queried in waitsig later.
* sigproc.cc (wait_sig): Don't deliver a signal if in a vfork.
* fork.cc (vfork): Deliver all signals on parent return from vfork.
* 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.
* dcrt0.cc (_cygwin_testing): Define.
(_dll_crt0): Set _cygwin_testing if CYGWIN_TESTING environment variable exists.
Don't issue "conflicting versions" error if _cygwin_testing is true.
* shared.cc (shared_name): Use _cygwin_testing global rather than testing the
environment.
* syscalls.cc (_write): Remove debugging info.
* dcrt0.cc (set_os_type): Set 'iswinnt' appropriately.
* cygheap.cc (init_cheap): Revert to using VirtualAlloc for allocating cygheap.
(cygheap_setup_for_child_cleanup): New function. Standard function to call
after calling CreateProcess to cleanup cygheap info passed to child.
(cygheap_fixup_in_child): Copy cygheap from shared memory into allocated space
under Windows 9x or if can't relocate shared space under NT.
* cygheap.h: Declare new function.
* spawn.cc (spawn_guts): Use cygheap_fixup_in_child.
* fork.cc (fork_parent): Ditto.
* winsup.h: Declare iswinnt.
fhandler.h.
* fhandler.h (fhandler_base::get_inheritance): New method.
* fhandler_socket.cc (fhandler_socket::create_secret_event): Use proper
close-on-exec inheritance when creating.
(fhandler_socket::check_peer_secret_event): Create handle as non-inheritable.
* dcrt0.cc (dll_crt0_1): Move uid initialization earlier.
* fork.cc (fork_parent): Move cygheap_setup_in_child to just prior to
CreateProcess so that all contents of cygheap are copied.
* spawn.cc (spawn_guts): Ditto.
(class child_info): Add an element.
* cygheap.cc (init_cheap): Allocate cygwin heap in shared memory area.
(cygheap_fixup_in_child): Map cygwin heap, passed from parent via shared memory
into correct address.
(cygheap_setup_for_child): New function.
* cygheap.h: Declare new functions.
* dcrt0.cc (dll_crt0_1): Accomodate new cygheap_fixup_in_child arguments.
Avoid protecting subproc_ready unless it is spawn/nowait.
* fork.cc (fork_parent): Use new cygheap_setup_for_child function to setup
cygwin heap info. Close passed cygheap shared memory handle.
* spawn.cc (spawn_guts): Ditto. Also, reorganize to avoid synchronization
between parent and child in non-P_OVERLAY case.
* sigproc.cc (wait_sig): Only signal subproc_ready when execing.
(_crealloc): Ditto.
* dcrt0.cc (dll_crt0_1): Default to always checking for executable for now.
* dtable.cc (dtable::not_open): Move method.
* dtable.h (dtable): Here.
* exceptions.cc (ctrl_c_handler): Don't expect process group leader to handle a
signal if it doesn't exist.
* fhandler.h (fhandler_base): Make openflags protected.
* localtime.c (tzsetwall): Check for __CYGWIN__ as well as __WIN32__.
* path.cc (path_conv::check): Add some comments. Change strcat to assignment.
* lib/_cygwin_S_IEXEC.cc (_cygwin_bob__): Eliminate.
* fhandler_tty.cc (fhandler_console::dup): Set controlling terminal if
necessary.
* fhandler_tty.cc (fhandler_tty_slave::dup): Ditto.
Throughout, change 'OutputStopped' to 'output_stopped', for consistency.
* dtable.cc (stdio_init): Set controlling tty if not set by stdio opens.
* exceptions.cc (ctrl_c_handler): Avoid special pgid checking if no tty is
associated with the process.
(Suggested by Tim Baker <dbaker@direct.ca>)
* external.cc (fillout_pinfo): Return actual tty number for ctty.
* fhandler_console.cc (get_tty_stuff): Set ctty when shared memory is
allocated. Accept flags input from open().
(set_console_ctty): New function.
(fhandler_console::open): Pass flags to get_tty_stuff and rely on this function
to set the ctty, if appropriate.
