From 681a45beecef09e52f3ddc77e38d9b50b96f587d Mon Sep 17 00:00:00 2001
From: midipix <writeonce@midipix.org>
Date: Jun 08 2020 14:22:12 +0000
Subject: daemon: implement the waiter queue as a true FIFO.


---

diff --git a/src/daemon/toks_daemon_acquire.c b/src/daemon/toks_daemon_acquire.c
index 6d89331..af262ac 100644
--- a/src/daemon/toks_daemon_acquire.c
+++ b/src/daemon/toks_daemon_acquire.c
@@ -152,25 +152,25 @@ static int32_t toks_daemon_queue(struct toks_daemon_ctx * dctx)
 {
 	int                         nwaiters;
 	struct toks_waiter *        waiter;
-	struct toks_waiter *        waiters;
 	nt_tty_port_msg *           msg;
-	int                         i;
 
 	msg      = &dctx->reply;
-	waiters  = toks_get_driver_waiters(dctx->driver_ctx);
 	nwaiters = toks_get_driver_nwaiters(dctx->driver_ctx);
 
 	if (nwaiters == TOKS_MAX_WAITERS)
 		return NT_STATUS_TIMEOUT;
 
-	for (i=0, waiter=0; !waiter && (i<TOKS_MAX_WAITERS); i++)
-		if (!waiters[i].msg.header.msg_id)
-			waiter = &waiters[i];
+	waiter = dctx->waiter_next;
 
 	toks_set_driver_nwaiters(
 		dctx->driver_ctx,
 		++nwaiters);
 
+	dctx->waiter_next++;
+
+	if (dctx->waiter_next == dctx->waiter_cap)
+		dctx->waiter_next = dctx->waiter_base;
+
 	ntapi->tt_generic_memcpy(
 		&waiter->msg,msg,
 		sizeof(*msg));
@@ -281,5 +281,4 @@ int32_t __stdcall toks_daemon_acquire(struct toks_daemon_ctx * dctx)
 	}
 
 	return NT_STATUS_SUCCESS;
-
 }
diff --git a/src/daemon/toks_daemon_release.c b/src/daemon/toks_daemon_release.c
index 2a91214..fbaffe1 100644
--- a/src/daemon/toks_daemon_release.c
+++ b/src/daemon/toks_daemon_release.c
@@ -24,23 +24,32 @@ static void toks_daemon_token_reset(struct toks_token * token)
 
 static int32_t toks_daemon_unqueue(struct toks_daemon_ctx * dctx)
 {
+	int                         status;
 	int                         nwaiters;
 	struct toks_waiter *        waiter;
-	struct toks_waiter *        waiters;
 	nt_tty_port_msg *           msg;
 	nt_tty_port_msg             cmsg;
-	int                         i;
 
 	msg      = &dctx->reply;
-	waiters  = toks_get_driver_waiters(dctx->driver_ctx);
 	nwaiters = toks_get_driver_nwaiters(dctx->driver_ctx);
 
 	if (nwaiters == 0)
 		return NT_STATUS_SUCCESS;
 
-	for (i=0, waiter=0; !waiter && (i<TOKS_MAX_WAITERS); i++)
-		if (waiters[i].msg.header.msg_id)
-			waiter = &waiters[i];
+
+
+	waiter = dctx->waiter_first;
+
+	toks_set_driver_nwaiters(
+		dctx->driver_ctx,
+		--nwaiters);
+
+	dctx->waiter_first++;
+
+	if (dctx->waiter_first == dctx->waiter_cap)
+		dctx->waiter_first = dctx->waiter_base;
+
+
 
 	ntapi->tt_generic_memcpy(
 		&cmsg,msg,
@@ -50,13 +59,8 @@ static int32_t toks_daemon_unqueue(struct toks_daemon_ctx * dctx)
 		msg,&waiter->msg,
 		sizeof(*msg));
 
