@ -12,6 +12,8 @@
# include <stdatomic.h>
# endif
# include <stdalign.h>
static void dummy_0 ( )
{
}
@ -158,6 +160,14 @@ _Noreturn void __pthread_exit(void *result)
self - > prev - > next = self - > next ;
self - > prev = self - > next = self ;
# ifndef __wasilibc_unmodified_upstream
/* On Linux, the thread is created with CLONE_CHILD_CLEARTID,
* and this lock will unlock by kernel when this thread terminates .
* So we should unlock it here in WebAssembly .
* See also set_tid_address ( 2 ) */
__tl_unlock ( ) ;
# endif
# ifdef __wasilibc_unmodified_upstream
if ( state = = DT_DETACHED & & self - > map_base ) {
/* Detached threads must block even implementation-internal
@ -174,6 +184,15 @@ _Noreturn void __pthread_exit(void *result)
* and then exits without touching the stack . */
__unmapself ( self - > map_base , self - > map_size ) ;
}
# else
if ( state = = DT_DETACHED & & self - > map_base ) {
// __syscall(SYS_exit) would unlock the thread, list
// do it manually here
__tl_unlock ( ) ;
free ( self - > map_base ) ;
// Can't use `exit()` here, because it is too high level
for ( ; ; ) __wasi_proc_exit ( 0 ) ;
}
# endif
/* Wake any joiner. */
@ -189,7 +208,11 @@ _Noreturn void __pthread_exit(void *result)
# ifdef __wasilibc_unmodified_upstream
for ( ; ; ) __syscall ( SYS_exit , 0 ) ;
# else
for ( ; ; ) exit ( 0 ) ;
// __syscall(SYS_exit) would unlock the thread, list
// do it manually here
__tl_unlock ( ) ;
// Can't use `exit()` here, because it is too high level
for ( ; ; ) __wasi_proc_exit ( 0 ) ;
# endif
}
@ -214,7 +237,7 @@ struct start_args {
# else
void * ( * start_func ) ( void * ) ;
void * start_arg ;
struct pthread * thread ;
void * tls_base ;
# endif
} ;
@ -249,22 +272,27 @@ static int start_c11(void *p)
}
# else
__attribute__ ( ( export_name ( " wasi_thread_start " ) ) )
int wasi_thread_start ( int tid , void * p )
_Noreturn void wasi_thread_start ( int tid , void * p )
{
struct start_args * args = p ;
__asm__ ( " .globaltype __tls_base, i32 \n "
" local.get %0 \n "
" global.set __tls_base \n "
: : " r " ( args - > tls_base ) ) ;
pthread_t self = __pthread_self ( ) ;
// Set the thread ID (TID) on the pthread structure. The TID is stored
// atomically since it is also stored by the parent thread; this way,
// whichever thread (parent or child) reaches this point first can proceed
// without waiting.
atomic_store ( ( atomic_int * ) & ( args - > thread - > tid ) , tid ) ;
// Save the pointer to the pthread structure as the global `pthread_self`.
__asm__ ( " local.set %0 \n "
" global.set __wasilibc_pthread_self \n "
: " =r " ( args - > thread ) ) ;
atomic_store ( ( atomic_int * ) & ( self - > tid ) , tid ) ;
// Set the stack pointer.
__asm__ ( " .globaltype __stack_pointer, i32 \n "
" local.get %0 \n "
" global.set __stack_pointer \n "
: : " r " ( self - > stack ) ) ;
// Execute the user's start function.
