kernel: remove event_t as it suffered from a lost wakeup issue

kernel-src/include/event.h

@@ -1,12 +0,0 @@
-#ifndef _EVENT_H
-#define _EVENT_H
-
-#include <semaphore.h>
-typedef semaphore_t event_t;
-
-int event_wait(event_t *event, bool interruptible);
-void event_signal(event_t *event);
-
-#define EVENT_INIT(x) SEMAPHORE_INIT(x, 0);
-
-#endif

kernel-src/include/kernel/net.h

@@ -6,7 +6,6 @@
 
 #include <hashtable.h>
 #include <mutex.h>
-#include <event.h>
 #include <string.h>
 #include <arch/cpu.h>
 #include <kernel/abi.h>

kernel-src/include/kernel/pipefs.h

@@ -4,7 +4,6 @@
 #include <kernel/vfs.h>
 #include <ringbuffer.h>
 #include <semaphore.h>
-#include <event.h>
 #include <kernel/poll.h>
 
 typedef struct pipenode_t {

kernel-src/io/block/nvme.c

@@ -50,7 +50,6 @@
 	(sub)->namespace = nsid;
 
 #define PAIR_INIT(pair, opcode, fused, memaccess, nsid) \
-	EVENT_INIT(&(pair)->event); \
 	SUB_INIT(&(pair)->sub, opcode, fused, memaccess, nsid);
 
 #define SUB_DW0_OPCODE_WRITE 0x1
@@ -222,7 +221,7 @@ typedef struct {
 typedef struct {
 	compentry_t comp;
 	subentry_t sub;
-	event_t event;
+	thread_t *thread;
 } entrypair_t;
 
 typedef struct {
@@ -277,7 +276,7 @@ static void nvme_dpc(context_t *, dpcarg_t arg) {
 		int subid = COMP_CMDINFO_CMDID(queue[pair->completion.index].cmdinfo);
 		pair->entries[subid]->comp = queue[pair->completion.index];
 
-		event_signal(&pair->entries[subid]->event);
+		sched_wakeup(pair->entries[subid]->thread, SCHED_WAKEUP_REASON_NORMAL);
 
 		pair->entries[subid] = NULL;
 		semaphore_signal(&pair->entrysem);
@@ -311,7 +310,7 @@ static isr_t *msixnewisrforqueue(queuepair_t *queuepair) {
 	return isr;
 }
 
-static void enqueue(queuepair_t *queuepair, entrypair_t *entries) {
+static void enqueueandwait(queuepair_t *queuepair, entrypair_t *entries) {
 	bool intstatus = interrupt_set(false);
 	semaphore_wait(&queuepair->entrysem, false);
 
@@ -328,16 +327,10 @@ static void enqueue(queuepair_t *queuepair, entrypair_t *entries) {
 	queuepair->submission.index %= queuepair->submission.entrycount;
 
 	*queuepair->submission.doorbell = queuepair->submission.index;
+	sched_preparesleep(false);
+	entries->thread = _cpu()->thread;
 	spinlock_release(&queuepair->lock);
-	interrupt_set(intstatus);
+	sched_yield();
-}
-
-static void enqueueandwait(queuepair_t *queuepair, entrypair_t *entries) {
-	bool intstatus = interrupt_set(false);
-
-	enqueue(queuepair, entries);
-	event_wait(&entries->event, false);
-
 	interrupt_set(intstatus);
 }
 

kernel-src/io/block/vioblk.c

@@ -6,7 +6,6 @@
 #include <semaphore.h>
 #include <kernel/block.h>
 #include <kernel/pmm.h>
-#include <event.h>
 #include <string.h>
 
 #define QUEUE_MAX_SIZE 128

kernel-src/io/net/arp.c

@@ -3,7 +3,6 @@
 #include <kernel/scheduler.h>
 #include <kernel/timekeeper.h>
 #include <logging.h>
-#include <event.h>
 #include <kernel/slab.h>
 #include <kernel/eth.h>
 #include <ringbuffer.h>
@@ -26,7 +25,6 @@ typedef struct {
 static scache_t *entryallocator;
 
 static thread_t *handlerthread;
-static event_t handlerthreadwakeup;
 
 static thread_t *cleanupthread;
 