-	toks_set_driver_nwaiters(
-		dctx->driver_ctx,
-		--nwaiters);
-
-	waiter->msg.header.msg_id = 0;
-
-	msg->ttyinfo.status = toks_daemon_acquire(dctx);
+	status              = toks_daemon_acquire(dctx);
+	msg->ttyinfo.status = status;
 	msg->ttyinfo.exarg  = waiter;
 
 	ntapi->zw_reply_port(
@@ -67,7 +71,7 @@ static int32_t toks_daemon_unqueue(struct toks_daemon_ctx * dctx)
 		msg,&cmsg,
 		sizeof(*msg));
 
-	return NT_STATUS_SUCCESS;
+	return status;
 }
 
 int32_t __stdcall toks_daemon_release(struct toks_daemon_ctx * dctx)
diff --git a/src/driver/toks_driver_ctx.c b/src/driver/toks_driver_ctx.c
index 3a1a359..44fd9ef 100644
--- a/src/driver/toks_driver_ctx.c
+++ b/src/driver/toks_driver_ctx.c
@@ -383,12 +383,19 @@ int toks_get_driver_ctx(
 	ctx->ctx.cctx		= &ctx->cctx;
 	ctx->cctx.uuid          = &ctx->uuid;
 
-	toks_daemon_ctx.driver_ctx = &ctx->ctx;
-
 	if (cctx.drvflags & TOKS_DRIVER_MODE_SERVER) {
-		if (!(ctx->waiters = toks_calloc(TOKS_MAX_WAITERS,sizeof(*ctx->waiters))))
+		if (!(ctx->waiters = toks_calloc(
+				TOKS_MAX_WAITERS,
+				sizeof(struct toks_waiter))))
 			return toks_get_driver_ctx_fail(meta);
 
+		toks_daemon_ctx.driver_ctx   = &ctx->ctx;
+		toks_daemon_ctx.waiter_base  = ctx->waiters;
+		toks_daemon_ctx.waiter_first = ctx->waiters;
+		toks_daemon_ctx.waiter_next  = ctx->waiters;
+		toks_daemon_ctx.waiter_cap   = &ctx->waiters[TOKS_MAX_WAITERS];
+
+
 		if (!(ctx->tokens = toks_calloc(ntokens,sizeof(*ctx->tokens))))
 			return toks_get_driver_ctx_fail(meta);
 
diff --git a/src/internal/toksvc_daemon_impl.h b/src/internal/toksvc_daemon_impl.h
index e976c01..548f536 100644
--- a/src/internal/toksvc_daemon_impl.h
+++ b/src/internal/toksvc_daemon_impl.h
@@ -46,6 +46,11 @@ typedef int32_t __stdcall toks_daemon_routine(struct toks_daemon_ctx *);
 struct toks_daemon_ctx {
 	struct toks_driver_ctx *driver_ctx;
 
+	struct toks_waiter *	waiter_base;
+	struct toks_waiter *	waiter_first;
+	struct toks_waiter *	waiter_next;
+	struct toks_waiter *	waiter_cap;
+
 	nt_port_keys		daemon_keys;
 	nt_port_attr		daemon_attr;
 	nt_port_name		daemon_name;
diff --git a/src/internal/toksvc_driver_impl.h b/src/internal/toksvc_driver_impl.h
index 7908a41..d4d1568 100644
--- a/src/internal/toksvc_driver_impl.h
+++ b/src/internal/toksvc_driver_impl.h
@@ -151,13 +151,6 @@ static inline const nt_guid * toks_get_driver_uuid(const struct toks_driver_ctx 
 	return &ictx->uuid;
 }
 
-static inline struct toks_waiter * toks_get_driver_waiters(const struct toks_driver_ctx * dctx)
-{
-	struct toks_driver_ctx_impl * ictx;
-	ictx = toks_get_driver_ictx(dctx);
-	return ictx->waiters;
-}
-
 static inline int toks_get_driver_nwaiters(const struct toks_driver_ctx * dctx)
 {
 	struct toks_driver_ctx_impl * ictx;