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Export through gambit.h functions to mask child interrupts; unblock S…
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…IGCHLD when Gambit runtime system starts (this allows removal of special case handling of SIGCHLD when forking a process to avoid problems when subprocess is a Gambit program)
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@feeley
feeley committed Aug 29, 2017
1 parent 98d2cc0 commit 6587c2e
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Showing 11 changed files with 252 additions and 204 deletions.
34 changes: 25 additions & 9 deletions include/gambit.h.in
View file
Expand Up @@ -8002,9 +8002,10 @@ typedef struct ___mask_interrupts_state_struct
} ___mask_interrupts_state;


typedef ___mask_interrupts_state ___mask_os_interrupts_state;
typedef ___mask_interrupts_state ___mask_all_interrupts_state;
typedef ___mask_interrupts_state ___mask_user_interrupts_state;
typedef ___mask_interrupts_state ___mask_heartbeat_interrupts_state;
typedef ___mask_interrupts_state ___mask_child_interrupts_state;


/*---------------------------------------------------------------------------*/
Expand Down Expand Up @@ -10034,11 +10035,11 @@ typedef struct ___global_state_struct
void (*___enable_interrupts_pstate)
___P((___processor_state ___ps),
());
void (*___mask_os_interrupts_begin)
___P((___mask_os_interrupts_state *state),
void (*___mask_all_interrupts_begin)
___P((___mask_all_interrupts_state *state),
());
void (*___mask_os_interrupts_end)
___P((___mask_os_interrupts_state *state),
void (*___mask_all_interrupts_end)
___P((___mask_all_interrupts_state *state),
());
void (*___mask_user_interrupts_begin)
___P((___mask_user_interrupts_state *state),
Expand All @@ -10052,6 +10053,12 @@ typedef struct ___global_state_struct
void (*___mask_heartbeat_interrupts_end)
___P((___mask_heartbeat_interrupts_state *state),
());
void (*___mask_child_interrupts_begin)
___P((___mask_child_interrupts_state *state),
());
void (*___mask_child_interrupts_end)
___P((___mask_child_interrupts_state *state),
());
#ifndef ___DEBUG_ALLOC_MEM
void *(*___alloc_mem)
___P((___SIZE_T bytes),
Expand Down Expand Up @@ -11389,11 +11396,11 @@ ___IMP_FUNC(void,___enable_interrupts_pstate)
#endif

#ifndef ___INCLUDED_FROM_OS_SETUP
___IMP_FUNC(void,___mask_os_interrupts_begin)
___P((___mask_os_interrupts_state *state),
___IMP_FUNC(void,___mask_all_interrupts_begin)
___P((___mask_all_interrupts_state *state),
());
___IMP_FUNC(void,___mask_os_interrupts_end)
___P((___mask_os_interrupts_state *state),
___IMP_FUNC(void,___mask_all_interrupts_end)
___P((___mask_all_interrupts_state *state),
());
#endif

Expand All @@ -11415,6 +11422,15 @@ ___IMP_FUNC(void,___mask_heartbeat_interrupts_end)
());
#endif

#ifndef ___INCLUDED_FROM_OS_IO
___IMP_FUNC(void,___mask_child_interrupts_begin)
___P((___mask_child_interrupts_state *state),
());
___IMP_FUNC(void,___mask_child_interrupts_end)
___P((___mask_child_interrupts_state *state),
());
#endif

#ifndef ___INCLUDED_FROM_OS_BASE
#ifndef ___DEBUG_ALLOC_MEM
___IMP_FUNC(void *,___alloc_mem)
Expand Down
213 changes: 126 additions & 87 deletions lib/os_io.c
View file
Expand Up @@ -8127,6 +8127,125 @@ ___BOOL use_pty;)
#endif


#ifdef USE_POSIX

___HIDDEN void sigchld_signal_handler
___P((int sig),
(sig)
int sig;)
{
int save_errno = errno;
#ifdef USE_signal
___set_signal_handler (SIGCHLD, sigchld_signal_handler);
#endif

/*
* A SIGCHLD signal indicates that at least one child has changed
* status. There may be more than one because signals are not
* queued. For example during a period when the SIGCHLD signal is
* blocked several child processes can terminate and only one call
* to the SIGCHLD handler will occur when the SIGCHLD signal is
* unblocked. For this reason we must call waitpid in a loop, until
* the last call indicates that no other child process is available.
*/

for (;;)
{
int status;
___device *head;
pid_t pid = ___waitpid_no_EINTR (-1, &status, WNOHANG);

if (pid <= 0)
break;

