#pragma once
// A process is basically :
// - a page directory and a list of segments mapped in user space
// - a list of file systems each associated to a name
// - some threads (currently, only one thread per process supported)
// Notes on memory mapping :
// - mmap creates an empty zone (zero-initialized)
// - mmap_file increments the refcount of the file handle
// - mchmap = change mode on already mapped zone (eg. after loading code)
#include <hashtbl.h>
#include <btree.h>
#include <thread.h>
#include <vfs.h>
#include <mmap.h>
#include <proc.h> // common header defining process statuses
#define USERSTACK_ADDR 0xB8000000
#define USERSTACK_SIZE 0x00020000 // 32 KB - it is allocated on demand so no worries
typedef struct process process_t;
typedef struct user_region {
process_t *proc;
void* addr;
size_t size;
int mode;
fs_handle_t *file; // null if not mmaped-file
size_t file_offset;
struct user_region *next;
} user_region_t;
typedef struct process {
pagedir_t *pd;
struct user_region *regions;
btree_t *regions_idx;
hashtbl_t *filesystems;
hashtbl_t *files;
int next_fd;
thread_t *threads;
uint64_t last_ran;
int pid;
int status, exit_code;
struct process *parent;
struct process *next_child;
struct process *children;
mutex_t lock;
} process_t;
typedef void* proc_entry_t;
// ---- Process creation, deletion, waiting, etc.
// Simple semantics :
// - When a process exits, all its ressources are freed immediately
// except for the process_t that remains attached to the parent process until it does
// a wait() and acknowleges the process' ending
// - When a process exits, if it has living children then they are terminated too. (a process
// is seen as a "virtual machine", and spawning sub-process is seen as "sharing some ressources
// it was allocated to create a new VM", therefore removing the ressource allocated to the
// parent implies removing the ressource from its children too)
process_t *current_process();
process_t *new_process(process_t *parent);
bool start_process(process_t *p, proc_entry_t entry); // maps a region for user stack
void process_exit(process_t *p, int status, int exit_code); // exit specified process (must not be current process)
void current_process_exit(int status, int exit_code);
bool process_new_thread(process_t *p, proc_entry_t entry, void* sp);
void process_thread_deleted(thread_t *t); // called by threading code when a thread exits
process_t *process_find_child(process_t *p, int pid);
void process_get_status(process_t *p, proc_status_t *st);
void process_wait(process_t *p, proc_status_t *st, bool block); // waits for exit and frees process_t structure
void process_wait_any_child(process_t *p, bool block);
// ---- Process FS namespace & FD set
bool proc_add_fs(process_t *p, fs_t *fs, const char* name);
fs_t *proc_find_fs(process_t *p, const char* name);
void proc_rm_fs(process_t *p, const char* name);
int proc_add_fd(process_t *p, fs_handle_t *f); // on error returns 0, nonzero other<ise
fs_handle_t *proc_read_fd(process_t *p, int fd);
void proc_close_fd(process_t *p, int fd);
// ---- Process virtual memory space
bool mmap(process_t *proc, void* addr, size_t size, int mode); // create empty zone
bool mmap_file(process_t *proc, fs_handle_t *h, size_t offset, void* addr, size_t size, int mode);
bool mchmap(process_t *proc, void* addr, int mode);
bool munmap(process_t *proc, void* addr);
// for syscalls : check that process is authorized to read/write given addresses
// (if not, process exits with a segfault)
void probe_for_read(const void* addr, size_t len);
void probe_for_write(const void* addr, size_t len);
/* vim: set ts=4 sw=4 tw=0 noet :*/
