newlib/winsup/cygwin/init.cc
Christopher Faylor e431827c7c Rename _threadinfo to _cygtls, throughout.
* cygtls.h (_cygtls::call_signal_handler): Rename from call_signal_handler_now.
(_cygtls::push): Make second argument mandatory.
(_cygtls::fixup_after_fork): Declare new function.
(_cygtls::lock): Ditto.
* cygtls.cc (_cygtls::fixup_after_fork): Define new function.
* dcrt0.cc (cygwin_finished_initializing): Define as bool.
(alloc_stack): Use _tlstop rather than arbitrary variable in probably vain
attempt to avoid strange fork problem on CTRL-C.
(dll_crt0_0): Remove obsolete winpids::init call.
* dll_init.cc (dll_dllcrt0): Detect forkee condition as equivalent to
initializing.
* winsup.h (cygwin_finished_initializing): Declare as bool.
* exceptions.cc (handle_exceptions): Rely on cygwin_finished_initializing to
determine how to handle exception during process startup.
(_cygtls::call_signal_handler): Rename from call_signal_handler_now.
(_cygtls::interrupt_now): Fill in second argument to push.
(signal_fixup_after_fork): Eliminate.
(setup_handler): Initialize locked to avoid potential inappropriate unlock.
Resume thread if it has acquired the stack lock.
(ctrl_c_handler): Just exit if ctrl-c is hit before cygiwn has finished
initializing.
* fork.cc (sync_with_child): Don't call abort since it can cause exit
deadlocks.
(sync_with_child): Change debugging output slightly.
(fork_child): Set cygwin_finished_initializing here.  Call _cygtls fork fixup
and explicitly call sigproc_init.
(fork_parent): Release malloc lock on fork failure.
(vfork): Call signal handler via _my_tls.
* sigproc.cc (sig_send): Ditto.
* syscalls.cc (readv): Ditto.
* termios.cc (tcsetattr): Ditto.
* wait.cc (wait4): Ditto.
* signal.cc (nanosleep): Ditto.
(abort): Ditto.
(kill_pgrp): Avoid killing self if exiting.
* sync.cc (muto::acquire): Remove (temporarily?) ill-advised exiting_thread
check.
* gendef (_sigfe): Be more agressive in protecting stack pointer from other
access by signal thread.
(_cygtls::locked): Define new function.
(_sigbe): Ditto.
(_cygtls::pop): Protect edx.
(_cygtls::lock): Use guaranteed method to set eax to 1.
(longjmp): Aggressively protect signal stack.
* miscfuncs.cc (low_priority_sleep): Reduce "sleep time" for secs == 0.
* pinfo.cc (winpids::set): Counterintuitively use malloc's lock to protect
simultaneous access to the pids list since there are pathological conditions
which can cause malloc to call winpid.
(winpids::init): Eliminate.
* pinfo.h (winpids::cs): Eliminate declaration.
* pinfo.h (winpids::init): Eliminate definition.
2004-02-12 03:01:58 +00:00

113 lines
2.9 KiB
C++

/* init.cc
Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Red Hat, Inc.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "winsup.h"
#include <stdlib.h>
#include "thread.h"
#include "perprocess.h"
#include "cygthread.h"
#include "cygtls.h"
int NO_COPY dynamically_loaded;
static char *search_for = (char *) cygthread::stub;
static unsigned threadfunc_ix __attribute__((section ("cygwin_dll_common"), shared)) = 0;
DWORD tls_func;
HANDLE sync_startup;
#define OLDFUNC_OFFSET -1
static void WINAPI
threadfunc_fe (VOID *arg)
{
_cygtls::call ((DWORD (*) (void *, void *)) (((char **) _tlsbase)[OLDFUNC_OFFSET]), arg);
}
static DWORD WINAPI
calibration_thread (VOID *arg)
{
ExitThread (0);
}
/* We need to know where the OS stores the address of the thread function
on the stack so that we can intercept the call and insert some tls
stuff on the stack. This function starts a known calibration thread.
When it starts, a call will be made to dll_entry which will call munge_threadfunc
looking for the calibration thread offset on the stack. This offset will
be stored and used by all executing cygwin processes. */
void
prime_threads ()
{
if (!threadfunc_ix)
{
DWORD id;
search_for = (char *) calibration_thread;
sync_startup = CreateThread (NULL, 0, calibration_thread, 0, 0, &id);
}
}
/* If possible, redirect the thread entry point to a cygwin routine which
adds tls stuff to the stack. */
static void
munge_threadfunc (HANDLE cygwin_hmodule)
{
char **ebp = (char **) __builtin_frame_address (0);
if (!threadfunc_ix)
{
for (char **peb = ebp; peb < (char **) _tlsbase; peb++)
if (*peb == search_for)
{
threadfunc_ix = peb - ebp;
goto foundit;
}
#ifdef DEBUGGING
system_printf ("non-fatal warning: unknown thread! search_for %p, cygthread::stub %p, calibration_thread %p, possible func offset %p",
search_for, cygthread::stub, calibration_thread, ebp[137]);
#endif
try_to_debug ();
return;
}
foundit:
char *threadfunc = ebp[threadfunc_ix];
if (threadfunc == (char *) calibration_thread)
/* no need for the overhead */;
else
{
ebp[threadfunc_ix] = (char *) threadfunc_fe;
((char **) _tlsbase)[OLDFUNC_OFFSET] = threadfunc;
// TlsSetValue (tls_func, (void *) threadfunc);
}
}
extern void __stdcall dll_crt0_0 ();
extern "C" int WINAPI
dll_entry (HANDLE h, DWORD reason, void *static_load)
{
switch (reason)
{
case DLL_PROCESS_ATTACH:
prime_threads ();
dynamically_loaded = (static_load == NULL);
dll_crt0_0 ();
break;
case DLL_PROCESS_DETACH:
break;
case DLL_THREAD_ATTACH:
munge_threadfunc (h);
break;
case DLL_THREAD_DETACH:
_my_tls.remove (0);
break;
}
return 1;
}