The current implementation is a very simple approach to implement
a statically sized sleep queue. The problem is that this code requires
a certain amount of synchronization because the slots in the queue are
used dynamically. To top it off, the Event objects used for sync'ing
are created and destroyed on demand. This is complicated, slow, and
error prone.
There's also a blatant bug here: The number of slots in the queue was
wrongly computed in size. It was too small if XSI IPC was used a lot.
Make the code more robust. Let the queue have the right size. Every
slot is now used for a specific IPC object. All sync objects (switched
to Semaphores) are only created when first required, but never destroyed.
This reduces the usage of a critical section to the creation of a new
sync object.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
* Makefile.in (CYGWIN_OBJS): Remove smallprint.o.
(cygserver.exe): Remove strfuncs.o
(strfuncs.o): Drop rule.
* bsd_log.cc (_vlog): Use snprintf/vsnprintf instead of
__small_sprintf/__small_vsprintf.
* sysv_sem.cc (seminit): Use sys_malloc instead of malloc. Use
snprintf instead of __small_sprintf.
(semunload): Free the above allocated sema_mtx names here.
* sysv_sem.cc (__semctl): Check copyin return value (from 1.76).
* sysv_shm.cc (shminit): Actually use the iterating variable in the
for loop when trying to avoid overflow (from 1.102).
* bsd_mutex.cc: Include stdlib.h, sys/msg.h and sys/sem.h.
(mtx_init): Initialize lock counter to 0.
(_mtx_lock): Increment and log mutex lock counter.
(mtx_owned): Add winpid argument. Return true only if mutex is
actually owned by process winpid.
(_mtx_assert): Add winpid argument accordingly.
(_mtx_unlock): Log owner and lock count.
(MSLEEP_MUTEX): Remove.
(MSLEEP_SEM): Ditto.
(MSLEEP_EVENT): Ditto.
(msleep_event_name): Ditto.
(msleep_cs): New global critical section.
(msleep_cnt): New global variable indicating msleep record usage.
(msleep_max_cnt): New global variable indicating msleep record size.
(msleep_arr): New global pointer to msleep records.
(msleep_init): Initialize msleep_cs. Allocate msleep_arr array.
(_msleep): Rewrite using new msleep_cs/msleep_arr based thread
synchronization. Don't be shy with debug output.
(wakeup): Rewrite using new msleep_cs/msleep_arr based thread
synchronization.
* bsd_mutex.h (struct mtx): Add lock counter for better debugging.
(mtx_owned): Declare with winpid argument.
(_mtx_assert): Ditto.
(mtx_assert): Define with winpid argument.
* cygserver.cc (version): Remove.
(SERVER_VERSION): New define, decoupling server version information
from source code control system.
(print_version): Simplify printing server version.
* process.cc (process::process): Fix wrong bracketing (and handle leak).
(process::~process): Only try to close _signal_arrived if valid.
* sysv_sem.cc: Include sys/smallprint.h.
(semundo_clear): Define with additional struct thread pointer argument.
Accomodate throughout.
(SEMUNDO_LOCKASSERT): Define with winpid argument. Accomodate
throughout.
(struct sem_undo): Define un_proc as pid_t on Cygwin. Accomodate
throughout.
(seminit): Improve debugging by adding the semid to the mutex name.
(semget): Correctly print key value as 64 bit hex value in debug
output.
(semexit_myhook): Remove Cygwin specific unlocking of mutexes owned
by exiting process. Keep semaphore global lock throughout whole
function to avoid races.
* sysv_shm.cc (GIANT_REQUIRED): Define empty on Cygwin. We know that
Giant is locked.
1.68: Reduce the overhead of semop() by using the kernel stack
instead of malloc'd memory to store the operations array if it
is small enough to fit.
1.69: Adjust the number of processes waiting on a semaphore properly
if we're woken up in the middle of sleeping.
process struct pointer, which isn't fixed under Cygwin.
(semexit_myhook): Ditto. Adjust debug print statements to print
Cygwin and Windows PIDs instead of process pointer under Cygwin.
throughout.
* Makefile.in: Accomodate all new files and name changes.
Add a *.d dependency.
(sbindir): Add.
(etcdir): Drop in favor of more appropriate sysconfdir definition.
(sysconfdir): Add.
(CXXFLAGS): Add -MMD flag. Add SYSCONFDIR definition.
(.SUFFIXES): Add.
(install): Add action items.
(libclean): New target.
(fullclean): Ditto.
* bsd_helper.cc: New file.
* bsd_helper.h: Ditto.
* bsd_log.cc: Ditto.
* bsd_log.h: Ditto.
* bsd_mutex.cc: Ditto.
* bsd_mutex.h: Ditto.
* client.cc: Rearrange to build as less as possible if
__INSIDE_CYGWIN__.
(client_request::handle_request): Add Message Queue and Semaphore
handling.
* cygserver.cc: Rearrange to build as less as possible if
__INSIDE_CYGWIN__. Use new debug/log/panic logging functions.
(DEF_CONFIG_FILE): New definition for configuration file. Use
throughout.
(getfunc): Remove.
(__cygserver__printf): Remove.
(client_request_attach_tty::serve): Return error if impersonation
fails.
(print_usage): Pump up help message.
(print_version): Add output of default configuration file.
(main): Accommodate new options. Allow overwrite of threading options
from config file. Call several new initialization functions. Drop
printing dots. Don't define SIGHANDLE inline.
* cygserver.conf: New file.
* cygserver_process.h: Rename to process.h.
* cygserver_transport.h: Rename to transport.h.
* cygserver_transport_pipes.h: Rename to transport_pipes.h.
* cygserver_transport_sockets.h: Rename to transport_sockets.h.
* msg.cc: Rewrite.
* sem.cc: Rewrite.
* shm.cc: Rewrite.
* sysv_msg.cc: New file, derived from FreeBSD version 1.52.
* sysv_sem.cc: New file, derived from FreeBSD version 1.66.
* sysv_shm.cc: New file, derived from FreeBSD version 1.89.
* threaded_queue.cc: Rearrange to build as less as possible if
__INSIDE_CYGWIN__.
* transport.cc (transport_layer_base::impersonate_client): Define bool.
(transport_layer_base::revert_to_self): Ditto.
* transport.h (transport_layer_base::impersonate_client): Declare bool.
(transport_layer_base::revert_to_self): Ditto.
* transport_pipes.cc (transport_layer_pipes::transport_layer_pipes):
Don't call init_security.
(init_security): Remove.
(transport_layer_pipes::accept): Use global sec_all_nih.
(transport_layer_pipes::connect): Ditto.
(transport_layer_pipes::impersonate_client): Define bool.
(transport_layer_pipes::revert_to_self): Ditt.
* transport_pipes.h (transport_layer_pipes::impersonate_client): Declare
bool.
(transport_layer_pipes::revert_to_self): Ditto.
* woutsup.h: Include bsd compatibility headers.
(SIGHANDLE): Add definition.
(__cygserver__printf): Remove definition.
(__noop_printf): Ditto.
(debug_printf): Define using debug.
(syscall_printf): Define using log.
(system_printf): Ditto.
Drop all other _printf definitions.
Corinna Vinschen