source: trunk/kernel/kern/process.h @ 27

Last change on this file since 27 was 23, checked in by alain, 7 years ago

Introduce syscalls.
File size: 22.2 KB
Line 
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)
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 structure defines an array of extended pointers on the open file descriptors
57 * for a given process. We use an extended pointer because the open file descriptor
58 * is always stored in the same cluster as the inode associated to the file.
59 * A free entry in this array contains the XPTR_NULL value.
60 * The array size is defined by a the CONFIG_PROCESS_FILE_MAX_NR parameter.
61 * All modifications (open/close) in this structure must be done by the reference cluster,
62 * and reported in process copies.
63 ********************************************************************************************/
64
65typedef struct fd_array_s
66{
67        remote_spinlock_t lock;             /*! lock protecting fd_array[] change.              */
68    uint32_t          current;          /*! current number of open files                    */
69        xptr_t            array[CONFIG_PROCESS_FILE_MAX_NR]; 
70}
71fd_array_t;
72
73/*********************************************************************************************
74 * This structure defines a process descriptor.
75 * A process is identified by a unique PID (process identifier):
76 * - The PID 16 LSB bits contain the LPID (Local Process Index)
77 * - The PID 16 MSB bits contain the owner cluster CXY.
78 * In each cluster, the process manager allocates LPID values for the process that are
79 * allocated to this cluster.
80 * The process descriptor for a PID process is replicated in all clusters containing
81 * at least one thread of the PID process, with the following rules :
82 *
83 * 1) The <pid>, <ppid>, <ref_xp>, <vfs_root_xp>, <vfs_bin_xp>  fields are defined
84 *    in all process descriptor copies.
85 * 2) The <vfs_cwd_xp> and associated <cwd_lock>, that can be dynamically modified,
86 *    are only defined in the reference process descriptor.
87 * 2) The <vmm>, containing the list of registered vsegs, and the page table, are only
88 *    complete in the reference process cluster, other copies are read-only caches.
89 * 3) the <fd_array>, containing extended pointers on the open file descriptors, is only
90 *    complete in the reference process cluster, other copies are read-only caches.
91 * 4) The <sem_root>, <mutex_root>, <barrier_root>, <condvar_root>, and the associated
92 *    <sync_lock>, that are dynamically allocated, are only defined in the reference cluster.
93 * 5) The <children_root>, and <children_nr> fields are only defined in the reference
94 *    cluster, and are undefined in other clusters.
95 * 6) The <brothers_list>, <local_list>, <copies_list>, <th_tbl>, <th_nr>, <th_lock> fields
96 *    are defined in all process descriptors copies.
97 * 7) The <sig_mgr> field is only defined in the reference cluster. TODO
98 ********************************************************************************************/
99
100typedef struct process_s
101{
102        vmm_t             vmm;              /*! embedded virtual memory manager                 */
103
104        fd_array_t        fd_array;         /*! embedded open file descriptors array            */
105
106        xptr_t            vfs_root_xp;      /*! extende pointer on current VFS root inode       */
107        xptr_t            vfs_bin_xp;       /*! extended pointer on .elf file inode             */
108        pid_t             pid;              /*! process identifier                              */
109        pid_t             ppid;             /*! parent process identifier                       */
110    xptr_t            ref_xp;           /*! extended pointer on reference process           */
111
112        xptr_t            vfs_cwd_xp;       /*! extended pointer on current working dir inode   */
113        remote_rwlock_t   cwd_lock;         /*! lock protecting working directory changes       */
114 
115        xlist_entry_t     children_root;    /*! root of the children process xlist              */
116    uint32_t          children_nr;      /*! number of children processes                    */
117
118        xlist_entry_t     brothers_list;    /*! member of list of children of same parent       */
119    xlist_entry_t     local_list;       /*! member of list of process in same cluster       */
120    xlist_entry_t     copies_list;      /*! member of list of copies of same process        */
121
122        spinlock_t        th_lock;          /*! lock protecting th_tbl[] concurrent access      */
123        uint32_t          th_nr;            /*! number of threads in this cluster               */
124        struct thread_s * th_tbl[CONFIG_THREAD_MAX_PER_CLUSTER]; /*! pointers on local threads  */
125
126    xlist_entry_t     sem_root;         /*! root of the process semaphore list              */
127    xlist_entry_t     mutex_root;       /*! root of the process mutex list                  */
128    xlist_entry_t     barrier_root;     /*! root of the process barrier list                */
129    xlist_entry_t     condvar_root;     /*! root of the process condvar list                */
130
131    remote_spinlock_t sync_lock;        /*! lock protecting sem,mutex,barrier,condvar lists */
132
133        sig_mgr_t         sig_mgr;          /*! embedded signal manager TODO [AG]               */
134}
135process_t;
136
137/*********************************************************************************************
138 * This structure defines the minimal information required by the process_make_exec()
139 * function to build a new reference process descriptor, and the associated main thread.
