This work inspires by Thomas Pfaff's pthread_fork patch (1).
* fork.cc (fork_child): Remove MTinterface fixup call, it's
adsorbed by pthread::atforkchild.
Rename __pthread_atforkchild to pthread::atforkchild to give
access to private members.
(fork_parent): Rename __pthread_atforkparent to
pthread::atforkparent to give it access to private members.
Ditto for __pthread_atforkprepare.
* thread.cc: Fix some formatting problems throughout.
(MTinterface::fixup_before_fork): Implement.
(MTinterface::fixup_after_fork): Fix pthread_keys.
(pthread_key::keys): Implement.
(pthread_key::fixup_before_fork): Ditto.
(pthread_key::fixup_after_fork): Ditto.
(pthread_key::pthread_key): Add to pthread_key::keys.
(pthread_key::~pthread_key): Remove from pthread_key::keys.
(pthread_key::saveKeyToBuffer): Implement.
(pthread_key::recreateKeyFromBuffer): Ditto.
(pthread::atforkprepare): Prepare all MT classes for fork.
(pthread::atforkchild): And fix them up afterwards.
* thread.h (pthread_key): Buffer the key value during
fork in fork_buf.
List the keys needing to be fixed up in a linked list with
head pthread_key::keys.
(pthread): Move atfork cygwin internal calls into the class.
(MTInterface): Provide a fixup_before_fork for objecst that
need to save state.
(__pthread_atforkprepare): Remove.
(__pthread_atforkparent): Remove.
(__pthread_atforkchild): Remove.
* init.cc (dll_entry): On thread detach, if the thread hasn't
exit()ed, do so.
* pthread.cc (pthread_getsequence_np): Remove the
__pthread_getsequence_np wrapper. This requires errno.h.
* thread.cc (pthread::self): Instantiate a new pthread object
when called and none exists. return a NULL object if instantiation
fails.
(pthread::precreate): Factor out common code.
(pthread::postcreate): Ditto.
(pthread::create): Ditto.
(pthread::exit): Remove the TLS value when we exit to prevent
double exits.
(MTinterface::Init): Bugfix - don't mark the TLS index as created
if one was not allocated.
Apply Extract Method to move pthread specific initialisation into
pthread.
(pthread::initMainThread): Extracted method from MTinterface::Init.
(pthread::setTlsSelfPointer): Extracted method from various pthread
calls, to make reading those functions easier.
(pthread::setThreadIdtoCurrent): Ditto.
(pthread::cancel_self): Bring into the .cc file, it's only used
within the class.
(pthread::getThreadId): Ditto.
(pthread::thread_init_wrapper): Apply Extract Method to the TLS
setting logic.
(pthread::isGoodObject): Extracted method from various pthread
wrapper calls, for clarity of reading.
(pthread::getsequence_np): Converted from __pthread_getsquence_np.
(__pthread_create): Apply Extract Method to the object validation.
(__pthread_cancel): Ditto.
(__pthread_join): Ditto.
(__pthread_detach): Ditto.
(__pthread_suspend): Ditto.
(__pthread_continue): Ditto.
(__pthread_getschedparam): Ditto.
(__pthread_getsequence_np): Remove.
(__pthread_setschedparam): Apply Extract Method to the object
validation.
(pthreadNull::getNullpthread): New method, return the pthreadNull
object.
(pthreadNull::pthreadNull): Private constructor to prevent accidental
use.
(pthreadNull::~pthreadNull): Prevent compile warnings.
(pthreadNull::create): Override pthread behaviour.
(pthreadNull::exit): Ditto.
(pthreadNull::cancel): Ditto.
(pthreadNull::testcancel): Ditto.
(pthreadNull::setcancelstate): Ditto.
(pthreadNull::setcanceltype): Ditto.
(pthreadNull::push_cleanup_handler): Ditto.
(pthreadNull::pop_cleanup_handler): Ditto.
(pthreadNull::getsequence_np): Ditto.
(pthreadNull::_instance): Ditto.
* thread.h (pthread): Declare pre- and post-create.
Move GetThreadId to private scope and rename to getThreadId.
Move setThreadIdtoCurrent to private scope.
Make create virtual.
Make ~pthread virtual.
Declare initMainThread.
Declare isGoodObject.
Make exit virtual.
Make cancel virtual.
Make testcancel virtual.