@@ -277,8 +275,6 @@ void arp_init() {
 	cleanupthread = sched_newthread(cleanupthreadfn, PAGE_SIZE * 4, 0, NULL, NULL);
 	__assert(cleanupthread);
 
-	EVENT_INIT(&handlerthreadwakeup);
-
 	MUTEX_INIT(&cachelock);
 
 	SEMAPHORE_INIT(&psem, 0);

kernel-src/io/net/loopback.c

@@ -3,7 +3,6 @@
 #include <kernel/pmm.h>
 #include <kernel/eth.h>
 #include <kernel/net.h>
-#include <event.h>
 #include <hashtable.h>
 #include <arch/cpu.h>
 

kernel-src/io/net/vionet.c

@@ -3,7 +3,6 @@
 #include <kernel/pmm.h>
 #include <kernel/eth.h>
 #include <kernel/net.h>
-#include <event.h>
 #include <hashtable.h>
 #include <arch/cpu.h>
 
@@ -18,7 +17,7 @@ typedef struct {
 	viodevice_t *viodevice;
 	vioqueue_t rxqueue;
 	vioqueue_t txqueue;
-	event_t *txwait[QUEUE_MAX_SIZE];
+	thread_t *txwait[QUEUE_MAX_SIZE];
 	semaphore_t txsem;
 	spinlock_t txlock;
 	dpc_t txdpc;
@@ -69,7 +68,7 @@ static void tx_dpc(context_t *context, dpcarg_t arg) {
 		int idx = netdev->txqueue.lastusedindex++ % netdev->txqueue.size;
 		int buffidx = VIO_QUEUE_DEV_RING(&netdev->txqueue)[idx].index;
 		__assert(netdev->txwait[buffidx / 2]);
-		event_signal(netdev->txwait[buffidx / 2]);
+		sched_wakeup(netdev->txwait[buffidx / 2], SCHED_WAKEUP_REASON_NORMAL);
 		netdev->txwait[buffidx / 2] = NULL;
 		buffers[buffidx].address = 0;
 		semaphore_signal(&netdev->txsem);
@@ -121,9 +120,6 @@ static int vionet_sendpacket(netdev_t *internal, netdesc_t desc, mac_t targetmac
 	memcpy(desc.address, &vioframe, sizeof(vioframe_t));
 	memcpy((void *)((uintptr_t)desc.address + sizeof(vioframe_t)), &ethframe, sizeof(ethframe_t));
 
-	event_t event;
-	EVENT_INIT(&event);
-
 	bool intstatus = interrupt_set(false);
 	semaphore_wait(&netdev->txsem, false);
 
@@ -142,13 +138,13 @@ static int vionet_sendpacket(netdev_t *internal, netdesc_t desc, mac_t targetmac
 	size_t driveridx = VIO_QUEUE_DRV_IDX(&netdev->txqueue)++;
 	VIO_QUEUE_DRV_RING(&netdev->txqueue)[driveridx % netdev->txqueue.size] = idx;
 
-	netdev->txwait[idx] = &event;
+	sched_preparesleep(false);
-
+	netdev->txwait[idx] = _cpu()->thread;
 	*netdev->txqueue.notify = 0;
 
 	spinlock_release(&netdev->txlock);
 
-	event_wait(&event, false);
+	sched_yield();
 
 	interrupt_set(intstatus);
 	return 0;

kernel-src/lib/event.c

@@ -1,19 +0,0 @@
-#include <event.h>
-
-// TODO while this works, it is built upon semaphores and might have some race conditions
-
-int event_wait(event_t *event, bool interruptible) {
-	int e = semaphore_wait(event, interruptible);
-	if (e)
-		return e;
-
-	if (semaphore_haswaiters(event))
-		semaphore_signal(event);
-
-	return 0;
-}
-
-void event_signal(event_t *event) {
-	if (semaphore_haswaiters(event))
-		semaphore_signal(event);
-}