140 ********************************************************************************************/
141
142typedef struct exec_info_s
143{
144    pid_t              pid;            /*! process identifier                               */
145    pid_t              ppid;           /*! parent process identifier                        */
146
147    xptr_t             fd_array_xp;    /*! extended pointer on parent process fd_array      */
148
149    xptr_t             vfs_root_xp;    /*! extended pointer on file system root             */
150    xptr_t             vfs_cwd_xp;     /*! extended pointer on current working directory    */
151    xptr_t             vfs_bin_xp;     /*! extended pointer on process .elf file            */
152
153    char               path[CONFIG_VFS_MAX_PATH_LENGTH];   /*!  .elf file path              */
154
155    char            ** args_pointers;  /*! physical base address of array of pointers       */
156    char             * args_buf_base;  /*! physical base address of kernel args buffer      */
157    uint32_t           args_nr;        /*! actual number of arguments                       */
158
159    char            ** envs_pointers;  /*! physical base address of array of pointers       */
160    char             * envs_buf_base;  /*! physical base address of kernel args buffer      */
161    char             * envs_buf_free;  /*! physical address of first free slot in envs_buf  */
162    uint32_t           envs_nr;        /*! actual number of environment variables           */
163}
164exec_info_t;
165
166/***************   Process Descriptor Operations    *****************************************/
167
168/*********************************************************************************************
169 * This function allocates memory in local cluster for a process descriptor.
170 *********************************************************************************************
171 * @ returns pointer on process descriptor if success / return NULL if failure
172 ********************************************************************************************/
173process_t * process_alloc();
174
175/*********************************************************************************************
176 * This function releases memory in local cluster for a process descriptor.
177 *********************************************************************************************
178 * @ process      : pointer on process descriptor to release.
179 ********************************************************************************************/
180void process_free( process_t * process );
181
182/*********************************************************************************************
183 * This function initializes the kernel process_zero descriptor (global variable) from
184 * informations found in the boot_info.
185 *********************************************************************************************
186 * @ info      : pointer on local boot_info_t structure.
187 ********************************************************************************************/
188void process_zero_init( boot_info_t * info );
189
190/*********************************************************************************************
191 * This function allocates memory and initialises the "process_init" descriptor and the
192 * associated thread descriptor from information found in the "process_zero" descriptor.
193 *********************************************************************************************
194 * Any error gives a kernel panic.
195 ********************************************************************************************/
196void process_init_create();
197
198/*********************************************************************************************
199 * This function intializes a new process descriptor, in the reference cluster.
200 * The PID value must have been defined previously by the owner cluster manager.
201 * The reference cluster can be different from the owner cluster.
202 * It set the pid / ppid / ref_xp fields.
203 * It registers this process descriptor in three lists:
204 * - the children_list in the parent process descriptor.
205 * - the local_list, rooted in the reference cluster manager.
206 * - the copies_list, rooted in the owner cluster manager.
