iofunc_mmap_default(), iofunc_mmap_default_ext()
Default handler for _IO_MMAP messages
Synopsis:
#include <sys/iofunc.h>
int iofunc_mmap_default ( resmgr_context_t * ctp,
io_mmap_t * msg,
iofunc_ocb_t * ocb );
int iofunc_mmap_default_ext( resmgr_context_t * const ctp,
io_mmap_t * const msg,
iofunc_ocb_t * const ocb );
Arguments:
- ctp
- A pointer to a resmgr_context_t structure that the resource-manager library uses to pass context information between functions.
- msg
- A pointer to the io_mmap_t structure that contains the message that the resource manager received. For more information, see the documentation for iofunc_mmap().
- ocb
- A pointer to the iofunc_ocb_t structure for the Open Control Block that was created when the client opened the resource.
Library:
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
Description:
The iofunc_mmap_default() and iofunc_mmap_default_ext() functions provide functionality for the _IO_MMAP message. This message is private to the memory manager (a part of the microkernel's procnto).
The iofunc_mmap_default_ext() function is an extended version of
iofunc_mmap_default() that can return extra information to the memory
manager. If called on a device that's mounted, it also fills in the stat
information and uses
_IO_MMAP_REPLY_FLAGS_STAT_FORM_FLAGS(_STAT_FORM_PREFERRED)
to set the
flags that it passes to iofunc_mmap_ext().
You can place one of these functions directly into the resmgr_io_funcs_t table passed as the io_funcs argument to resmgr_attach(), at the mmap position, or you can call iofunc_func_init() to initialize all of the functions to their default values.
The iofunc_mmap_default() function calls iofunc_mmap() to do the actual work; iofunc_mmap_default_ext() calls iofunc_mmap_ext().
Note that if you write your own handler for _IO_MMAP messages, and you want the process manager to be able to execute binaries from the resource, then your handler must use the iofunc_mmap() or iofunc_mmap_ext() function.
Returns:
- A nonpositive value (i.e., less than or equal to 0)
- Successful completion.
- EACCES
- The client doesn't have the appropriate permissions.
- ENOMEM
- Insufficient memory exists to allocate internal resources required to effect the mapping.
- EROFS
- There was an attempt to memory map (mmap) a read-only file using the PROT_WRITE page protection mode.
Classification:
Safety: | |
---|---|
Cancellation point | No |
Signal handler | Yes |
Thread | Yes |