source: trunk/kernel/kern/process.h @ 433

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1/*
2 * process.h - process related management functions
3 *
4 * Authors  Ghassan Almaless (2008,2009,2010,2011,2012)
5 *          Mohamed Lamine Karaoui (2015)
6 *          Alain Greiner (2016,2017,2018)
7 *
8 * Copyright (c) UPMC Sorbonne Universites
9 *
10 * This file is part of ALMOS-MKH.
11 *
12 * ALMOS-MKH is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; version 2.0 of the License.
15 *
16 * ALMOS-MKH is distributed in the hope that it will be useful, but
17 * WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19 * General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
23 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
24 */
25
26#ifndef _PROCESS_H_
27#define _PROCESS_H_
28
29#include <kernel_config.h>
30#include <errno.h>
31#include <hal_types.h>
32#include <list.h>
33#include <xlist.h>
34#include <bits.h>
35#include <spinlock.h>
36#include <hal_atomic.h>
37#include <vmm.h>
38#include <signal.h>
39#include <cluster.h>
40#include <vfs.h>
41
42/****  Forward declarations  ****/
43
44struct thread_s;
45
46/*********************************************************************************************
47 * These macros are used to compose or decompose global process identifier (PID)
48 * to or from cluster identifier / local process index (CXY , LPID)
49 ********************************************************************************************/
50
51#define LPID_FROM_PID( pid )       (lpid_t)(pid & 0x0000FFFF)
52#define CXY_FROM_PID( pid )        (cxy_t)(pid >> 16)
53#define PID( cxy , lpid )          (pid_t)((cxy << 16) | lpid )
54
55/*********************************************************************************************
56 * This enum defines the actions that can be executed by the process_sigaction() function.
57 ********************************************************************************************/
58
59enum process_sigactions
60{
61    BLOCK_ALL_THREADS    = 11,
62    UNBLOCK_ALL_THREADS  = 22,
63    DELETE_ALL_THREADS   = 33, 
64};
65
66/*********************************************************************************************
67 * The termination state is a 32 bits word:
68 * - the 8 LSB bits contain the user defined exit status
69 * - the 24 other bits contain the flags defined below
70 ********************************************************************************************/
71
72#define PROCESS_FLAG_BLOCK 0x100  /*! process received as SIGSTOP signal                    */
73#define PROCESS_FLAG_KILL  0x200  /*! process terminated by a sys_kill()                    */
74#define PROCESS_FLAG_EXIT  0x400  /*! process terminated by a sys_exit()                    */ 
75#define PROCESS_FLAG_WAIT  0x800  /*! parent process executed successfully a sys_wait()     */
76
77/*********************************************************************************************
78 * This structure defines an array of extended pointers on the open file descriptors
79 * for a given process. We use an extended pointer because the open file descriptor
80 * is always stored in the same cluster as the inode associated to the file.
81 * A free entry in this array contains the XPTR_NULL value.
82 * The array size is defined by a the CONFIG_PROCESS_FILE_MAX_NR parameter.
83 * All modifications (open/close) in this structure must be done by the reference cluster,
84 * and reported in process copies.
85 ********************************************************************************************/
86
87typedef struct fd_array_s
88{
89        remote_spinlock_t lock;                               /*! lock protecting fd_array      */
90    uint32_t          current;                            /*! current number of open files  */
91        xptr_t            array[CONFIG_PROCESS_FILE_MAX_NR];  /*! xptr on open file descriptors */
92}
93fd_array_t;
94
95/*********************************************************************************************
96 * This structure defines a process descriptor.
97 * A process is identified by a unique PID (process identifier):
98 * - The PID 16 LSB bits contain the LPID (Local Process Index)
99 * - The PID 16 MSB bits contain the owner cluster CXY.
100 * In each cluster, the process manager allocates  the LPID values for the process that
101 * are owned by this cluster.