Make setcancelstate virtual.
Make setcanceltype virtual.
Make push_cleanup_handler virtual.
Make pop_cleanup_handler virtual.
Declare getsequence_np.
Declare setTlsSelfPointer.
(pthreadNull): New null object class for pthread.
(__pthread_getsequence_np): Remove.
* thread.h (pthread::cleanup_stack): Renamed cleanup_handlers to
cleanup_stack.
* thread.cc (pthread::pthread): Ditto.
(pthread::create): Fixed mutex verification.
(pthread::push_cleanup_handler): Renamed cleanup_handlers to
cleanup_stack.
Mutex calls removed, used InterlockedExchangePointer instead.
(pthread::pop_cleanup_handler): Renamed cleanup_handlers to
cleanup_stack.
(pthread::pop_all_cleanup_handlers): Ditto.
(__pthread_once): Check state first and return if already done.
(__pthread_join): DEADLOCK test reverted to __pthread_equal
call.
(__pthread_detach): Unlock mutex before deletion.
* cygwin.din: Add _pthread_cleanup_push and _pthread_cleanup_pop.
* pthread.cc: Change __pthread_self to pthread::self() thruoghout.
(_pthread_cleanup_push): New function.
(_pthread_cleanup_pop): Ditto.
* thread.cc: Thanks to Thomas Pfaff for the pthread cleanup_push,_pop
patch, this work is derived from that.
Change __pthread_self to pthread::self() thruoghout.
(__pthread_self): Rename to pthread::self.
(pthread::self): New method.
(pthread::pthread): Initialize new member.
(pthread::push_cleanup_handler): New method.
(pthread::pop_cleanup_handler): New method.
(pthread::pop_all_cleanup_handlers): New method.
(__pthread_exit): Pop all cleanup handlers.
* thread.h (pthread::push_cleanup_handler): Declare.
(pthread::pop_cleanup_handler): Ditto.
(pthread::pop_all_cleanup_handlers): Ditto.
(pthread::self): New static method.
(__pthread_exit): Give C++ linkage.
(__pthread_join): Ditto.
(__pthread_detach): Ditto.
(__pthread_self): Remove.
2002-04-24 Thomas Pfaff <tpfaff@gmx.net>
* include/pthread.h (__pthread_cleanup_handler): New structure
(pthread_cleanup_push): Rewritten .
(pthread_cleanup_pop): Ditto.
(_pthread_cleanup_push): New prototype.
(_pthread_cleanup_pop) Ditto.
2002-04-24 Thomas Pfaff <tpfaff@gmx.net>
* thread.cc (thread_init_wrapper): Check if thread is already joined.
(__pthread_join): Set joiner first.
(__pthread_detach): Ditto.
* thread.cc (pthread_cond::Signal): Use a separate flag for signal detection
and broadcast semantics.
(__pthread_cond_dowait): Ditto.
* thread.h (pthread_cond): New flag for testing when a waiter has woken.
* autoload.cc (LoadDLLfuncEx): Auto load TryEnterCriticalSection - its a
n NT only call.
* thread.cc (pthread_cond::TimedWait): Use critical sections for NT.
(pthread_cond::fixup_after_fork): Don't detect bad apps.
(pthread_mutex::pthread_mutex): Use critical sections for NT.
(pthread_mutex::~pthread_mutex): Ditto.
(pthread_mutex::Lock): Ditto.
(pthread_mutex::TryLock): Ditto.
(pthread_mutex::UnLock): Ditto.
(pthread_mutex::fixup_after_fork): Ditto. Also do not detect bad apps.
(__pthread_mutex_trylock): Move WIN32 specific test into the class metho
d.
(__pthread_mutex_destroy): Prevent dereferencing passed pointer without
valid address.
* thread.h (pthread_mutex): Use critical sections for NT.
* dcrt0.cc (cygwin_finished_initializing): Copy _mtinterf on fork;
* fork.cc (fork_child): fixup thread-related structures after fork;
* thread.cc (MTinterface::Init): Initialise the new mutex, condition and semaphore lists.
(MTinterface::fixup_after_fork): Iterate through each list and fixup the objects.
(pthread_cond::pthread_cond): Add this to the condition list.
(pthread_cond::~pthread_cond): Remove this from the condition list.
(pthread_cond::fixup_after_fork): Recreate as best we can the pre-fork state.
