am 18368fc8: am f246c589: Merge "Clean up the pthread_create trampoline."

* commit '18368fc8e696c54adbd1537bf2d7c5c217210957':
  Clean up the pthread_create trampoline.
This commit is contained in:
Elliott Hughes 2013-11-21 08:09:46 -08:00 committed by Android Git Automerger
commit a8276f64b2
5 changed files with 28 additions and 66 deletions

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@ -290,7 +290,6 @@ libc_bionic_src_files := \
bionic/sysconf.cpp \
bionic/thread_atexit.cpp \
bionic/tdestroy.cpp \
bionic/__thread_entry.cpp \
bionic/timer.cpp \
bionic/tmpfile.cpp \
bionic/unlink.cpp \

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@ -1,59 +0,0 @@
/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <pthread.h>
#include "pthread_internal.h"
#include "private/bionic_tls.h"
// This trampoline is called from the assembly __bionic_clone function.
int __thread_entry(void* arg) {
pthread_internal_t* thread = reinterpret_cast<pthread_internal_t*>(arg);
// Wait for our creating thread to release us. This lets it have time to
// notify gdb about this thread before we start doing anything.
// This also provides the memory barrier needed to ensure that all memory
// accesses previously made by the creating thread are visible to us.
pthread_mutex_t* start_mutex = (pthread_mutex_t*) &thread->tls[TLS_SLOT_START_MUTEX];
pthread_mutex_lock(start_mutex);
pthread_mutex_destroy(start_mutex);
__init_tls(thread);
__init_alternate_signal_stack(thread);
if ((thread->internal_flags & PTHREAD_INTERNAL_FLAG_THREAD_INIT_FAILED) != 0) {
pthread_exit(NULL);
}
void* result = thread->start_routine(thread->start_routine_arg);
pthread_exit(result);
return 0;
}

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@ -134,6 +134,31 @@ static void* __create_thread_stack(pthread_internal_t* thread) {
return stack;
}
static int __pthread_start(void* arg) {
pthread_internal_t* thread = reinterpret_cast<pthread_internal_t*>(arg);
// Wait for our creating thread to release us. This lets it have time to
// notify gdb about this thread before we start doing anything.
// This also provides the memory barrier needed to ensure that all memory
// accesses previously made by the creating thread are visible to us.
pthread_mutex_t* start_mutex = (pthread_mutex_t*) &thread->tls[TLS_SLOT_START_MUTEX];
pthread_mutex_lock(start_mutex);
pthread_mutex_destroy(start_mutex);
__init_tls(thread);
__init_alternate_signal_stack(thread);
if ((thread->internal_flags & PTHREAD_INTERNAL_FLAG_THREAD_INIT_FAILED) != 0) {
pthread_exit(NULL);
}
void* result = thread->start_routine(thread->start_routine_arg);
pthread_exit(result);
return 0;
}
int pthread_create(pthread_t* thread_out, pthread_attr_t const* attr,
void* (*start_routine)(void*), void* arg) {
ErrnoRestorer errno_restorer;
@ -198,7 +223,7 @@ int pthread_create(pthread_t* thread_out, pthread_attr_t const* attr,
thread->start_routine_arg = arg;
int flags = CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND | CLONE_THREAD | CLONE_SYSVSEM | CLONE_SETTLS;
int tid = __bionic_clone(flags, child_stack, NULL, thread->tls, NULL, __thread_entry, thread);
int tid = __bionic_clone(flags, child_stack, NULL, thread->tls, NULL, __pthread_start, thread);
if (tid < 0) {
int clone_errno = errno;
if ((thread->attr.flags & PTHREAD_ATTR_FLAG_USER_ALLOCATED_STACK) == 0) {
@ -213,7 +238,7 @@ int pthread_create(pthread_t* thread_out, pthread_attr_t const* attr,
int init_errno = _init_thread(thread, true);
if (init_errno != 0) {
// Mark the thread detached and let its __thread_entry run to
// Mark the thread detached and let its __pthread_start run to
// completion. (It'll just exit immediately, cleaning up its resources.)
thread->internal_flags |= PTHREAD_INTERNAL_FLAG_THREAD_INIT_FAILED;
thread->attr.flags |= PTHREAD_ATTR_FLAG_DETACHED;

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@ -55,9 +55,6 @@ struct pthread_internal_t {
char dlerror_buffer[__BIONIC_DLERROR_BUFFER_SIZE];
};
extern "C" {
__LIBC_HIDDEN__ int __thread_entry(void* arg); // Called from assembler.
}
__LIBC_HIDDEN__ int _init_thread(pthread_internal_t* thread, bool add_to_thread_list);
__LIBC_HIDDEN__ void __init_tls(pthread_internal_t* thread);
__LIBC_HIDDEN__ void __init_alternate_signal_stack(pthread_internal_t*);

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@ -215,7 +215,7 @@ int pthread_key_delete(pthread_key_t key) {
// Skip zombie threads. They don't have a valid TLS area any more.
// Similarly, it is possible to have t->tls == NULL for threads that
// were just recently created through pthread_create() but whose
// startup trampoline (__thread_entry) hasn't been run yet by the
// startup trampoline (__pthread_start) hasn't been run yet by the
// scheduler. t->tls will also be NULL after a thread's stack has been
// unmapped but before the ongoing pthread_join() is finished.
if ((t->attr.flags & PTHREAD_ATTR_FLAG_ZOMBIE) || t->tls == NULL) {