source: trunk/kernel/kern/thread.h @ 536

Last change on this file since 536 was 527, checked in by viala@…, 6 years ago

Rewrite if-then-else return function into switch case.

For safety reason and performance:

1) Safety: GCC complain with a warning if you forgot an enum variant.
2) code-gen just outperform naive if-then-else.
File size: 26.0 KB
Line 
1/*
2 * thread.h -  Thread and related operations definition.
3 *
4 * Author  Ghassan Almaless (2008,2009,2010,2011,2012)
5 *         Alain Greiner (2016)
6 *
7 * Copyright (c) UPMC Sorbonne Universites
8 *
9 * This file is part of ALMOS-MKH.
10 *
11 * ALMOS-MKH is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; version 2.0 of the License.
14 *
15 * ALMOS-MKH is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
22 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
25#ifndef _THREAD_H_
26#define _THREAD_H_
27
28#include <hal_kernel_types.h>
29#include <shared_syscalls.h>
30#include <hal_special.h>
31#include <xlist.h>
32#include <list.h>
33#include <hal_context.h>
34#include <spinlock.h>
35#include <core.h>
36#include <chdev.h>
37#include <cluster.h>
38#include <process.h>
39#include <dev_ioc.h>
40#include <dev_nic.h>
41#include <dev_txt.h>
42#include <dev_mmc.h>
43#include <dev_dma.h>
44
45/***************************************************************************************
46 * These macros are used to compose or decompose the global thread identifier (TRDID)
47 * to or from cluster identifier / local thread index (CXY , LTID)
48 **************************************************************************************/
49
50#define LTID_FROM_TRDID( trdid )   (ltid_t)(trdid & 0x0000FFFF)
51#define CXY_FROM_TRDID( trdid )    (cxy_t)(trdid >> 16)
52#define TRDID( cxy , ltid )        (trdid_t)((cxy << 16) | ltid )
53
54/***************************************************************************************
55 * This enum defines the thread types.
56 **************************************************************************************/
57
58typedef enum
59{
60        THREAD_USER    = 0,          /*! user thread (pthread)                            */
61        THREAD_RPC     = 1,          /*! kernel thread executing pending RPCs             */
62        THREAD_DEV     = 2,          /*! kernel thread executing I/O device commands      */
63        THREAD_IDLE    = 3,          /*! kernel idle thread                               */
64}
65thread_type_t;
66
67/***************************************************************************************
68 * This defines the thread flags bit-vector.
69 **************************************************************************************/
70
71#define THREAD_FLAG_DETACHED     0x0001  /*! This thread is detached from parent      */
72#define THREAD_FLAG_JOIN_DONE    0x0002  /*! Parent thread made a join request        */
73#define THREAD_FLAG_KILL_DONE    0x0004  /*! This thread received a kill request      */
74#define THREAD_FLAG_SCHED        0x0008  /*! Scheduling required for this thread      */
75#define THREAD_FLAG_REQ_ACK      0x0010  /*! Acknowledge required from scheduler      */
76#define THREAD_FLAG_REQ_DELETE   0x0020  /*! Destruction required from scheduler      */
77
78/***************************************************************************************
79 * This defines the thread blocking causes bit-vector.
80 **************************************************************************************/
81
82#define THREAD_BLOCKED_GLOBAL    0x0001  /*! thread deactivated / wait activation     */
83#define THREAD_BLOCKED_IO        0x0002  /*! thread wait IO operation completion      */
84#define THREAD_BLOCKED_MAPPER    0x0004  /*! thread wait mapper                       */
85#define THREAD_BLOCKED_EXIT      0x0008  /*! thread blocked in join / wait exit       */
86#define THREAD_BLOCKED_JOIN      0x0010  /*! thread blocked in exit / wait join       */
87#define THREAD_BLOCKED_SEM       0x0020  /*! thread wait semaphore                    */
88#define THREAD_BLOCKED_PAGE      0x0040  /*! thread wait page access                  */
89#define THREAD_BLOCKED_IDLE      0x0080  /*! thread RPC wait RPC_FIFO non empty       */
90#define THREAD_BLOCKED_USERSYNC  0x0100  /*! thread wait (cond/mutex/barrier)         */
91#define THREAD_BLOCKED_RPC       0x0200  /*! thread wait RPC completion               */
92#define THREAD_BLOCKED_ISR       0x0400  /*! thread DEV wait ISR                      */
93#define THREAD_BLOCKED_WAIT      0x0800  /*! thread wait child process termination    */
94
95/***************************************************************************************
96 * This structure defines thread instrumentation informations.
