1 /* Linuxthreads - a simple clone()-based implementation of Posix */
2 /* threads for Linux. */
3 /* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
5 /* This program is free software; you can redistribute it and/or */
6 /* modify it under the terms of the GNU Library General Public License */
7 /* as published by the Free Software Foundation; either version 2 */
8 /* of the License, or (at your option) any later version. */
10 /* This program is distributed in the hope that it will be useful, */
11 /* but WITHOUT ANY WARRANTY; without even the implied warranty of */
12 /* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
13 /* GNU Library General Public License for more details. */
15 /* Internal data structures */
23 #include <sys/types.h>
24 #include <bits/libc-tsd.h> /* for _LIBC_TSD_KEY_N */
26 #include "pt-machine.h"
29 # define THREAD_GETMEM(descr, member) descr->member
31 #ifndef THREAD_GETMEM_NC
32 # define THREAD_GETMEM_NC(descr, member) descr->member
35 # define THREAD_SETMEM(descr, member, value) descr->member = (value)
37 #ifndef THREAD_SETMEM_NC
38 # define THREAD_SETMEM_NC(descr, member, value) descr->member = (value)
41 /* Arguments passed to thread creation routine */
43 struct pthread_start_args
{
44 void * (*start_routine
)(void *); /* function to run */
45 void * arg
; /* its argument */
46 sigset_t mask
; /* initial signal mask for thread */
47 int schedpolicy
; /* initial scheduling policy (if any) */
48 struct sched_param schedparam
; /* initial scheduling parameters (if any) */
52 /* We keep thread specific data in a special data structure, a two-level
53 array. The top-level array contains pointers to dynamically allocated
54 arrays of a certain number of data pointers. So we can implement a
55 sparse array. Each dynamic second-level array has
56 PTHREAD_KEY_2NDLEVEL_SIZE
57 entries. This value shouldn't be too large. */
58 #define PTHREAD_KEY_2NDLEVEL_SIZE 32
60 /* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
61 keys in each subarray. */
62 #define PTHREAD_KEY_1STLEVEL_SIZE \
63 ((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
64 / PTHREAD_KEY_2NDLEVEL_SIZE)
67 #define PTHREAD_START_ARGS_INITIALIZER { NULL, NULL, {{0, }}, 0, { 0 } }
69 /* The type of thread descriptors */
71 typedef struct _pthread_descr_struct
* pthread_descr
;
73 struct _pthread_descr_struct
{
74 pthread_descr p_nextlive
, p_prevlive
;
75 /* Double chaining of active threads */
76 pthread_descr p_nextwaiting
; /* Next element in the queue holding the thr */
77 pthread_descr p_nextlock
; /* can be on a queue and waiting on a lock */
78 pthread_t p_tid
; /* Thread identifier */
79 int p_pid
; /* PID of Unix process */
80 int p_priority
; /* Thread priority (== 0 if not realtime) */
81 struct _pthread_fastlock
* p_lock
; /* Spinlock for synchronized accesses */
82 int p_signal
; /* last signal received */
83 sigjmp_buf
* p_signal_jmp
; /* where to siglongjmp on a signal or NULL */
84 sigjmp_buf
* p_cancel_jmp
; /* where to siglongjmp on a cancel or NULL */
85 char p_terminated
; /* true if terminated e.g. by pthread_exit */
86 char p_detached
; /* true if detached */
87 char p_exited
; /* true if the assoc. process terminated */
88 void * p_retval
; /* placeholder for return value */
89 int p_retcode
; /* placeholder for return code */
90 pthread_descr p_joining
; /* thread joining on that thread or NULL */
91 struct _pthread_cleanup_buffer
* p_cleanup
; /* cleanup functions */
92 char p_cancelstate
; /* cancellation state */
93 char p_canceltype
; /* cancellation type (deferred/async) */
94 char p_canceled
; /* cancellation request pending */
95 int * p_errnop
; /* pointer to used errno variable */
96 int p_errno
; /* error returned by last system call */
97 int * p_h_errnop
; /* pointer to used h_errno variable */
98 int p_h_errno
; /* error returned by last netdb function */
99 char * p_in_sighandler
; /* stack address of sighandler, or NULL */
100 char p_sigwaiting
; /* true if a sigwait() is in progress */
101 struct pthread_start_args p_start_args
; /* arguments for thread creation */
102 void ** p_specific
[PTHREAD_KEY_1STLEVEL_SIZE
]; /* thread-specific data */
103 void * p_libc_specific
[_LIBC_TSD_KEY_N
]; /* thread-specific data for libc */
104 int p_userstack
; /* nonzero if the user provided the stack */
105 void *p_guardaddr
; /* address of guard area or NULL */
106 size_t p_guardsize
; /* size of guard area */
107 pthread_descr p_self
; /* Pointer to this structure */
108 int p_nr
; /* Index of descriptor in __pthread_handles */
109 } __attribute__ ((aligned(32))); /* We need to align the structure so that
110 doubles are aligned properly. This is 8
111 bytes on MIPS and 16 bytes on MIPS64.
