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 */
19 #include <bits/libc-lock.h> /* for _LIBC_TSD_KEY_N */
24 #include <sys/types.h>
26 #include "pt-machine.h"
28 /* Arguments passed to thread creation routine */
30 struct pthread_start_args
{
31 void * (*start_routine
)(void *); /* function to run */
32 void * arg
; /* its argument */
33 sigset_t mask
; /* initial signal mask for thread */
34 int schedpolicy
; /* initial scheduling policy (if any) */
35 struct sched_param schedparam
; /* initial scheduling parameters (if any) */
39 /* We keep thread specific data in a special data structure, a two-level
40 array. The top-level array contains pointers to dynamically allocated
41 arrays of a certain number of data pointers. So we can implement a
42 sparse array. Each dynamic second-level array has
43 PTHREAD_KEY_2NDLEVEL_SIZE
44 entries. This value shouldn't be too large. */
45 #define PTHREAD_KEY_2NDLEVEL_SIZE 32
47 /* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
48 keys in each subarray. */
49 #define PTHREAD_KEY_1STLEVEL_SIZE \
50 ((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
51 / PTHREAD_KEY_2NDLEVEL_SIZE)
54 #define PTHREAD_START_ARGS_INITIALIZER { NULL, NULL, {{0, }}, 0, { 0 } }
56 /* The type of thread descriptors */
58 typedef struct _pthread_descr_struct
* pthread_descr
;
60 struct _pthread_descr_struct
{
61 pthread_descr p_nextlive
, p_prevlive
;
62 /* Double chaining of active threads */
63 pthread_descr p_nextwaiting
; /* Next element in the queue holding the thr */
64 pthread_t p_tid
; /* Thread identifier */
65 int p_pid
; /* PID of Unix process */
66 int p_priority
; /* Thread priority (== 0 if not realtime) */
67 struct _pthread_fastlock
* p_lock
; /* Spinlock for synchronized accesses */
68 int p_signal
; /* last signal received */
69 sigjmp_buf
* p_signal_jmp
; /* where to siglongjmp on a signal or NULL */
70 sigjmp_buf
* p_cancel_jmp
; /* where to siglongjmp on a cancel or NULL */
71 char p_terminated
; /* true if terminated e.g. by pthread_exit */
72 char p_detached
; /* true if detached */
73 char p_exited
; /* true if the assoc. process terminated */
74 void * p_retval
; /* placeholder for return value */
75 int p_retcode
; /* placeholder for return code */
76 pthread_descr p_joining
; /* thread joining on that thread or NULL */
77 struct _pthread_cleanup_buffer
* p_cleanup
; /* cleanup functions */
78 char p_cancelstate
; /* cancellation state */
79 char p_canceltype
; /* cancellation type (deferred/async) */
80 char p_canceled
; /* cancellation request pending */
81 int * p_errnop
; /* pointer to used errno variable */
82 int p_errno
; /* error returned by last system call */
83 int * p_h_errnop
; /* pointer to used h_errno variable */
84 int p_h_errno
; /* error returned by last netdb function */
85 char * p_in_sighandler
; /* stack address of sighandler, or NULL */
86 char p_sigwaiting
; /* true if a sigwait() is in progress */
87 struct pthread_start_args p_start_args
; /* arguments for thread creation */
88 void ** p_specific
[PTHREAD_KEY_1STLEVEL_SIZE
]; /* thread-specific data */
89 void * p_libc_specific
[_LIBC_TSD_KEY_N
]; /* thread-specific data for libc */
90 int p_userstack
; /* nonzero if the user provided the stack */
91 void *p_guardaddr
; /* address of guard area or NULL */
92 size_t p_guardsize
; /* size of guard area */
95 /* The type of thread handles. */
97 typedef struct pthread_handle_struct
* pthread_handle
;
99 struct pthread_handle_struct
{
100 struct _pthread_fastlock h_lock
; /* Fast lock for sychronized access */
101 pthread_descr h_descr
; /* Thread descriptor or NULL if invalid */
102 char * h_bottom
; /* Lowest address in the stack thread */
105 /* The type of messages sent to the thread manager thread */
107 struct pthread_request
{
108 pthread_descr req_thread
; /* Thread doing the request */
109 enum { /* Request kind */
110 REQ_CREATE
, REQ_FREE
, REQ_PROCESS_EXIT
, REQ_MAIN_THREAD_EXIT
,
113 union { /* Arguments for request */
114 struct { /* For REQ_CREATE: */
115 const pthread_attr_t
* attr
; /* thread attributes */
116 void * (*fn
)(void *); /* start function */
117 void * arg
; /* argument to start function */
118 sigset_t mask
; /* signal mask */
120 struct { /* For REQ_FREE: */
121 pthread_t thread_id
; /* identifier of thread to free */
123 struct { /* For REQ_PROCESS_EXIT: */
124 int code
; /* exit status */
126 void * post
; /* For REQ_POST: the semaphore */
131 /* Signals used for suspend/restart and for cancellation notification. */
133 extern int __pthread_sig_restart
;
134 extern int __pthread_sig_cancel
;
136 /* Default signals used if we don't have realtime signals */
138 #define DEFAULT_SIG_RESTART SIGUSR1
139 #define DEFAULT_SIG_CANCEL SIGUSR2
141 /* Global array of thread handles, used for validating a thread id
142 and retrieving the corresponding thread descriptor. Also used for
143 mapping the available stack segments. */
145 extern struct pthread_handle_struct __pthread_handles
[PTHREAD_THREADS_MAX
];
147 /* Descriptor of the initial thread */
149 extern struct _pthread_descr_struct __pthread_initial_thread
;
151 /* Descriptor of the manager thread */
153 extern struct _pthread_descr_struct __pthread_manager_thread
;
155 /* Descriptor of the main thread */
157 extern pthread_descr __pthread_main_thread
;
159 /* Limit between the stack of the initial thread (above) and the
160 stacks of other threads (below). Aligned on a STACK_SIZE boundary.
