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* winsup.h (child_copy): Change prototype to match new functionality.

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* cygheap.cc (cygheap_fixup_in_child): Accommodate new child_copy arguments.
* dcrt0.cc (dll_data_start): Move definition here from fork.
(dll_data_end): Ditto.
(dll_bss_start): Ditto.
(dll_bss_end): Ditto.
(handle_fork): New function.  Called when forked to deal with fork issues and
copy data to this process from the parent.
(dll_crt0_0): Call handle_fork when _PROC_FORK condition.
(dll_crt0): Don't copy user_data when we've forked.  Don't zero first element
of main_environment ever.
(cygwin_dll_init): Ditto.
* fork.cc (child_copy): Rename from fork_copy and change arguments so that each
pair of things to copy gets its own descriptor.
(frok::child): Remove fixup_mmaps_after_fork call here.  Move to handle_fork in
dcrt0.cc.
(frok::parent): Use child_copy rather than fork_copy and accommodate changes in
parameters.
* exceptions.cc (setup_handler): Delay test of whether we're locked until after
GetThreadContext has been called since there are apparently cases where
SuspendThread does not cause an immediate thread suspension.
This commit is contained in:
Christopher Faylor
2005-12-17 04:36:39 +00:00
parent a249fd1c9b
commit ad02bb70e3
6 changed files with 134 additions and 105 deletions
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151
winsup/cygwin/fork.cc
View File

@@ -37,11 +37,6 @@ details. */
/* FIXME: Once things stabilize, bump up to a few minutes. */
#define FORK_WAIT_TIMEOUT (300 * 1000) /* 300 seconds */
#define dll_data_start &_data_start__
#define dll_data_end &_data_end__
#define dll_bss_start &_bss_start__
#define dll_bss_end &_bss_end__
class frok
{
dll *first_dll;
@@ -55,60 +50,6 @@ class frok
friend int fork ();
};
/* Copy memory from parent to child.
The result is a boolean indicating success. */
static int
fork_copy (PROCESS_INFORMATION& pi, const char *what, ...)
{
va_list args;
char *low;
int pass = 0;
va_start (args, what);
while ((low = va_arg (args, char *)))
{
char *high = va_arg (args, char *);
DWORD todo = wincap.chunksize () ?: high - low;
char *here;
for (here = low; here < high; here += todo)
{
DWORD done = 0;
if (here + todo > high)
todo = high - here;
int res;
if (pi.hThread)
res = WriteProcessMemory (pi.hProcess, here, here, todo, &done);
else
res = ReadProcessMemory (pi.hProcess, here, here, todo, &done);
debug_printf ("child handle %p, low %p, high %p, res %d", pi.hProcess,
low, high, res);
if (!res || todo != done)
{
if (!res)
__seterrno ();
/* If this happens then there is a bug in our fork
implementation somewhere. */
system_printf ("%s pass %d failed, %p..%p, done %d, windows pid %u, %E",
what, pass, low, high, done, pi.dwProcessId);
goto err;
}
}
pass++;
}
debug_printf ("done");
return 1;
err:
TerminateProcess (pi.hProcess, 1);
set_errno (EAGAIN);
return 0;
}
static int
resume_child (HANDLE forker_finished)
{
@@ -198,9 +139,6 @@ frok::child (void *)
MALLOC_CHECK;
if (fixup_mmaps_after_fork (hParent))
api_fatal ("recreate_mmaps_after_fork_failed");
#ifdef USE_SERVER
/* Incredible but true: If we use sockets and SYSV IPC shared memory,
there's a good chance that a duplicated socket in the child occupies
@@ -367,7 +305,6 @@ frok::parent (void *stack_here)
goto cleanup;
}
/* Fixup the parent datastructure if needed and resume the child's
main thread. */
if (cygheap->fdtab.need_fixup_before ())
@@ -446,22 +383,21 @@ frok::parent (void *stack_here)
MALLOC_CHECK;
void *impure_beg;
void *impure_end;
const void *impure_beg;
const void *impure_end;
const char *impure;
if (&_my_tls == _main_tls)
impure_beg = impure_end = NULL;
impure_beg = impure_end = impure = NULL;
else
{
impure = "impure";
impure_beg = _impure_ptr;
impure_end = _impure_ptr + 1;
}
rc = fork_copy (pi, "user/cygwin data",
user_data->data_start, user_data->data_end,
user_data->bss_start, user_data->bss_end,
cygheap->user_heap.base, cygheap->user_heap.ptr,
stack_here, ch.stackbottom,
dll_data_start, dll_data_end,
dll_bss_start, dll_bss_end, impure_beg, impure_end, NULL);
rc = child_copy (pi.hProcess, true,
"stack", stack_here, ch.stackbottom,
impure, impure_beg, impure_end,
NULL);
__malloc_unlock ();
locked = false;
@@ -473,9 +409,10 @@ frok::parent (void *stack_here)
for (dll *d = dlls.istart (DLL_LINK); d; d = dlls.inext ())
{
debug_printf ("copying data/bss of a linked dll");
if (!fork_copy (pi, "linked dll data/bss", d->p.data_start, d->p.data_end,
d->p.bss_start, d->p.bss_end,
NULL))
if (!child_copy (pi.hProcess, true,
"linked dll data", d->p.data_start, d->p.data_end,
"linked dll bss", d->p.bss_start, d->p.bss_end,
NULL))
{
this_errno = get_errno ();
#ifdef DEBUGGING
@@ -505,9 +442,10 @@ frok::parent (void *stack_here)
for (dll *d = dlls.istart (DLL_LOAD); d; d = dlls.inext ())
{
debug_printf ("copying data/bss for a loaded dll");
if (!fork_copy (pi, "loaded dll data/bss", d->p.data_start, d->p.data_end,
d->p.bss_start, d->p.bss_end,
NULL))
if (!child_copy (pi.hProcess, true,
"loaded dll data", d->p.data_start, d->p.data_end,
"loaded dll bss", d->p.bss_start, d->p.bss_end,
NULL))
{
this_errno = get_errno ();
#ifdef DEBUGGING
@@ -690,13 +628,52 @@ vfork ()
#endif
}
int
child_copy (HANDLE h, DWORD pid, const char *what, void *child_start, void *child_end)
/* Copy memory from one process to another. */
bool
child_copy (HANDLE hp, bool write, ...)
{
PROCESS_INFORMATION pi;
pi.hProcess = h;
pi.dwProcessId = pid;
pi.hThread = NULL;
debug_printf ("%s, start %p, end %p", what, child_start, child_end);
return fork_copy (pi, what, child_start, child_end, NULL);
va_list args;
va_start (args, write);
static const char *huh[] = {"read", "write"};
char *what;
while ((what = va_arg (args, char *)))
{
char *low = va_arg (args, char *);
char *high = va_arg (args, char *);
DWORD todo = wincap.chunksize () ?: high - low;
char *here;
for (here = low; here < high; here += todo)
{
DWORD done = 0;
if (here + todo > high)
todo = high - here;
int res;
if (write)
res = WriteProcessMemory (hp, here, here, todo, &done);
else
res = ReadProcessMemory (hp, here, here, todo, &done);
debug_printf ("hp %p, low %p, high %p, res %d", hp, low, high, res);
if (!res || todo != done)
{
if (!res)
__seterrno ();
/* If this happens then there is a bug in our fork
implementation somewhere. */
system_printf ("%s %s copy failed, %p..%p, done %d, windows pid %u, %E",
what, huh[write], low, high, done);
goto err;
}
}
}
debug_printf ("done");
return true;
err:
TerminateProcess (hp, 1);
set_errno (EAGAIN);
return false;
}