int ( * start ) ( void * ) = ( int ( * ) ( void * ) ) args - > start_func ;
__pthread_exit ( ( void * ) ( uintptr_t ) start ( args - > start_arg ) ) ;
return 0 ;
}
# endif
@ -299,8 +327,18 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att
# endif
pthread_attr_t attr = { 0 } ;
sigset_t set ;
# ifndef __wasilibc_unmodified_upstream
size_t tls_size = __builtin_wasm_tls_size ( ) ;
size_t tls_align = __builtin_wasm_tls_align ( ) ;
void * tls_base = __builtin_wasm_tls_base ( ) ;
void * new_tls_base ;
size_t tls_offset ;
tls_size + = tls_align ;
# endif
# ifdef __wasilibc_unmodified_upstream
if ( ! libc . can_do_threads ) return ENOSYS ;
# endif
self = __pthread_self ( ) ;
if ( ! libc . threaded ) {
for ( FILE * f = * __ofl_lock ( ) ; f ; f = f - > next )
@ -327,7 +365,11 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att
}
if ( attr . _a_stackaddr ) {
# ifdef __wasilibc_unmodified_upstream
size_t need = libc . tls_size + __pthread_tsd_size ;
# else
size_t need = tls_size + __pthread_tsd_size ;
# endif
size = attr . _a_stacksize ;
stack = ( void * ) ( attr . _a_stackaddr & - 16 ) ;
stack_limit = ( void * ) ( attr . _a_stackaddr - size ) ;
@ -336,7 +378,11 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att
* application ' s stack space . */
if ( need < size / 8 & & need < 2048 ) {
tsd = stack - __pthread_tsd_size ;
# ifdef __wasilibc_unmodified_upstream
stack = tsd - libc . tls_size ;
# else
stack = tsd - tls_size ;
# endif
memset ( stack , 0 , need ) ;
} else {
size = ROUND ( need ) ;
@ -345,7 +391,11 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att
} else {
guard = ROUND ( attr . _a_guardsize ) ;
size = guard + ROUND ( attr . _a_stacksize
# ifdef __wasilibc_unmodified_upstream
+ libc . tls_size + __pthread_tsd_size ) ;
# else
+ tls_size + __pthread_tsd_size ) ;
# endif
}
if ( ! tsd ) {
@ -368,12 +418,22 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att
# endif
tsd = map + size - __pthread_tsd_size ;
if ( ! stack ) {
# ifdef __wasilibc_unmodified_upstream
stack = tsd - libc . tls_size ;
# else
stack = tsd - tls_size ;
# endif
stack_limit = map + guard ;
}
}
# ifdef __wasilibc_unmodified_upstream
new = __copy_tls ( tsd - libc . tls_size ) ;
# else
new_tls_base = __copy_tls ( tsd - tls_size ) ;
tls_offset = new_tls_base - tls_base ;
new = ( void * ) ( ( uintptr_t ) self + tls_offset ) ;
# endif
new - > map_base = map ;
new - > map_size = size ;
new - > stack = stack ;
@ -394,12 +454,12 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att
/* Setup argument structure for the new thread on its stack.
* It ' s safe to access from the caller only until the thread
* list is unlocked . */
# ifdef __wasilibc_unmodified_upstream
stack - = ( uintptr_t ) stack % sizeof ( uintptr_t ) ;
stack - = sizeof ( struct start_args ) ;
struct start_args * args = ( void * ) stack ;
args - > start_func = entry ;
args - > start_arg = arg ;
# ifdef __wasilibc_unmodified_upstream
args - > control = attr . _a_sched ? 1 : 0 ;
/* Application signals (but not the synccall signal) must be
@ -414,9 +474,19 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att
args - > sig_mask [ ( SIGCANCEL - 1 ) / 8 / sizeof ( long ) ] & =
~ ( 1UL < < ( ( SIGCANCEL - 1 ) % ( 8 * sizeof ( long ) ) ) ) ;
# else
/* The new thread needs a pointer to the pthread struct so that it can set
* up its ` wasilibc_pthread_self ` global . */
args - > thread = new ;
/* Align the stack to struct start_args */
stack - = sizeof ( struct start_args ) ;
stack - = ( uintptr_t ) stack % alignof ( struct start_args ) ;
struct start_args * args = ( void * ) stack ;
/* Align the stack to 16 and store it */
new - > stack = ( void * ) ( ( uintptr_t ) stack & - 16 ) ;
/* Correct the stack size */
new - > stack_size = stack - stack_limit ;
args - > start_func = entry ;
args - > start_arg = arg ;
args - > tls_base = ( void * ) new_tls_base ;
# endif
__tl_lock ( ) ;
@ -457,7 +527,7 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att
if ( ret < 0 ) {
ret = - EAGAIN ;
} else {
atomic_store ( ( atomic_int * ) & ( args - > thread - > tid ) , ret ) ;
atomic_store ( ( atomic_int * ) & ( new - > tid ) , ret ) ;
}
# endif
韩朴宇
2 years ago
GitHub