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design: memory: assorted formatting and markup fixes

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Reynaldo H. Verdejo Pinochet 2017-02-03 15:37:27 -08:00
parent 1687511e4e
commit b4e0ffdfd7
1 changed files with 21 additions and 22 deletions
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markdown/design/memory.md
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@ -12,13 +12,13 @@ multimedia data passed around in the pipeline.
## Memory layout
`GstMemory` manages a memory region. The accessible part of the managed region is
defined by an offset relative to the start of the region and a size. This
`GstMemory` manages a memory region. The accessible part of the managed region
is defined by an offset relative to the start of the region and a size. This
means that the managed region can be larger than what is visible to the user of
`GstMemory` API.
Schematically, `GstMemory` has a pointer to a memory region of _maxsize_. The area
starting from `offset` and `size` is accessible.
Schematically, `GstMemory` has a pointer to a memory region of _maxsize_. The
area starting from `offset` and `size` is accessible.
```
memory
@ -32,13 +32,13 @@ GstMemory ->*----------------------------------------------------*
The current properties of the accessible memory can be retrieved with:
``` c
gsize gst_memory_get_sizes (GstMemory *mem, gsize *offset, gsize *maxsize);
gsize gst_memory_get_sizes (GstMemory *mem, gsize *offset, gsize *maxsize);
```
The offset and size can be changed with:
``` c
void gst_memory_resize (GstMemory *mem, gssize offset, gsize size);
void gst_memory_resize (GstMemory *mem, gssize offset, gsize size);
```
## Allocators
@ -79,9 +79,8 @@ GStreamer system. This way, the allocator can be retrieved by name.
After an allocator is created, new `GstMemory` can be created with
``` c
GstMemory * gst_allocator_alloc (const GstAllocator * allocator,
gsize size,
GstAllocationParams *params);
GstMemory * gst_allocator_alloc (const GstAllocator * allocator,
gsize size, GstAllocationParams *params);
```
`GstAllocationParams` contain extra info such as flags, alignment, prefix and
@ -99,11 +98,11 @@ It is also possible to create a new `GstMemory` object that wraps existing
memory with:
``` c
GstMemory * gst_memory_new_wrapped (GstMemoryFlags flags,
gpointer data, gsize maxsize,
gsize offset, gsize size,
gpointer user_data,
GDestroyNotify notify);
GstMemory * gst_memory_new_wrapped (GstMemoryFlags flags,
gpointer data, gsize maxsize,
gsize offset, gsize size,
gpointer user_data,
GDestroyNotify notify);
```
## Lifecycle
@ -131,16 +130,16 @@ After the data has been accessed in the object, the `unmap()` call must be
performed, which will unlock the memory again.
It is allowed to recursively map multiple times with the same or narrower
access modes. For each of the map calls, a corresponding unmap call needs to
be made. WRITE-only memory cannot be mapped in READ mode and READ-only memory
cannot be mapped in WRITE mode.
access modes. For each of the `map()` calls, a corresponding `unmap()` call
needs to be made. WRITE-only memory cannot be mapped in READ mode and
READ-only memory cannot be mapped in WRITE mode.
The memory pointer returned from the map call is guaranteed to remain valid in
the requested mapping mode until the corresponding unmap call is performed on
the pointer.
The memory pointer returned from the `map()` call is guaranteed to remain
valid in the requested mapping mode until the corresponding `unmap()` call is
performed on the pointer.
When multiple map operations are nested and return the same pointer, the pointer
is valid until the last unmap call is done.
When multiple `map()` operations are nested and return the same pointer, the
pointer is valid until the last `unmap()` call is done.
When the final reference on a memory object is dropped, all outstanding
mappings should have been unmapped.