161 Initially 0, meaning that the current thread is (by definition)
162 the initial thread. */
164 extern char *__pthread_initial_thread_bos
;
166 /* Indicate whether at least one thread has a user-defined stack (if 1),
167 or all threads have stacks supplied by LinuxThreads (if 0). */
169 extern int __pthread_nonstandard_stacks
;
171 /* File descriptor for sending requests to the thread manager.
172 Initially -1, meaning that __pthread_initialize_manager must be called. */
174 extern int __pthread_manager_request
;
176 /* Other end of the pipe for sending requests to the thread manager. */
178 extern int __pthread_manager_reader
;
180 /* Limits of the thread manager stack. */
182 extern char *__pthread_manager_thread_bos
;
183 extern char *__pthread_manager_thread_tos
;
185 /* Pending request for a process-wide exit */
187 extern int __pthread_exit_requested
, __pthread_exit_code
;
189 /* Set to 1 by gdb if we're debugging */
191 extern volatile int __pthread_threads_debug
;
193 /* Return the handle corresponding to a thread id */
195 static inline pthread_handle
thread_handle(pthread_t id
)
197 return &__pthread_handles
[id
% PTHREAD_THREADS_MAX
];
200 /* Validate a thread handle. Must have acquired h->h_spinlock before. */
202 static inline int invalid_handle(pthread_handle h
, pthread_t id
)
204 return h
->h_descr
== NULL
|| h
->h_descr
->p_tid
!= id
;
207 /* Fill in defaults left unspecified by pt-machine.h. */
209 /* The page size we can get from the system. This should likely not be
210 changed by the machine file but, you never know. */
212 #define PAGE_SIZE (sysconf (_SC_PAGE_SIZE))
215 /* The max size of the thread stack segments. If the default
216 THREAD_SELF implementation is used, this must be a power of two and
217 a multiple of PAGE_SIZE. */
219 #define STACK_SIZE (2 * 1024 * 1024)
222 /* The initial size of the thread stack. Must be a multiple of PAGE_SIZE. */
223 #ifndef INITIAL_STACK_SIZE
224 #define INITIAL_STACK_SIZE (4 * PAGE_SIZE)
227 /* Size of the thread manager stack. The "- 32" avoids wasting space
228 with some malloc() implementations. */
229 #ifndef THREAD_MANAGER_STACK_SIZE
230 #define THREAD_MANAGER_STACK_SIZE (2 * PAGE_SIZE - 32)
233 /* The base of the "array" of thread stacks. The array will grow down from
234 here. Defaults to the calculated bottom of the initial application
236 #ifndef THREAD_STACK_START_ADDRESS
237 #define THREAD_STACK_START_ADDRESS __pthread_initial_thread_bos
240 /* Get some notion of the current stack. Need not be exactly the top
241 of the stack, just something somewhere in the current frame. */
242 #ifndef CURRENT_STACK_FRAME
243 #define CURRENT_STACK_FRAME ({ char __csf; &__csf; })
246 /* Recover thread descriptor for the current thread */
248 extern pthread_descr
__pthread_find_self (void) __attribute__ ((const));
250 static inline pthread_descr
thread_self (void) __attribute__ ((const));
251 static inline pthread_descr
thread_self (void)
256 char *sp
= CURRENT_STACK_FRAME
;
257 if (sp
>= __pthread_initial_thread_bos
)
258 return &__pthread_initial_thread
;
259 else if (sp
>= __pthread_manager_thread_bos
260 && sp
< __pthread_manager_thread_tos
)
261 return &__pthread_manager_thread
;
262 else if (__pthread_nonstandard_stacks
)
263 return __pthread_find_self();
265 return (pthread_descr
)(((unsigned long)sp
| (STACK_SIZE
-1))+1) - 1;
269 /* Max number of times we must spin on a spinlock calling sched_yield().
270 After MAX_SPIN_COUNT iterations, we put the calling thread to sleep. */
272 #ifndef MAX_SPIN_COUNT
273 #define MAX_SPIN_COUNT 50
276 /* Duration of sleep (in nanoseconds) when we can't acquire a spinlock
277 after MAX_SPIN_COUNT iterations of sched_yield().
278 With the 2.0 and 2.1 kernels, this MUST BE > 2ms.
279 (Otherwise the kernel does busy-waiting for realtime threads,
280 giving other threads no chance to run.) */
282 #ifndef SPIN_SLEEP_DURATION
283 #define SPIN_SLEEP_DURATION 2000001
290 #define ASSERT assert
291 #define MSG __pthread_message
294 #define MSG(msg,arg...)
297 /* Internal global functions */
299 void __pthread_destroy_specifics(void);
300 void __pthread_perform_cleanup(void);
301 int __pthread_initialize_manager(void);
302 void __pthread_message(char * fmt
, ...);
303 int __pthread_manager(void *reqfd
);
304 void __pthread_manager_sighandler(int sig
);
305 void __pthread_reset_main_thread(void);
306 void __fresetlockfiles(void);
307 void __pthread_manager_adjust_prio(int thread_prio
);
309 /* Prototypes for the function without cancelation support when the
310 normal version has it. */
311 extern int __libc_close (int fd
);
312 extern int __libc_nanosleep (const struct timespec
*requested_time
,
313 struct timespec
*remaining
);
314 extern int __libc_read (int fd
, void *buf
, size_t count
);
315 extern pid_t
__libc_waitpid (pid_t pid
, int *stat_loc
, int options
);
316 extern int __libc_write (int fd
, const void *buf
, size_t count
);