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* exceptions.cc (interruptible): Change method for determining if something is

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interruptible.
(call_handler): Avoid suspending a thread if it owns a mutex.  Only set
signal_arrived if the thread was actually interrupted.
(events_init): Initialize module information needed by interruptible().
(sigdelayed): Don't call sig_dispatch_pending since it could screw up
* init.cc (dll_entry): Record module handle of main for use by interruptible().
(proc_subproc): Reorganize handling of terminated child so that the bulk of the
processing comes from the signal thread.
(wait_sig): Force processing of waiting threads if SIGCHLD is not processed.
* sync.cc (muto::release): Set tid == 0 after lock is released or signal
processor will be confused.
This commit is contained in:
Christopher Faylor
2000-02-24 02:49:44 +00:00
parent 58dabf5040
commit f02f1f1444
17 changed files with 164 additions and 96 deletions
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101
winsup/cygwin/sigproc.cc
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@ -85,8 +85,6 @@ Static HANDLE hwait_subproc = NULL; // Handle of sig_subproc thread
Static HANDLE wait_sig_inited = NULL; // Control synchronization of
// message queue startup
Static muto *sync_proc_subproc = NULL; // Control access to
// subproc stuff
/* Used by WaitForMultipleObjects. These are handles to child processes.
*/
@ -100,6 +98,9 @@ Static int nzombies = 0; // Number of deceased children
Static waitq waitq_head = {0, 0, 0, 0, 0, 0, 0};// Start of queue for wait'ing threads
Static waitq waitq_main; // Storage for main thread
muto NO_COPY *sync_proc_subproc = NULL; // Control access to
// subproc stuff
DWORD NO_COPY maintid = 0; // ID of the main thread
Static DWORD sigtid = 0; // ID of the signal thread
@ -244,7 +245,7 @@ proc_subproc (DWORD what, DWORD val)
int potential_match;
DWORD exitcode;
pinfo *child;
int send_sigchld = 0;
int clearing = 0;
waitq *w;
#define wval ((waitq *) val)
@ -284,14 +285,6 @@ proc_subproc (DWORD what, DWORD val)
wake_wait_subproc ();
break;
/* A child is in the stopped state. Scan wait() queue to see if anyone
* should be notified. (Called from wait_sig thread)
*/
case PROC_CHILDSTOPPED:
child = myself; // Just to avoid accidental NULL dereference
sip_printf ("Received stopped notification");
goto scan_wait;
/* A child process had terminated.
* Possibly this is just due to an exec(). Cygwin implements an exec()
* as a "handoff" from one windows process to another. If child->hProcess
@ -310,7 +303,6 @@ proc_subproc (DWORD what, DWORD val)
ForceCloseHandle1 (hchildren[val], childhProc);
hchildren[val] = child->hProcess; /* Filled out by child */
ProtectHandle1 (child->hProcess, childhProc);
wake_wait_subproc ();
break; // This was an exec()
}
@ -318,46 +310,21 @@ proc_subproc (DWORD what, DWORD val)
child->pid, val, hchildren[val], nchildren, nzombies);
remove_child (val); // Remove from children arrays
zombies[nzombies++] = child; // Add to zombie array
wake_wait_subproc (); // Notify wait_subproc thread that
// nchildren has changed.
child->process_state = PID_ZOMBIE;// Walking dead
if (!proc_loop_wait) // Don't bother if wait_subproc is
break; // exiting
send_sigchld = 1;
scan_wait:
/* Scan the linked list of wait()ing threads. If a wait's parameters
* match this pid, then activate it.
*/
for (w = &waitq_head; w->next != NULL; w = w->next)
{
if ((potential_match = checkstate (w)) > 0)
sip_printf ("released waiting thread");
else if (potential_match < 0)
sip_printf ("only found non-terminated children");
else if (potential_match == 0) // nothing matched
{
sip_printf ("waiting thread found no children");
HANDLE oldw = w->next->ev;
w->next->ev = NULL;
if (!SetEvent (oldw))
system_printf ("couldn't wake up wait event %p, %E", oldw);
w->next = w->next->next;
}
if (w->next == NULL)
break;
}
sip_printf ("finished processing terminated/stopped child");
if (!send_sigchld)
break; // No need to send a SIGCHLD
/* Send a SIGCHLD to myself. */
sync_proc_subproc->release (); // Avoid a potential deadlock
rc = sig_send (NULL, SIGCHLD); // Send a SIGCHLD
goto out1; // Don't try to unlock. We don't have a lock.
rc = sig_send (myself_nowait, SIGCHLD); // Send a SIGCHLD
break; // Don't try to unlock. We don't have a lock.
/* A child is in the stopped state. Scan wait() queue to see if anyone
* should be notified. (Called from wait_sig thread)
*/
case PROC_CHILDSTOPPED:
child = myself; // Just to avoid accidental NULL dereference
sip_printf ("Received stopped notification");
goto scan_wait;
/* Clear all waiting threads. Called from exceptions.cc prior to
* the main thread's dispatch to a signal handler function.
@ -366,15 +333,41 @@ proc_subproc (DWORD what, DWORD val)
case PROC_CLEARWAIT:
/* Clear all "wait"ing threads. */
sip_printf ("clear waiting threads");
clearing = 1;
case PROC_SIGCHLD:
scan_wait:
/* Scan the linked list of wait()ing threads. If a wait's parameters
* match this pid, then activate it.
*/
for (w = &waitq_head; w->next != NULL; w = w->next)
{
sip_printf ("clearing waiting thread, pid %d", w->next->pid);
w->next->status = -1; /* flag that a signal was received */
if (!SetEvent (w->next->ev))
system_printf ("Couldn't wake up wait event, %E");
if ((potential_match = checkstate (w)) > 0)
sip_printf ("released waiting thread");
else if (!clearing && potential_match < 0)
sip_printf ("only found non-terminated children");
else if (potential_match <= 0) // nothing matched
{
sip_printf ("waiting thread found no children");
HANDLE oldw = w->next->ev;
w->next->ev = NULL;
if (clearing)
w->next->status = -1; /* flag that a signal was received */
if (!SetEvent (oldw))
system_printf ("couldn't wake up wait event %p, %E", oldw);
w->next = w->next->next;
}
if (w->next == NULL)
break;
}
if (!clearing)
sip_printf ("finished processing terminated/stopped child");
else
{
waitq_head.next = NULL;
sip_printf ("finished clearing");
}
waitq_head.next = NULL;
sip_printf ("finished clearing");
break;
/* Handle a wait4() operation. Allocates an event for the calling
@ -1252,6 +1245,10 @@ wait_sig (VOID *)
/* A normal UNIX signal */
default:
sip_printf ("Got signal %d", sig);
int wasdispatched = sig_handle (sig);
dispatched |= wasdispatched;
if (sig == SIGCHLD && !wasdispatched)
proc_subproc (PROC_SIGCHLD, 0);
dispatched |= sig_handle (sig);
goto nextsig;
}