Deliverables 3 and 4

[lttng-tools.git] / src / common / pipe.c

diff --git a/src/common/pipe.c b/src/common/pipe.c
index 5e2fc6c392b6a5734cebfa28dee50881a3f0f05f..ffdecc0d5e2086076fa78c21d5f75b5e8fc451e7 100644 (file)
--- a/src/common/pipe.c
+++ b/src/common/pipe.c
@@ -15,7 +15,7 @@
  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <assert.h>
 #include <fcntl.h>
 #include <unistd.h>
@@ -118,6 +118,7 @@ end:
  *
  * Return a newly allocated lttng pipe on success or else NULL.
  */
+LTTNG_HIDDEN
 struct lttng_pipe *lttng_pipe_open(int flags)
 {
        int ret;
@@ -165,6 +166,7 @@ error:
  *
  * Return 0 on success else a negative value.
  */
+LTTNG_HIDDEN
 int lttng_pipe_read_close(struct lttng_pipe *pipe)
 {
        int ret;
@@ -184,6 +186,7 @@ int lttng_pipe_read_close(struct lttng_pipe *pipe)
  *
  * Return 0 on success else a negative value.
  */
+LTTNG_HIDDEN
 int lttng_pipe_write_close(struct lttng_pipe *pipe)
 {
        int ret;
@@ -202,6 +205,7 @@ int lttng_pipe_write_close(struct lttng_pipe *pipe)
  *
  * Return 0 on success else a negative value.
  */
+LTTNG_HIDDEN
 int lttng_pipe_close(struct lttng_pipe *pipe)
 {
        int ret, ret_val = 0;
@@ -224,6 +228,7 @@ int lttng_pipe_close(struct lttng_pipe *pipe)
 /*
  * Close and destroy a lttng pipe object. Finally, pipe is freed.
  */
+LTTNG_HIDDEN
 void lttng_pipe_destroy(struct lttng_pipe *pipe)
 {
        int ret;
@@ -260,6 +265,7 @@ void lttng_pipe_destroy(struct lttng_pipe *pipe)
  * 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;
@@ -285,6 +291,7 @@ error:
  * 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)
 {
@@ -304,3 +311,69 @@ error:
        unlock_write_side(pipe);
        return ret;
 }
+
+/*
+ * 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;
+       }
+
+       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;
+}
+
+/*
+ * 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;
+}