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 e8fc8d70384910139306e0d2d0fbcfc41cbcb615..3a61a39d5e1d86a77d1df100017fe12b7a737ff1 100644 (file)
--- a/libringbuffer/shm.h
+++ b/libringbuffer/shm.h
@@ -4,15 +4,28 @@
 /*
  * libringbuffer/shm.h
  *
- * Copyright 2011 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
- * Dual LGPL v2.1/GPL v2 license.
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; only
+ * version 2.1 of the License.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <stdint.h>
-#include <lttng/usterr-signal-safe.h>
-#include "lttng/core.h"
+#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
@@ -87,8 +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
@@ -107,7 +149,9 @@ int shm_get_wait_fd(struct lttng_ust_shm_handle *handle, struct shm_ref *ref)
 
 static inline
 int shm_get_object_data(struct lttng_ust_shm_handle *handle, struct shm_ref *ref,
-               int *shm_fd, int *wait_fd, uint64_t *memory_map_size)
+                       int **shm_fd, char **shm_path,
+                       int **wait_fd, char **wait_pipe_path,
+                       uint64_t **memory_map_size)
 {
        struct shm_object_table *table = handle->table;
        struct shm_object *obj;
@@ -117,9 +161,11 @@ int shm_get_object_data(struct lttng_ust_shm_handle *handle, struct shm_ref *ref
        if (caa_unlikely(index >= table->allocated_len))
                return -EPERM;
        obj = &table->objects[index];
-       *shm_fd = obj->shm_fd;
-       *wait_fd = obj->wait_fd[0];
-       *memory_map_size = obj->allocated_len;
+       *shm_fd   = &obj->shm_fd;
+       *shm_path = obj->shm_path;
+       *wait_fd        = &obj->wait_fd[0];
+       *wait_pipe_path = obj->wait_pipe_path;
+       *memory_map_size = &obj->allocated_len;
        return 0;
 }