* fhandler_termios.cc (fhandler_termios::set_ctty): Move to tty_min class.
* fhandler_tty.cc (fhandler_tty_slave::open): Use tc field to access
set_ctty().
* tty.h (TTY_CONSOLE): Move to include/sys/cygwin.h.
(tty_min): Add set_ctty class here.
* include/sys/cygwin.h (TTY_CONSOLE): New home here.
* path.cc (symlink_info): Make contents an actual buffer. Pass more flags to
case_check.
(path_conv::check): Reorganize to do parsing based on posix path rather than
native path.
(symlink_info::check): Expect posix path as input. Translate to native path
here. Accept path_conv flags. Stop parsing if not a symlink regardless of
whether previous path was a symlink.
defined. Wrap definitions in extern "C". Include winsup.h to assure proper
definitions.
* dcrt0.cc (dll_crt0_1): Call stdio_init after premain run so that binmode.o,
etc., will control default stdio settings.
* dtable.cc (dtable::init_std_file_from_handle): Allow __fmode to force
binmode/textmode settings. Default pipes to binmode.
chrisiasci@aol.com).
* cygwin.din: Add a new, internally used export - _check_for_executable.
* dcrt0.cc (dll_crt0_1): Set _check_for_executable for older binaries. Pass
user_data to premain functions.
* fhandler.cc (fhandler_disk_file::open): Only check for executable if the
linked program is intereested in the executable bit.
(fhandler_disk_file::check_execable_p): Delete.
* fhandler.h (executable_states): New enumeration of various states of
executable bit caring.
(fhandler_base::set_execable_p): New method.
* fhandler_termios.cc (fhandler_termios::line_edit): Flag when a signal has
been sent to the tty. Return -1 when this is so.
* fhandler_console.cc (fhandler_console::read): Return -1 when signal sending
character encountered.
* path.cc (path_conv::check): Record when path refers to a disk device. Move
executable extension check here.
(check_sysfile): Accomodate new EXEC path states.
(has_suffix): Remove.
(next_suffix): Remove.
(class suffix_scan): New clas.
(suffix_scan::has): New method.
(suffix_scan:next): New method.
(symlink_info::check): Use suffix_scan method to control for scanning for
suffixes.
* path.h (path_conv::exec_state): New method.
* perprocess.h: Make "C" friendly.
* include/cygwin/version.h: Define CYGWIN_VERSION_CHECK_FOR_S_IEXEC. Bump
CYGWIN_VERSION_API_MINOR.
* include/sys/cygwin.h: Change premain declarations.
* winsup.h: Move __cplusplus test to after builtin defines.
* thread.cc (MTinterface::Init): Remove the initialization of `reent_data'.
* dcrt0.cc: Add the initalizer to the declaration of `reent_data'.
* include/cygwin/version.h: Bump CYGWIN_VERSION_API_MINOR to 35.
does.
* cygheap.cc (init_cheap): Don't specify a load address for the heap. It
doesn't work on #!*& Windows 9x.
(cygheap_init): Move GetUserName to memory_init.
* dcrt0.cc (dll_crt0_1): Call new memory_init functin, eliminate call to
heap_init.
* heap.cc (heap_init): Improve error output.
* heap.h: Correct some declarations.
* shared.cc (mount_table_init): Remove.
(memory_init): Renamed from shared_init. Reorganize to accomodate strange
Windows 9x problems with cygheap/heap interaction.
* shared_info.h: Rename shared_init to memory_init.
* child_info.h (child_info): Move shared_h, console_h to cygheap. Add mount_h.
* cygheap.h (init_cygheap): Add shared_h, console_h.
* cygheap.cc (init_cheap): Initialize heap at a fixed location after the shared
memory regions. Initialize cygheap->user name here.
* dcrt0.cc (dll_crt0_1): Call getpagesize () to initialize constants. Remove
cygheap_init since it is done in shared_init now.
(_dll_crt0): Initialize mount_h, remove shared_h and console_h initialization.
