diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/thread.c | 8 | ||||
| -rw-r--r-- | src/xgselect.c | 42 | ||||
| -rw-r--r-- | src/xgselect.h | 2 |
3 files changed, 38 insertions, 14 deletions
diff --git a/src/thread.c b/src/thread.c index b638dd77f8b..b4d8a53cf68 100644 --- a/src/thread.c +++ b/src/thread.c @@ -28,6 +28,12 @@ along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. */ #include "pdumper.h" #include "keyboard.h" +#ifdef HAVE_GLIB +#include <xgselect.h> +#else +#define release_select_lock() do { } while (0) +#endif + union aligned_thread_state { struct thread_state s; @@ -586,6 +592,8 @@ really_call_select (void *arg) sa->result = (sa->func) (sa->max_fds, sa->rfds, sa->wfds, sa->efds, sa->timeout, sa->sigmask); + release_select_lock (); + block_interrupt_signal (&oldset); /* If we were interrupted by C-g while inside sa->func above, the signal handler could have called maybe_reacquire_global_lock, in diff --git a/src/xgselect.c b/src/xgselect.c index f8d0bac7fac..be70107b756 100644 --- a/src/xgselect.c +++ b/src/xgselect.c @@ -29,6 +29,27 @@ along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. */ #include "blockinput.h" #include "systime.h" +static ptrdiff_t threads_holding_glib_lock; +static GMainContext *glib_main_context; + +void release_select_lock (void) +{ + if (--threads_holding_glib_lock == 0) + g_main_context_release (glib_main_context); +} + +static void acquire_select_lock (GMainContext *context) +{ + if (threads_holding_glib_lock++ == 0) + { + glib_main_context = context; + while (!g_main_context_acquire (context)) + { + /* Spin. */ + } + } +} + /* `xg_select' is a `pselect' replacement. Why do we need a separate function? 1. Timeouts. Glib and Gtk rely on timer events. If we did pselect with a greater timeout then the one scheduled by Glib, we would @@ -54,26 +75,19 @@ xg_select (int fds_lim, fd_set *rfds, fd_set *wfds, fd_set *efds, GPollFD *gfds = gfds_buf; int gfds_size = ARRAYELTS (gfds_buf); int n_gfds, retval = 0, our_fds = 0, max_fds = fds_lim - 1; - bool context_acquired = false; int i, nfds, tmo_in_millisec, must_free = 0; bool need_to_dispatch; context = g_main_context_default (); - context_acquired = g_main_context_acquire (context); - /* FIXME: If we couldn't acquire the context, we just silently proceed - because this function handles more than just glib file descriptors. - Note that, as implemented, this failure is completely silent: there is - no feedback to the caller. */ + acquire_select_lock (context); if (rfds) all_rfds = *rfds; else FD_ZERO (&all_rfds); if (wfds) all_wfds = *wfds; else FD_ZERO (&all_wfds); - n_gfds = (context_acquired - ? g_main_context_query (context, G_PRIORITY_LOW, &tmo_in_millisec, - gfds, gfds_size) - : -1); + n_gfds = g_main_context_query (context, G_PRIORITY_LOW, &tmo_in_millisec, + gfds, gfds_size); if (gfds_size < n_gfds) { @@ -151,8 +165,10 @@ xg_select (int fds_lim, fd_set *rfds, fd_set *wfds, fd_set *efds, #else need_to_dispatch = true; #endif - if (need_to_dispatch && context_acquired) + if (need_to_dispatch) { + acquire_select_lock (context); + int pselect_errno = errno; /* Prevent g_main_dispatch recursion, that would occur without block_input wrapper, because event handlers call @@ -162,11 +178,9 @@ xg_select (int fds_lim, fd_set *rfds, fd_set *wfds, fd_set *efds, g_main_context_dispatch (context); unblock_input (); errno = pselect_errno; + release_select_lock (); } - if (context_acquired) - g_main_context_release (context); - /* To not have to recalculate timeout, return like this. */ if ((our_fds > 0 || (nfds == 0 && tmop == &tmo)) && (retval == 0)) { diff --git a/src/xgselect.h b/src/xgselect.h index a38591f3296..512bf3ad85f 100644 --- a/src/xgselect.h +++ b/src/xgselect.h @@ -29,4 +29,6 @@ extern int xg_select (int max_fds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timespec *timeout, sigset_t *sigmask); +extern void release_select_lock (void); + #endif /* XGSELECT_H */ |