112 32 bytes might give better cache
116 /* The type of thread handles. */
118 typedef struct pthread_handle_struct
* pthread_handle
;
120 struct pthread_handle_struct
{
121 struct _pthread_fastlock h_lock
; /* Fast lock for sychronized access */
122 pthread_descr h_descr
; /* Thread descriptor or NULL if invalid */
123 char * h_bottom
; /* Lowest address in the stack thread */
126 /* The type of messages sent to the thread manager thread */
128 struct pthread_request
{
129 pthread_descr req_thread
; /* Thread doing the request */
130 enum { /* Request kind */
131 REQ_CREATE
, REQ_FREE
, REQ_PROCESS_EXIT
, REQ_MAIN_THREAD_EXIT
,
134 union { /* Arguments for request */
135 struct { /* For REQ_CREATE: */
136 const pthread_attr_t
* attr
; /* thread attributes */
137 void * (*fn
)(void *); /* start function */
138 void * arg
; /* argument to start function */
139 sigset_t mask
; /* signal mask */
141 struct { /* For REQ_FREE: */
142 pthread_t thread_id
; /* identifier of thread to free */
144 struct { /* For REQ_PROCESS_EXIT: */
145 int code
; /* exit status */
147 void * post
; /* For REQ_POST: the semaphore */
152 /* Signals used for suspend/restart and for cancellation notification. */
154 extern int __pthread_sig_restart
;
155 extern int __pthread_sig_cancel
;
157 /* Signal used for interfacing with gdb */
159 extern int __pthread_sig_debug
;
161 /* Global array of thread handles, used for validating a thread id
162 and retrieving the corresponding thread descriptor. Also used for
163 mapping the available stack segments. */
165 extern struct pthread_handle_struct __pthread_handles
[PTHREAD_THREADS_MAX
];
167 /* Descriptor of the initial thread */
169 extern struct _pthread_descr_struct __pthread_initial_thread
;
171 /* Descriptor of the manager thread */
173 extern struct _pthread_descr_struct __pthread_manager_thread
;
175 /* Descriptor of the main thread */
177 extern pthread_descr __pthread_main_thread
;
179 /* Limit between the stack of the initial thread (above) and the
180 stacks of other threads (below). Aligned on a STACK_SIZE boundary.
181 Initially 0, meaning that the current thread is (by definition)
182 the initial thread. */
184 extern char *__pthread_initial_thread_bos
;
186 /* Indicate whether at least one thread has a user-defined stack (if 1),
187 or all threads have stacks supplied by LinuxThreads (if 0). */
189 extern int __pthread_nonstandard_stacks
;
191 /* File descriptor for sending requests to the thread manager.
192 Initially -1, meaning that __pthread_initialize_manager must be called. */
194 extern int __pthread_manager_request
;
196 /* Other end of the pipe for sending requests to the thread manager. */
198 extern int __pthread_manager_reader
;
200 /* Limits of the thread manager stack. */
202 extern char *__pthread_manager_thread_bos
;
203 extern char *__pthread_manager_thread_tos
;
205 /* Pending request for a process-wide exit */
207 extern int __pthread_exit_requested
, __pthread_exit_code
;
209 /* Set to 1 by gdb if we're debugging */
211 extern volatile int __pthread_threads_debug
;
213 /* Return the handle corresponding to a thread id */
215 static inline pthread_handle
thread_handle(pthread_t id
)
217 return &__pthread_handles
[id
% PTHREAD_THREADS_MAX
];
220 /* Validate a thread handle. Must have acquired h->h_spinlock before. */
222 static inline int invalid_handle(pthread_handle h
, pthread_t id
)
224 return h
->h_descr
== NULL
|| h
->h_descr
->p_tid
!= id
;
227 /* Fill in defaults left unspecified by pt-machine.h. */
229 /* The page size we can get from the system. This should likely not be
230 changed by the machine file but, you never know. */
232 #define PAGE_SIZE (sysconf (_SC_PAGE_SIZE))
235 /* The max size of the thread stack segments. If the default
236 THREAD_SELF implementation is used, this must be a power of two and
237 a multiple of PAGE_SIZE. */
239 #define STACK_SIZE (2 * 1024 * 1024)
