[ovs-dev] [PATCH] poll-loop: windows poll_block implementation
Linda Sun
lsun at vmware.com
Wed Dec 18 22:52:17 UTC 2013
Use WaitForMultipleObjects for polling on windows. This works on all kinds
of objects, e.g. sockets, files, especially ioctl calls to the kernel.
poll_fd_wait_event() is used if events need to be passed to pollfds.
latch is signaled with event, to be waited/polled by WaitForMultipleObjects()
as well.
Changed array of fds to hmap to check for duplicate fds.
Signed-off-by: Linda Sun <lsun at vmware.com>
---
include/linux/types.h | 2 +
lib/latch.c | 2 +-
lib/latch.h | 4 ++
lib/poll-loop.c | 119 +++++++++++++++++++++++++++++++++++++++----------
lib/poll-loop.h | 5 ++-
lib/timeval.c | 20 +++++++--
lib/timeval.h | 4 +-
7 files changed, 124 insertions(+), 32 deletions(-)
diff --git a/include/linux/types.h b/include/linux/types.h
index b88fb1c..4114b0f 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -55,4 +55,6 @@ typedef uint32_t __bitwise__ __be32;
typedef uint64_t __bitwise__ __be64;
#endif /* no <linux/types.h> */
+typedef __u32 HANDLE;
+
#endif /* <linux/types.h> */
diff --git a/lib/latch.c b/lib/latch.c
index bf518b9..20a6575 100644
--- a/lib/latch.c
+++ b/lib/latch.c
@@ -83,5 +83,5 @@ latch_is_set(const struct latch *latch)
void
latch_wait_at(const struct latch *latch, const char *where)
{
- poll_fd_wait_at(latch->fds[0], POLLIN, where);
+ poll_fd_wait_at(latch->fds[0], 0, POLLIN, where);
}
diff --git a/lib/latch.h b/lib/latch.h
index 0b6e8a3..250e48e 100644
--- a/lib/latch.h
+++ b/lib/latch.h
@@ -27,6 +27,10 @@
struct latch {
int fds[2];
+#ifdef WIN32
+ HANDLE wevent;
+ bool is_set;
+#endif
};
void latch_init(struct latch *);
diff --git a/lib/poll-loop.c b/lib/poll-loop.c
index 5e3618b..06911dc 100644
--- a/lib/poll-loop.c
+++ b/lib/poll-loop.c
@@ -30,18 +30,24 @@
#include "socket-util.h"
#include "timeval.h"
#include "vlog.h"
+#include "hmap.h"
+#include "hash.h"
VLOG_DEFINE_THIS_MODULE(poll_loop);
COVERAGE_DEFINE(poll_fd_wait);
COVERAGE_DEFINE(poll_zero_timeout);
+struct poll_node {
+ struct hmap_node hmap_node;
+ struct pollfd poll_fd; /* Events to pass to time_poll() */
+ HANDLE wevent; /* events for waitformultipleobjects */
+ const char *where; /* where each pollfd was created */
+};
+
struct poll_loop {
/* All active poll waiters. */
- struct pollfd *pollfds; /* Events to pass to poll(). */
- const char **where; /* Where each pollfd was created. */
- size_t n_waiters; /* Number of elems in 'where' and 'pollfds'. */
- size_t allocated_waiters; /* Allocated elems in 'where' and 'pollfds'. */
+ struct hmap poll_nodes;
/* Time at which to wake up the next call to poll_block(), LLONG_MIN to
* wake up immediately, or LLONG_MAX to wait forever. */
@@ -51,6 +57,20 @@ struct poll_loop {
static struct poll_loop *poll_loop(void);
+/* Look up the node with same fd and wevent */
+static struct poll_node *
+poll_fd_node_find(struct poll_loop *loop, int fd, uint32_t wevent)
+{
+ struct poll_node *node;
+
+ HMAP_FOR_EACH_WITH_HASH(node, hmap_node, hash_2words(fd, wevent), &loop->poll_nodes) {
+ if (node->poll_fd.fd == fd && node->wevent == wevent) {
+ return node;
+ }
+ }
+ return NULL;
+}
+
/* Registers 'fd' as waiting for the specified 'events' (which should be POLLIN
* or POLLOUT or POLLIN | POLLOUT). The following call to poll_block() will
* wake up when 'fd' becomes ready for one or more of the requested events.
