void *additional_data;
/* custom tag that can be set by caller */
uint64_t tag;
+ struct tevent_fd_mpx {
+ struct tevent_fd_mpx *prev, *next;
+ struct tevent_fd *fde;
+ struct tevent_fd *primary;
+ struct tevent_fd_mpx *list;
+ uint16_t total_flags;
+ bool has_mpx;
+ } mpx;
};
struct tevent_timer {
#include "tevent_dlinklist.h"
+static inline void tevent_common_fd_mpx_reinit(struct tevent_fd *fde)
+{
+ fde->mpx = (struct tevent_fd_mpx) { .fde = fde, };
+}
+
static inline void tevent_common_fd_disarm(struct tevent_fd *fde)
{
if (fde->event_ctx != NULL) {
DLIST_REMOVE(fde->event_ctx->fd_events, fde);
fde->event_ctx = NULL;
}
+ tevent_common_fd_mpx_reinit(fde);
fde->wrapper = NULL;
}
+
+/*
+ * tevent_common_fd_mpx_primary() returns the fde that is responsible
+ * for the low level state.
+ *
+ * By default (when there's no multiplexing) it just returns 'any_fde'.
+ *
+ * Note it always returns a valid pointer.
+ */
+static inline
+struct tevent_fd *tevent_common_fd_mpx_primary(struct tevent_fd *any_fde)
+{
+ struct tevent_fd *primary = NULL;
+
+ if (any_fde->mpx.primary != NULL) {
+ primary = any_fde->mpx.primary;
+ } else {
+ primary = any_fde;
+ }
+
+ return primary;
+}
+
+/*
+ * tevent_common_fd_mpx_update_flags() needs to be called
+ * if update_fde->flags has changed. It is needed in
+ * order to let tevent_common_fd_mpx_flags() return a valid
+ * result.
+ */
+static inline
+void tevent_common_fd_mpx_update_flags(struct tevent_fd *update_fde)
+{
+ struct tevent_fd *primary = tevent_common_fd_mpx_primary(update_fde);
+ struct tevent_fd_mpx *mpx = NULL;
+ uint16_t new_total_flags = 0;
+
+ if (!primary->mpx.has_mpx) {
+ primary->mpx.total_flags = primary->flags;
+ return;
+ }
+
+ for (mpx = primary->mpx.list; mpx != NULL; mpx = mpx->next) {
+ struct tevent_fd *mpx_fde = mpx->fde;
+ /* we don't care that mpx_fde might be == primary */
+ new_total_flags |= mpx_fde->flags;
+ }
+
+ primary->mpx.total_flags = new_total_flags;
+}
+
+/*
+ * tevent_common_fd_mpx_flags() return the effective flags
+ * (TEVEND_FD_*) of the primary fde and all multiplexed fdes.
+ *
+ * Valid after tevent_common_fd_mpx_update_flags() was called
+ */
+static inline
+uint16_t tevent_common_fd_mpx_flags(struct tevent_fd *any_fde)
+{
+ struct tevent_fd *primary = tevent_common_fd_mpx_primary(any_fde);
+
+ return primary->mpx.total_flags;
+}
+
+/*
+ * tevent_common_fd_mpx_clear_writeable() clears TEVENT_FD_WRITE
+ * from all fdes belonging together.
+ */
+static inline
+void tevent_common_fd_mpx_clear_writeable(struct tevent_fd *any_fde)
+{
+ struct tevent_fd *primary = tevent_common_fd_mpx_primary(any_fde);
+ struct tevent_fd_mpx *mpx = NULL;
+
+ primary->flags &= ~TEVENT_FD_WRITE;
+
+ for (mpx = primary->mpx.list; mpx != NULL; mpx = mpx->next) {
+ struct tevent_fd *mpx_fde = mpx->fde;
+ /* we don't care that mpx_fde might be == primary */
+ mpx_fde->flags &= ~TEVENT_FD_WRITE;
+ }
+
+ primary->mpx.total_flags &= ~TEVENT_FD_WRITE;
+}
+
+/*
+ * tevent_common_fd_mpx_additional_flags() modifies
+ * fde->additional_flags for all fdes belonging together.
