tequilaOS/platform_bionic
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

PTHREAD_KEYS_MAX cleanup.

Browse source 
I fixed this bug a while back, but didn't remove it from the list,
could have added a better test, and could have written clearer code
that didn't require a comment.

Change-Id: Iebdf0f9a54537a7d5cbca254a5967b1543061f3d
This commit is contained in:
Elliott Hughes 2013-12-12 11:02:41 -08:00
parent 38fcbbb35a
commit 1887621de8
3 changed files with 14 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
ABI-bugs.txt
View file

@ -8,8 +8,5 @@ KNOWN ABI BUGS
sigset_t is too small on ARM and x86 (but correct on MIPS), so support
for real-time signals is broken. http://b/5828899
Too few TLS slots mean we can't allocate 128 pthread_key_t instances,
which POSIX says should be the minimum.
atexit(3) handlers registered by a shared library aren't called on
dlclose(3); this only affects ARM. http://b/4998315

17
libc/private/bionic_tls.h
View file

@ -30,6 +30,7 @@
#define __BIONIC_PRIVATE_BIONIC_TLS_H_
#include <sys/cdefs.h>
#include <sys/limits.h>
#include "__get_tls.h"
__BEGIN_DECLS
@ -74,21 +75,21 @@ enum {
};
/*
* Maximum number of elements in the TLS array.
* POSIX says this must be at least 128, but Android has traditionally had only 64, minus those
* ones used internally by bionic itself.
* There are two kinds of slot used internally by bionic --- there are the well-known slots
* enumerated above, and then there are those that are allocated during startup by calls to
* pthread_key_create; grep for GLOBAL_INIT_THREAD_LOCAL_BUFFER to find those. We need to manually
* maintain that second number, but pthread_test will fail if we forget.
*/
#define GLOBAL_INIT_THREAD_LOCAL_BUFFER_COUNT 4
/*
* This is PTHREAD_KEYS_MAX + TLS_SLOT_FIRST_USER_SLOT + GLOBAL_INIT_THREAD_LOCAL_BUFFER_COUNT
* rounded up to maintain stack alignment.
*/
#define BIONIC_ALIGN(x, a) (((x) + (a - 1)) & ~(a - 1))
#define BIONIC_TLS_SLOTS BIONIC_ALIGN(128 + TLS_SLOT_FIRST_USER_SLOT + GLOBAL_INIT_THREAD_LOCAL_BUFFER_COUNT, 4)
/*
* Maximum number of elements in the TLS array.
* This includes space for pthread keys and our own internal slots.
* We need to round up to maintain stack alignment.
*/
#define BIONIC_TLS_SLOTS BIONIC_ALIGN(PTHREAD_KEYS_MAX + TLS_SLOT_FIRST_USER_SLOT + GLOBAL_INIT_THREAD_LOCAL_BUFFER_COUNT, 4)
__END_DECLS

5
tests/pthread_test.cpp
View file

@ -33,6 +33,11 @@ TEST(pthread, pthread_key_create) {
#if !defined(__GLIBC__) // glibc uses keys internally that its sysconf value doesn't account for.
TEST(pthread, pthread_key_create_lots) {
// POSIX says PTHREAD_KEYS_MAX should be at least 128.
ASSERT_GE(PTHREAD_KEYS_MAX, 128);
// sysconf shouldn't return a smaller value.
ASSERT_GE(sysconf(_SC_THREAD_KEYS_MAX), PTHREAD_KEYS_MAX);
// We can allocate _SC_THREAD_KEYS_MAX keys.
std::vector<pthread_key_t> keys;
for (int i = 0; i < sysconf(_SC_THREAD_KEYS_MAX); ++i) {