health_code_update(&health_thread_kernel);
- ret = create_thread_poll_set(&events, 2);
- if (ret < 0) {
- goto error_poll_create;
- }
-
- ret = lttng_poll_add(&events, kernel_poll_pipe[0], LPOLLIN);
- if (ret < 0) {
- goto error;
- }
-
if (testpoint(thread_manage_kernel_before_loop)) {
- goto error;
+ goto error_testpoint;
}
while (1) {
health_code_update(&health_thread_kernel);
if (update_poll_flag == 1) {
- /*
- * Reset number of fd in the poll set. Always 2 since there is the thread
- * quit pipe and the kernel pipe.
- */
- events.nb_fd = 2;
+ /* Clean events object. We are about to populate it again. */
+ lttng_poll_clean(&events);
+
+ ret = create_thread_poll_set(&events, 2);
+ if (ret < 0) {
+ goto error_poll_create;
+ }
+
+ ret = lttng_poll_add(&events, kernel_poll_pipe[0], LPOLLIN);
+ if (ret < 0) {
+ goto error;
+ }
+ /* This will add the available kernel channel if any. */
ret = update_kernel_poll(&events);
if (ret < 0) {
goto error;
update_poll_flag = 0;
}
- DBG("Thread kernel polling on %d fds", events.nb_fd);
+ DBG("Thread kernel polling on %d fds", LTTNG_POLL_GETNB(&events));
/* Poll infinite value of time */
restart:
health_code_update(&health_thread_app_manage);
while (1) {
- DBG("Apps thread polling on %d fds", events.nb_fd);
+ DBG("Apps thread polling on %d fds", LTTNG_POLL_GETNB(&events));
/* Inifinite blocking call, waiting for transmission */
restart:
*/
#define _GNU_SOURCE
+#include <assert.h>
#include <fcntl.h>
#include <limits.h>
#include <stdlib.h>
unsigned int poll_max_size;
+/*
+ * Resize the epoll events structure of the new size.
+ *
+ * Return 0 on success or else -1 with the current events pointer untouched.
+ */
+static int resize_poll_event(struct lttng_poll_event *events,
+ uint32_t new_size)
+{
+ struct epoll_event *ptr;
+
+ assert(events);
+
+ ptr = realloc(events->events, new_size * sizeof(*ptr));
+ if (ptr == NULL) {
+ PERROR("realloc epoll add");
+ goto error;
+ }
+ events->events = ptr;
+ events->alloc_size = new_size;
+
+ return 0;
+
+error:
+ return -1;
+}
+
/*
* Create epoll set and allocate returned events structure.
*/
goto error_close;
}
- events->events_size = size;
+ events->alloc_size = events->init_size = size;
events->nb_fd = 0;
return 0;
*/
int compat_epoll_add(struct lttng_poll_event *events, int fd, uint32_t req_events)
{
- int ret, new_size;
- struct epoll_event ev, *ptr;
+ int ret;
+ struct epoll_event ev;
if (events == NULL || events->events == NULL || fd < 0) {
ERR("Bad compat epoll add arguments");
events->nb_fd++;
- if (events->nb_fd >= events->events_size) {
- new_size = 2 * events->events_size;
- ptr = realloc(events->events, new_size * sizeof(struct epoll_event));
- if (ptr == NULL) {
- PERROR("realloc epoll add");
- goto error;
- }
- events->events = ptr;
- events->events_size = new_size;
- }
-
end:
return 0;
int compat_epoll_wait(struct lttng_poll_event *events, int timeout)
{
int ret;
+ uint32_t new_size;
- if (events == NULL || events->events == NULL ||
- events->events_size < events->nb_fd) {
+ if (events == NULL || events->events == NULL) {
ERR("Wrong arguments in compat_epoll_wait");
goto error;
}
+ /*
+ * Resize if needed before waiting. We could either expand the array or
+ * shrink it down. It's important to note that after this step, we are
+ * ensured that the events argument of the epoll_wait call will be large
+ * enough to hold every possible returned events.
+ */
+ if (events->nb_fd > events->alloc_size) {
+ /* Expand if the nb_fd is higher than the actual size. */
+ new_size = events->alloc_size << 1UL;
+ } else if ((events->nb_fd << 1UL) <= events->alloc_size &&
+ events->nb_fd >= events->init_size) {
+ /* Shrink if nb_fd multiplied by two is <= than the actual size. */
+ new_size = events->alloc_size >> 1UL;
+ } else {
+ /* Indicate that we don't want to resize. */
+ new_size = 0;
+ }
+
+ if (new_size) {
+ ret = resize_poll_event(events, new_size);
+ if (ret < 0) {
+ /* ENOMEM problem at this point. */
+ goto error;
+ }
+ }
+
do {
ret = epoll_wait(events->epfd, events->events, events->nb_fd, timeout);
} while (ret == -1 && errno == EINTR);
}
poll_max_size = atoi(buf);
- if (poll_max_size <= 0) {
+ if (poll_max_size == 0) {
/* Extra precaution */
poll_max_size = DEFAULT_POLL_SIZE;
}
*/
#define _GNU_SOURCE
+#include <assert.h>
#include <stdlib.h>
#include <sys/resource.h>
#include <sys/time.h>
unsigned int poll_max_size;
+/*
+ * Resize the epoll events structure of the new size.