* fhandler_console.cc (console_shared_h): Eliminate.
(get_tty_stuff): Use cygheap->console_h rather than console_shared_h.
* heap.cc (heap_init): Use page size constant calculated earlier in
initialization.
* shared.cc: Eliminate cygwin_shared_h. Add cygwin_mount_h.
(mount_table_init): New function for initializing a user mount table.
(open_shared_file_map): Use constant for shared memory region. Initialize
cygheap and mount table here.
(open_shared): Improve debugging output.
(shared_info::initialize): Eliminate call to mount.init.
(shared_terminate): Use cygheap->shared_h. Close cygwin_mount_h.
(open_shared_file_map): Eliminate.
* shared_info.h (mount_info): Add a version field.
(shared_align_past): New macro for calculating location for shared memory
regions.
* sigproc.cc (init_child_info): Eliminate shared_h, console_h.
* spawn.cc (spawn_guts): Pass on cygwin_mount_h iff not a different user.
* syscalls.cc (system_info): New global holding system memory defaults.
(getpagesize): Use system_info.
* uinfo.cc (internal_getlogin): Only fill in user name if nonexistent.
* winsup.h: Declare system_info.
* passwd.cc (read_etc_passwd): Use cygheap->user.name () rather than retrieving
the name again.
* environ.cc (codepage_init): To here.
* exceptoins.cc (SIG_NONMASKABLE): Remove SIGCONT from consideration since it
is supposed to be maskable.
* signal.cc (sigaction): Ditto.
* sigproc.cc (wait_sig): Ditto.
* winsup.h: Eliminate global declaration of codepage_init.
* dcrt0.cc (dll_crt0_1): Translate command line to OEM if current codepage is
OEM.
* environ.cc: Add new option 'codepage' to CYGWIN environment variable.
* fhandler_clipboard.cc (fhandler_clipboard::read): Read clipboard in OEM mode
if current codepage is OEM.
* fhandler_console.cc (fhandler_console::read): Only translate console input if
current codepage is ANSI.
* fhandler_console.cc (fhandler_console::write_normal): Translate output data
if current codepage is ANSI.
* pinfo.cc (codepage_init): New function. Setup current codepage from CYGWIN
environment variable and set codepage for file APIs.
* security.cc (read_sd): Translate file name to it if current codepage is OEM.
* winsup.h: (sys_wcstombs,sys_mbstowcs): Use current codepage for translations
between multibyte and widechar string and vice versa.
* child_info.h (child_info): Eliminate parent_alive.
* dcrt0.cc (dll_crt0_1): Call fork_init for debugging pid creation.
* fork.cc (fork_child): Reflect change to fixup_mmaps_after_fork arguments.
(slow_pid_reuse): New function to grab last 'n' pids to prevent pid reuse.
(fork_parent): Move last_fork_proc into slow_pid_reuse. Handle fork_pids
debugging. Eliminate unnecessary call to set_child_mmap_ptr.
(fork_init): New debugging function.
* mmap.cc (fixup_mmaps_after_fork): Renamed from recreate_mmaps_after_fork.
Rely on copied data after a fork.
(set_child_mmap_ptr): Eliminate.
* pinfo.h (_pinfo): Eliminate parent_alive, mmap_ptr and reflect above changes.
* spawn.cc (spawn_guts): Eliminate vestiges of "old way" of sending new hProc
to parent process.
(cygheap_root::~cygheap_root): Ditto.
(cygheap_root::operator=): Ditto.
(cygheap_user::~cygheap_user): Ditto.
(cygheap_user::set_name): Ditto.
(cygheap_user::set_logsrv): Ditto.
(cygheap_user::set_domain): Ditto.
(cygheap_user::set_sid): Ditto.
* cygheap.h (cygheap_root): New class.
(cygheap_user): Ditto.
(init_cygheap): Change type of `root' member to cygheap_root.
Add `user' member.
* dir.cc (opendir): Use new `cygheap_root' class.
* dcrt0.cc (dll_crt0_1): Use new `cygheap_user' class.
