wip

1 files changed, 0 insertions, 95 deletions

diff --git a/libcr_ipc/coroutine_sema.c b/libcr_ipc/coroutine_sema.c
deleted file mode 100644
index a8b5ec4..0000000
--- a/libcr_ipc/coroutine_sema.c
+++ /dev/null
@@ -1,95 +0,0 @@
-/* coroutine_sema.h - Simple semaphores for coroutine.{h,c}
- *
- * Copyright (C) 2024  Luke T. Shumaker <lukeshu@lukeshu.com>
- * SPDX-Licence-Identifier: AGPL-3.0-or-later
- */
-
-#include <assert.h>
-
-#include "coroutine_sema.h"
-
-struct cid_list {
-	cid_t                    val;
-	struct cid_list         *next;
-};
-
-/* head->next->next->tail */
-
-struct _cr_sema {
-	int              cnt;
-
-	struct cid_list  *head, **tail;
-	/* locked indicates that a call from within a coroutine is is
-	 * messing with ->{head,tail}, so a signal handler can't read
-	 * it.  */
-	bool             locked;
-};
-
-/** Drain the sema->{head,tail} list.  Returns true if cr_getcid() was drained.  */
-static inline bool drain(volatile cr_sema_t *sema) {
-	assert(!sema->locked);
-	cid_t self = cr_getcid();
-
-	enum drain_result {
-		DRAINING,
-		DRAINED_SELF, /* stopped because drained `self` */
-		DRAINED_ALL,  /* stopped because sema->head == NULL */
-		DRAINED_SOME, /* stopped because sema->cnt == 0 */
-	} state = DRAINING;
-	do { 
-		sema->locked = true;
-		while (state == DRAINING) {
-			if (!sema->head) {
-				state = DRAINED_ALL;
-			} else if (!sema->cnt) {
-				state = DRAINED_SOME;
-			} else {
-				sema->cnt--;
-				cid_t cid = sema->head->val;
-				if (cid == self)
-					state = DRAINED_SELF;
-				else
-					cr_unpause(sema->head->val);
-				sema->head = sema->head->next;
-				if (!sema->head)
-					sema->tail = &sema->head;
-			}
-		}
-		sema->locked = false;
-		/* If there are still coroutines in sema->head, check
-		 * that sema->cnt wasn't incremented between `if
-		 * (!sema->cnt)` and `sema->locked = false`.  */
-	} while (state == DRAINED_SOME && cnt);
-	/* If state == DRAINED_SELF, then we better have been the last
-	 * item in the list!  */
-	assert(state != DRAINED_SELF || !sema->head);
-	return state == DRAINED_SELF;
-}
-
-void cr_sema_signal(volatile cr_sema_t *sema) {
-	sema->cnt++;
-	if (!sema->locked)
-		drain();
-}
-
-void cr_sema_wait(volatile cr_sema_t *sema) {
-	struct cid_list self = {
-		.val = cr_getcid(),
-		.next = NULL,
-	};
-
-	sema->locked = true;
-	if (!sema->tail)
-		sema->head = &self;
-	else
-		*(sema->tail) = &self;
-	sema->tail = &(self.next);
-	sema->locked = false;
-
-	if (drain())
-		/* DRAINED_SELF: (1) No need to pause+yield, (2) we
-		 * better have been the last item in the list!  */
-		assert(!self.next);
-	else
-		cr_pause_and_yield();
-}