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path: root/libc/bionic/pthread_join.cpp
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* Pass caller names to __pthread_internal_find for better errors.Elliott Hughes2019-02-011-1/+1
| | | | | | | | | | | | | | | On http://b/122082295 we had this abort: 12-27 15:29:31.237 10222 10814 10848 F libc : invalid pthread_t 0xb1907960 passed to libc This wasn't super helpful. We can do better. Now you get something like this instead: 03-27 02:34:58.754 25329 25329 W libc : invalid pthread_t (0) passed to pthread_join Test: adb shell crasher Bug: http://b/123255692 Change-Id: I1d545665a233308480cc3747ec3120e2b6de0453
* Add tracepoints for pthread_create and pthread_joinPhilip Cuadra2019-01-281-0/+2
| | | | | | | Add additional tracepoints for clarity. Test: cpatured trace with bionic, confirmed trace points Change-Id: I4f9952c38a2637d53edb69ad99b43beb5a892da6
* Modernize codebase by replacing NULL with nullptrYi Kong2018-08-021-2/+2
| | | | | | | | Fixes -Wzero-as-null-pointer-constant warning. Test: m Bug: 68236239 Change-Id: I5b4123bc6709641315120a191e36cc57541349b2
* Mark __BIONIC_WEAK_FOR_NATIVE_BRIDGE symbolsdimitry2017-10-271-0/+2
| | | | | | | | | To make it easier for Native Bridge implementations to override these symbols. Bug: http://b/67993967 Test: make Change-Id: I4c53e53af494bca365dd2b3305ab0ccc2b23ba44
* Revert "Remove the global thread list."Elliott Hughes2017-02-021-2/+5
| | | | | | | | This reverts commit b0e8c565a622b5519e03d4416b0b5b1a5f20d7f5. Breaks swiftshader (http:/b/34883464). Change-Id: I7b21193ba8a78f07d7ac65e41d0fe8516940a83b
* Remove the global thread list.Elliott Hughes2017-01-071-5/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Another release, another attempt to fix this bug. This change affects pthread_detach, pthread_getcpuclockid, pthread_getschedparam/pthread_setschedparam, pthread_join, and pthread_kill: instead of returning ESRCH when passed an invalid pthread_t, they'll now SEGV. Note that this doesn't change behavior as much as you might think: the old lookup only held the global thread list lock for the duration of the lookup, so there was still a race between that and the dereference in the caller, given that callers actually need the tid to pass to some syscall or other, and sometimes update fields in the pthread_internal_t struct too. We can't check thread->tid against 0 to see whether a pthread_t is still valid because a dead thread gets its thread struct unmapped along with its stack, so the dereference isn't safe. Taking the affected functions one by one: * pthread_getcpuclockid and pthread_getschedparam/pthread_setschedparam should be fine. Unsafe calls to those seem highly unlikely. * Unsafe pthread_detach callers probably want to switch to pthread_attr_setdetachstate instead, or using pthread_detach(pthread_self()) from the new thread's start routine rather than doing the detach in the parent. * pthread_join calls should be safe anyway, because a joinable thread won't actually exit and unmap until it's joined. If you're joining an unjoinable thread, the fix is to stop marking it detached. If you're joining an already-joined thread, you need to rethink your design. * Unsafe pthread_kill calls aren't portably fixable. (And are obviously inherently non-portable as-is.) The best alternative on Android is to use pthread_gettid_np at some point that you know the thread to be alive, and then call kill/tgkill directly. That's still not completely safe because if you're too late, the tid may have been reused, but then your code is inherently unsafe anyway. If we find too much code is still broken, we can come back and disable the global thread list lookups for anything targeting >= O and then have another go at really removing this in P... Bug: http://b/19636317 Test: N6P boots, bionic tests pass Change-Id: Ia92641212f509344b99ee2a9bfab5383147fcba6
* Let g_thread_list_lock only protect g_thread_list.Yabin Cui2015-03-231-24/+16
| | | | | | | | | As glibc/netbsd don't protect access to thread struct members by a global lock, we don't want to do it either. This change reduces the responsibility of g_thread_list_lock to only protect g_thread_list. Bug: 19636317 Change-Id: I897890710653dac165d8fa4452c7ecf74abdbf2b
* Make pthread join_state not protected by g_thread_list_lock.Yabin Cui2015-03-121-5/+4
| | | | | | | | | | | 1. Move the representation of thread join_state from pthread.attr.flag to pthread.join_state. This clarifies thread state change. 2. Use atomic operations for pthread.join_state. So we don't need to protect it by g_thread_list_lock. g_thread_list_lock will be reduced to only protect g_thread_list or even removed in further changes. Bug: 19636317 Change-Id: I31fb143a7c69508c7287307dd3b0776993ec0f43
* Use mmap to create the pthread_internal_tYabin Cui2014-12-191-1/+1
| | | | | | | | | Add name to mmaped regions. Add pthread benchmark code. Allocate pthread_internal_t on regular stack. Bug: 16847284 Change-Id: Id60835163bb0d68092241f1a118015b5a8f85069
* Fix pthread_join.Elliott Hughes2013-11-181-15/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | Let the kernel keep pthread_internal_t::tid updated, including across forks and for the main thread. This then lets us fix pthread_join to only return after the thread has really exited. Also fix the thread attributes of the main thread so we don't unmap the main thread's stack (which is really owned by the dynamic linker and contains things like environment variables), which fixes crashes when joining with an exited main thread and also fixes problems reported publicly with accessing environment variables after the main thread exits (for which I've added a new unit test). In passing I also fixed a bug where if the clone(2) inside pthread_create(3) fails, we'd unmap the child's stack and TLS (which contains the mutex) and then try to unlock the mutex. Boom! It wasn't until after I'd uploaded the fix for this that I came across a new public bug reporting this exact failure. Bug: 8206355 Bug: 11693195 Bug: https://code.google.com/p/android/issues/detail?id=57421 Bug: https://code.google.com/p/android/issues/detail?id=62392 Change-Id: I2af9cf6e8ae510a67256ad93cad891794ed0580b
* Handles spurious wake-ups in pthread_join()msg5552013-06-121-14/+8
| | | | | | | | | | | | | | | | | | | Removed 'join_count' from pthread_internal_t and switched to using the flag PTHREAD_ATTR_FLAG_JOINED to indicate if a thread is being joined. Combined with a switch to a while loop in pthread_join, this fixes spurious wake-ups but prevents a thread from being joined multiple times. This is fine for two reasons: 1) The pthread_join specification allows for undefined behavior when multiple threads try to join a single thread. 2) There is no thread safe way to allow multiple threads to join a single thread with the pthread interface. The second thread calling pthread_join could be pre-empted until the thread is destroyed and its handle reused for a different thread. Therefore multi-join is always an error. Bug: https://code.google.com/p/android/issues/detail?id=52255 Change-Id: I8b6784d47620ffdcdbfb14524e7402e21d46c5f7
* Fix pthreads functions that should return ESRCH.Elliott Hughes2013-02-191-0/+68
imgtec pointed out that pthread_kill(3) was broken, but most of the other functions that ought to return ESRCH for invalid/exited threads were equally broken. Change-Id: I96347f6195549aee0c72dc39063e6c5d06d2e01f