(pthread_mutex::pthread_mutex): Add this to the mutex list.
(pthread_mutex::~pthread_mutex): Remove this from the mutex list.
(pthread_mutex::fixup_after_fork): Recreate as best we can the pre-fork state.
(semaphore::semaphore): Store the initial value, and add this to the semaphore list.
(semaphore::~semaphore): Remove this from the semaphore list.
(semaphore::Post): Increment the current semaphore value.
(semaphore::TryWait): Decrement the current semaphore value.
(semaphore::Wait): Ditto.
(semaphote::fixup_after_fork): Recreate the pre-fork state as best we can.
* thread.h (pthread_mutex): New members to allow fixup_after_fork.
(pthread_cond): Ditto.
(semaphore): Ditto.
(MTinterface): New list heads for tracking conds and semaphores.
* thread.cc (pthread_cond::TimedWait): Check for WAIT_TIMEOUT as well as
WAIT_ABANDONED.
(__pthread_cond_timedwait): Calculate a relative wait from the abstime
parameter.
* thread.h (pthread_cond): New element cond_access to allow atomic broadcasts.
* thread.cc (pthread_cond::pthread_cond): Initialise cond_access.
(pthread_cond::~pthread_cond): Destroy cond_access.
(pthread_cond::Broadcast): Use cond_access.
(pthread_cond::Signal): Use cond_access.
(pthread_cond_wait): Use cond_access.
(pthread_cond_timedwait): Use cond_access.
(read_etc_group): Substitute MAX_DOMAIN_NAME by
INTERNET_MAX_HOST_NAME_LENGTH.
* passwd.cc (parse_pwd): Don't force pw_name to be lower case.
* sec_helper.cc: Substitute MAX_USER_NAME by UNLEN,
MAX_COMPUTERNAME_LENGTH by INTERNET_MAX_HOST_NAME_LENGTH throughout.
(lookup_name): Slight cleanup.
* security.cc (alloc_sd): Substitute MAX_USER_NAME by UNLEN.
* security.h: Define DEFAULT_UID as DOMAIN_USER_RID_ADMIN and
DEFAULT_GID as DOMAIN_ALIAS_RID_ADMINS.
* shared.cc (memory_init): Substitute MAX_USER_NAME by UNLEN.
* thread.h: Ditto.
* uinfo.cc (internal_getlogin): Substitute MAX_USER_NAME by UNLEN.
Substitute MAX_COMPUTERNAME_LENGTH and MAX_HOST_NAME by
INTERNET_MAX_HOST_NAME_LENGTH.
* winsup.h: Include lmcons.h. Eliminate MAX_USER_NAME and
MAX_HOST_NAME. Move DEFAULT_UID and DEFAULT_GID to security.h.
* thread.h (MTinterface): Add threadcount.
* thread.cc (MTinterface::Init): Set threadcount to 1.
(__pthread_create): Increment threadcount.
(__pthread_exit): Decrement threadcount and call exit() from the last thread.
(fork_parent): Call the __pthread_atforkparent function.
* cygwin.din: Export pthread_atfork.
* thread.h (callback): New class.
(MTinterface): Use it.
* thread.cc (__pthread_atforkprepare): New function.
(__pthread_atforkparent): New function.
(__pthread_atforkchild): New function.
(__pthread_atfork): New function.
* pthread.cc (pthread_atfork): New function.
* cygwin.din: Remove @PTH_ALLOW@ prefixes to pthread functions.
Add new pthread exports.
* pthread.cc: New wrapper functions for the above new exports.
* sched.cc (valid_sched_parameters): New function.
(sched_setparam): Use it.
(sched_set_thread_priority): New function. Used by pthread_sched*.
* thread.cc (pthread_key_destructor::InsertAfter): New function.
(pthread_key_destructor::UnlinkNext): New function.
(pthread_key_destructor::Next): New function.
(pthread_key_destructor_list::Insert): New function.
(pthread_key_destructor_list::Remove): New function.
(pthread_key_destructor_list::Pop): New function.
(pthread_key_destructor::pthread_key_destructor): New function.
(pthread_key_destructor_list::IterateNull): New function.
(MTinterface::Init): Initialise new member.
(pthread::pthread): Initialise new members.
(pthread::create): Copy new attributes. Set the new thread priority.
(pthread_attr::pthread_attr): Initialise new members.