+ *
+ * Return 0 on success or else -1 with the current events pointer untouched.
+ */
+static int resize_poll_event(struct compat_poll_event_array *array,
+ uint32_t new_size)
+{
+ struct pollfd *ptr;
+
+ assert(array);
+
+ ptr = realloc(array->events, new_size * sizeof(*ptr));
+ if (ptr == NULL) {
+ PERROR("realloc epoll add");
+ goto error;
+ }
+ array->events = ptr;
+ array->alloc_size = new_size;
+
+ return 0;
+
+error:
+ return -1;
+}
+
+/*
+ * Update events with the current events object.
+ */
+static int update_current_events(struct lttng_poll_event *events)
+{
+ int ret;
+ struct compat_poll_event_array *current, *wait;
+
+ assert(events);
+
+ current = &events->current;
+ wait = &events->wait;
+
+ wait->nb_fd = current->nb_fd;
+ if (events->need_realloc) {
+ ret = resize_poll_event(wait, current->alloc_size);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+ memcpy(wait->events, current->events,
+ current->nb_fd * sizeof(*current->events));
+
+ /* Update is done and realloc as well. */
+ events->need_update = 0;
+ events->need_realloc = 0;
+
+ return 0;
+
+error:
+ return -1;
+}
+
/*
* Create pollfd data structure.
*/
int compat_poll_create(struct lttng_poll_event *events, int size)
{
+ struct compat_poll_event_array *current, *wait;
+
if (events == NULL || size <= 0) {
ERR("Wrong arguments for poll create");
goto error;
size = poll_max_size;
}
+ /* Reset everything before begining the allocation. */
+ memset(events, 0, sizeof(struct lttng_poll_event));
+
+ /* Ease our life a bit. */
+ current = &events->current;
+ wait = &events->wait;
+
/* This *must* be freed by using lttng_poll_free() */
- events->events = zmalloc(size * sizeof(struct pollfd));
- if (events->events == NULL) {
+ wait->events = zmalloc(size * sizeof(struct pollfd));
+ if (wait->events == NULL) {
perror("zmalloc struct pollfd");
goto error;
}
- events->events_size = size;
- events->nb_fd = 0;
+ wait->alloc_size = wait->init_size = size;
+
+ current->events = zmalloc(size * sizeof(struct pollfd));
+ if (current->events == NULL) {
+ perror("zmalloc struct current pollfd");
+ goto error;
+ }
+
+ current->alloc_size = current->init_size = size;
return 0;
int compat_poll_add(struct lttng_poll_event *events, int fd,
uint32_t req_events)
{
- int new_size;
- struct pollfd *ptr;
+ int new_size, ret, i;
+ struct compat_poll_event_array *current;
- if (events == NULL || events->events == NULL || fd < 0) {
+ if (events == NULL || events->current.events == NULL || fd < 0) {
ERR("Bad compat poll add arguments");
goto error;
}
- /* Reallocate pollfd structure by a factor of 2 if needed. */
- if (events->nb_fd >= events->events_size) {
- new_size = 2 * events->events_size;
- ptr = realloc(events->events, new_size * sizeof(struct pollfd));
- if (ptr == NULL) {
- perror("realloc poll add");
+ /* Ease our life a bit. */
+ current = &events->current;
+
+ /* Check if fd we are trying to add is already there. */
+ for (i = 0; i < current->nb_fd; i++) {
+ /* Don't put back the fd we want to delete */
+ if (current->events[i].fd == fd) {
+ errno = EEXIST;
goto error;
}
- events->events = ptr;
- events->events_size = new_size;
}
- events->events[events->nb_fd].fd = fd;
- events->events[events->nb_fd].events = req_events;
- events->nb_fd++;
+ /* Check for a needed resize of the array. */
+ if (current->nb_fd > current->alloc_size) {
+ /* Expand it by a power of two of the current size. */
+ new_size = current->alloc_size << 1UL;
+ ret = resize_poll_event(current, new_size);
+ if (ret < 0) {
+ goto error;
+ }
+ events->need_realloc = 1;
+ }
- DBG("fd %d of %d added to pollfd", fd, events->nb_fd);
+ current->events[current->nb_fd].fd = fd;
+ current->events[current->nb_fd].events = req_events;
+ current->nb_fd++;
+ events->need_update = 1;
+
+ DBG("fd %d of %d added to pollfd", fd, current->nb_fd);
return 0;
*/
int compat_poll_del(struct lttng_poll_event *events, int fd)
{
- int new_size, i, count = 0;
- struct pollfd *old = NULL, *new = NULL;
+ int new_size, i, count = 0, ret;
+ struct compat_poll_event_array *current;
- if (events == NULL || events->events == NULL || fd < 0) {
+ if (events == NULL || events->current.events == NULL || fd < 0) {
ERR("Wrong arguments for poll del");
goto error;
}
- old = events->events;
- new_size = events->events_size - 1;
+ /* Ease our life a bit. */
+ current = &events->current;
/* Safety check on size */
if (new_size > poll_max_size) {
new_size = poll_max_size;
}
- new = zmalloc(new_size * sizeof(struct pollfd));
- if (new == NULL) {
- perror("zmalloc poll del");
- goto error;
+ /* Check if we need to shrink it down. */
+ if ((current->nb_fd << 1UL) <= current->alloc_size &&
+ current->nb_fd >= current->init_size) {
+ /*
+ * Shrink if nb_fd multiplied by two is <= than the actual size and we
+ * are above the initial size.
