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#pragma once
#include <u.h>
#include <libn.h>
/*
* A thread functions much like a GNU job -> it's just a simple execution stack
* We just need to modify the following datastructures:
*
* 1. Need to store the list of all "active" and "foreground" threads
* - Right now we just have Thread *proc which is the running process.
* - Need to move this to a linked list (how does this interact with the link?)
* - Linked list stores the independent roots of each individual process tree
* 2. Child pids are stored inside waitpid right now. Need to associate this more explictly with a thread.
* 3. Wait needs to be generalized to act on threads.
* 4. our "start" function is equivalent to the launch_job function
* 5. running the interpreter runs the launch_process implicitly (with forks called as interpreter functions)
*/
// -----------------------------------------------------------------------
// types
typedef struct Io Io;
typedef struct Var Var;
typedef struct Word Word;
typedef struct List List;
typedef struct Tree Tree;
typedef struct Redir Redir;
typedef union Code Code;
typedef struct Thread Thread;
typedef struct Shell Shell;
struct Io
{
int fd, cap;
char *s;
char *b, *e, buf[];
};
struct Tree
{
int type;
char *str;
Tree *child[3];
Tree *link;
};
struct Word
{
char *str;
Word *link;
};
struct List
{
Word *word;
List *link;
};
/*
* the first word of any code vector is a reference count
* always create a new reference to a code vector by calling copycode()
* always call freecode() when deleting a reference
*/
union Code
{
int i;
void (*f)(void);
char *s;
};
struct Var
{
char *name;
Word *val;
short new : 1;
short newfunc : 1;
Code *func;
void (*update)(Var *);
Var *link;
};
enum
{
Rclose,
Rdup,
Ropen,
};
struct Redir
{
char type; /* what to do */
short from, to; /* what to do it to */
struct Redir *link; /* what else to do (reverse order) */
};
enum
{
PNil,
PRun,
PStop,
PSig,
PAgain,
PDone,
};
struct WaitItem
{
int pid;
ushort status;
};
struct Thread
{
struct {
int i;
Code *exe;
} code; // execution stack
struct {
Io *io;
char *path;
} cmd; // command input
List *args; // argument stack
Var *local; // local variables
Redir *redir; // list of redirections
struct {
ushort i : 1;
ushort eof : 1;
} flag;
struct {
ushort status;
int len, cap;
struct WaitItem *on;
} wait;
int pid, pgid, status;
long line;
Thread *link; // process we return to
Thread *next; // next job
};
struct Shell
{
int pid;
Io *err;
int status;
int interactive;
Thread *jobs;
};
// -----------------------------------------------------------------------
// globals
extern Shell shell;
extern Thread *runner;
extern Code *compiled;
// -----------------------------------------------------------------------
// functions
/* util.c */
void itoa(char*, long i);
void fatal(char *, ...);
void *emalloc(uintptr);
void *erealloc(void*, uintptr);
void efree(void*);
/* read.c */
int readline(char *);
void enablevi(void);
/* prompt.c */
int prompt(ushort *);
/* io.c */
Io *openfd(int fd);
Io *openstr(void);
void terminate(Io *io);
int get(Io *);
int put(Io **, char);
void flush(Io *io);
void print(Io *, char *, ...);
/* lex.c */
int iswordchar(int c);
int yylex(void);
/* tree.c */
Tree *maketree(void);
Tree *maketree1(int, Tree*);
Tree *maketree2(int, Tree*, Tree*);
Tree *maketree3(int, Tree*, Tree*, Tree*);
Tree *token(int, char *);
Tree *hangchild1(Tree *, Tree *, int at);
void freeparsetree(void);
/* sys.c */
void initenv(void);
void execute(Word *, Word*);
/* wait.c */
void addwait(Thread *, int);
void clearwait(Thread*);
int waitall(Thread *);
void killzombies(void);
/* job.c */
Thread *getjob(int, int*);
void addjob(Thread *);
void deljob(Thread *);
void wakeup(Thread *);
void report(Thread *, int);
void foreground(Thread *, int);
void background(Thread *, int);
/* exec.c */
// XXX: odd place for this
int count(Word *);
Word *makeword(char *str, Word *link);
void freeword(Word *w);
void initpath(void);
/* var.c */
Var *var(char*);
Var *definevar(char*, Var *);
Var *globalvar(char*);
Var *makevar(char *name, Var *link);
void setvar(char *, Word *);
char **mkenv(void);
/* code.c */
int compile(Tree *);
Code *copycode(Code *c);
void freecode(Code *c);
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