242 /* The initial size of the thread stack. Must be a multiple of PAGE_SIZE. */
243 #ifndef INITIAL_STACK_SIZE
244 #define INITIAL_STACK_SIZE (4 * PAGE_SIZE)
247 /* Size of the thread manager stack. The "- 32" avoids wasting space
248 with some malloc() implementations. */
249 #ifndef THREAD_MANAGER_STACK_SIZE
250 #define THREAD_MANAGER_STACK_SIZE (2 * PAGE_SIZE - 32)
253 /* The base of the "array" of thread stacks. The array will grow down from
254 here. Defaults to the calculated bottom of the initial application
256 #ifndef THREAD_STACK_START_ADDRESS
257 #define THREAD_STACK_START_ADDRESS __pthread_initial_thread_bos
260 /* Get some notion of the current stack. Need not be exactly the top
261 of the stack, just something somewhere in the current frame. */
262 #ifndef CURRENT_STACK_FRAME
263 #define CURRENT_STACK_FRAME ({ char __csf; &__csf; })
266 /* Recover thread descriptor for the current thread */
268 extern pthread_descr
__pthread_find_self (void) __attribute__ ((const));
270 static inline pthread_descr
thread_self (void) __attribute__ ((const));
271 static inline pthread_descr
thread_self (void)
276 char *sp
= CURRENT_STACK_FRAME
;
277 if (sp
>= __pthread_initial_thread_bos
)
278 return &__pthread_initial_thread
;
279 else if (sp
>= __pthread_manager_thread_bos
280 && sp
< __pthread_manager_thread_tos
)
281 return &__pthread_manager_thread
;
282 else if (__pthread_nonstandard_stacks
)
283 return __pthread_find_self();
285 return (pthread_descr
)(((unsigned long)sp
| (STACK_SIZE
-1))+1) - 1;
289 /* Max number of times we must spin on a spinlock calling sched_yield().
290 After MAX_SPIN_COUNT iterations, we put the calling thread to sleep. */
292 #ifndef MAX_SPIN_COUNT
293 #define MAX_SPIN_COUNT 50
296 /* Duration of sleep (in nanoseconds) when we can't acquire a spinlock
297 after MAX_SPIN_COUNT iterations of sched_yield().
298 With the 2.0 and 2.1 kernels, this MUST BE > 2ms.
299 (Otherwise the kernel does busy-waiting for realtime threads,
300 giving other threads no chance to run.) */
302 #ifndef SPIN_SLEEP_DURATION
303 #define SPIN_SLEEP_DURATION 2000001
310 #define ASSERT assert
311 #define MSG __pthread_message
314 #define MSG(msg,arg...)
317 /* Internal global functions */
319 void __pthread_destroy_specifics(void);
320 void __pthread_perform_cleanup(void);
321 int __pthread_initialize_manager(void);
322 void __pthread_message(char * fmt
, ...);
323 int __pthread_manager(void *reqfd
);
324 void __pthread_manager_sighandler(int sig
);
325 void __pthread_reset_main_thread(void);
326 void __fresetlockfiles(void);
327 void __pthread_manager_adjust_prio(int thread_prio
);
329 extern int __pthread_attr_setguardsize
__P ((pthread_attr_t
*__attr
,
330 size_t __guardsize
));
331 extern int __pthread_attr_getguardsize
__P ((__const pthread_attr_t
*__attr
,
332 size_t *__guardsize
));
333 extern int __pthread_attr_setstackaddr
__P ((pthread_attr_t
*__attr
,
335 extern int __pthread_attr_getstackaddr
__P ((__const pthread_attr_t
*__attr
,
336 void **__stackaddr
));
337 extern int __pthread_attr_setstacksize
__P ((pthread_attr_t
*__attr
,
338 size_t __stacksize
));
339 extern int __pthread_attr_getstacksize
__P ((__const pthread_attr_t
*__attr
,
340 size_t *__stacksize
));
341 extern int __pthread_getconcurrency
__P ((void));
342 extern int __pthread_setconcurrency
__P ((int __level
));
343 extern int __pthread_mutexattr_gettype
__P ((__const pthread_mutexattr_t
*__attr
,
345 extern void __pthread_kill_other_threads_np
__P ((void));
347 /* Prototypes for the function without cancelation support when the
348 normal version has it. */
349 extern int __libc_close (int fd
);
350 extern int __libc_nanosleep (const struct timespec
*requested_time
,
351 struct timespec
*remaining
);
352 extern int __libc_read (int fd
, void *buf
, size_t count
);
353 extern pid_t
__libc_waitpid (pid_t pid
, int *stat_loc
, int options
);
354 extern int __libc_write (int fd
, const void *buf
, size_t count
);