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* dcrt0.cc (child_info_fork::alloc_stack_hard_way): Change sense of guard test.

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Increase size of stack reserved and increase size before the current stack
pointer.  Use pointers when doing arithmetic.
(dll_crt0_1): Initialize exception handler when we notice we're the child of a
fork from non-main thread.
* fork.cc (frok::parent): Make argument volatile.
(frok::child): Ditto.
(lock_signals): New class.
(lock_pthread): Ditto.
(hold_everhthing): Ditto.
(frok::parent): Move atforkprepare and atforkparent to lock_pthread class.
(fork): Make ischild boolean.  Use hold_everything variable within limited
scope to set various mutexes in such a way as to avoid deadlocks.
* thread.h (pthread_mutex::tid): New variable, active when debugging for
tracking thread id of owner.
(pthread_mutex::set_owner): Set tid when debugging.
* thread.cc (pthread_mutex::pthread_mutex): Clear tid.
(pthread_mutex::_unlock): Ditto when unlocking.
(pthread_mutex::fixup_after_fork): Set tid to special value after forking since
owner is unknown.
This commit is contained in:
Christopher Faylor
2007-02-22 12:34:55 +00:00
parent bd8f891e8a
commit 39fc0d36ae
5 changed files with 171 additions and 55 deletions
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24
winsup/cygwin/dcrt0.cc
View File

@@ -451,8 +451,7 @@ check_sanity_and_sync (per_process *p)
child_info NO_COPY *child_proc_info = NULL;
#define CYGWIN_GUARD ((wincap.has_page_guard ()) ? \
PAGE_EXECUTE_READWRITE|PAGE_GUARD : PAGE_NOACCESS)
#define CYGWIN_GUARD (PAGE_EXECUTE_READWRITE | PAGE_GUARD)
void
child_info_fork::alloc_stack_hard_way (volatile char *b)
@@ -461,7 +460,7 @@ child_info_fork::alloc_stack_hard_way (volatile char *b)
MEMORY_BASIC_INFORMATION m;
void *newbase;
int newlen;
bool noguard;
bool guard;
if (!VirtualQuery ((LPCVOID) &b, &m, sizeof m))
api_fatal ("fork: couldn't get stack info, %E");
@@ -472,28 +471,29 @@ child_info_fork::alloc_stack_hard_way (volatile char *b)
{
newbase = curbot;
newlen = (LPBYTE) stackbottom - (LPBYTE) curbot;
noguard = 1;
guard = false;
}
else
{
newbase = stacktop;
newlen = (DWORD) stackbottom - (DWORD) stacktop;
noguard = 0;
newbase = (LPBYTE) stacktop - (128 * 1024);
newlen = (LPBYTE) stackbottom - (LPBYTE) newbase;
guard = true;
}
if (!VirtualAlloc (newbase, newlen, MEM_RESERVE, PAGE_NOACCESS))
api_fatal ("fork: can't reserve memory for stack %p - %p, %E",
stacktop, stackbottom);
new_stack_pointer = (void *) ((LPBYTE) stackbottom - stacksize);
new_stack_pointer = (void *) ((LPBYTE) stackbottom - (stacksize += 8192));
if (!VirtualAlloc (new_stack_pointer, stacksize, MEM_COMMIT,
PAGE_EXECUTE_READWRITE))
api_fatal ("fork: can't commit memory for stack %p(%d), %E",
new_stack_pointer, stacksize);
if (!VirtualQuery ((LPCVOID) new_stack_pointer, &m, sizeof m))
api_fatal ("fork: couldn't get new stack info, %E");
if (!noguard)
if (guard)
{
m.BaseAddress = (LPVOID) ((DWORD) m.BaseAddress - 1);
m.BaseAddress = (LPBYTE) m.BaseAddress - 1;
if (!VirtualAlloc ((LPVOID) m.BaseAddress, 1, MEM_COMMIT,
CYGWIN_GUARD))
api_fatal ("fork: couldn't allocate new stack guard page %p, %E",
@@ -826,7 +826,9 @@ dll_crt0_1 (void *)
{
_tlsbase = (char *) fork_info->stackbottom;
_tlstop = (char *) fork_info->stacktop;
_my_tls.init_exception_handler (_cygtls::handle_exceptions);
}
longjmp (fork_info->jmp, true);
}