(pthread_key::pthread_key): Setup destructor function.
(pthread_key::~pthread_key): Remove destructor function.
(pthread_mutexattr::pthread_mutexattr): New function.
(pthread_mutexattr::~pthread_mutexattr): New function.
(__pthread_once): New function.
(__pthread_cleanup): New function.
(__pthread_cancel): New function.
(__pthread_setcancelstate): New function.
(__pthread_setcanceltype): New function.
(__pthread_testcancel): New function.
(__pthread_attr_getinheritsched): New function.
(__pthread_attr_getschedparam): New function.
(__pthread_attr_getschedpolicy): New function.
(__pthread_attr_getscope): New function.
(__pthread_attr_setinheritsched): New function.
(__pthread_attr_setschedparam): New function.
(__pthread_attr_setschedpolicy): New function.
(__pthread_attr_setscope): New function.
(__pthread_exit): Call any key destructors on thread exit.
(__pthread_join): Use the embedded attr values.
(__pthread_detach): Use the embedded attr values.
(__pthread_getconcurrency): New function.
(__pthread_getschedparam): New function.
(__pthread_key_create): Pass the destructor on object creation.
(__pthread_key_delete): Correct incorrect prototype.
(__pthread_setconcurrency): New function.
(__pthread_setschedparam): New function.
(__pthread_cond_timedwait): Support static mutex initialisers.
(__pthread_cond_wait): Ditto.
(__pthread_mutex_getprioceiling): New function.
(__pthread_mutex_lock): Support static mutex initialisers.
(__pthread_mutex_trylock): Ditto.
(__pthread_mutex_unlock): Ditto.
(__pthread_mutex_destroy): Ditto.
(__pthread_mutex_setprioceiling): New function.
(__pthread_mutexattr_getprotocol): New function.
(__pthread_mutexattr_getpshared): New function.
(__pthread_mutexattr_gettype): New function.
(__pthread_mutexattr_init): New function.
(__pthread_mutexattr_destroy): New function.
(__pthread_mutexattr_setprotocol): New function.
(__pthread_mutexattr_setprioceiling): New function.
(__pthread_mutexattr_getprioceiling): New function.
(__pthread_mutexattr_setpshared): New function.
(__pthread_mutexattr_settype): New function.
Remove stubs for non MT_SAFE compilation.
* thread.h: Remove duplicate #defines.
Add prototypes for new functions in thread.cc.
(pthread_key_destructor): New class.
(pthread_key_destructor_list): New class.
(pthread_attr): Add new members.
(pthread): Remove members that are duplicated in the pthread_attr class.
(pthread_mutex_attr): Add new members.
(pthread_once): New class.
* include/pthread.h: Add prototypes for new functions exported from cygwin1.dll.
Remove typedefs.
* include/sched.h: Add prototypes for new functions in sched.cc.
* include/cygwin/types.h: Add typedefs from pthread.h
element.
* path.cc (mount_info::getmntent): Report "/cygdrive" drives when mounted
drives are exhausted.
(fillout_mntent): New function.
(mount_item::getmntent): Use fillout_mntent.
(cygdrives_mntent): New function. Returns next available "/cygdrive".
(setmntent): Initialize available "/cygdrives".
* syscalls.cc: Remove some if 0'ed code.
* times.cc (timezone): Use more descriptive variable name.
* pthread.cc (pthread_cond_*): Add wrapper functions that call __pthread_cond*
functions.
* thread.cc (__pthread_cond_*): Implement the pthread_cond* functions.
* thread.h: Add new class entries and prototypes for __pthread_cond* functions.
* include/pthread.h: user land header prototypes for pthread_cond* functions
and related defines.
* dcrt0.cc (dll_crt0_1): Call signal_fixup_after_exec where appropriate. Set
myself->uid from parent version. Just use ThreadItem Init method. Close or
store hexec_proc as appropriate.
(_dll_crt0): Store user_data->forkee here so that proper tests can be made
subsequently.
(do_exit): Remove hExeced stuff.
* environ.cc (environ_init): Accept environ count as well as environ pointer.
* environ.h: Reflect above change.
* pinfo.cc (pinfo_init): Ditto. Accept environ count.
(fixup_in_spawned_child): Remove.
* spawn.cc (spawn_guts): Move signal code to dll_crt0_1. Don't suspend execing
process since it is no longer necessary. Store envc.
