Files
MentOS/libc/inc/sys/shm.h
T
Enrico Fraccaroli (Galfurian) 7972ddeac7 - Add missing comments;
- Reimplement a more safer dirname;
- Implement a simple and safe tokenize function;
2023-06-23 14:37:24 -04:00

206 lines
6.9 KiB
C

/// @file shm.h
/// @brief Definition of structure for managing shared memories.
/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
/// See LICENSE.md for details.
#pragma once
#include "sys/types.h"
#include "stddef.h"
#include "sys/ipc.h"
#include "time.h"
/// Data type for storing the number of attaches.
typedef unsigned long shmatt_t;
/// @brief Shared memory data structure.
struct shmid_ds {
/// Operation permission struct.
struct ipc_perm shm_perm;
/// Size of segment in bytes.
size_t shm_segsz;
/// Time of last shmat().
time_t shm_atime;
/// Time of last shmdt().
time_t shm_dtime;
/// Time of last change by shmctl().
time_t shm_ctime;
/// Pid of creator.
pid_t shm_cpid;
/// Pid of last shmop.
pid_t shm_lpid;
/// Number of current attaches.
shmatt_t shm_nattch;
/// Pointer to the next shared memory data structure.
struct shmid_ds *next;
/// Where shm created is memorized, should be a file.
void *shm_location;
};
#if 0
#include "debug.h"
#include "time.h"
#include "kheap.h"
#include "stddef.h"
#include "paging.h"
#include "syscall.h"
#include "scheduler.h"
//======== Permission flag for shmget ==========================================
// or S_IRUGO from <linux/stat.h>.
#define SHM_R 0400
// or S_IWUGO from <linux/stat.h>.
#define SHM_W 0200
//==============================================================================
//======== Flags for shmat =====================================================
// Attach read-only else read-write.
#define SHM_RDONLY 010000
// Round attach address to SHMLBA.
#define SHM_RND 020000
// Take-over region on attach.
#define SHM_REMAP 040000
// Execution access.
#define SHM_EXEC 0100000
//==============================================================================
//======== Commands for shmctl =================================================
// Lock segment (root only).
#define SHM_LOCK 11
// Unlock segment (root only).
#define SHM_UNLOCK 12
//==============================================================================
// Ipcs ctl commands.
#define SHM_STAT 13
#define SHM_INFO 14
#define SHM_STAT_ANY 15
//======== shm_mode upper byte flags ===========================================
// segment will be destroyed on last detach.
#define SHM_DEST 01000
// Segment will not be swapped.
#define SHM_LOCKED 02000
// Segment is mapped via hugetlb.
#define SHM_HUGETLB 04000
// Don't check for reservations.
#define SHM_NORESERVE 010000
/// @@brief Syscall Service Routine: Shared memory control operation.
int syscall_shmctl(int *args);
/// @@brief Syscall Service Routine: Get shared memory segment.
int syscall_shmget(int *args);
/// @@brief Syscall Service Routine: Attach shared memory segment.
void *syscall_shmat(int *args);
/// @@brief Syscall Service Routine: Detach shared memory segment.
int syscall_shmdt(int *args);
/// @@brief User Wrapper: Shared memory control operation.
int shmctl(int shmid, int cmd, struct shmid_ds *buf);
/// @@brief User Wrapper: Get shared memory segment.
int shmget(key_t key, size_t size, int flags);
/// @@brief User Wrapper: Attach shared memory segment.
void *shmat(int shmid, void *shmaddr, int flag);
/// @@brief User Wrapper: Detach shared memory segment.
int shmdt(void *shmaddr);
/// @@brief Find shmid_ds on list.
struct shmid_ds *find_shm_fromid(int shmid);
/// @@brief Find shmid_ds on list.
struct shmid_ds *find_shm_fromkey(key_t key);
/// @@brief shmid_ds on list.
struct shmid_ds *find_shm_fromvaddr(void *shmvaddr);
#endif
#ifdef __KERNEL__
/// @brief Get a System V shared memory identifier.
/// @param key can be used either to obtain the identifier of a previously
/// created shared memory, or to create a new one.
/// @param size of the shared memory, rounded up to a multiple of PAGE_SIZE.
/// @param flag controls the behaviour of the function.
/// @return the shared memory identifier, -1 on failure, and errno is set to
/// indicate the error.
long sys_shmget(key_t key, size_t size, int flag);
/// @brief Attaches the shared memory segment identified by shmid to the address
/// space of the calling process.
/// @param shmid the shared memory identifier.
/// @param shmaddr the attaching address.
/// @param shmflg controls the behaviour of the function.
/// @return returns the address of the attached shared memory segment; on error
/// (void *) -1 is returned, and errno is set to indicate the error.
void * sys_shmat(int shmid, const void *shmaddr, int shmflg);
/// @brief Detaches the shared memory segment located at the address specified
/// by shmaddr from the address space of the calling process
/// @param shmaddr the address of the shared memory segment.
/// @return 0 on success, -1 on failure and errno is set to indicate the error.
long sys_shmdt(const void *shmaddr);
/// @brief Performs the control operation specified by cmd on the shared memory
/// segment whose identifier is given in shmid.
/// @param shmid the shared memory identifier.
/// @param cmd the command to perform.
/// @param buf is a pointer to a shmid_ds structure.
/// @return a non-negative value basedon on the requested operation, -1 on
/// failure and errno is set to indicate the error.
long sys_shmctl(int shmid, int cmd, struct shmid_ds *buf);
#else
/// @brief Get a System V shared memory identifier.
/// @param key can be used either to obtain the identifier of a previously
/// created shared memory, or to create a new one.
/// @param size of the shared memory, rounded up to a multiple of PAGE_SIZE.
/// @param flag controls the behaviour of the function.
/// @return the shared memory identifier, -1 on failure, and errno is set to
/// indicate the error.
long shmget(key_t key, size_t size, int flag);
/// @brief Attaches the shared memory segment identified by shmid to the address
/// space of the calling process.
/// @param shmid the shared memory identifier.
/// @param shmaddr the attaching address.
/// @param shmflg controls the behaviour of the function.
/// @return returns the address of the attached shared memory segment; on error
/// (void *) -1 is returned, and errno is set to indicate the error.
void * shmat(int shmid, const void *shmaddr, int shmflg);
/// @brief Detaches the shared memory segment located at the address specified
/// by shmaddr from the address space of the calling process
/// @param shmaddr the address of the shared memory segment.
/// @return 0 on success, -1 on failure and errno is set to indicate the error.
long shmdt(const void *shmaddr);
/// @brief Performs the control operation specified by cmd on the shared memory
/// segment whose identifier is given in shmid.
/// @param shmid the shared memory identifier.
/// @param cmd the command to perform.
/// @param buf is a pointer to a shmid_ds structure.
/// @return a non-negative value basedon on the requested operation, -1 on
/// failure and errno is set to indicate the error.
long shmctl(int shmid, int cmd, struct shmid_ds *buf);
#endif