97 **************************************************************************************/
98
99typedef struct thread_info_s
100{
101        uint32_t              pgfault_nr;    /*! cumulated number of page fault           */
102        uint32_t              sched_nr;      /*! TODO ???  [AG]                           */
103        uint32_t              u_err_nr;      /*! TODO ???  [AG]                           */
104        uint32_t              m_err_nr;      /*! TODO ???  [AG]                           */
105        cycle_t               last_cycle;    /*! last cycle counter value (date)          */
106        cycle_t               usr_cycles;    /*! user execution duration (cycles)         */
107        cycle_t               sys_cycles;    /*! system execution duration (cycles)       */
108}
109thread_info_t;
110
111/***************************************************************************************
112 * This structure defines a thread descriptor.
113 * It is used for both the user threads and the kernel threads.
114 * In a process, a user thread is identified by a unique TRDID (thread identifier):
115 * - The TRDID 16 LSB bits contain the LTID (Local Thread Index).
116 * - The TRDID 16 MSB bits contain the CXY of cluster containing the thread.
117 * The main thread LTID value is always 0.
118 * The LTID is used to index the th_tbl[] array in the local process descriptor.
119 * This TRDID is computed by the process_register_thread() function, when the user
120 * thread is registered in the local copy of the process descriptor.
121 * WARNING : Don't modify the first 4 fields order, as this order is used by the
122 * hal_kentry assembly code for the TSAR architecture.
123 **************************************************************************************/
124
125#define THREAD_SIGNATURE    0xDEADBEEF
126
127typedef struct thread_s
128{
129        void              * cpu_context;     /*! pointer on CPU context switch            */
130        void              * fpu_context;     /*! pointer on FPU context switch            */
131    void              * uzone_current;   /*! used by hal_do_syscall & hal_do_except   */
132    void              * uzone_previous;  /*! used by hal_do_syscall & hal_do_except   */
133
134        intptr_t            k_stack_base;    /*! kernel stack base address                */
135        uint32_t            k_stack_size;    /*! kernel stack size (bytes)                */
136
137        uint32_t            trdid;           /*! thread index (cxy.ltid)                  */
138        thread_type_t       type;            /*! thread type                              */
139        uint32_t            quantum;         /*! number of clock ticks given to thread    */
140        uint32_t            ticks_nr;        /*! number of ticks used                     */
141        uint32_t            time_last_check; /*! last cpu_time_stamp                      */
142        core_t            * core;            /*! pointer to the owner core                */
143        process_t         * process;         /*! pointer on local process descriptor      */
144    xptr_t              parent;          /*! extended pointer on parent thread        */
145
146    remote_spinlock_t   join_lock;       /*! lock protecting the join/exit            */
147    xptr_t              join_xp;         /*! joining/killer thread extended pointer   */
148
149    uint32_t          * ack_rsp_count;   /*! pointer on acknowledge response counter  */
150
151        intptr_t            u_stack_base;    /*! user stack base address                  */
152        uint32_t            u_stack_size;    /*! user stack size (bytes)                  */
153
154    void              * entry_func;      /*! pointer on entry function                */
155    void              * entry_args;      /*! pointer on entry function arguments      */
156    uint32_t            main_argc;       /*! main thread number of arguments          */
157    char             ** main_argv;       /*! main thread array of strings arguments   */
158
159    uint32_t            flags;           /*! bit vector of flags                      */
160    uint32_t            blocked;         /*! bit vector of blocking causes            */
161
162        error_t             errno;           /*! errno value set by last system call      */
163    uint32_t            utls;            /*! user thread local storage                */
164
165    bool_t              fork_user;       /*! user defined placement for next fork()   */
166    cxy_t               fork_cxy;        /*! target cluster  for next fork()          */
167
168        list_entry_t        sched_list;      /*! member of threads attached to same core  */
169
170    chdev_t           * chdev;           /*! chdev pointer (for a DEV thread only)    */
171
172    reg_t               save_sr;         /*! used by sched_yield() function           */
173
174    ioc_command_t       ioc_cmd;         /*! IOC device generic command               */
175    txt_command_t       txt_cmd;         /*! TXT device generic command               */
176    nic_command_t       nic_cmd;         /*! NIC device generic command               */
177    mmc_command_t       mmc_cmd;         /*! MMC device generic command               */
178    dma_command_t       dma_cmd;         /*! DMA device generic command               */
179
180        cxy_t               rpc_client_cxy;  /*! client cluster index (for a RPC thread)  */
181
182    xlist_entry_t       wait_list;       /*! member of threads blocked on same cond   */
183
184    list_entry_t        locks_root;      /*! root of list of locks taken              */
185    xlist_entry_t       xlocks_root;     /*! root of xlist of remote locks taken      */
186        uint32_t            local_locks;         /*! number of local locks owned by thread    */
187        uint32_t            remote_locks;        /*! number of remote locks owned by thread   */
188
189        thread_info_t       info;            /*! embedded thread_info_t                   */
190
191        uint32_t            signature;       /*! for kernel stack overflow detection      */
192}
193thread_t;
194
195/***************************************************************************************
196 * This macro returns a pointer on the calling thread from the core hardware register.