* exceptions.cc (signal_fixup_after_exec): New function.
(call_handler): Remove hExeced test.
* child_info.h (cygheap_exec_info): Store envc as well as envp.
(child_info_spawn): Store hexec_proc so that it can be closed in child.
* path.cc (normalize_posix_path): Avoid intermediate use of temporary cwd buf.
(normalize_win32_path): Ditto.
(cwdstuff::get_initial): Always set lock.
* sigproc.h: Remove hExeced.
* strace.cc (strace::vsprntf): Modify to accomodate for lack of hExeced.
* thread.cc (MTinterface::Init): Merge Init1 and ClearReent into this method.
(MTinterface::Init1): Eliminate.
(MTinterface::ClearReent): Eliminate.
* thread.h: Reflect above changes.
* include/sys/strace.h (strace): Make microseconds() public. Make various
functions 'regparm', throughout.
* pinfo.h (_pinfo): Inline simple signal manipulation functions. Requires
inclusion of thread.h which was removed from .cc files, where appropriate.
throughout.
* pinfo.cc: Eliminate signal manipulation functions.
(_pinfo::exit): Calculate total rusage for exiting process here.
* cygheap.cc (size2bucket): Eliminate.
(init_buckets): Ditto.
(_cmalloc): Calculate size and bits in a loop rather than going through a
function call.
(_crealloc): Use stored array index to calculate allocated size.
* spawn.cc (spawn_guts): Use _pinfo exit method to exit, calculating cpu usage.
console_handler_thread_waiter. It is obsolete.
(ctrl_c_handler): Don't use console_handler_thread_waiter.
* path.cc (hash_path_name): Fix handling of relative names. Make case
insensitive.
* path.h (suffix_info): Use initializers.
* pinfo.h (_pinfo): Avoid initializers for null case.
* resource.cc (fill_rusage): Zero rest of rusage structure.
* security.cc (set_process_privileges): Don't reopen parent process. Just use
hMainProc.
* signal.cc (signal): Track when a signal handler has been used.
(sigaction): Ditto.
* sigproc.cc (pchildren): Use default initializer.
(zombies): Ditto.
(sigproc_terminate): Avoid closing handles that will be closed on exit anyway.
(wait_sig): Send signal to "parent" on EXECing, not FORKing.
(wait_subproc): Send SIGCHLD here rather than in proc_wait to avoid potential
muto conflicts.
* sigproc.h (sigthread): Don't initialize to zero. It's the default.
* spawn.cc (spawn_guts): Fill in resources from exec parent prior to
termination.
* sync.h (muto): Don't initialize to zero.
* syscalls.cc (close_all_files): Use one lock around entire loop and call
fhandler close/release stuff directly.
(_read): Don't use ready_for_read if there are not signal handlers active.
* dcrt0.cc (dll_crt0_1): Fix display of "title".
(do_exit): Use pinfo exit method to exit.
(__api_fatal): Ditto.
* exceptions.cc (signal_exit): Ditto.
* fork.cc (fork_child): Remove debugging stuff. Use pinfo_fixup_after fork in
place of exec_fixup_after_fork.
* pinfo.cc (pinfo_fixup_after_fork): New method.
(pinfo_fixup_in_spawned_child): Ditto.
(_pinfo::exit): New method.
(_pinfo::init): Remove recursion. Detect pathological case where pinfo
structure already exists for new pid.
* pinfo.h (_pinfo): Reorganize slightly. Add new method and new function
declarations.
* sigproc.cc (proc_exists): Previous simplification was a little to simple.
Try harder to detect if a process exists.
(proc_terminate): Use PID_EXITED setting to determine if process is still
around.
(WFSO): Remove debugging statement.
(WFMO): Ditto.
* spawn.cc (exec_fixup_after_fork): Eliminate.
(spawn_guts): Always set old_title to NULL. Is it really needed? Move
hexec_proc to pinfo.cc. Call pinfo_fixup_in_spawned_child to eliminate handle
link after a spawn.
* include/sys/cygwin.h: Remove PID_NOT_IN_USE. Add PID_EXITED.
* environ.cc (environ_init): Remember to reparse CYGWIN if envp is
supplied.
* heap.cc (_sbrk): Remember frame for signal handling.
* syscalls.cc (read_handler): Eliminate.
