* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
#include <assert.h>
#include <fcntl.h>
#include <unistd.h>
*
* Return a newly allocated lttng pipe on success or else NULL.
*/
+LTTNG_HIDDEN
struct lttng_pipe *lttng_pipe_open(int flags)
{
int ret;
*
* Return 0 on success else a negative value.
*/
+LTTNG_HIDDEN
int lttng_pipe_read_close(struct lttng_pipe *pipe)
{
int ret;
*
* Return 0 on success else a negative value.
*/
+LTTNG_HIDDEN
int lttng_pipe_write_close(struct lttng_pipe *pipe)
{
int ret;
*
* Return 0 on success else a negative value.
*/
+LTTNG_HIDDEN
int lttng_pipe_close(struct lttng_pipe *pipe)
{
int ret, ret_val = 0;
/*
* Close and destroy a lttng pipe object. Finally, pipe is freed.
*/
+LTTNG_HIDDEN
void lttng_pipe_destroy(struct lttng_pipe *pipe)
{
int ret;
/*
* Read on a lttng pipe and put the data in buf of at least size count.
*
- * Return 0 on success or else a negative errno message from read(2).
+ * 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, read_len, read_left, index;
+ ssize_t ret;
assert(pipe);
assert(buf);
lock_read_side(pipe);
-
if (!lttng_pipe_is_read_open(pipe)) {
- ret = -EBADF;
+ ret = -1;
+ errno = EBADF;
goto error;
}
-
- read_left = count;
- index = 0;
- do {
- read_len = read(pipe->fd[0], buf + index, read_left);
- if (read_len < 0) {
- ret = -errno;
- if (errno == EINTR) {
- /* Read again. */
- continue;
- } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
- /*
- * Return the number of bytes read up to this point if any.
- */
- if (index) {
- ret = index;
- }
- goto error;
- } else {
- PERROR("lttng pipe read");
- goto error;
- }
- }
- read_left -= read_len;
- index += read_len;
- } while (read_left > 0);
-
- /* Everything went fine. */
- ret = index;
-
+ 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 0 on success or else a negative errno message from write(2).
+ * 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, write_len, write_left, index;
+ ssize_t ret;
assert(pipe);
assert(buf);
lock_write_side(pipe);
-
if (!lttng_pipe_is_write_open(pipe)) {
- ret = -EBADF;
+ ret = -1;
+ errno = EBADF;
goto error;
}
+ ret = lttng_write(pipe->fd[1], buf, count);
+error:
+ unlock_write_side(pipe);
+ return ret;
+}
- write_left = count;
- index = 0;
- do {
- write_len = write(pipe->fd[1], buf + index, write_left);
- if (write_len < 0) {
- ret = -errno;
- if (errno == EINTR) {
- /* Read again. */
- continue;
- } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
- /*
- * Return the number of bytes read up to this point if any.
- */
- if (index) {
- ret = index;
- }
- goto error;
- } else {
- PERROR("lttng pipe write");
- goto error;
- }
- }
- write_left -= write_len;
- index += write_len;
- } while (write_left > 0);
+/*
+ * Return and release the read end of the pipe.
+ *
+ * This call transfers the ownership of the read fd of the underlying pipe
+ * to the caller if it is still open.
+ *
+ * Returns the fd of the read end of the pipe, or -1 if it was already closed or
+ * released.
+ */
+LTTNG_HIDDEN
+int lttng_pipe_release_readfd(struct lttng_pipe *pipe)
+{
+ int ret;
+
+ if (!pipe) {
+ ret = -1;
+ goto end;
+ }
- /* Everything went fine. */
- ret = index;
+ lock_read_side(pipe);
+ if (!lttng_pipe_is_read_open(pipe)) {
+ ret = -1;
+ goto end_unlock;
+ }
+ ret = pipe->fd[0];
+ pipe->fd[0] = -1;
+ pipe->r_state = LTTNG_PIPE_STATE_CLOSED;
+end_unlock:
+ unlock_read_side(pipe);
+end:
+ return ret;
+}
-error:
+/*
+ * Return and release the write end of the pipe.
+ *
+ * This call transfers the ownership of the write fd of the underlying pipe
+ * to the caller if it is still open.
+ *
+ * Returns the fd of the write end of the pipe, or -1 if it was alwritey closed
+ * or released.
+ */
+LTTNG_HIDDEN
+int lttng_pipe_release_writefd(struct lttng_pipe *pipe)
+{
+ int ret;
+
+ if (!pipe) {
+ ret = -1;
+ goto end;
+ }
+
+ lock_write_side(pipe);
+ if (!lttng_pipe_is_write_open(pipe)) {
+ ret = -1;
+ goto end_unlock;
+ }
+ ret = pipe->fd[1];
+ pipe->fd[1] = -1;
+ pipe->w_state = LTTNG_PIPE_STATE_CLOSED;
+end_unlock:
unlock_write_side(pipe);
+end:
return ret;
}
projects / lttng-tools.git / blobdiff