1 #include "pthread_impl.h"
2 #include "stdio_impl.h"
8 weak_alias(dummy_0, __acquire_ptc);
9 weak_alias(dummy_0, __release_ptc);
10 weak_alias(dummy_0, __pthread_tsd_run_dtors);
12 _Noreturn void pthread_exit(void *result)
14 pthread_t self = pthread_self();
17 self->result = result;
19 while (self->cancelbuf) {
20 void (*f)(void *) = self->cancelbuf->__f;
21 void *x = self->cancelbuf->__x;
22 self->cancelbuf = self->cancelbuf->__next;
26 __pthread_tsd_run_dtors();
28 __lock(self->exitlock);
30 /* Mark this thread dead before decrementing count */
31 __lock(self->killlock);
33 __unlock(self->killlock);
35 /* Block all signals before decrementing the live thread count.
36 * This is important to ensure that dynamically allocated TLS
37 * is not under-allocated/over-committed, and possibly for other
39 __syscall(SYS_rt_sigprocmask, SIG_BLOCK, SIGALL_SET, 0, _NSIG/8);
41 do n = libc.threads_minus_1;
42 while (n && a_cas(&libc.threads_minus_1, n, n-1)!=n);
45 if (self->detached && self->map_base) {
46 /* Detached threads must avoid the kernel clear_child_tid
47 * feature, since the virtual address will have been
48 * unmapped and possibly already reused by a new mapping
49 * at the time the kernel would perform the write. In
50 * the case of threads that started out detached, the
51 * initial clone flags are correct, but if the thread was
52 * detached later (== 2), we need to clear it here. */
53 if (self->detached == 2) __syscall(SYS_set_tid_address, 0);
55 /* The following call unmaps the thread's stack mapping
56 * and then exits without touching the stack. */
57 __unmapself(self->map_base, self->map_size);
60 for (;;) __syscall(SYS_exit, 0);
63 void __do_cleanup_push(struct __ptcb *cb)
65 struct pthread *self = pthread_self();
66 cb->__next = self->cancelbuf;
70 void __do_cleanup_pop(struct __ptcb *cb)
72 __pthread_self()->cancelbuf = cb->__next;
75 static int start(void *p)
78 if (self->startlock[0]) {
79 __wait(self->startlock, 0, 1, 1);
80 if (self->startlock[0]) {
84 __syscall(SYS_rt_sigprocmask, SIG_SETMASK,
85 self->sigmask, 0, _NSIG/8);
87 if (self->unblock_cancel)
88 __syscall(SYS_rt_sigprocmask, SIG_UNBLOCK,
89 SIGPT_SET, 0, _NSIG/8);
90 pthread_exit(self->start(self->start_arg));
94 #define ROUND(x) (((x)+PAGE_SIZE-1)&-PAGE_SIZE)
96 /* pthread_key_create.c overrides this */
97 static const size_t dummy = 0;
98 weak_alias(dummy, __pthread_tsd_size);
100 static FILE *const dummy_file = 0;
101 weak_alias(dummy_file, __stdin_used);
102 weak_alias(dummy_file, __stdout_used);
103 weak_alias(dummy_file, __stderr_used);
105 static void init_file_lock(FILE *f)
107 if (f && f->lock<0) f->lock = 0;
110 void *__copy_tls(unsigned char *);
112 int pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict attrp, void *(*entry)(void *), void *restrict arg)
116 struct pthread *self = pthread_self(), *new;
117 unsigned char *map = 0, *stack = 0, *tsd = 0, *stack_limit;
118 unsigned flags = 0x7d8f00;
120 pthread_attr_t attr = {0};
122 if (!self) return ENOSYS;
123 if (!libc.threaded) {
124 for (FILE *f=libc.ofl_head; f; f=f->next)
126 init_file_lock(__stdin_used);
127 init_file_lock(__stdout_used);
128 init_file_lock(__stderr_used);
131 if (attrp) attr = *attrp;
135 if (attr._a_stackaddr) {
136 size_t need = libc.tls_size + __pthread_tsd_size;
137 size = attr._a_stacksize + DEFAULT_STACK_SIZE;
138 stack = (void *)(attr._a_stackaddr & -16);
139 stack_limit = (void *)(attr._a_stackaddr - size);
140 /* Use application-provided stack for TLS only when
141 * it does not take more than ~12% or 2k of the
142 * application's stack space. */
143 if (need < size/8 && need < 2048) {
144 tsd = stack - __pthread_tsd_size;
145 stack = tsd - libc.tls_size;
151 guard = ROUND(DEFAULT_GUARD_SIZE + attr._a_guardsize);
152 size = guard + ROUND(DEFAULT_STACK_SIZE + attr._a_stacksize
153 + libc.tls_size + __pthread_tsd_size);
158 map = mmap(0, size, PROT_NONE, MAP_PRIVATE|MAP_ANON, -1, 0);
159 if (map == MAP_FAILED) goto fail;
160 if (mprotect(map+guard, size-guard, PROT_READ|PROT_WRITE)) {
165 map = mmap(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0);
166 if (map == MAP_FAILED) goto fail;
168 tsd = map + size - __pthread_tsd_size;
170 stack = tsd - libc.tls_size;
171 stack_limit = map + guard;
175 new = __copy_tls(tsd - libc.tls_size);
177 new->map_size = size;
179 new->stack_size = stack - stack_limit;
180 new->pid = self->pid;
181 new->errno_ptr = &new->errno_val;
183 new->start_arg = arg;
185 new->tsd = (void *)tsd;
186 if (attr._a_detach) {
191 do_sched = new->startlock[0] = 1;
192 __syscall(SYS_rt_sigprocmask, SIG_BLOCK,
193 SIGALL_SET, self->sigmask, _NSIG/8);
195 new->unblock_cancel = self->cancel;
196 new->canary = self->canary;
198 a_inc(&libc.threads_minus_1);
199 ret = __clone(start, stack, flags, new, &new->tid, TP_ADJ(new), &new->tid);
204 __syscall(SYS_rt_sigprocmask, SIG_SETMASK,
205 new->sigmask, 0, _NSIG/8);
209 a_dec(&libc.threads_minus_1);
210 if (map) munmap(map, size);
215 ret = __syscall(SYS_sched_setscheduler, new->tid,
216 attr._a_policy, &attr._a_prio);
217 a_store(new->startlock, ret<0 ? 2 : 0);
218 __wake(new->startlock, 1, 1);
219 if (ret < 0) return -ret;