(_read): Move read_handler code here. Reorganize for one path through
'ready_for_read'.
* child_info.h: Add specific exec class.
* cygheap.h: New file. Contains declarations for cygwin heap.
* cygheap.cc: New file. Implements cygwin heap functions.
* dcrt0.cc (quoted): Simplify due to new method for passing arguments between
cygwin programs.
(alloc_stack_hard_way): Attempt to handle overlapped stack.
(dll_crt0_1): Move child_info processing here. Accomodate new method for
passing arguments between cygwin programs. Initialize cygwin heap. Establish
__argc and __argv variables.
(_dll_crt0): Move most of child_info processing to dll_crt0_1.
(cygwin_dll_init): Remove duplication.
* dtable.cc (dtable::extend): Allocate dtable using cygwin heap.
(dtable::build_fhandler): Ditto for fhandler type being constructed.
(dtable::dup_worker): Free new fhandler from cygwin heap on error.
(dtable::select_*): Don't assume that this == fdtab.
(dtable::linearize_fd_array): Delete.
(dtable::delinearize_fd_array): Delete.
(dtable::fixup_after_exec): New file.
(dtable::vfork_child_dup): Use cygwin heap.
(dtable::vfork_parent_restore): Ditto.
* dtable.h: Remove obsolete methods. Add new method.
* environ.cc (posify): Eliminate already_posix parameter and logic.
(envsize): New function.
(_addenv): Use envsize.
(environ_init): Accept an argument pointing to an existing environment list.
If supplied, allocate space for this in the the program's heap.
* fhandler.cc (fhandler_base::operator =): Move here from fhandler.h. Use
cygwin heap to allocate filenames.
(fhandler_base::set_name): Allocate/free names from cygwin heap.
(fhandler_base::linearize): Delete.
(fhandler_base::de_linearize): Delete.
(fhandler_base::operator delete): Free from cygwin heap.
(fhandler_base::~fhandler_base): Ditto.
* fhandler.h: Accomodate elimination of *linearize and other changes above.
* fhandler_console.cc (fhandler_console::fixup_after_exec): Rename from
de_linearize.
* heap.h: New file.
* fhandler_tty.cc (fhandler_tty_slave::fhandler_tty_slave): Use cygwin heap for
name. fhandler_tty::fixup_after_exec): Rename from de_linearize.
* fork.cc (fork): Call cygheap_fixup_in_child.
* heap.cc: Use declarations in heap.h.
* malloc.cc: Sprinkle assertions throughout to catch attempts to free/realloc
something from the cygwin heap.
* path.cc: Throughout, eliminate use of per-thread cache for cwd. Use cwd_*
functions rather than cwd_* variables to access cwd_win32 and cwd_posix.
(cwd_win32): New function.
(cwd_posix): New function.
(cwd_hash): New function.
(cwd_fixup_after_exec): New function.
* path.h: Accomodate path.cc changes.
* pinfo.cc (pinfo_init): Accept a pointer to an environment table. Pass this
to environ_init. Eliminate old 'title' tests.
* pinfo.h: Accomodate above change in argument.
* spawn.cc (struct av): New method for building argv list.
(av::unshift): New method.
(spawn_guts): Allocate everything that the child process needs in the cygwin
heap and pass a pointer to this to the child. Build argv list using new
method. Eliminate delinearize stuff.
* thread.h: Eliminate _cwd_win32 and _cwd_posix buffers.
* winsup.h: Eliminate obsolete functions. Add envsize() declaration.
* path.cc: Ditto.
(normalize_posix_path): Add some extra debugging info.
(chdir): Ditto. Store chdir'ed posix and MS-DOS directory names in "cache"
here rather than trying to derive them later.
interruptible.
(call_handler): Avoid suspending a thread if it owns a mutex. Only set
signal_arrived if the thread was actually interrupted.
(events_init): Initialize module information needed by interruptible().
(sigdelayed): Don't call sig_dispatch_pending since it could screw up
* init.cc (dll_entry): Record module handle of main for use by interruptible().
(proc_subproc): Reorganize handling of terminated child so that the bulk of the
processing comes from the signal thread.
(wait_sig): Force processing of waiting threads if SIGCHLD is not processed.
* sync.cc (muto::release): Set tid == 0 after lock is released or signal
processor will be confused.
Robert Collins
Christopher Faylor
Corinna Vinschen