102 * The process descriptor is replicated in all clusters containing at least one thread
103 * of the PID process, with the following rules :
104 * 1) The <pid>, <ppid>, <ref_xp>, <vfs_root_xp>, <vfs_bin_xp>  fields are defined
105 *    in all process descriptor copies.
106 * 2) The <vfs_cwd_xp> and associated <cwd_lock>, that can be dynamically modified,
107 *    are only defined in the reference process descriptor.
108 * 2) The <vmm>, containing the VSL (list of registered vsegs), and the GPT (generic
109 *    page table), are only complete in the reference process cluster, other copies
110 *    are actually use as read-only caches.
111 * 3) the <fd_array>, containing extended pointers on the open file descriptors, is only
112 *    complete in the reference process cluster, other copies are read-only caches.
113 * 4) The <sem_root>, <mutex_root>, <barrier_root>, <condvar_root>, and the associated
114 *    <sync_lock>, that are dynamically allocated, are only defined in the reference cluster.
115 * 5) The <children_root>, <children_nr>, <brothers_list>, and <txt_list> fields are only
116 *    defined in the reference cluster, and are undefined in other clusters.
117 * 6) The <local_list>, <copies_list>, <th_tbl>, <th_nr>, <th_lock> fields
118 *    are defined in all process descriptors copies.
119 * 7) The termination <flags> and <exit_status> are only defined in the reference cluster.
120 ********************************************************************************************/
121
122typedef struct process_s
123{
124        vmm_t             vmm;              /*! embedded virtual memory manager                 */
125
126        fd_array_t        fd_array;         /*! embedded open file descriptors array            */
127
128        xptr_t            vfs_root_xp;      /*! extended pointer on current VFS root inode      */
129        xptr_t            vfs_bin_xp;       /*! extended pointer on .elf file descriptor        */
130        pid_t             pid;              /*! process identifier                              */
131    xptr_t            ref_xp;           /*! extended pointer on reference process           */
132    xptr_t            parent_xp;        /*! extended pointer on parent process              */
133
134        xptr_t            vfs_cwd_xp;       /*! extended pointer on current working dir inode   */
135        remote_rwlock_t   cwd_lock;         /*! lock protecting working directory changes       */
136
137        xlist_entry_t     children_root;    /*! root of the children process xlist              */
138    remote_spinlock_t children_lock;    /*! lock protecting children process xlist          */
139    uint32_t          children_nr;      /*! number of children processes                    */
140
141        xlist_entry_t     children_list;    /*! member of list of children of same parent       */
142    xlist_entry_t     local_list;       /*! member of list of process in same cluster       */
143    xlist_entry_t     copies_list;      /*! member of list of copies of same process        */
144    xlist_entry_t     txt_list;         /*! member of list of processes sharing same TXT    */
145
146        spinlock_t        th_lock;          /*! lock protecting th_tbl[] concurrent access      */
147        uint32_t          th_nr;            /*! number of threads in this cluster               */
148
149        struct thread_s * th_tbl[CONFIG_THREAD_MAX_PER_CLUSTER]; /*! pointers on local threads  */
150
151    xlist_entry_t     sem_root;         /*! root of the process semaphore list              */
152    xlist_entry_t     mutex_root;       /*! root of the process mutex list                  */
153    xlist_entry_t     barrier_root;     /*! root of the process barrier list                */
154    xlist_entry_t     condvar_root;     /*! root of the process condvar list                */
155    remote_spinlock_t sync_lock;        /*! lock protecting sem,mutex,barrier,condvar lists */
156
157    uint32_t          term_state;       /*! termination status (flags & exit status)        */
158
159    bool_t            txt_owner;        /*! current TXT owner                               */
160}
161process_t;
162
163/*********************************************************************************************
164 * This structure defines the information required by the process_make_exec() function
165 * to create a new reference process descriptor, and the associated main thread.
