+++ /dev/null
-/*
- * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License, version 2 only, as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 51
- * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-#define _GNU_SOURCE
-#define _LGPL_SOURCE
-#include <assert.h>
-#include <fcntl.h>
-#include <unistd.h>
-
-#include <common/common.h>
-
-#include "pipe.h"
-
-/*
- * Lock read side of a pipe.
- */
-static void lock_read_side(struct lttng_pipe *pipe)
-{
- pthread_mutex_lock(&pipe->read_mutex);
-}
-
-/*
- * Unlock read side of a pipe.
- */
-static void unlock_read_side(struct lttng_pipe *pipe)
-{
- pthread_mutex_unlock(&pipe->read_mutex);
-}
-
-/*
- * Lock write side of a pipe.
- */
-static void lock_write_side(struct lttng_pipe *pipe)
-{
- pthread_mutex_lock(&pipe->write_mutex);
-}
-
-/*
- * Unlock write side of a pipe.
- */
-static void unlock_write_side(struct lttng_pipe *pipe)
-{
- pthread_mutex_unlock(&pipe->write_mutex);
-}
-
-/*
- * Internal function. Close read side of pipe WITHOUT locking the mutex.
- *
- * Return 0 on success else a negative errno from close(2).
- */
-static int _pipe_read_close(struct lttng_pipe *pipe)
-{
- int ret, ret_val = 0;
-
- assert(pipe);
-
- if (!lttng_pipe_is_read_open(pipe)) {
- goto end;
- }
-
- do {
- ret = close(pipe->fd[0]);
- } while (ret < 0 && errno == EINTR);
- if (ret < 0) {
- PERROR("close lttng read pipe");
- ret_val = -errno;
- }
- pipe->r_state = LTTNG_PIPE_STATE_CLOSED;
-
-end:
- return ret_val;
-}
-
-/*
- * Internal function. Close write side of pipe WITHOUT locking the mutex.
- *
- * Return 0 on success else a negative errno from close(2).
- */
-static int _pipe_write_close(struct lttng_pipe *pipe)
-{
- int ret, ret_val = 0;
-
- assert(pipe);
-
- if (!lttng_pipe_is_write_open(pipe)) {
- goto end;
- }
-
- do {
- ret = close(pipe->fd[1]);
- } while (ret < 0 && errno == EINTR);
- if (ret < 0) {
- PERROR("close lttng write pipe");
- ret_val = -errno;
- }
- pipe->w_state = LTTNG_PIPE_STATE_CLOSED;
-
-end:
- return ret_val;
-}
-
-
-/*
- * Open a new lttng pipe and set flags using fcntl().
- *
- * Return a newly allocated lttng pipe on success or else NULL.
- */
-LTTNG_HIDDEN
-struct lttng_pipe *lttng_pipe_open(int flags)
-{
- int ret;
- struct lttng_pipe *p;
-
- p = zmalloc(sizeof(*p));
- if (!p) {
- PERROR("zmalloc pipe open");
- goto error;
- }
-
- ret = pipe(p->fd);
- if (ret < 0) {
- PERROR("lttng pipe");
- goto error;
- }
-
- if (flags) {
- int i;
-
- for (i = 0; i < 2; i++) {
- ret = fcntl(p->fd[i], F_SETFD, flags);
- if (ret < 0) {
- PERROR("fcntl lttng pipe %d", flags);
- goto error;
- }
- }
- }
-
- pthread_mutex_init(&p->read_mutex, NULL);
- pthread_mutex_init(&p->write_mutex, NULL);
- p->r_state = LTTNG_PIPE_STATE_OPENED;
- p->w_state = LTTNG_PIPE_STATE_OPENED;
- p->flags = flags;
-
- return p;
-
-error:
- lttng_pipe_destroy(p);
- return NULL;
-}
-
-/*
- * Close read side of a lttng pipe.
- *
- * Return 0 on success else a negative value.
- */
-LTTNG_HIDDEN
-int lttng_pipe_read_close(struct lttng_pipe *pipe)
-{
- int ret;
-
- assert(pipe);
-
- /* Handle read side first. */
- lock_read_side(pipe);
- ret = _pipe_read_close(pipe);
- unlock_read_side(pipe);
-
- return ret;
-}
-
-/*
- * Close write side of a lttng pipe.
- *
- * Return 0 on success else a negative value.
- */
-LTTNG_HIDDEN
-int lttng_pipe_write_close(struct lttng_pipe *pipe)
-{
- int ret;
-
- assert(pipe);
-
- lock_write_side(pipe);
- ret = _pipe_write_close(pipe);
- unlock_write_side(pipe);
-
- return ret;
-}
-
-/*
- * Close both read and write side of a lttng pipe.
- *
- * Return 0 on success else a negative value.
- */
-LTTNG_HIDDEN
-int lttng_pipe_close(struct lttng_pipe *pipe)
-{
- int ret, ret_val = 0;
-
- assert(pipe);
-
- ret = lttng_pipe_read_close(pipe);
- if (ret < 0) {
- ret_val = ret;
- }
-
- ret = lttng_pipe_write_close(pipe);
- if (ret < 0) {
- ret_val = ret;
- }
-
- return ret_val;
-}
-
-/*
- * Close and destroy a lttng pipe object. Finally, pipe is freed.
- */
-LTTNG_HIDDEN
-void lttng_pipe_destroy(struct lttng_pipe *pipe)
-{
- int ret;
-
- if (!pipe) {
- return;
- }
-
- /*
- * Destroy should *never* be called with a locked mutex. These must always
- * succeed so we unlock them after the close pipe below.
- */
- ret = pthread_mutex_trylock(&pipe->read_mutex);
- assert(!ret);
- ret = pthread_mutex_trylock(&pipe->write_mutex);
- assert(!ret);
-
- /* Close pipes WITHOUT trying to lock the pipes. */
- (void) _pipe_read_close(pipe);
- (void) _pipe_write_close(pipe);
-
- unlock_read_side(pipe);
- unlock_write_side(pipe);
-
- (void) pthread_mutex_destroy(&pipe->read_mutex);
- (void) pthread_mutex_destroy(&pipe->write_mutex);
-
- free(pipe);
-}
-
-/*
- * Read on a lttng pipe and put the data in buf of at least size count.
- *
- * Return "count" on success. Return < count on error. errno can be used
- * to check the actual error.
- */
-LTTNG_HIDDEN
-ssize_t lttng_pipe_read(struct lttng_pipe *pipe, void *buf, size_t count)
-{
- ssize_t ret;
-
- assert(pipe);
- assert(buf);
-
- lock_read_side(pipe);
- if (!lttng_pipe_is_read_open(pipe)) {
- ret = -1;
- errno = EBADF;
- goto error;
- }
- ret = lttng_read(pipe->fd[0], buf, count);
-error:
- unlock_read_side(pipe);
- return ret;
-}
-
-/*
- * Write on a lttng pipe using the data in buf and size of count.
- *
- * Return "count" on success. Return < count on error. errno can be used
- * to check the actual error.
- */
-LTTNG_HIDDEN
-ssize_t lttng_pipe_write(struct lttng_pipe *pipe, const void *buf,
- size_t count)
-{
- ssize_t ret;
-
- assert(pipe);
- assert(buf);
-
- lock_write_side(pipe);
- if (!lttng_pipe_is_write_open(pipe)) {
- ret = -1;
- errno = EBADF;
- goto error;
- }
- ret = lttng_write(pipe->fd[1], buf, count);
-error:
- unlock_write_side(pipe);
- return ret;
-}
projects / lttng-tools.git / blobdiff