Cygwin: Introduce new LTTNG_UST_STREAM_PIPE command to open wakeup pipe

[lttng-ust.git] / libringbuffer / shm.h

diff --git a/libringbuffer/shm.h b/libringbuffer/shm.h
index a745d34592bab4b962990b6a90255b3e74e60222..3a61a39d5e1d86a77d1df100017fe12b7a737ff1 100644 (file)
--- a/libringbuffer/shm.h
+++ b/libringbuffer/shm.h
@@ -25,6 +25,7 @@
 #include <usterr-signal-safe.h>
 #include <urcu/compiler.h>
 #include "shm_types.h"
+#include <fcntl.h>
 
 /*
  * Pointer dereferencing. We don't trust the shm_ref, so we validate
@@ -99,8 +100,37 @@ int shm_get_wakeup_fd(struct lttng_ust_shm_handle *handle, struct shm_ref *ref)
        if (caa_unlikely(index >= table->allocated_len))
                return -EPERM;
        obj = &table->objects[index];
+
        return obj->wait_fd[1];
+}
+
+static inline
+int shm_open_wakeup_pipe(struct lttng_ust_shm_handle *handle, struct shm_ref *ref)
+{
+       struct shm_object_table *table = handle->table;
+       struct shm_object *obj;
+       size_t index;
+       int fd, ret = -1;
+
+       index = (size_t) ref->index;
+       if (caa_unlikely(index >= table->allocated_len))
+               return -EPERM;
+
+       obj = &table->objects[index];
 
+       if (obj->wait_fd[1] < 0 && obj->wait_pipe_path != NULL) {
+               fd = open(obj->wait_pipe_path, O_WRONLY);
+               if (fd < 0) {
+                       ret = -1;
+               } else {
+                       /* FIXME: What if fcntl fail? */
+                       fcntl(fd, F_SETFD, FD_CLOEXEC);
+                       obj->wait_fd[1] = fd;
+                       ret = 0;
+               }
+       }
+
+       return ret;
 }
 
 static inline