@@ -63,23 +83,37 @@ static struct poll_loop *poll_loop(void);
* automatically provide the caller's source file and line number for
* 'where'.) */
void
-poll_fd_wait_at(int fd, short int events, const char *where)
+poll_fd_wait_at(int fd, HANDLE wevent, short int events, const char *where)
{
struct poll_loop *loop = poll_loop();
+ struct poll_node *node;
COVERAGE_INC(poll_fd_wait);
- if (loop->n_waiters >= loop->allocated_waiters) {
- loop->where = x2nrealloc(loop->where, &loop->allocated_waiters,
- sizeof *loop->where);
- loop->pollfds = xrealloc(loop->pollfds,
- (loop->allocated_waiters
- * sizeof *loop->pollfds));
+
+#ifdef WIN32
+ /* null event cannot be polled */
+ if (wevent == 0) {
+ VLOG_ERR("No event to wait fd %d\n", fd);
+ return;
}
+#endif
- loop->where[loop->n_waiters] = where;
- loop->pollfds[loop->n_waiters].fd = fd;
- loop->pollfds[loop->n_waiters].events = events;
- loop->n_waiters++;
+ /* check for duplicate. If found, "or" the event */
+ node = poll_fd_node_find(loop, fd, wevent);
+ if (node) {
+ node->poll_fd.events |= events;
+ } else {
+ node = xzalloc(sizeof *node);
+ if (node == NULL) {
+ return;
+ }
+ node->where = where;
+ node->poll_fd.fd = fd;
+ node->wevent = wevent;
+ node->poll_fd.events = events;
+ hmap_insert(&loop->poll_nodes, &node->hmap_node,
+ hash_2words(fd, wevent));
+ }
}
/* Causes the following call to poll_block() to block for no more than 'msec'
@@ -215,8 +249,12 @@ void
poll_block(void)
{
struct poll_loop *loop = poll_loop();
+ struct poll_node *node, *next;
+ struct pollfd *pollfds;
+ HANDLE *wevents = NULL;
int elapsed;
int retval;
+ int i = 0;
/* Register fatal signal events before actually doing any real work for
* poll_block. */
@@ -227,7 +265,29 @@ poll_block(void)
}
timewarp_wait();
- retval = time_poll(loop->pollfds, loop->n_waiters,
+ pollfds = xzalloc(hmap_count(&loop->poll_nodes) * sizeof *pollfds);
+ if (pollfds == NULL) {
+ return;
+ }
+
+#ifdef WIN32
+ wevents = xzalloc(hmap_count(&loop->poll_nodes) * sizeof *wevents);
+ if (wevents == NULL) {
+ free(pollfds);
+ return;
+ }
+#endif
+
+ /* populate with all the fds and events */
+ HMAP_FOR_EACH(node, hmap_node, &loop->poll_nodes) {
+ memcpy(&pollfds[i], &node->poll_fd, sizeof node->poll_fd);
+#ifdef WIN32
+ wevents[i] = node->wevent;
+#endif
+ i++;
+ }
+
+ retval = time_poll(pollfds, hmap_count(&loop->poll_nodes), wevents,
loop->timeout_when, &elapsed);
if (retval < 0) {
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
@@ -235,18 +295,23 @@ poll_block(void)
} else if (!retval) {
log_wakeup(loop->timeout_where, NULL, elapsed);
} else if (get_cpu_usage() > 50 || VLOG_IS_DBG_ENABLED()) {
- size_t i;
-
- for (i = 0; i < loop->n_waiters; i++) {
- if (loop->pollfds[i].revents) {
- log_wakeup(loop->where[i], &loop->pollfds[i], 0);
+ HMAP_FOR_EACH(node, hmap_node, &loop->poll_nodes) {
+ if (node->poll_fd.revents) {
+ log_wakeup(node->where, &node->poll_fd, 0);
}
}
}
+ HMAP_FOR_EACH_SAFE(node, next, hmap_node, &loop->poll_nodes) {
+ hmap_remove(&loop->poll_nodes, &node->hmap_node);
+ free(node);
+ }
+
loop->timeout_when = LLONG_MAX;
loop->timeout_where = NULL;
- loop->n_waiters = 0;
+ free(pollfds);
+ if (wevents)
+ free(wevents);
/* Handle any pending signals before doing anything else. */
fatal_signal_run();
@@ -258,9 +323,14 @@ static void
