetExitCodeThread (thread_handles[i], &thread_retval))
|
||||
retval = retval == -1 ? -1 : thread_retval == -1 ? -1 : retval + thread_retval;
|
||||
|
||||
CloseHandle (thread_handles[i]);
|
||||
}
|
||||
|
||||
if (retval == -1)
|
||||
for (f = fds; f < &fds[nfds]; ++f)
|
||||
f->revents = 0;
|
||||
|
||||
g_free (threads_data);
|
||||
CloseHandle ((HANDLE)stop_event.fd);
|
||||
|
||||
return retval;
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user