* fork.cc (fork_parent): Ditto.
* grp.cc (getgroups): Ditto.
* passwd.cc (search_for): Ditto.
* path.cc: Use new `cygheap_root' class throughout.
* pinfo.h (_pinfo): Remove `use_psid'. Move `username', `psid',
`logsrv', `domain', `orig_{uid,gid}' and `real_{uid,gid}' to
cygheap_user class.
* security.cc: Use new `cygheap_user' class throughout.
* shared.cc (sec_user): Ditto.
* sigproc.cc (proc_subproc): Remove copy statements for user
related information moved to `cygheap_user' class.
* spawn.cc (spawn_guts): Invalidate current chroot settings
when creating Windows environment. Use new `cygheap_user' class.
* syscalls.cc: Use new `cygheap_user' class throughout.
* uinfo.cc: Ditto.
* uinfo.cc (internal_getlogin): Change parameters to reflect the
move of user information to cygheap.
heap.
* child_info.h (child_info): Change pointer type of cygheap to init_cygheap.
* cygheap.cc (init_cheap): Point cygheap_max after contents of cygheap. Move
some stuff into cygheap.h.
* dir.cc (opendir): Change to use root and rootlen in cygheap rather than in
myself.
(mkdir): Change to use umask in cygheap rather than in myself.
* path.cc: Ditto, throughout.
* syscalls.cc (_open): Ditto. Change to use umask in cygheap rather than in
myself.
(chroot): Change to allocate root dir on the cygwin heap.
(umask): Change to use umask in cygheap rather than in myself.
(cygwin_bind): Ditto.
* sigproc.cc (proc_subproc): Don't copy umask or root stuff as this happens
automatically now.
* pinfo.h (_pinfo): Migrate stuff out of here and into init_cheap.
* dcrt0.cc (dll_crt0_1): Call cygheap_init later in startup for first cygwin
process.
(dll_crt0_1): Disable case-insensitive globbing before calling `main'.
* environ.cc (glob_init): New static function to set or clear
`ignore_case_with_glob'.
(known): Changed "glob" entry to call `glob_init'.
* glob.c (match): Use case-insensitive globbing if needed.
(dll_crt0_1): Move sigthread lock initialization to earlier in startup.
* exceptions.cc (interrupt_on_return): Remove previous kludgy attempt to detect
an invalid frame.
(call_handler): Eliminate inner for loop. Grab signal critical section lock
where appropriate.
* sigproc.cc (proc_subproc): Restore uid setting.
* sigproc.h (sigthread): Reinstitute sigthread lock as a critical section.
(sigframe): Grab the sigthread lock before clearing frame to avoid having the
signal thread use an invalid frame.
parent handle.
* dcrt0.cc (_dll_crt0): Close parent's parent handle when spawned or forked.
* debug.cc (add_handle): Correct erroneous reference to handle structure when
printing warning.
* exceptions.cc (interrupt_now): Always return 1.
(interrupt_on_return): Accept a sigthread argument. Check to see if this
argument has been trashed prior to setting up the stack return.
(call_handler): Add a loop around attempts to dispatch signals to detect case
where interrupt_on_return fails.
(_sigdelayed): Set up a temporary frame pointer prior to calling stuff that
could trigger an interrupt or the stack walking code will be very confused.
* fork.cc (fork_parent): Move a lot of the setup of the child process into
proc_subproc.
* spawn.cc (spawn_guts): Ditto. Use ppid_handle to contact logical parent when
reparenting.
* pinfo.h (_pinfo): Remember the logical handle of the parent process.
* sigproc.cc (proc_subproc): Record most stuff necessary for the _pinfo
structure that is inferrable from myself when adding children.
(wait_sig): Always set 'pending_signals' flag when about to kick off the signal
scanning loop. Reset it only if there are no pending signals.
process has never created any children.
* fork.cc (fork): Set flag indicating that there is another process with our
process group.
* spawn.cc (spawn_guts): Ditto.
* pinfo.h (set_has_pgid_children): New methods for setting when process has
children in its process group.