197 **************************************************************************************/
198
199#define CURRENT_THREAD  (hal_get_current_thread())
200
201/***************************************************************************************
202 * This function returns a printable string for a thread type.
203 ***************************************************************************************
204 * @ type    : thread type.
205 * returns pointer on string.
206 **************************************************************************************/
207const char * thread_type_str( thread_type_t type );
208
209/***************************************************************************************
210 * This function is used by the pthread_create() system call to create a "new" thread
211 * in an existing process. It allocates memory for an user thread descriptor in the
212 * local cluster, and initializes it from information contained in the arguments.
213 * The CPU context is initialized from scratch.
214 * It is registered in the local process descriptor specified by the <pid> argument.
215 * The THREAD_BLOCKED_GLOBAL bit is set => the thread must be activated by the caller
216 * to start at the next scheduling point.
217 ***************************************************************************************
218 * @ pid          : process identifier.
219 * @ start_func   : pointer on entry function.
220 * @ start_args   : pointer on function argument (can be NULL).
221 * @ attr         : pointer on pthread attributes descriptor.
222 * @ new_thread   : [out] address of buffer for new thread descriptor pointer.
223 * @ returns 0 if success / returns ENOMEM if error.
224 **************************************************************************************/
225error_t thread_user_create( pid_t             pid,
226                            void            * start_func,
227                            void            * start_arg,
228                            pthread_attr_t  * attr,
229                            thread_t       ** new_thread );
230
231/***************************************************************************************
232 * This function is used by the sys_fork() system call to create the "child" thread
233 * in the local cluster. It allocates memory for a thread descriptor, and initializes
234 * it from the "parent" thread descriptor defined by the <parent_thread_xp> argument.
235 * The new thread is attached to the core that has the lowest load in local cluster.
236 * It is registered in the "child" process defined by the <child_process> argument.
237 * This new thread inherits its user stack from the parent thread, as it uses the
238 * Copy-On-Write mechanism to get a private stack when required.
239 * The content of the parent kernel stack is copied into the child kernel stack, as
240 * the Copy-On-Write mechanism cannot be used for kernel segments (because kernel
241 * uses physical addressing on some architectures).
242 * The CPU and FPU execution contexts are created and linked to the new thread.
243 * but the actual context copy is NOT done, and must be done by by the sys_fork().
244 * The THREAD_BLOCKED_GLOBAL bit is set => the thread must be activated to start.
245 ***************************************************************************************
246 * @ parent_thread_xp  : extended pointer on parent thread descriptor.
247 * @ child_process     : local pointer on child process descriptor.
248 * @ child_thread      : [out] address of buffer for child thread descriptor pointer.
249 * @ returns 0 if success / returns -1 if error.
250 **************************************************************************************/
251error_t thread_user_fork( xptr_t      parent_thread_xp,
252                          process_t * child_process,
253                          thread_t ** child_thread );
254
255/***************************************************************************************
256 * This function is called by the process_make_exec() function to re-initialise the
257 * thread descriptor of the calling thread (that will become the new process main
258 * thread), and immediately jump to user code without returning to kentry!!!
259 * It must be called by the main thread of the calling process.
260 * - A new user stack vseg is created and initialised.
261 * - The kernel stack (currently in use) is not modified. 
262 * - The function calls the hal_cpu_context_exec() to re-initialize the CPU context
263 *   an jump to user code. 
264 ***************************************************************************************
265 * @ entry_func : main thread entry point.
