diff options
Diffstat (limited to 'nptl/nptl_deallocate_tsd.c')
| -rw-r--r-- | nptl/nptl_deallocate_tsd.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/nptl/nptl_deallocate_tsd.c b/nptl/nptl_deallocate_tsd.c new file mode 100644 index 0000000000..c665f4a08a --- /dev/null +++ b/nptl/nptl_deallocate_tsd.c @@ -0,0 +1,112 @@ +/* Deallocation thread-specific data structures related to pthread_key_create. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. + + 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 <pthreadP.h> + +/* Deallocate POSIX thread-local-storage. */ +void +__nptl_deallocate_tsd (void) +{ + struct pthread *self = THREAD_SELF; + + /* Maybe no data was ever allocated. This happens often so we have + a flag for this. */ + if (THREAD_GETMEM (self, specific_used)) + { + size_t round; + size_t cnt; + + round = 0; + do + { + size_t idx; + + /* So far no new nonzero data entry. */ + THREAD_SETMEM (self, specific_used, false); + + for (cnt = idx = 0; cnt < PTHREAD_KEY_1STLEVEL_SIZE; ++cnt) + { + struct pthread_key_data *level2; + + level2 = THREAD_GETMEM_NC (self, specific, cnt); + + if (level2 != NULL) + { + size_t inner; + + for (inner = 0; inner < PTHREAD_KEY_2NDLEVEL_SIZE; + ++inner, ++idx) + { + void *data = level2[inner].data; + + if (data != NULL) + { + /* Always clear the data. */ + level2[inner].data = NULL; + + /* Make sure the data corresponds to a valid + key. This test fails if the key was + deallocated and also if it was + re-allocated. It is the user's + responsibility to free the memory in this + case. */ + if (level2[inner].seq + == __pthread_keys[idx].seq + /* It is not necessary to register a destructor + function. */ + && __pthread_keys[idx].destr != NULL) + /* Call the user-provided destructor. */ + __pthread_keys[idx].destr (data); + } + } + } + else + idx += PTHREAD_KEY_1STLEVEL_SIZE; + } + + if (THREAD_GETMEM (self, specific_used) == 0) + /* No data has been modified. */ + goto just_free; + } + /* We only repeat the process a fixed number of times. */ + while (__builtin_expect (++round < PTHREAD_DESTRUCTOR_ITERATIONS, 0)); + + /* Just clear the memory of the first block for reuse. */ + memset (&THREAD_SELF->specific_1stblock, '\0', + sizeof (self->specific_1stblock)); + + just_free: + /* Free the memory for the other blocks. */ + for (cnt = 1; cnt < PTHREAD_KEY_1STLEVEL_SIZE; ++cnt) + { + struct pthread_key_data *level2; + + level2 = THREAD_GETMEM_NC (self, specific, cnt); + if (level2 != NULL) + { + /* The first block is allocated as part of the thread + descriptor. */ + free (level2); + THREAD_SETMEM_NC (self, specific, cnt, NULL); + } + } + + THREAD_SETMEM (self, specific_used, false); + } +} +libc_hidden_def (__nptl_deallocate_tsd) |