+ */
+ new_size = current->alloc_size >> 1UL;
+ ret = resize_poll_event(current, new_size);
+ if (ret < 0) {
+ goto error;
+ }
+ events->need_realloc = 1;
}
- for (i = 0; i < events->events_size; i++) {
+ for (i = 0; i < current->nb_fd; i++) {
/* Don't put back the fd we want to delete */
- if (old[i].fd != fd) {
- new[count].fd = old[i].fd;
- new[count].events = old[i].events;
+ if (current->events[i].fd != fd) {
+ current->events[count].fd = current->events[i].fd;
+ current->events[count].events = current->events[i].events;
count++;
}
}
- events->events_size = new_size;
- events->events = new;
- events->nb_fd--;
-
- free(old);
+ current->nb_fd--;
+ events->need_update = 1;
return 0;
{
int ret;
- if (events == NULL || events->events == NULL ||
- events->events_size < events->nb_fd) {
+ if (events == NULL || events->current.events == NULL) {
ERR("poll wait arguments error");
goto error;
}
- ret = poll(events->events, events->nb_fd, timeout);
+ if (events->current.nb_fd == 0) {
+ /* Return an invalid error to be consistent with epoll. */
+ errno = EINVAL;
+ goto error;
+ }
+
+ if (events->need_update) {
+ ret = update_current_events(events);
+ if (ret < 0) {
+ errno = ENOMEM;
+ goto error;
+ }
+ }
+
+ ret = poll(events->wait.events, events->wait.nb_fd, timeout);
if (ret < 0) {
/* At this point, every error is fatal */
perror("poll wait");
* poll() should always iterate on all FDs since we handle the pollset in
* user space and after poll returns, we have to try every fd for a match.
*/
- return events->nb_fd;
+ return events->wait.nb_fd;
error:
return -1;
}
poll_max_size = lim.rlim_cur;
- if (poll_max_size <= 0) {
+ if (poll_max_size == 0) {
/* Extra precaution */
poll_max_size = DEFAULT_POLL_SIZE;
}
struct compat_epoll_event {
int epfd;
uint32_t nb_fd; /* Current number of fd in events */
- uint32_t events_size; /* Size of events array */
+ uint32_t alloc_size; /* Size of events array */
+ uint32_t init_size; /* Initial size of events array */
struct epoll_event *events;
};
#define lttng_poll_event compat_epoll_event
LTTNG_CLOEXEC = 0xdead,
};
-struct compat_poll_event {
+struct compat_poll_event_array {
uint32_t nb_fd; /* Current number of fd in events */
- uint32_t events_size; /* Size of events array */
+ uint32_t alloc_size; /* Size of events array */
+ /* Initial size of the pollset. We never shrink below that. */
+ uint32_t init_size;
struct pollfd *events;
};
+
+struct compat_poll_event {
+ /*
+ * Modified by the wait action. Updated using current fields if the
+ * need_update flag is set.
+ */
+ struct compat_poll_event_array wait;
+ /*
+ * This is modified by add/del actions being the _current_ flow of
+ * execution before a poll wait is done.
+ */
+ struct compat_poll_event_array current;
+ /* Indicate if wait.events needs to be realloc. */
+ int need_realloc:1;
+ /* Indicate if wait.events need to be updated from current. */
+ int need_update:1;
+};
#define lttng_poll_event compat_poll_event
/*
* For the following calls, consider 'e' to be a lttng_poll_event pointer and i
* being the index of the events array.
*/
-#define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->events[i].fd
-#define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->events[i].revents
-#define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->nb_fd
-#define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->events_size
+#define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->wait.events[i].fd
+#define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->wait.events[i].revents
+#define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->wait.nb_fd
+#define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->wait.events_size
/*
* Create a pollfd structure of size 'size'.
static inline void lttng_poll_clean(struct lttng_poll_event *events)
{
if (events) {
- __lttng_poll_free((void *) events->events);
+ __lttng_poll_free((void *) events->wait.events);
+ __lttng_poll_free((void *) events->current.events);
}
}
projects / lttng-tools.git / commitdiff