266 * @ argc       : number of main thread arguments.
267 * @ argv       : array of pointers on stringarguments.
268 * @ returns 0 if success / returns ENOMEM if error.
269 **************************************************************************************/
270error_t thread_user_exec( void     * entry_func,
271                          uint32_t   argc,
272                          char    ** argv);
273
274/***************************************************************************************
275 * This function allocates memory for a kernel thread descriptor in the local cluster,
276 * and initializes it from arguments values.
277 * It is called by kernel_init() to statically create all DEV server threads
278 * It is also called to dynamically create RPC threads when required.
279 * The THREAD_BLOCKED_GLOBAL bit is set, and the thread must be activated to start.
280 ***************************************************************************************
281 * @ new_thread   : address of buffer for new thread pointer.
282 * @ type         : kernel thread type.
283 * @ func         : pointer on function.
284 * @ args         : function arguments.
285 * @ core_lid     : local core index.
286 * @ returns 0 if success / returns ENOMEM if error
287 **************************************************************************************/
288error_t thread_kernel_create( thread_t     ** new_thread,
289                              thread_type_t   type,
290                              void          * func,
291                              void          * args,
292                              lid_t           core_lid );
293
294/***************************************************************************************
295 * This function is called by the kernel_init() function to initialize the IDLE thread
296 * descriptor from arguments values.
297 * The THREAD_BLOCKED_GLOBAL bit is set, and the thread must be activated to start.
298 * It returns a kernel panic if failure.
299 ***************************************************************************************
300 * @ thread   : pointer on existing thread descriptor.
301 * @ type     : kernel thread type.
302 * @ func     : pointer on function.
303 * @ args     : function arguments.
304 * @ core_lid : local core index.
305 **************************************************************************************/
306void thread_idle_init( thread_t      * thread,
307                       thread_type_t   type,
308                       void          * func,
309                       void          * args,
310                       lid_t           core_lid );
311
312/***************************************************************************************
313 * This function is called by the sched_handle_signals() function to releases
314 * the physical memory allocated for a thread in a given cluster, when this thread
315 * is marked for delete. This include the thread descriptor itself, the associated
316 * CPU and FPU context, and the physical memory allocated for an user thread local stack.
317 * The destroyed thread is removed from the local process th_tbl[] array, and returns
318 * true when the destroyed thread was the last thread registered in process.
319 ***************************************************************************************
320 * @ thread  : pointer on the thread descriptor to release.
321 * @ return true, if the thread was the last registerd thread in local process.
322 **************************************************************************************/
323bool_t thread_destroy( thread_t * thread );
324
325/***************************************************************************************
326 * This function defines the code of the thread executed by all cores after kernel_init,
327 * or when no other thread is runnable for a given core.
328 * It enter and infinite loop in wich:
329 * - it unmask the IRQs
330 * - it optionally calls the hal_core_sleep() function to reduce the power consumption
331 *   (this behavior is controlled by the CONFIG_THREAD_IDLE_MODE_SLEEP flag).
332 * - it call the sched_yield() function to find another runnable thread.
333 *
334 * TODO: In the TSAR architecture the hal_core_sleep() function forces the core to
335 * low-power mode. Any IRQ will force the core to exit this low-power mode, but no ISR
336 * is executed. We must analyse if we have the same behaviour for I86 architectures...
337 **************************************************************************************/
338void thread_idle_func( void );
339
340/***************************************************************************************
341 * This function is used by a "blocker" thread running in the same cluster as a "target"
342 * thread to request the scheduler of the target thread to acknowledge that the target
343 * thread is blocked and not running, at the next context switch.
344 * This function executes atomically the following actions :
345 * - it set the request_pending boolean in the target scheduler descriptor.
346 * - it set the REQ_ACK flag in the "flags" field of the target thread descriptor.
347 * - It registers the responses counter pointer in the target thread descriptor.
348 * The request_pending flag is handled as a set/reset flip-flop by the "blocker" thread
349 * and by the "target" scheduler.
350 ***************************************************************************************
351 * @ target        : local pointer on target thread.
352 * @ ack_rsp_count : local pointer on responses counter.
353 **************************************************************************************/
354void thread_set_req_ack( thread_t * target,
355                         uint32_t * ack_rsp_count );
356
357/***************************************************************************************
358 * This function is used by the sched_handle_signal() function executed by the
359 * scheduler of a "target" thread to reset a "blocked not running" acknowledge request
360 * in both the target thread descriptor, and in the target  thread scheduler.