+ */
+static inline
+void tevent_common_fd_mpx_additional_flags(struct tevent_fd *any_fde,
+ uint64_t clear_flags,
+ uint64_t add_flags)
+{
+ struct tevent_fd *primary = tevent_common_fd_mpx_primary(any_fde);
+ struct tevent_fd_mpx *mpx = NULL;
+
+ primary->additional_flags &= ~clear_flags;
+ primary->additional_flags |= add_flags;
+
+ for (mpx = primary->mpx.list; mpx != NULL; mpx = mpx->next) {
+ struct tevent_fd *mpx_fde = mpx->fde;
+ /* we don't care that mpx_fde might be == primary */
+ mpx_fde->additional_flags &= ~clear_flags;
+ mpx_fde->additional_flags |= add_flags;
+ }
+}
+
+/*
+ * tevent_common_fd_mpx_disarm_all() detaches
+ * all fdes currently belonging together from each other
+ * and also from the tevent_context, which means their
+ * handler will never be called again.
+ */
+static inline
+void tevent_common_fd_mpx_disarm_all(struct tevent_fd *any_fde)
+{
+ struct tevent_fd *primary = tevent_common_fd_mpx_primary(any_fde);
+ struct tevent_fd_mpx *mpx = NULL, *next = NULL;
+
+ for (mpx = primary->mpx.list; mpx != NULL; mpx = next) {
+ struct tevent_fd *mpx_fde = mpx->fde;
+
+ next = mpx->next;
+ DLIST_REMOVE(primary->mpx.list, mpx);
+
+ if (mpx_fde == primary) {
+ /* primary is handled below */
+ continue;
+ }
+
+ tevent_common_fd_disarm(mpx_fde);
+ }
+
+ tevent_common_fd_disarm(primary);
+}
+
+/*
+ * tevent_common_fd_mpx_select() selects the handler that
+ * should be called for the given low level event.
+ *
+ * Note it's important to pass the primary fde!
+ */
+static inline
+struct tevent_fd *tevent_common_fd_mpx_select(struct tevent_fd *primary,
+ uint16_t flags,
+ bool got_error)
+{
+ struct tevent_fd_mpx *mpx = NULL;
+ struct tevent_fd *selected = NULL;
+
+ /* optimize for the single event case. */
+ if (!primary->mpx.has_mpx) {
+ /*
+ * If we got an error, we won't report it if
+ * the caller only asked for TEVENT_FD_WRITE.
+ */
+ if (got_error && !(primary->flags & TEVENT_FD_READ)) {
+ return NULL;
+ }
+
+ if (flags & primary->flags) {
+ return primary;
+ }
+
+ return NULL;
+ }
+
+ for (mpx = primary->mpx.list; mpx != NULL; mpx = mpx->next) {
+ struct tevent_fd *mpx_fde = mpx->fde;
+
+ /*
+ * If we got an error, we won't report it if
+ * the caller only asked for TEVENT_FD_WRITE.
+ */
+ if (got_error && !(mpx_fde->flags & TEVENT_FD_READ)) {
+ continue;
+ }
+
+ if (flags & mpx_fde->flags) {
+ selected = mpx_fde;
+ break;
+ }
+ }
+
+ if (selected == NULL) {
+ return NULL;
+ }
+
+ /*
+ * Maintain fairness and demote the just selected fde
+ */
+ DLIST_DEMOTE_SHORT(primary->mpx.list, &selected->mpx);
+ return selected;
+}
+
+/*
+ * tevent_common_fd_mpx_add() searches for an existing (active) fde
+ * for the same low level fd and adds the given 'add_fde'
+ * as multiplexed to the found fde.
+ *
+ * If another fde was found it is returned.
+ * NULL is returned to indicate no match
+ */
+static inline
+struct tevent_fd *tevent_common_fd_mpx_add(struct tevent_fd *add_fde)
+{
+ struct tevent_context *ev = add_fde->event_ctx;
+ struct tevent_fd *add_primary = tevent_common_fd_mpx_primary(add_fde);
+ uint16_t add_flags = tevent_common_fd_mpx_flags(add_primary);
+ struct tevent_fd *mpx_fde = NULL;
+ struct tevent_fd *mpx_primary = NULL;
+ struct tevent_fd_mpx *tmp = NULL;
+ struct tevent_fd_mpx *next = NULL;
+
+ /* Find the existing fde that caused the EEXIST error. */
+ for (mpx_fde = ev->fd_events; mpx_fde; mpx_fde = mpx_fde->next) {
+ mpx_primary = tevent_common_fd_mpx_primary(mpx_fde);
+
+ if (mpx_primary->fd != add_primary->fd) {
+ mpx_primary = NULL;
+ continue;
+ }
+
+ if (mpx_primary == add_primary) {
+ mpx_primary = NULL;
+ continue;
+ }
+
+ if (add_flags != 0 &&
+ tevent_common_fd_mpx_flags(mpx_primary) == 0)
+ {
+ /*
+ * only active events should match
+ */
+ mpx_primary = NULL;
+ continue;
+ }
+ break;
+ }
+ if (mpx_primary == NULL) {
+ tevent_debug(ev, TEVENT_DEBUG_FATAL,
+ "can't find multiplex fde for fd[%d]",
+ add_fde->fd);
+ return NULL;
+ }
+
+ /*
+ * If add_primary is not in it's own list
+ * we add it in order to simplify the loop below.
