diff options
| -rw-r--r-- | sysdeps/htl/dl-thread_gscope_wait.c | 55 | ||||
| -rw-r--r-- | sysdeps/mach/hurd/i386/tls.h | 21 | ||||
| -rw-r--r-- | sysdeps/mach/hurd/tls.h | 20 |
3 files changed, 76 insertions, 20 deletions
diff --git a/sysdeps/htl/dl-thread_gscope_wait.c b/sysdeps/htl/dl-thread_gscope_wait.c new file mode 100644 index 0000000..7557e77 --- /dev/null +++ b/sysdeps/htl/dl-thread_gscope_wait.c @@ -0,0 +1,55 @@ +/* Out-of-line notification function for the GSCOPE locking mechanism. + Copyright (C) 2007-2021 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <ldsodefs.h> +#include <pthread.h> +#include <htl/pt-internal.h> + +void +__thread_gscope_wait (void) +{ + size_t i; + struct __pthread *t; + int *gscope_flagp; + + __libc_rwlock_rdlock (GL (dl_pthread_threads_lock)); + + /* Iterate over the list of threads. */ + for (i = 0; i < GL (dl_pthread_num_threads); ++i) + { + t = GL (dl_pthread_threads[i]); + if (t == NULL || t->tcb->gscope_flag == THREAD_GSCOPE_FLAG_UNUSED) + continue; + + gscope_flagp = &t->tcb->gscope_flag; + + /* We have to wait until this thread is done with the global + scope. First tell the thread that we are waiting and + possibly have to be woken. */ + if (atomic_compare_and_exchange_bool_acq (gscope_flagp, + THREAD_GSCOPE_FLAG_WAIT, + THREAD_GSCOPE_FLAG_USED)) + continue; + + do + lll_wait (gscope_flagp, THREAD_GSCOPE_FLAG_WAIT, LLL_PRIVATE); + while (*gscope_flagp == THREAD_GSCOPE_FLAG_WAIT); + } + + __libc_rwlock_unlock (GL (dl_pthread_threads_lock)); +} diff --git a/sysdeps/mach/hurd/i386/tls.h b/sysdeps/mach/hurd/i386/tls.h index 057b261..2ac65df 100644 --- a/sysdeps/mach/hurd/i386/tls.h +++ b/sysdeps/mach/hurd/i386/tls.h @@ -369,6 +369,27 @@ _hurd_tls_new (thread_t child, struct i386_thread_state *state, tcbhead_t *tcb) return err; } +/* Global scope switch support. */ +# define THREAD_GSCOPE_IN_TCB 1 + +# define THREAD_GSCOPE_FLAG_UNUSED 0 +# define THREAD_GSCOPE_FLAG_USED 1 +# define THREAD_GSCOPE_FLAG_WAIT 2 + +# define THREAD_GSCOPE_SET_FLAG() \ + THREAD_SETMEM (THREAD_SELF, gscope_flag, THREAD_GSCOPE_FLAG_USED) + +# define THREAD_GSCOPE_RESET_FLAG() \ + ({ \ + int __flag; \ + asm volatile ("xchgl %0, %%gs:%P1" \ + : "=r" (__flag) \ + : "i" (offsetof (tcbhead_t, gscope_flag)), \ + "0" (THREAD_GSCOPE_FLAG_UNUSED)); \ + if (__flag == THREAD_GSCOPE_FLAG_WAIT) \ + lll_wake (THREAD_SELF->gscope_flag, LLL_PRIVATE); \ + }) + #endif /* !__ASSEMBLER__ */ #endif /* i386/tls.h */ diff --git a/sysdeps/mach/hurd/tls.h b/sysdeps/mach/hurd/tls.h index f83956d..8e66d5f 100644 --- a/sysdeps/mach/hurd/tls.h +++ b/sysdeps/mach/hurd/tls.h @@ -52,26 +52,6 @@ # define GET_DTV(descr) \ (((tcbhead_t *) (descr))->dtv) -/* Global scope switch support. */ -#define THREAD_GSCOPE_IN_TCB 0 -#define THREAD_GSCOPE_GLOBAL -#define THREAD_GSCOPE_SET_FLAG() \ - atomic_exchange_and_add_acq (&GL(dl_thread_gscope_count), 1) -#define THREAD_GSCOPE_RESET_FLAG() \ - do \ - if (atomic_exchange_and_add_rel (&GL(dl_thread_gscope_count), -1) == 1) \ - lll_wake (GL(dl_thread_gscope_count), 0); \ - while (0) -#define THREAD_GSCOPE_WAIT() \ - do \ - { \ - int count; \ - atomic_write_barrier (); \ - while ((count = GL(dl_thread_gscope_count))) \ - lll_wait (GL(dl_thread_gscope_count), count, 0); \ - } \ - while (0) - #endif /* !ASSEMBLER */ |