free_poll_loop(void *loop_)
{
struct poll_loop *loop = loop_;
+ struct poll_node *node, *next;
- free(loop->pollfds);
- free(loop->where);
+ HMAP_FOR_EACH_SAFE(node, next, hmap_node, &loop->poll_nodes) {
+ hmap_remove(&loop->poll_nodes, &node->hmap_node);
+ free(node);
+ }
+
+ hmap_destroy(&loop->poll_nodes);
free(loop);
}
@@ -279,6 +349,7 @@ poll_loop(void)
loop = pthread_getspecific(key);
if (!loop) {
loop = xzalloc(sizeof *loop);
+ hmap_init(&loop->poll_nodes);
xpthread_setspecific(key, loop);
}
return loop;
diff --git a/lib/poll-loop.h b/lib/poll-loop.h
index 0397853..2db3fff 100644
--- a/lib/poll-loop.h
+++ b/lib/poll-loop.h
@@ -50,8 +50,9 @@ extern "C" {
* caller to supply a location explicitly, which is useful if the caller's own
* caller would be more useful in log output. See timer_wait_at() for an
* example. */
-void poll_fd_wait_at(int fd, short int events, const char *where);
-#define poll_fd_wait(fd, events) poll_fd_wait_at(fd, events, SOURCE_LOCATOR)
+void poll_fd_wait_at(int fd, uint32_t wevent, short int events, const char *where);
+#define poll_fd_wait(fd, events) poll_fd_wait_at(fd, 0, events, SOURCE_LOCATOR)
+#define poll_fd_wait_event(fd, wevent, events) poll_fd_wait_at(fd, wevent, events, SOURCE_LOCATOR)
void poll_timer_wait_at(long long int msec, const char *where);
#define poll_timer_wait(msec) poll_timer_wait_at(msec, SOURCE_LOCATOR)
diff --git a/lib/timeval.c b/lib/timeval.c
index 2ce45fc..8548448 100644
--- a/lib/timeval.c
+++ b/lib/timeval.c
@@ -232,12 +232,12 @@ time_alarm(unsigned int secs)
*
* Stores the number of milliseconds elapsed during poll in '*elapsed'. */
int
-time_poll(struct pollfd *pollfds, int n_pollfds, long long int timeout_when,
- int *elapsed)
+time_poll(struct pollfd *pollfds, int n_pollfds, HANDLE *handles,
+ long long int timeout_when, int *elapsed)
{
long long int *last_wakeup = last_wakeup_get();
long long int start;
- int retval;
+ int retval = 0;
time_init();
coverage_clear();
@@ -261,10 +261,24 @@ time_poll(struct pollfd *pollfds, int n_pollfds, long long int timeout_when,
time_left = timeout_when - now;
}
+#ifndef WIN32
+ if (handles) {
+ /* non-windows platform shouldn't really create these handles */
+ }
retval = poll(pollfds, n_pollfds, time_left);
if (retval < 0) {
retval = -errno;
}
+#else
+ if (n_pollfds != 0) {
+ retval = WaitForMultipleObjects(n_pollfds, handles, FALSE, time_left);
+ }
+ if (retval < 0) {
+ /* This will be replace by a win error to errno conversion function */
+ retval = -WSAGetLastError();
+ retval = -EINVAL;
+ }
+#endif
if (deadline <= time_msec()) {
fatal_signal_handler(SIGALRM);
diff --git a/lib/timeval.h b/lib/timeval.h
index 1bbfd5c..4162f63 100644
--- a/lib/timeval.h
+++ b/lib/timeval.h
@@ -52,8 +52,8 @@ long long int time_wall_msec(void);
void time_timespec(struct timespec *);
void time_wall_timespec(struct timespec *);
void time_alarm(unsigned int secs);
-int time_poll(struct pollfd *, int n_pollfds, long long int timeout_when,
- int *elapsed);
+int time_poll(struct pollfd *, int n_pollfds, HANDLE *handles,
+ long long int timeout_when, int *elapsed);
long long int timespec_to_msec(const struct timespec *);
long long int timeval_to_msec(const struct timeval *);
--
1.7.9.5
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