166 ********************************************************************************************/
167
168typedef struct exec_info_s
169{
170    char               path[CONFIG_VFS_MAX_PATH_LENGTH];   /*!  .elf file path              */
171
172    char            ** args_pointers;  /*! physical base address of array of pointers       */
173    char             * args_buf_base;  /*! physical base address of kernel args buffer      */
174    uint32_t           args_nr;        /*! actual number of arguments                       */
175
176    char            ** envs_pointers;  /*! physical base address of array of pointers       */
177    char             * envs_buf_base;  /*! physical base address of kernel args buffer      */
178    char             * envs_buf_free;  /*! physical address of first free slot in envs_buf  */
179    uint32_t           envs_nr;        /*! actual number of environment variables           */
180}
181exec_info_t;
182
183/***************   Process Descriptor Operations    *****************************************/
184
185/*********************************************************************************************
186 * This function allocates memory in local cluster for a process descriptor.
187 *********************************************************************************************
188 * @ returns pointer on process descriptor if success / return NULL if failure
189 ********************************************************************************************/
190process_t * process_alloc();
191
192/*********************************************************************************************
193 * This function releases memory in local cluster for a process descriptor.
194 *********************************************************************************************
195 * @ process      : pointer on process descriptor to release.
196 ********************************************************************************************/
197void process_free( process_t * process );
198
199/*********************************************************************************************
200 * This function initialize, in each cluster, the kernel "process_zero", that is the owner
201 * of all kernel threads in a given cluster. It is called by the kernel_init() function.
202 * The process_zero descriptor is allocated as a global variable in file kernel_init.c
203 * Both the PID and PPID fields are set to zero, the ref_xp is the local process_zero,
204 * and the parent process is set to XPTR_NULL. The th_tbl[] is initialized as empty.
205 *********************************************************************************************
206 * @ process      : [in] pointer on local process descriptor to initialize.
207 ********************************************************************************************/
208void process_zero_create( process_t * process );
209
210/*********************************************************************************************
211 * This function allocates memory and initializes the "process_init" descriptor and the
212 * associated "thread_init" descriptor. It is called once at the end of the kernel
213 * initialisation procedure. Its local process identifier is 1, and parent process
214 * is the kernel process in cluster 0.
215 * The "process_init" is the first user process, and all other user processes will be forked
216 * from this process. The code executed by "process_init" is stored in a .elf file, whose
217 * pathname is defined by the CONFIG_PROCESS_INIT_PATH configuration variable.
218 * The process_init does not use the [STDIN/STDOUT/STDERR] streams, but it is linked
219 * to kernel TXT0, because these streams must be defined for all user processes.
220 ********************************************************************************************/
221void process_init_create();
222
223/*********************************************************************************************
224 * This function initializes a local, reference, user process descriptor from another process
225 * descriptor, defined by the <model_xp> argument. The <process> and <pid> arguments must
226 * be previously allocated by he caller. This function can be called by three functions:
227 * 1) process_init_create() : process is the reference INIT process / pid = 1 /
228 *    the parent and model process descriptors are both the kernel process_zero.
229 * 2) process_make_fork() : the model process descriptor is the (generally remote)
230 *    parent process.
231 * 3) process_make exec() : the model process is the local old_process, the new_process
232 *    parent is the same as the old_process parent.
233 * The following fields are initialised :
234 * - It set the pid / ppid / ref_xp / parent_xp / state fields.
235 * - It initializes the VMM (register the kentry, args, envs vsegs in VSL)
236 * - It initializes the FDT, defining the three pseudo files STDIN / STDOUT / STDERR.
237 * - It set the root_xp, bin_xp, cwd_xp fields.
238 * - It reset the children list as empty, but does NOT register it in parent children list.
239 * - It reset the TH_TBL list of threads as empty.
240 * - It reset the semaphore / mutex / barrier / condvar lists as empty.
241 * - It registers the process in the local_list, rooted in the local cluster manager.
242 * - It registers the process in the copies_list, rooted in the owner cluster manager.
243 * - It registers the process extended pointer in the local pref_tbl[] array.
244 *********************************************************************************************
245 * @ process      : [in] pointer on local process descriptor to initialize.
