1 files changed, 157 insertions, 0 deletions
diff --git a/src/svm/svm_fifo.h b/src/svm/svm_fifo.h
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+++ b/src/svm/svm_fifo.h
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+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef __included_ssvm_fifo_h__
+#define __included_ssvm_fifo_h__
+
+#include <vppinfra/clib.h>
+#include <vppinfra/vec.h>
+#include <vppinfra/mheap.h>
+#include <vppinfra/heap.h>
+#include <vppinfra/pool.h>
+#include <vppinfra/format.h>
+#include <pthread.h>
+
+typedef enum
+{
+  SVM_FIFO_TAG_NOT_HELD = 0,
+  SVM_FIFO_TAG_DEQUEUE,
+  SVM_FIFO_TAG_ENQUEUE,
+} svm_lock_tag_t;
+
+/** Out-of-order segment */
+typedef struct
+{
+  u32 next;	/**< Next linked-list element pool index */
+  u32 prev;	/**< Previous linked-list element pool index */
+
+  u32 fifo_position;	/**< Start of segment, normalized*/
+  u32 length;		/**< Length of segment */
+} ooo_segment_t;
+
+#define OOO_SEGMENT_INVALID_INDEX ((u32)~0)
+
+typedef struct
+{
+  pthread_mutex_t mutex;	/* 8 bytes */
+  pthread_cond_t condvar;	/* 8 bytes */
+  u32 owner_pid;
+  svm_lock_tag_t tag;
+  volatile u32 cursize;
+  u32 nitems;
+
+  /* Backpointers */
+  u32 server_session_index;
+  u32 client_session_index;
+  u8 server_thread_index;
+  u8 client_thread_index;
+    CLIB_CACHE_LINE_ALIGN_MARK (end_shared);
+  u32 head;
+    CLIB_CACHE_LINE_ALIGN_MARK (end_consumer);
+
+  /* producer */
+  u32 tail;
+
+  ooo_segment_t *ooo_segments;	/**< Pool of ooo segments */
+  u32 ooos_list_head;		/**< Head of out-of-order linked-list */
+  u32 ooos_newest;		/**< Last segment to have been updated */
+
+    CLIB_CACHE_LINE_ALIGN_MARK (data);
+} svm_fifo_t;
+
+static inline int
+svm_fifo_lock (svm_fifo_t * f, u32 pid, u32 tag, int nowait)
+{
+  if (PREDICT_TRUE (nowait == 0))
+    pthread_mutex_lock (&f->mutex);
+  else
+    {
+      if (pthread_mutex_trylock (&f->mutex))
+	return -1;
+    }
+  f->owner_pid = pid;
+  f->tag = tag;
+  return 0;
+}
+
+static inline void
+svm_fifo_unlock (svm_fifo_t * f)
+{
+  f->owner_pid = 0;
+  f->tag = 0;
+  CLIB_MEMORY_BARRIER ();
+  pthread_mutex_unlock (&f->mutex);
+}
+
+static inline u32
+svm_fifo_max_dequeue (svm_fifo_t * f)
+{
+  return f->cursize;
+}
+
+static inline u32
+svm_fifo_max_enqueue (svm_fifo_t * f)
+{
+  return f->nitems - f->cursize;
+}
+
+static inline u8
+svm_fifo_has_ooo_data (svm_fifo_t * f)
+{
+  return f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX;
+}
+
+svm_fifo_t *svm_fifo_create (u32 data_size_in_bytes);
+
+int svm_fifo_enqueue_nowait (svm_fifo_t * f, int pid, u32 max_bytes,
+			     u8 * copy_from_here);
+
+int svm_fifo_enqueue_with_offset (svm_fifo_t * f, int pid,
+				  u32 offset, u32 required_bytes,
+				  u8 * copy_from_here);
+
+int svm_fifo_dequeue_nowait (svm_fifo_t * f, int pid, u32 max_bytes,
+			     u8 * copy_here);
+
+int svm_fifo_peek (svm_fifo_t * f, int pid, u32 offset, u32 max_bytes,
+		   u8 * copy_here);
+int svm_fifo_dequeue_drop (svm_fifo_t * f, int pid, u32 max_bytes);
+
+always_inline ooo_segment_t *
+svm_fifo_newest_ooo_segment (svm_fifo_t * f)
+{
+  return f->ooo_segments + f->ooos_newest;
+}
+
+always_inline u32
+ooo_segment_offset (svm_fifo_t * f, ooo_segment_t * s)
+{
+  return ((f->nitems + s->fifo_position - f->tail) % f->nitems);
+}
+
+always_inline u32
+ooo_segment_end_offset (svm_fifo_t * f, ooo_segment_t * s)
+{
+  return ((f->nitems + s->fifo_position + s->length - f->tail) % f->nitems);
+}
+
+#endif /* __included_ssvm_fifo_h__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */