1 files changed, 117 insertions, 0 deletions
diff --git a/cpukit/libmisc/capture/capture_buffer.c b/cpukit/libmisc/capture/capture_buffer.c
new file mode 100644
index 0000000000..9557f70ba8
--- /dev/null
+++ b/cpukit/libmisc/capture/capture_buffer.c
@@ -0,0 +1,117 @@
+/*
+  ------------------------------------------------------------------------
+
+  COPYRIGHT (c) 2014.
+  On-Line Applications Research Corporation (OAR).
+
+  The license and distribution terms for this file may be
+  found in the file LICENSE in this distribution.
+
+  This software with is provided ``as is'' and with NO WARRANTY.
+
+  ------------------------------------------------------------------------
+
+  RTEMS Performance Monitoring and Measurement Framework.
+
+  This is the Target Interface Command Line Interface. You need
+  start the RTEMS monitor.
+
+*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems.h>
+#include <rtems/score/assert.h>
+#include "capture_buffer.h"
+
+void * rtems_capture_buffer_allocate( rtems_capture_buffer_t* buffer, size_t size )
+{
+  static uint32_t   end;
+  static void       *ptr;
+
+  if ( rtems_capture_buffer_is_full( buffer ) )
+    return NULL;
+
+  if ( (buffer->count + size) > buffer->end )
+    return NULL;
+
+  /*
+   *  Determine if the end of free space is marked with
+   *  the end of buffer space, or the head of allocated
+   *  space.
+   *
+   *  |...|head| freespace |tail| ...| end
+   *
+   *  tail|.....|head| freespace| end
+   *
+   */
+  if (buffer->tail > buffer->head) {
+    end = buffer->tail;
+  } else {
+    end = buffer->end;
+  }
+
+  /*
+   *  Can we allocate it easily?
+   */
+  if ((buffer->head + size) <= end) {
+    ptr = &buffer->buffer[ buffer->head ];
+    buffer->head += size;
+    buffer->count = buffer->count + size;
+    return ptr;
+  }
+
+  /*
+   * We have to consider wrapping around to the front of the buffer
+   */
+
+  /* If there is not room at the end of the buffer         */
+  /* and we have we already wrapped then we can't allocate */
+  if ( end == buffer->tail )
+    return NULL;
+
+  /* Is there no room at the front of the buffer */
+  if ( (buffer->tail  < size ))
+    return NULL;
+
+  /* change the end pointer to the last used byte, so a read will wrap when out of data */
+  buffer->end = buffer->head;
+
+  /* now return the buffer */
+  ptr = buffer->buffer;
+  buffer->head = size;
+  buffer->count = buffer->count + size;
+
+  return ptr; 
+}
+
+void *rtems_capture_buffer_free( rtems_capture_buffer_t* buffer, size_t size ) 
+{
+    static void             *ptr;
+    static uint32_t         next;
+    size_t                  buff_size;
+
+    if (size == 0)
+      return NULL;
+
+    ptr = rtems_capture_buffer_peek(buffer, &buff_size);
+    next = buffer->tail + size;
+
+   /* Check if we are freeing space past the end of the buffer */
+    _Assert( ! rtems_capture_buffer_is_empty( buffer ) );
+    _Assert( !((buffer->tail > buffer->head) && (next > buffer->end)) );
+    _Assert( !((buffer->tail < buffer->head) && (next > buffer->head)) );
+
+    buffer->count = buffer->count - size;
+
+    if (next == buffer->end) {
+      buffer->end = buffer->size;
+      buffer->tail = 0;
+    } else {
+      buffer->tail = next;
+    }
+     
+    return ptr;
+}