246 * @ pid          : [in] process identifier.
247 * @ parent_xp    : [in] extended pointer on parent process descriptor.
248 * @ model_xp     : [in] extended pointer on model process descriptor.
249 ********************************************************************************************/
250void process_reference_init( process_t * process,
251                             pid_t       pid,
252                             xptr_t      parent_xp,
253                             xptr_t      model_xp );
254
255/*********************************************************************************************
256 * This function initializes a copy process descriptor, in the local cluster,
257 * from information defined in the reference remote process descriptor.
258 *********************************************************************************************
259 * @ process              : [in] local pointer on process descriptor to initialize.
260 * @ reference_process_xp : [in] extended pointer on reference process descriptor.
261 * @ return 0 if success / return ENOMEM if failure
262 ********************************************************************************************/
263error_t process_copy_init( process_t * local_process,
264                           xptr_t      reference_process_xp );
265
266/*********************************************************************************************
267 * This function releases all memory allocated for a process descriptor in the local cluster,
268 * including memory allocated for embedded substructures (fd_array, vmm, etc).
269 * The local th_tbl[] array must be empty.
270 *********************************************************************************************
271 * @ process     : pointer on the process descriptor.
272 ********************************************************************************************/
273void process_destroy( process_t * process );
274
275/*********************************************************************************************
276 * This debug function diplays on the kernel terminal TXT0 detailed informations on a
277 * reference process identified by the <process_xp> argument.
278 * It can be called by a thread running in any cluster.
279 *********************************************************************************************
280 * @ process_xp : extended pointer on reference process.
281 ********************************************************************************************/
282void process_display( xptr_t process_xp );
283
284/*********************************************************************************************
285 * This function returns a printable string defining the sigaction type.
286 *********************************************************************************************
287 * @ sigaction_type   : BLOCK_ALL_THREADS / UNBLOCK_ALL_THREADS / DELETE_ALL_THREADS
288 * @ return a string pointer.
289 ********************************************************************************************/
290char * process_action_str( uint32_t sigaction_type );
291
292/*********************************************************************************************
293 * This function allows a client thread running in the owner cluster of a process identified
294 * by the <process> argument to block, unblock or delete all threads of the target process,
295 * depending on the <action_type> argument.  The scenario is the following:
296 * - It uses the multicast, non blocking rpc_process_sigaction_client() function to send
297 *   parallel requests to all remote clusters containing a process copy. Then it blocks
298 $   and deschedule to wait completion of these parrallel requests.
299 * - In each remote cluster, the rpc_process_sigaction_server() function, calls directly
300 *   the relevant process_block(), process_unblock(), or process_delete() function, and
301 *   decrement the responses counter to signal completion. The last server unblock
302 *   the client thread.
303 * - Finally, the client thread calls directly the process_block(), process_unblock(), or
304 *   process_delete() function in the owner cluster.
305 * It is used by the sys_kill() & sys_exit() functions to handle the "kill" & "exit" syscalls.
306 * It is also used by the process_make_exec() function to handle the "exec" syscall.
307 * WARNING : the DELETE and the BLOCK actions are NOT executed on the client thread.
308 *********************************************************************************************
309 * @ process     : pointer on the process descriptor in owner cluster.
310 * @ action_type : BLOCK_ALL_THREADS / UNBLOCK_ALL_THREADS / DELETE_ALL_THREADS
311 ********************************************************************************************/
312void process_sigaction( process_t * process,
313                        uint32_t    action_type );
314
315/*********************************************************************************************
316 * This function blocks all threads for a given <process> in a given cluster.
317 * The calling thread cannot be a target thread.
318 * It loops on all local threads of the process, set the THREAD_BLOCKED_GLOBAL bit,
319 * and request the relevant schedulers to acknowledge the blocking, using IPI if required.
320 * The threads are not detached from the scheduler, and not detached from the local process.
321 * This function returns only when all blockable threads in cluster are actually blocked.
322 *********************************************************************************************
323 * @ process     : pointer on the target process descriptor.