207 * It reset the embedded structures such as the VMM or the file descriptor array.
208 *********************************************************************************************
209 * @ process      : [in] pointer on process descriptor to initialize.
210 * @ pid          : [in] process identifier defined by owner cluster.
211 * @ ppid         : [in] parent process identifier.
212 ********************************************************************************************/
213void process_reference_init( process_t * process,
214                             pid_t       pid,
215                             pid_t       ppid );
216
217/*********************************************************************************************
218 * This function intializes a copy process descriptor, in the local cluster,
219 * from informations defined in the reference remote process descriptor.
220 *********************************************************************************************
221 * @ process              : [in] local pointer on process descriptor to initialize.
222 * @ reference_process_xp : [in] extended pointer on reference process descriptor.
223 * @ return 0 if success / return ENOMEM if failure
224 ********************************************************************************************/
225error_t process_copy_init( process_t * local_process,
226                           xptr_t      reference_process_xp );
227
228/*********************************************************************************************
229 * This function releases all memory allocated for a process descriptor in the local cluster,
230 * including memory allocated for embedded substructures (fd_array, vmm, etc).
231 * The local th_tbl[] array must be empty.
232 *********************************************************************************************
233 * @ process     : pointer on the process descriptor.
234 ********************************************************************************************/
235void process_destroy( process_t * process );
236
237/*********************************************************************************************
238 * This function kills an user process in a given cluster.
239 * It can be directly called in the reference cluster, or it can be called through the
240 * PROCESS_KILL RPC.
241 * - In a first loop, it set the THREAD_SIG_KILL signal to all threads of process.
242 * - In a second loop, it wait, for each thread the reset of the THREAD_SIG_KILL signal
243 *   by the scheduler, and completes the thread descriptor destruction.
244 *********************************************************************************************
245 * @ process     : pointer on the process descriptor.
246 ********************************************************************************************/
247void process_kill( process_t * process );
248
249/*********************************************************************************************
250 * This function returns a pointer on the local copy of a process identified by its PID.
251 * If this local copy does not exist yet, it is dynamically created, from the reference
252 * process descriptor, registered in the global copies_list, and registered in the local_list.
253 * This function is used by the thread_user_create() function.
254 *********************************************************************************************
255 * @ pid     : searched process identifier.
256 * @ returns pointer on the local process descriptor if success / returns NULL if failure.
257 ********************************************************************************************/
258process_t * process_get_local_copy( pid_t pid );
259
260/*********************************************************************************************
261 * This function builds a new reference process descriptor and associated main thread.
262 * It is executed in the local cluster, that becomes both "owner" and "reference".
263 * The new process descriptor and the main_thread are initialised using only informations
264 * found in the local exec_info structure, that must be build by the caller.
265 * - It can be called by the process_init_create() function to build the "init" process.
266 * - It can be called directly by the sys_exec() function in case of local exec.
267 * - It can be called through the rpc_process_exec_server() function in case of remote exec.
268 *********************************************************************************************
269 * @ exec_info   : [in]  pointer on the exec_info structure.
270 * @ return 0 if success / return non-zero if error.
271 ********************************************************************************************/
272error_t process_make_exec( exec_info_t * exec_info );
273
274
275/********************   Signal Management Operations   **************************************/ 
276
277/*********************************************************************************************
278 * This function TODO [AG]
279 ********************************************************************************************/
280void process_signal_handler( process_t * process );
281
282
283/********************   File Management Operations   ****************************************/ 
284
285/*********************************************************************************************
286 * This function initialises all entries of the local fd_array as empty.
287 *********************************************************************************************
288 * @ process  : pointer on the local process descriptor.
289 ********************************************************************************************/
290void process_fd_init( process_t * process );
291
292/*********************************************************************************************
293 * This function uses as many remote accesses as required, to reset an entry in fd_array[],
294 * in all clusters containing a copy. The entry is identified by the <file_id> argument.
295 * This function must be executed by a thread running reference cluster, that contain
296 * the complete list of process descriptors copies.
