pipefs: use poll internally rather than keeping the old events

This commit is contained in:
Matheus
2023-09-30 12:49:38 -03:00
parent 9519e4c67a
commit 1bb152b446
2 changed files with 90 additions and 73 deletions
+90 -72
View File
@@ -46,56 +46,86 @@ int pipefs_close(vnode_t *node, int flags, cred_t *cred) {
}
if (pipenode->readers == 0)
event_signal(&pipenode->readevent);
poll_event(&pipenode->pollheader, POLLERR);
if (pipenode->writers == 0)
event_signal(&pipenode->writeevent);
poll_event(&pipenode->pollheader, POLLHUP);
VOP_UNLOCK(node);
return 0;
}
static int internalpoll(vnode_t *node, polldata_t *data, int events) {
pipenode_t *pipenode = (pipenode_t *)node;
int revents = 0;
if (events & POLLIN) {
events |= POLLHUP;
if (pipenode->writers == 0)
revents |= POLLHUP;
else if (RINGBUFFER_DATACOUNT(&pipenode->data) > 0)
revents |= POLLIN;
}
if (events & POLLOUT) {
events |= POLLERR;
if (pipenode->readers == 0)
revents |= POLLERR;
else if (RINGBUFFER_DATACOUNT(&pipenode->data) < BUFFER_SIZE)
revents |= POLLOUT;
}
if (revents == 0 && data)
poll_add(&pipenode->pollheader, data, events);
return revents;
}
int pipefs_read(vnode_t *node, void *buffer, size_t size, uintmax_t offset, int flags, size_t *readc, cred_t *cred) {
pipenode_t *pipenode = (pipenode_t *)node;
VOP_LOCK(node);
int error = 0;
*readc = 0;
size_t datacount = 0;
// wait until there is data to read or return if nonblock
while (datacount == 0) {
datacount = RINGBUFFER_DATACOUNT(&pipenode->data);
if (datacount == 0) {
if (pipenode->writers == 0)
goto leave;
while (1) {
// check for available data or if the write end has been closed
int revents = internalpoll(node, NULL, POLLIN);
if (revents)
break;
if (flags & V_FFLAGS_NONBLOCKING) {
error = EAGAIN;
goto leave;
}
// to make it harder for a race condition to happen TODO figure out a way to fix this
bool status = interrupt_set(false);
VOP_UNLOCK(node);
error = event_wait(&pipenode->writeevent, true);
interrupt_set(status);
if (error)
return error;
VOP_LOCK(node);
if (flags & V_FFLAGS_NONBLOCKING) {
error = EAGAIN;
goto leave;
}
// do the wait
polldesc_t desc = {0};
error = poll_initdesc(&desc, 1);
if (error)
goto leave;
revents = internalpoll(node, &desc.data[0], POLLIN);
VOP_UNLOCK(node);
error = poll_dowait(&desc, 0);
poll_leave(&desc);
poll_destroydesc(&desc);
if (error)
return error;
VOP_LOCK(node);
}
*readc = ringbuffer_read(&pipenode->data, buffer, size);
if (*readc < datacount) {
// signal that there is space to write for any threads blocked on this pipe
if (*readc)
poll_event(&pipenode->pollheader, POLLOUT);
event_signal(&pipenode->writeevent);
}
event_signal(&pipenode->readevent);
leave:
VOP_UNLOCK(node);
@@ -109,27 +139,37 @@ int pipefs_write(vnode_t *node, void *buffer, size_t size, uintmax_t offset, int
int error = 0;
*writec = 0;
// wait until there is space to write data into or return if nonblock
size_t datacount = BUFFER_SIZE;
while (datacount == BUFFER_SIZE && pipenode->readers) {
datacount = RINGBUFFER_DATACOUNT(&pipenode->data);
if (datacount == BUFFER_SIZE) {
if (flags & V_FFLAGS_NONBLOCKING) {
error = EAGAIN;
goto leave;
}
// wait until there is space to write data or return if nonblock
while (1) {
// check for space or if the read end has been closed
int revents = internalpoll(node, NULL, POLLOUT);
if (revents)
break;
// to make it harder for a race condition to happen TODO figure out a way to fix this
bool status = interrupt_set(false);
VOP_UNLOCK(node);
error = event_wait(&pipenode->readevent, true);
interrupt_set(status);
if (error)
return error;
VOP_LOCK(node);
if (flags & V_FFLAGS_NONBLOCKING) {
error = EAGAIN;
goto leave;
}
// do the wait
polldesc_t desc = {0};
error = poll_initdesc(&desc, 1);
if (error)
goto leave;
revents = internalpoll(node, &desc.data[0], POLLOUT);
VOP_UNLOCK(node);
error = poll_dowait(&desc, 0);
poll_leave(&desc);
poll_destroydesc(&desc);
if (error)
return error;
VOP_LOCK(node);
}
if (pipenode->readers == 0) {
@@ -140,12 +180,8 @@ int pipefs_write(vnode_t *node, void *buffer, size_t size, uintmax_t offset, int
*writec = ringbuffer_write(&pipenode->data, buffer, size);
if (datacount + *writec < BUFFER_SIZE) {
poll_event(&pipenode->pollheader, POLLIN);
event_signal(&pipenode->readevent);
}
event_signal(&pipenode->writeevent);
__assert(*writec);
poll_event(&pipenode->pollheader, POLLIN);
leave:
VOP_UNLOCK(node);
@@ -153,26 +189,10 @@ int pipefs_write(vnode_t *node, void *buffer, size_t size, uintmax_t offset, int
}
int pipefs_poll(vnode_t *node, polldata_t *data, int events) {
pipenode_t *pipenode = (pipenode_t *)node;
int revents = 0;
VOP_LOCK(node);
if (events & POLLIN) {
if (pipenode->writers == 0)
revents |= POLLHUP;
else if (RINGBUFFER_DATACOUNT(&pipenode->data) > 0)
revents |= POLLIN;
}
if (events & POLLOUT) {
if (pipenode->readers == 0)
revents |= POLLERR;
else if (RINGBUFFER_DATACOUNT(&pipenode->data) < BUFFER_SIZE)
revents |= POLLOUT;
}
if (revents == 0 && data)
poll_add(&pipenode->pollheader, data, events);
revents = internalpoll(node, data, events);
VOP_UNLOCK(node);
return revents;
@@ -244,8 +264,6 @@ static void ctor(scache_t *cache, void *obj) {
memset(node, 0, sizeof(pipenode_t));
VOP_INIT(&node->vnode, &vnops, 0, V_TYPE_FIFO, NULL);
node->attr.inode = ++currentinode;
EVENT_INIT(&node->writeevent);
EVENT_INIT(&node->readevent);
POLL_INITHEADER(&node->pollheader);
}
-1
View File
@@ -12,7 +12,6 @@ typedef struct pipenode_t {
vattr_t attr;
ringbuffer_t data;
size_t readers, writers;
event_t readevent, writeevent;
pollheader_t pollheader;
} pipenode_t;