324 ********************************************************************************************/
325void process_block_threads( process_t * process );
326
327/*********************************************************************************************
328 * This function unblocks all threads of a given user process in a given cluster.
329 *********************************************************************************************
330 * @ process     : pointer on the process descriptor.
331 ********************************************************************************************/
332void process_unblock_threads( process_t * process );
333
334/*********************************************************************************************
335 * This function marks for deletion all threads - but one _ for a given <process>
336 * in a given cluster. The main thread in owner cluster is NOT marked.
337 * It will be marked for deletion by the parent process sys_wait().
338 * The calling thread cannot be a target thread.
339 * It loops on all local threads of the process, and set the THREAD_FLAG_REQ_DELETE bit.
340 * For each marked thread, the following actions will be done by the scheduler at the next
341 * scheduling point:
342 * - the thread will be detached from the scheduler.
343 * - the thread will be detached from the local process descriptor.
344 * - the thread will be detached from parent if required.
345 * - the memory allocated to the thread descriptor is released.
346 * - the memory allocated to the process descriptor is released, if it is the last thread.
347 *********************************************************************************************
348 * @ process     : pointer on the process descriptor.
349 ********************************************************************************************/
350void process_delete_threads( process_t * process );
351
352/*********************************************************************************************
353 * This function returns a pointer on the local copy of a process identified by its PID.
354 * If this local copy does not exist yet, it is dynamically created, from the reference
355 * process descriptor, registered in the global copies_list, and registered in the local_list.
356 * This function is used by the thread_user_create() function.
357 *********************************************************************************************
358 * @ pid     : searched process identifier.
359 * @ returns pointer on the local process descriptor if success / returns NULL if failure.
360 ********************************************************************************************/
361process_t * process_get_local_copy( pid_t pid );
362
363/*********************************************************************************************
364 * This function implements the "exec" system call, and is called by the sys_exec() function.
365 * The "new" process keep the "old" process PID and PPID, all open files, and env variables,
366 * the vfs_root and vfs_cwd, but build a brand new memory image (new VMM from the new .elf).
367 * It actually creates a "new" reference process descriptor, and copies all relevant
368 * information from the "old" process descriptor to the "new" process descriptor.
369 * It completes the "new" process descriptor, from information found in the <exec_info>
370 * structure (defined in the process.h file), that must be built by the caller.
371 * It creates and initializes the associated main thread. It finally destroys all copies
372 * of the "old" process in all clusters, and destroys all old associated threads.
373 * It is executed in the local cluster, that becomes both the "owner" and the "reference"
374 * cluster for the "new" process.
375 *********************************************************************************************
376 * @ exec_info   : [in]  pointer on the exec_info structure.
377 * @ return 0 if success / return non-zero if error.
378 ********************************************************************************************/
379error_t process_make_exec( exec_info_t * exec_info );
380
381/*********************************************************************************************
382 * This function implements the "fork" system call, and is called by the sys_fork() function.
383 * It allocates memory and initializes a new "child" process descriptor, and the
384 * associated "child" thread descriptor in the local cluster. This function can involve
385 * up to three different clusters :
386 * - the child (local) cluster can be any cluster defined by the sys_fork function.
387 * - the parent cluster must be the reference cluster for the parent process.
388 * - the client cluster containing the thread requesting the fork can be any cluster.
389 * The new "child" process descriptor is initialised from informations found in the "parent"
390 * reference process descriptor, containing the complete process description.
391 * The new "child" thread descriptor is initialised from informations found in the "parent"
392 * thread descriptor.
393 *********************************************************************************************
394 * @ parent_process_xp  : extended pointer on the reference parent process.
395 * @ parent_thread_xp   : extended pointer on the parent thread requesting the fork.
396 * @ child_pid          : [out] child process identifier.
397 * @ child_thread_ptr   : [out] local pointer on child thread in target cluster.
398 * @ return 0 if success / return non-zero if error.
399 ********************************************************************************************/
400error_t process_make_fork(  xptr_t             parent_process_xp,
401                            xptr_t             parent_thread_xp,
402                            pid_t            * child_pid, 
403                            struct thread_s ** child_thread_ptr );
404
405/*********************************************************************************************
406 * This function is called by both the sys_kill() and sys_exit() system calls.
407 * It must be executed by an RPC thread running in the target process owner cluster.
408 * It uses twice the process_sigaction() function:
409 * - first, to block all target process threads, in all clusters.
410 * - second, to delete all target process threads in all clusters.
411 * Finally, it synchronizes with the parent process sys_wait() function that MUST be called
412 * by the parent process main thread.
413 *********************************************************************************************
414 * @ process      : pointer on process descriptor in owner cluster.
415 * @ is_exit      : true when called by sys_exit() / false when called by sys_kill().
416 * @ exit_status  : exit status, when called by sys_exit().
417 ********************************************************************************************/
418void process_make_kill( process_t * process,
419                        bool_t      is_exit,
420                        uint32_t    exit_status );
421
422
423/********************   File Management Operations   ****************************************/
424
425/*********************************************************************************************
426 * This function initializes all entries of the local fd_array as empty.
427 *********************************************************************************************
428 * @ process  : pointer on the local process descriptor.
429 ********************************************************************************************/
430void process_fd_init( process_t * process );
431
432/*********************************************************************************************
433 * This function uses as many remote accesses as required, to reset an entry in fd_array[],
434 * in all clusters containing a copy. The entry is identified by the <fdid> argument.
435 * This function must be executed by a thread running reference cluster, that contains
436 * the complete list of process descriptors copies.
437 *********************************************************************************************
438 * @ process  : pointer on the local process descriptor.
439 * @ fdid     : file descriptor index in the fd_array.
440 ********************************************************************************************/
441void process_fd_remove( process_t * process,
442                        uint32_t    fdid );
443
444/*********************************************************************************************
445 * This function returns an extended pointer on a file descriptor identified by its index
446 * in fd_array. It can be called by any thread running in any cluster.
447 * It accesses first the local process descriptor. In case of local miss, it uses remote
448 * access to access the reference process descriptor.
449 * It updates the local fd_array when the file descriptor exists in reference cluster.
450 * The file descriptor refcount is not incremented.
451 *********************************************************************************************
452 * @ process  : pointer on the local process descriptor.
453 * @ fdid     : file descriptor index in the fd_array.
454 * @ return extended pointer on file descriptor if success / return XPTR_NULL if not found.
455 ********************************************************************************************/
456xptr_t process_fd_get_xptr( process_t * process,
457                            uint32_t    fdid );
458
459/*********************************************************************************************
460 * This function checks the number of open files for a given process.
461 * It can be called by any thread in any cluster, because it uses portable remote access
462 * primitives to access the reference process descriptor.
463 *********************************************************************************************
464 * @ returns true if file descriptor array full.
465 ********************************************************************************************/
466bool_t process_fd_array_full();
467
468/*********************************************************************************************
469 * This function allocates a free slot in the fd_array of the reference process,
470 * register the <file_xp> argument in the allocated slot, and return the slot index.
471 * It can be called by any thread in any cluster, because it uses portable remote access
472 * primitives to access the reference process descriptor.
473 *********************************************************************************************
474 * @ file_xp  : extended pointer on the file descriptor to be registered.
475 * @ fdid     : [out] buffer for fd_array slot index.
476 * @ return 0 if success / return EMFILE if array full.
477 ********************************************************************************************/
478error_t process_fd_register( process_t * process,
479                             xptr_t      file_xp,
480                             uint32_t  * fdid );
481
482/*********************************************************************************************
483 * This function copies all non-zero entries (other than the three first stdin/stdout/stderr)
484 * from a remote <src_xp> fd_array, embedded in a process descriptor, to another remote
485 * <dst_xp> fd_array, embedded in another process descriptor.
486 * The calling thread can be running in any cluster.
