fix static linking dependency bloat with cancellation

[musl] / src / thread / pthread_create.c

diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c
index 844d7bf..a6afd1e 100644 (file)
--- a/src/thread/pthread_create.c
+++ b/src/thread/pthread_create.c
@@ -1,70 +1,49 @@
 #include "pthread_impl.h"
+#include "stdio_impl.h"
 
 static void dummy_0()
 {
 }
-weak_alias(dummy_0, __rsyscall_lock);
-weak_alias(dummy_0, __rsyscall_unlock);
+weak_alias(dummy_0, __synccall_lock);
+weak_alias(dummy_0, __synccall_unlock);
+weak_alias(dummy_0, __pthread_tsd_run_dtors);
 
-static void dummy_1(pthread_t self)
+void __pthread_do_unwind(struct __ptcb *cb)
 {
-}
-weak_alias(dummy_1, __pthread_tsd_run_dtors);
-
-#ifdef __pthread_unwind_next
-#undef __pthread_unwind_next
-#define __pthread_unwind_next __pthread_unwind_next_3
-#endif
-
-void __pthread_unwind_next(struct __ptcb *cb)
-{
-       pthread_t self;
+       pthread_t self = pthread_self();
        int n;
 
-       if (cb->__next) longjmp((void *)cb->__next->__jb, 1);
-
-       self = pthread_self();
+       if (cb->__next) {
+               self->cancelbuf = cb->__next->__next;
+               longjmp((void *)cb->__next->__jb, 1);
+       }
 
-       LOCK(&self->exitlock);
+       __pthread_tsd_run_dtors();
 
-       __pthread_tsd_run_dtors(self);
+       __lock(&self->exitlock);
 
        /* Mark this thread dead before decrementing count */
+       __lock(&self->killlock);
        self->dead = 1;
+       a_store(&self->killlock, 0);
 
        do n = libc.threads_minus_1;
        while (n && a_cas(&libc.threads_minus_1, n, n-1)!=n);
        if (!n) exit(0);
 
        if (self->detached && self->map_base) {
-               __syscall(SYS_rt_sigprocmask, SIG_BLOCK, (long)(uint64_t[1]){-1},0,8);
+               __syscall(SYS_rt_sigprocmask, SIG_BLOCK, (uint64_t[]){-1},0,8);
                __unmapself(self->map_base, self->map_size);
        }
 
        __syscall(SYS_exit, 0);
 }
 
-static void init_threads()
-{
-       sigset_t set;
-       libc.lock = __lock;
-       libc.lockfile = __lockfile;
-
-       sigemptyset(&set);
-       sigaddset(&set, SIGSYSCALL);
-       sigaddset(&set, SIGCANCEL);
-       __libc_sigprocmask(SIG_UNBLOCK, &set, 0);
-}
-
 static int start(void *p)
 {
        struct pthread *self = p;
-       if (self->unblock_cancel) {
-               sigset_t set;
-               sigemptyset(&set);
-               sigaddset(&set, SIGCANCEL);
-               __libc_sigprocmask(SIG_UNBLOCK, &set, 0);
-       }
+       if (self->unblock_cancel)
+               __syscall(SYS_rt_sigprocmask, SIG_UNBLOCK, SIGPT_SET, 0, 8);
        pthread_exit(self->start(self->start_arg));
        return 0;
 }
@@ -77,21 +56,39 @@ int __uniclone(void *, int (*)(), void *);
 static const size_t dummy = 0;
 weak_alias(dummy, __pthread_tsd_size);
 
+static FILE *const dummy_file = 0;
+weak_alias(dummy_file, __stdin_used);
+weak_alias(dummy_file, __stdout_used);
+weak_alias(dummy_file, __stderr_used);
+
+static void init_file_lock(FILE *f)
+{
+       if (f && f->lock<0) f->lock = 0;
+}
+
 int pthread_create(pthread_t *res, const pthread_attr_t *attr, void *(*entry)(void *), void *arg)
 {
-       static int init;
        int ret;
-       size_t size, guard;
+       size_t size = DEFAULT_STACK_SIZE + DEFAULT_GUARD_SIZE;
+       size_t guard = DEFAULT_GUARD_SIZE;
        struct pthread *self = pthread_self(), *new;
        unsigned char *map, *stack, *tsd;
-       const pthread_attr_t default_attr = { 0 };
 
        if (!self) return ENOSYS;
-       if (!init && ++init) init_threads();
+       if (!libc.threaded) {
+               for (FILE *f=libc.ofl_head; f; f=f->next)
+                       init_file_lock(f);
+               init_file_lock(__stdin_used);
+               init_file_lock(__stdout_used);
+               init_file_lock(__stderr_used);
+               __syscall(SYS_rt_sigprocmask, SIG_UNBLOCK, SIGPT_SET, 0, 8);
+               libc.threaded = 1;
+       }
 
-       if (!attr) attr = &default_attr;
-       guard = ROUND(attr->_a_guardsize + DEFAULT_GUARD_SIZE);
-       size = guard + ROUND(attr->_a_stacksize + DEFAULT_STACK_SIZE);
+       if (attr) {
+               guard = ROUND(attr->_a_guardsize + DEFAULT_GUARD_SIZE);
+               size = guard + ROUND(attr->_a_stacksize + DEFAULT_STACK_SIZE);
+       }
        size += __pthread_tsd_size;
        map = mmap(0, size, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANON, -1, 0);
        if (!map) return EAGAIN;
@@ -107,20 +104,18 @@ int pthread_create(pthread_t *res, const pthread_attr_t *attr, void *(*entry)(vo
        new->start_arg = arg;
        new->self = new;
        new->tsd = (void *)tsd;
-       new->detached = attr->_a_detach;
-       new->attr = *attr;
+       if (attr) new->detached = attr->_a_detach;
        new->unblock_cancel = self->cancel;
-       new->result = PTHREAD_CANCELED;
        memcpy(new->tlsdesc, self->tlsdesc, sizeof new->tlsdesc);
        new->tlsdesc[1] = (uintptr_t)new;
        stack = (void *)((uintptr_t)new-1 & ~(uintptr_t)15);
 
-       __rsyscall_lock();
+       __synccall_lock();
 
        a_inc(&libc.threads_minus_1);
        ret = __uniclone(stack, start, new);
 
-       __rsyscall_unlock();
+       __synccall_unlock();
 
        if (ret < 0) {
                a_dec(&libc.threads_minus_1);
@@ -136,7 +131,5 @@ void pthread_exit(void *result)
        struct pthread *self = pthread_self();
        struct __ptcb cb = { .__next = self->cancelbuf };
        self->result = result;
-       self->canceldisable = 1;
-       self->cancelasync = 0;
        __pthread_unwind_next(&cb);
 }