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homepage/content/projects/noxos/docs/codebase/proc/file_descriptor.h.md

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file_descriptor.h Processes have no direct access to the VFS, instead they have file descriptors

File descriptors are numbers that represent files. They are mostly used in file related syscalls.

FILE_DESCRIPTOR_ARRAY_CHUNK_SIZE - macro

The amount of file descriptors a file_descriptor_array_chunk_T (reference needed) can hold.

file_descriptor_t - typedef

This is a typedef of ìnt32_t and represents a file descriptor.

std_file_descriptors_E - enum

These are reserved file descriptors.

  • FILE_DESCRIPTOR_INVALID - This represents an invalid file descriptor, just like NULL is an invalid pointer.

file_descriptor_array_chunk_T - struct

Name Type Description
prev file_descriptor_array_chunk_T* The previous chunk
next file_descriptor_array_chunk_T* The next chunk
lookup vfs_node_T* [FILE_DESCRIPTOR_ARRAY_CHUNK_SIZE] The array of file pointers, that the file descriptors reference
bitmap bitmap_T This bitmap indicates which file descriptors of this chunk are free nad which are used
amount uint32_t The amount of file descriptors which the chunk actually holds

file_descriptor_array_T - struct

Name Type Description
base_chunk file_descriptor_array_chunk_T* The first chunk in the array

file_descriptor_request(fd_array, node) - function (file_descriptor_t)

Requests and returns new file descriptor, which will be linked with node.

file_descriptor_resolve(fd_array, fd) - function (vfs_node_T*)

Returns the VFS node, with which fd is linked.

file_descriptor_free(fd_array, fd) - function (void)

Frees fd and marks it as reclaimable.

file_descriptor_array_alloc() - function (file_descriptor_array_T*)

Allocates a new chunked file descriptor array.

file_descriptor_array_destruct(fd_array) - function (void)

Destructs fd_array and all its resources, like e.g. chunks.

file_descriptor_array_chunk_alloc(prev) - function (file_descriptor_array_chunk_T*)

Allocates a new chunk for a file descriptor array. prev has to be the last chunk of an array or NULL when the chunk is the base chunk for a fresh file descriptor array.

file_descriptor_array_chunk_destruct(chunk) - function (void)

Destructs chunk and all its resources.