297 *********************************************************************************************
298 * @ process  : pointer on the local process descriptor.
299 * @ file_id  : file descriptor index in the fd_array.
300 ********************************************************************************************/
301void process_fd_remove( process_t * process,
302                        uint32_t    file_id );
303
304/*********************************************************************************************
305 * This function returns an extended pointer on a file descriptor identified by its index
306 * in fd_array. It can be called by any thread running in any cluster.
307 * It access first the local process descriptor. In case of local miss, it uses remote access
308 * to access the reference process descriptor.
309 * It updates the local fd_array when the file descriptor exist in reference cluster.
310 * The file descriptor refcount is not incremented.
311 *********************************************************************************************
312 * @ process  : pointer on the local process descriptor.
313 * @ file_id  : file descriptor index in the fd_array.
314 * @ return extended pointer on file descriptor if success / return XPTR_NULL if not found.
315 ********************************************************************************************/
316xptr_t process_fd_get_xptr( process_t * process,
317                            uint32_t    file_id );
318
319/*********************************************************************************************
320 * This function checks the number of open files for a given process.
321 * It can be called by any thread in any cluster, because it uses portable remote access
322 * primitives to access the reference process descriptor.
323 *********************************************************************************************
324 * @ returns true if file descriptor array full.
325 ********************************************************************************************/
326bool_t process_fd_array_full();
327
328/*********************************************************************************************
329 * This function allocates a free slot in the fd_array of the reference process,
330 * register the <file_xp> argument in the allocated slot, and return the slot index.
331 * It can be called by any thread in any cluster, because it uses portable remote access
332 * primitives to access the reference process descriptor.
333 *********************************************************************************************
334 * @ file_xp  : extended pointer on the file descriptor to be registered.
335 * @ file_id  : [out] buffer for fd_array slot index.
336 * @ return 0 if success / return EMFILE if array full.
337 ********************************************************************************************/
338error_t process_fd_register( xptr_t      file_xp, 
339                             uint32_t  * file_id );
340
341/*********************************************************************************************
342 * This function copies all non-zero entries from a remote <src_xp> fd_array,
343 * embedded in a process descriptor, to another remote <dst_xp> fd_array, embedded
344 * in another process descriptor. The calling thread can be running in any cluster.
345 * It takes the remote lock protecting the <src_xp> fd_array during the copy.
346 * For each involved file descriptor, the refcount is incremented.
347 *********************************************************************************************
348 * @ dst_xp   : extended pointer on the destination fd_array_t.
349 * @ src_xp   : extended pointer on the source fd_array_t.
350 ********************************************************************************************/
351void process_fd_remote_copy( xptr_t dst_xp,
352                             xptr_t src_xp );
353
354
355
356/********************   Thread Related Operations   *****************************************/ 
357
358/*********************************************************************************************
359 * This function registers a new thread in the local process descriptor.
360 * It checks that there is an available slot in the local th_tbl[] array,
361 * allocates a new LTID, and registers the new thread in the th_tbl[].
362 * WARNING : the lock protecting the th_tbl[] must be taken by the caller.
363 *********************************************************************************************
364 * @ process  : pointer on the local process descriptor.
365 * @ thread   : pointer on new thread to be registered.
366 * @ trdid    : [out] address of buffer for allocated trdid.
367 * @ returns 0 if success / returns non zero if no slot available.
368 ********************************************************************************************/
369error_t process_register_thread( process_t       * process,
370                                 struct thread_s * thread,
371                                 trdid_t         * trdid );
372
373/*********************************************************************************************
374 * This function removes a thread registration from the local process descriptor.
375 * WARNING : the lock protecting the th_tbl[] must be taken by the caller.
376 *********************************************************************************************
377 * @ thread   : local pointer on thread to be removed.
378 ********************************************************************************************/
379void process_remove_thread( struct thread_s * thread );
380
381
382
383#endif  /* _PROCESS_H_ */
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