487 * It takes the remote lock protecting the <src_xp> fd_array during the copy.
488 * For each involved file descriptor, the refcount is incremented.
489 *********************************************************************************************
490 * @ dst_xp   : extended pointer on the destination fd_array_t.
491 * @ src_xp   : extended pointer on the source fd_array_t.
492 ********************************************************************************************/
493void process_fd_remote_copy( xptr_t dst_xp,
494                             xptr_t src_xp );
495
496
497
498/********************   Thread Related Operations   *****************************************/
499
500/*********************************************************************************************
501 * This function registers a new thread in the local process descriptor.
502 * It checks that there is an available slot in the local th_tbl[] array,
503 * allocates a new LTID, and registers the new thread in the th_tbl[].
504 * WARNING : the lock protecting the th_tbl[] must be taken by the caller.
505 *********************************************************************************************
506 * @ process  : pointer on the local process descriptor.
507 * @ thread   : pointer on new thread to be registered.
508 * @ trdid    : [out] address of buffer for allocated trdid.
509 * @ returns 0 if success / returns non zero if no slot available.
510 ********************************************************************************************/
511error_t process_register_thread( process_t       * process,
512                                 struct thread_s * thread,
513                                 trdid_t         * trdid );
514
515/*********************************************************************************************
516 * This function removes a thread registration from the local process descriptor.
517 * WARNING : the lock protecting the th_tbl[] must be taken by the caller.
518 *********************************************************************************************
519 * @ thread   : local pointer on thread to be removed.
520 ********************************************************************************************/
521void process_remove_thread( struct thread_s * thread );
522
523
524/***************   Terminals related operations  ********************************************/
525
526/*********************************************************************************************
527 * This function scan the set of user TXT terminals to find a free terminal
528 * (the list of attached processes is empty for a free TXT terminal).
529 * It is called only by the process_reference_init() function when creating a KSH process.
530 * It makes a kernel panic if no free TXT terminal is found.
531 * As a KSH process is never deleted, the allocated TXT terminal is never released.
532 *********************************************************************************************
533 * @ return TXT terminal index if succes / kernel panic if no terminal found.
534 ********************************************************************************************/
535uint32_t process_txt_alloc();
536
537/*********************************************************************************************
538 * This function attach a reference process descriptor, identified by the <process>
539 * argument to a TXT terminal, identified by its <txt_id> channel index argument.
540 * It insert the process descriptor in the xlist rooted in the TXT_RX device.
541 * It is called by the process_reference_init() function.
542 *********************************************************************************************
543 * @ process  : local pointer on process descriptor.
544 * @ txt_id   : TXT channel index.
545 ********************************************************************************************/
546void process_txt_attach( process_t * process,
547                         uint32_t    txt_id );
548
549/*********************************************************************************************
550 * This function detach a reference process descriptor, identified by the <process_xp>
551 * argument, from the list of process attached to a given TXT terminal.
552 * It is called when the process is killed.
553 *********************************************************************************************
554 * @ process  : local pointer on process descriptor.
555 ********************************************************************************************/
556void process_txt_detach( process_t * process );                     
557
558/*********************************************************************************************
559 * This function gives to a process identified by the <process_xp> argument, and attached
560 * to terminal TXT[i] the exclusive ownership of the TXT_RX[i] terminal.
561 *********************************************************************************************
562 * @ process_xp  : extended pointer on reference process descriptor.
563 ********************************************************************************************/
564void process_txt_set_ownership( xptr_t process_xp );
565
566/*********************************************************************************************
567 * When the process identified by the <process_xp> argument has the exclusive ownership
568 * of the TXT_RX[i] terminal, this function gives this ownership to the KSH[i] process.
569 * It does nothing if the process is not the owner.
570 *********************************************************************************************
571 * @ process_xp  : extended pointer on reference process descriptor.
572 ********************************************************************************************/
573void process_txt_reset_ownership( xptr_t process_xp );
574
575#endif  /* _PROCESS_H_ */
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