361 ***************************************************************************************
362 * @ target    : local pointer on target thread.
363 **************************************************************************************/
364void thread_reset_req_ack( thread_t * target );
365
366/***************************************************************************************
367 * This function checks if the calling thread can deschedule.
368 ***************************************************************************************
369 * @ returns true if no locks taken.
370 **************************************************************************************/
371inline bool_t thread_can_yield( void );
372
373/***************************************************************************************
374 * This function implements the delayed descheduling mechanism : It is called  by
375 * all lock release functions, and calls the sched_yield() function when all locks
376 * have beeen released and the calling thread THREAD_FLAG_SCHED flag is set.
377 **************************************************************************************/
378void thread_check_sched( void );
379
380/***************************************************************************************
381 * This function is used by the four sys_thread_cancel(), sys_thread_exit(),
382 * sys_kill() and sys_exit() system calls to mark for delete a given thread.
383 * It set the THREAD_BLOCKED_GLOBAL bit and set the the THREAD_FLAG_REQ_DELETE bit
384 * in the thread descriptor identified by the <thread_xp> argument, to ask the scheduler
385 * to asynchronously delete the target thread, at the next scheduling point.
386 * The calling thread can run in any cluster, as it uses remote accesses, but
387 * the target thread cannot be the main thread of the process identified by the <pid>,
388 * because the main thread must be deleted by the parent process argument.
389 * If the target thread is running in "attached" mode, and the <is_forced> argument
390 * is false, this function implements the required sychronisation with the joining
391 * thread, blocking the calling thread until the pthread_join() syscall is executed.
392 ***************************************************************************************
393 * @ thread_xp   : extended pointer on the target thread.
394 * @ pid         : process identifier (to get the owner cluster identifier).
395 * @ is_forced   : the deletion does not depends on the attached mode.
396 **************************************************************************************/
397void thread_delete( xptr_t  thread_xp,
398                    pid_t   pid,
399                    bool_t  is_forced );
400
401/***************************************************************************************
402 * This function registers a blocking cause defined by the <cause> argument
403 * in a remote thread descriptor identified by the <thread_xp> argument.
404 * We need an extended pointer, because this function can be called by another thread
405 * than the target thread, executing the sys_kill() function.
406 * WARNING : this function does not deschedule the target thread, and the descheduling
407 * must be explicitely forced by a sched_yield().
408 ***************************************************************************************
409 * @ thread_xp   : extended pointer on remote thread descriptor.
410 * @ cause       : mask defining the cause (one hot).
411 **************************************************************************************/
412void thread_block( xptr_t   thread_xp,
413                   uint32_t cause );
414
415/***************************************************************************************
416 * This function resets the bit identified by the <cause> argument in a remote
417 * thread descriptor identified by the <thread_xp> argument.
418 * We need an extended pointer, because the client thread of an I/O operation on a
419 * given device is not in the same cluster as the associated device descriptor.
420 * WARNING : this function does not reschedule the remote thread.
421 * The scheduling can be forced by sending an IPI to the core running the remote thread.
422 ***************************************************************************************
423 * @ thread_xp   : extended pointer the remote thread.
424 * @ cause       : mask defining the cause (one hot).
425 * @ return non zero if the bit-vector was actually modified / return 0 otherwise
426 **************************************************************************************/
427uint32_t thread_unblock( xptr_t   thread_xp,
428                         uint32_t cause );
429
430/***************************************************************************************
431 * This function updates the calling thread user_time or kernel_time counters.
432 ***************************************************************************************
433 * @ thread   : local pointer on target thread.
434 * @ is_user  : update user time if non zero / update kernel time if zero
435 **************************************************************************************/
436void thread_time_update( thread_t * thread,
437                         uint32_t   is_user );
438
439/***************************************************************************************
440 * This function returns the extended pointer on a thread descriptor identified
441 * by its thread identifier, and process identifier.
442 * It can be called by any thread running in any cluster.
443 ***************************************************************************************
444 * @ pid     : process identifier.
445 * @ trdid   : thread identifier.
446 * @ return the extended pointer if thread found / return XPTR_NULL if not found.
447 **************************************************************************************/
448xptr_t thread_get_xptr( pid_t    pid,
449                        trdid_t  trdid );
450
451
452#endif  /* _THREAD_H_ */
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