* syscalls.cc (setpgid): Clear has_gid_children if pgid changes.
is not available.
* dcrt0.cc (sigthread::init): Ditto.
(dll_crt0_1): Move set_process_privileges call (temporarily?) to pinfo_init.
(pinfo_init): Only call set_process_privileges when allow_ntsec.
* environ.cc (conv_start_chars): Cache a table of "first
characters" for environment variables needing conversion.
(getwinenv): Use it.
(environ_init): Create it, also check first chars for TERM and
CYGWIN.
* path.cc: Use lookup table for case insensitive comparisons.
* Makefile.in: include fhandler_clipboard.o in DLL_OFILES list.
* fhandler.h: add FH_CLIPBOARD to the devices enum.
(fhandler_dev_clipboard): new
* path.cc (windows_device_names): add "\\dev\\clipboard"
(get_device_number): check for "clipboard"
* dcrt0.cc: declare a few more functions from winuser.h
* dtable.cc (dtable::build_fhandler): check for FH_CLIPBOARD in
switch().
* 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.
parent.
* dcrt0.cc (do_exit): Don't cleanup pinfo on exit. That happens automatically
now.
* exceptions.cc (signal_exit): Ditto.
* fork.cc (fork_parent): Use stack_here value passed in from fork().
(fork): Figure out top of stack here and pass it to fork_parent.
* pinfo.cc (_pinfo::record_death): Eliminate.
* pinfo.h (_pinfo): Ditto.
* sigproc.cc (proc_exists): Simplify.
(proc_terminate): Ditto.
(remove_zombie): Don't cleanup pinfo stuff.
(wait_sig): Send subproc_ready signal whether execed or spawned.
* spawn.cc (spawn_guts): Always create subproc_ready event. Use it for both
exec and spawn.
(_spawnve): Send proper mode to spawn_guts when mode != _P_OVERLAY.
(child_info): Move some fields from child_info_spawn to here.
* cygheap.cc: Make cygheap pointers NOCOPY.
* dcrt0.cc (dll_crt0_1): Copy cygwin heap here regardless of whether we've been
forked or execed.
* dtable.cc (dtable::fixup_after_fork): Just release close-on-exec fds.
* exceptions.cc (stackdump): Respond to C warning.
* fork.cc: Reorganize to minimize stack copying.
(fork_child): New function.
(fork_parent): Ditto.
(sync_with_child): Don't suspend the forkee.
(sync_with_parent): Ditto. Make into a function.
* heap.cc (heap_init): Add some debugging output.
* path.cc (path_conv::check): Add an assertion.
(has_suffix): Ditto.
* security.cc (get_pw_sid): Defend against NULL.
* sigproc.cc (proc_subproc): Fix debugging output.
(wait_sig): Ditto.
* strace.cc: Make statics NO_COPY throughout.
(strace::vsprntf): Defend against NULL.
* fhandler.cc (fhandler_base::fstat): Move to inline method in fhandler.h.
(fhandler_base::set_io_handle): Ditto.
* fhandler.h (fhandler_base): Make some methods inline.
* fhandler_console.cc (fhandler_console::write_normal): Make buffer larger.
* sigproc.h (sigframe::sigframe): Actually use set ebp parameter correctly.
* spawn.cc (spawn_guts): Set dwProcessId when exec'ing. Just exit immediately
after reparenting.
* syscalls.cc: Sprinkle sigframe stuff throughout.
* wait.cc (wait4): Set signal frame here.
* dcrt0.cc (__api_fatal): Don't rely on small_printf to display errors. Always
display problems to the console, if possible.
(_cmalloc): Reorganize to accomodate muto locking.
(_cfree): Use muto lock to avoid multi-thread problems.
* cygheap.h (incygheap): Just use cygheap_max to find upper cygwin heap bounds.
* dcrt0.cc (dll_crt0_1): Reinstitute cygheap_init call.
* path.cc (getcwd): Just return cwdstuff::get result, allowing correct handling
of negative length.
(cwdstuff::get): Malloc a buffer if one is not available.