diff options
Diffstat (limited to '0017-GSocket-Fix-race-conditions-on-Win32-if-multiple-thr.patch')
| -rw-r--r-- | 0017-GSocket-Fix-race-conditions-on-Win32-if-multiple-thr.patch | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/0017-GSocket-Fix-race-conditions-on-Win32-if-multiple-thr.patch b/0017-GSocket-Fix-race-conditions-on-Win32-if-multiple-thr.patch new file mode 100644 index 000000000000..8634bacab38d --- /dev/null +++ b/0017-GSocket-Fix-race-conditions-on-Win32-if-multiple-thr.patch @@ -0,0 +1,309 @@ +From e5ae075ff9b3cba2ee7b7393bc7f4b49c3d3ee79 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com> +Date: Mon, 5 Dec 2016 12:28:57 +0200 +Subject: [PATCH] GSocket: Fix race conditions on Win32 if multiple threads are + waiting on conditions for the same socket + +WSAWaitForMultipleEvents() only returns for one of the waiting threads, and +that one might not even be the one waiting for the condition that changed. As +such, only let a single thread wait on the event and use a GCond for all other +threads. + +With this it is possible to e.g. have an UDP socket that is written to from +one thread and read from in another thread on Win32 too. On POSIX systems this +was working before already. + +https://bugzilla.gnome.org/show_bug.cgi?id=762283 +--- + gio/gsocket.c | 94 ++++++++++++++++++++++++++++++++++++++++++----------------- + 1 file changed, 68 insertions(+), 26 deletions(-) + +diff --git a/gio/gsocket.c b/gio/gsocket.c +index 5a2f33285..ff5403b6f 100644 +--- a/gio/gsocket.c ++++ b/gio/gsocket.c +@@ -249,11 +249,14 @@ struct _GSocketPrivate + guint connect_pending : 1; + #ifdef G_OS_WIN32 + WSAEVENT event; ++ gboolean waiting; ++ DWORD waiting_result; + int current_events; + int current_errors; + int selected_events; + GList *requested_conditions; /* list of requested GIOCondition * */ + GMutex win32_source_lock; ++ GCond win32_source_cond; + #endif + + struct { +@@ -333,8 +336,10 @@ socket_strerror (int err) + static void + _win32_unset_event_mask (GSocket *socket, int mask) + { ++ g_mutex_lock (&socket->priv->win32_source_lock); + socket->priv->current_events &= ~mask; + socket->priv->current_errors &= ~mask; ++ g_mutex_unlock (&socket->priv->win32_source_lock); + } + #else + #define win32_unset_event_mask(_socket, _mask) +@@ -831,6 +836,7 @@ g_socket_finalize (GObject *object) + + g_assert (socket->priv->requested_conditions == NULL); + g_mutex_clear (&socket->priv->win32_source_lock); ++ g_cond_clear (&socket->priv->win32_source_cond); + #endif + + for (i = 0; i < RECV_ADDR_CACHE_SIZE; i++) +@@ -1058,6 +1064,7 @@ g_socket_init (GSocket *socket) + #ifdef G_OS_WIN32 + socket->priv->event = WSA_INVALID_EVENT; + g_mutex_init (&socket->priv->win32_source_lock); ++ g_cond_init (&socket->priv->win32_source_cond); + #endif + } + +@@ -2441,6 +2448,8 @@ g_socket_accept (GSocket *socket, + + while (TRUE) + { ++ win32_unset_event_mask (socket, FD_ACCEPT); ++ + if ((ret = accept (socket->priv->fd, NULL, 0)) < 0) + { + int errsv = get_socket_errno (); +@@ -2455,8 +2464,6 @@ g_socket_accept (GSocket *socket, + errsv == EAGAIN) + #endif + { +- win32_unset_event_mask (socket, FD_ACCEPT); +- + if (socket->priv->blocking) + { + if (!g_socket_condition_wait (socket, +@@ -2473,8 +2480,6 @@ g_socket_accept (GSocket *socket, + break; + } + +- win32_unset_event_mask (socket, FD_ACCEPT); +- + #ifdef G_OS_WIN32 + { + /* The socket inherits the accepting sockets event mask and even object, +@@ -2563,6 +2568,8 @@ g_socket_connect (GSocket *socket, + + while (1) + { ++ win32_unset_event_mask (socket, FD_CONNECT); ++ + if (connect (socket->priv->fd, (struct sockaddr *) &buffer, + g_socket_address_get_native_size (address)) < 0) + { +@@ -2577,8 +2584,6 @@ g_socket_connect (GSocket *socket, + if (errsv == WSAEWOULDBLOCK) + #endif + { +- win32_unset_event_mask (socket, FD_CONNECT); +- + if (socket->priv->blocking) + { + if (g_socket_condition_wait (socket, G_IO_OUT, cancellable, error)) +@@ -2604,8 +2609,6 @@ g_socket_connect (GSocket *socket, + break; + } + +- win32_unset_event_mask (socket, FD_CONNECT); +- + socket->priv->connected_read = TRUE; + socket->priv->connected_write = TRUE; + +@@ -2785,6 +2788,8 @@ g_socket_receive_with_timeout (GSocket *socket, + + while (1) + { ++ win32_unset_event_mask (socket, FD_READ); ++ + if ((ret = recv (socket->priv->fd, buffer, size, 0)) < 0) + { + int errsv = get_socket_errno (); +@@ -2799,8 +2804,6 @@ g_socket_receive_with_timeout (GSocket *socket, + errsv == EAGAIN) + #endif + { +- win32_unset_event_mask (socket, FD_READ); +- + if (timeout != 0) + { + if (!block_on_timeout (socket, G_IO_IN, timeout, start_time, +@@ -2811,14 +2814,10 @@ g_socket_receive_with_timeout (GSocket *socket, + } + } + +- win32_unset_event_mask (socket, FD_READ); +- + socket_set_error_lazy (error, errsv, _("Error receiving data: %s")); + return -1; + } + +- win32_unset_event_mask (socket, FD_READ); +- + break; + } + +@@ -2984,6 +2983,8 @@ g_socket_send_with_timeout (GSocket *socket, + + while (1) + { ++ win32_unset_event_mask (socket, FD_WRITE); ++ + if ((ret = send (socket->priv->fd, buffer, size, G_SOCKET_DEFAULT_SEND_FLAGS)) < 0) + { + int errsv = get_socket_errno (); +@@ -2998,8 +2999,6 @@ g_socket_send_with_timeout (GSocket *socket, + errsv == EAGAIN) + #endif + { +- win32_unset_event_mask (socket, FD_WRITE); +- + if (timeout != 0) + { + if (!block_on_timeout (socket, G_IO_OUT, timeout, start_time, +@@ -3414,7 +3413,7 @@ remove_condition_watch (GSocket *socket, + } + + static GIOCondition +-update_condition (GSocket *socket) ++update_condition_unlocked (GSocket *socket) + { + WSANETWORKEVENTS events; + GIOCondition condition; +@@ -3481,6 +3480,16 @@ update_condition (GSocket *socket) + + return condition; + } ++ ++static GIOCondition ++update_condition (GSocket *socket) ++{ ++ GIOCondition res; ++ g_mutex_lock (&socket->priv->win32_source_lock); ++ res = update_condition_unlocked (socket); ++ g_mutex_unlock (&socket->priv->win32_source_lock); ++ return res; ++} + #endif + + typedef struct { +@@ -3876,11 +3885,44 @@ g_socket_condition_timed_wait (GSocket *socket, + if (timeout == -1) + timeout = WSA_INFINITE; + +- current_condition = update_condition (socket); ++ g_mutex_lock (&socket->priv->win32_source_lock); ++ current_condition = update_condition_unlocked (socket); + while ((condition & current_condition) == 0) + { +- res = WSAWaitForMultipleEvents (num_events, events, +- FALSE, timeout, FALSE); ++ if (!socket->priv->waiting) ++ { ++ socket->priv->waiting = TRUE; ++ socket->priv->waiting_result = 0; ++ g_mutex_unlock (&socket->priv->win32_source_lock); ++ ++ res = WSAWaitForMultipleEvents (num_events, events, FALSE, timeout, FALSE); ++ ++ g_mutex_lock (&socket->priv->win32_source_lock); ++ socket->priv->waiting = FALSE; ++ socket->priv->waiting_result = res; ++ g_cond_broadcast (&socket->priv->win32_source_cond); ++ } ++ else ++ { ++ if (timeout != WSA_INFINITE) ++ { ++ if (!g_cond_wait_until (&socket->priv->win32_source_cond, &socket->priv->win32_source_lock, timeout)) ++ { ++ res = WSA_WAIT_TIMEOUT; ++ break; ++ } ++ else ++ { ++ res = socket->priv->waiting_result; ++ } ++ } ++ else ++ { ++ g_cond_wait (&socket->priv->win32_source_cond, &socket->priv->win32_source_lock); ++ res = socket->priv->waiting_result; ++ } ++ } ++ + if (res == WSA_WAIT_FAILED) + { + int errsv = get_socket_errno (); +@@ -3901,7 +3943,7 @@ g_socket_condition_timed_wait (GSocket *socket, + if (g_cancellable_set_error_if_cancelled (cancellable, error)) + break; + +- current_condition = update_condition (socket); ++ current_condition = update_condition_unlocked (socket); + + if (timeout != WSA_INFINITE) + { +@@ -3910,6 +3952,7 @@ g_socket_condition_timed_wait (GSocket *socket, + timeout = 0; + } + } ++ g_mutex_unlock (&socket->priv->win32_source_lock); + remove_condition_watch (socket, &condition); + if (num_events > 1) + g_cancellable_release_fd (cancellable); +@@ -4405,6 +4448,8 @@ g_socket_send_message_with_timeout (GSocket *socket, + + while (1) + { ++ win32_unset_event_mask (socket, FD_WRITE); ++ + if (address) + result = WSASendTo (socket->priv->fd, + bufs, num_vectors, +@@ -4426,8 +4471,6 @@ g_socket_send_message_with_timeout (GSocket *socket, + + if (errsv == WSAEWOULDBLOCK) + { +- win32_unset_event_mask (socket, FD_WRITE); +- + if (timeout != 0) + { + if (!block_on_timeout (socket, G_IO_OUT, timeout, +@@ -4875,6 +4918,8 @@ g_socket_receive_message_with_timeout (GSocket *socket, + /* do it */ + while (1) + { ++ win32_unset_event_mask (socket, FD_READ); ++ + addrlen = sizeof addr; + if (address) + result = WSARecvFrom (socket->priv->fd, +@@ -4896,8 +4941,6 @@ g_socket_receive_message_with_timeout (GSocket *socket, + + if (errsv == WSAEWOULDBLOCK) + { +- win32_unset_event_mask (socket, FD_READ); +- + if (timeout != 0) + { + if (!block_on_timeout (socket, G_IO_IN, timeout, +@@ -4911,7 +4954,6 @@ g_socket_receive_message_with_timeout (GSocket *socket, + socket_set_error_lazy (error, errsv, _("Error receiving message: %s")); + return -1; + } +- win32_unset_event_mask (socket, FD_READ); + break; + } + +-- +2.11.0 + |