+ */
+
+ if (add_primary->mpx.prev == NULL && add_primary->mpx.next == NULL) {
+ DLIST_ADD_END(add_primary->mpx.list, &add_primary->mpx);
+ }
+
+ /*
+ * Add the new mpx_primary to its own list before others,
+ * if it is not already added.
+ */
+ if (mpx_primary->mpx.prev == NULL && mpx_primary->mpx.next == NULL) {
+ DLIST_ADD_END(mpx_primary->mpx.list, &mpx_primary->mpx);
+ }
+
+ /*
+ * Now we clear all entries and move them to the
+ * new primary
+ */
+ for (tmp = add_primary->mpx.list; tmp != NULL; tmp = next) {
+ struct tevent_fd *tmp_fde = tmp->fde;
+
+ next = tmp->next;
+
+ DLIST_REMOVE(add_primary->mpx.list, tmp);
+ tevent_common_fd_mpx_reinit(tmp_fde);
+ DLIST_ADD_END(mpx_primary->mpx.list, tmp);
+ tmp->primary = mpx_primary;
+ tmp->has_mpx = true;
+ }
+
+ mpx_primary->mpx.has_mpx = true;
+ return mpx_primary;
+}
+
+/*
+ * tevent_common_fd_mpx_update() calls tevent_common_fd_mpx_update_flags()
+ * and compares tevent_common_fd_mpx_flags() before and after.
+ *
+ * When there's a low level update needed the primary fde,
+ * otherwise NULL is returned.
+ */
+static inline
+struct tevent_fd *tevent_common_fd_mpx_update(struct tevent_fd *update_fde)
+{
+ struct tevent_fd *primary = tevent_common_fd_mpx_primary(update_fde);
+ uint16_t old_total_flags;
+ uint16_t new_total_flags;
+
+ old_total_flags = primary->mpx.total_flags;
+ tevent_common_fd_mpx_update_flags(primary);
+ new_total_flags = primary->mpx.total_flags;
+
+ if (old_total_flags == new_total_flags) {
+ /* No update needed */
+ return NULL;
+ }
+
+ return primary;
+}
+
+/*
+ * tevent_common_fd_mpx_remove() removes remove_fde from its possible primary,
+ * if remove_fde is a primary itself, a new primary is selected.
+ *
+ * The remaining primary or NULL is returned.
+ */
+static inline
+struct tevent_fd *tevent_common_fd_mpx_remove(struct tevent_fd *remove_fde)
+{
+ struct tevent_fd *primary = tevent_common_fd_mpx_primary(remove_fde);
+ struct tevent_fd_mpx *mpx = NULL, *next = NULL;
+ struct tevent_fd *new_primary = NULL;
+
+ DLIST_REMOVE(primary->mpx.list, &remove_fde->mpx);
+
+ if (primary != remove_fde) {
+ tevent_common_fd_mpx_reinit(remove_fde);
+ return primary;
+ }
+
+ for (mpx = primary->mpx.list; mpx != NULL; mpx = next) {
+ struct tevent_fd *mpx_fde = mpx->fde;
+
+ next = mpx->next;
+
+ DLIST_REMOVE(primary->mpx.list, &mpx_fde->mpx);
+ tevent_common_fd_mpx_reinit(mpx_fde);
+ mpx->primary = new_primary;
+ if (new_primary == NULL) {
+ /*
+ * Select the first one as the new primary and add
+ * itself as the first mpx-fde to the mpx list
+ */
+ new_primary = mpx_fde;
+ DLIST_ADD(new_primary->mpx.list, &mpx_fde->mpx);
+ continue;
+ }
+ new_primary->mpx.has_mpx = true;
+ mpx->has_mpx = true;
+ DLIST_ADD_END(new_primary->mpx.list, &mpx_fde->mpx);
+ }
+
+ /* primary == remove_fde */
+ tevent_common_fd_mpx_reinit(primary);
+ return new_primary;
+}
projects / thirdparty / samba.git / commitdiff