/*
* Find the process device structure for the process which
* terminated, and save the exit status with the process device.
*/

head = ___global_device_group ()->list;

if (head != NULL)
{
___device *d = head->prev;

do
{
if (___device_kind (d) == ___PROCESS_DEVICE_KIND)
{
___device_process *dev = ___CAST(___device_process*,d);

if (dev->pid == pid)
{
if (WIFEXITED(status) || WIFSIGNALED(status))
___device_process_status_set (dev, status); /* ignore error */
break;
}
}
d = d->prev;
} while (d != head);
}
}
errno = save_errno;
}

#endif


___SCMOBJ ___setup_child_interrupt_handling ___PVOID
{
#ifdef USE_POSIX

___set_signal_handler (SIGPIPE, SIG_IGN);
___set_signal_handler (SIGCHLD, sigchld_signal_handler);

___thread_sigmask1 (SIG_UNBLOCK, SIGCHLD, NULL);

#endif

return ___FIX(___NO_ERR);
}


void ___cleanup_child_interrupt_handling ___PVOID
{
#ifdef USE_POSIX

___set_signal_handler (SIGPIPE, SIG_DFL);
___set_signal_handler (SIGCHLD, SIG_DFL);

___thread_sigmask1 (SIG_UNBLOCK, SIGCHLD, NULL);

#endif
}


___EXP_FUNC(void,___mask_child_interrupts_begin)
___P((___mask_child_interrupts_state *state),
(state)
___mask_child_interrupts_state *state;)
{
#ifdef USE_POSIX

___thread_sigmask1 (SIG_BLOCK, SIGCHLD, ___CAST(___sigset_type*,state)+2);

#endif
}


___EXP_FUNC(void,___mask_child_interrupts_end)
___P((___mask_child_interrupts_state *state),
(state)
___mask_child_interrupts_state *state;)
{
#ifdef USE_POSIX

___thread_sigmask (SIG_SETMASK, ___CAST(___sigset_type*,state)+2, NULL);

#endif
}


#ifdef USE_CreateProcess

#define ___ESCAPE_PROCESS_ARGS
Expand Down Expand Up @@ -8356,7 +8475,9 @@ int options;)
* sigchld_signal_handler will find it in the device group.
*/

___sigset_type oldmask = ___block_signal (SIGCHLD);
___mask_all_interrupts_state all_interrupts;

___mask_all_interrupts_begin (&all_interrupts);

fdp.input.writing_fd = -1;
fdp.output.reading_fd = -1;
Expand All @@ -8370,10 +8491,6 @@ int options;)
e = err_code_from_errno ();
else
{
___mask_os_interrupts_state os_interrupts;

___mask_os_interrupts_begin (&os_interrupts);

if ((pid = fork ()) < 0)
{
e = err_code_from_errno ();
Expand All @@ -8383,9 +8500,6 @@ int options;)
___close_half_duplex_pipe (&fdp.output, 2);
}
}

if (pid > 0)
___mask_os_interrupts_end (&os_interrupts);
}

if (e != ___FIX(___NO_ERR))
Expand All @@ -8398,9 +8512,7 @@ int options;)
{
/* child process */

___restore_sigmask (oldmask);

___cleanup_os_interrupt_handling ();
___cleanup_all_interrupt_handling ();

if (options & (STDIN_REDIR | STDOUT_REDIR | STDERR_REDIR))
{
Expand Down Expand Up @@ -8528,7 +8640,7 @@ int options;)
___close_half_duplex_pipe (&hdp_errno, 0);
}

___restore_sigmask (oldmask);
___mask_all_interrupts_end (&all_interrupts);

return e;

Expand Down Expand Up @@ -9748,71 +9860,6 @@ ___SCMOBJ options;)
}


#ifdef USE_POSIX

___HIDDEN void sigchld_signal_handler
___P((int sig),
(sig)
int sig;)
{
int save_errno = errno;
#ifdef USE_signal
___set_signal_handler (SIGCHLD, sigchld_signal_handler);
#endif

/*
* A SIGCHLD signal indicates that at least one child has changed
* status. There may be more than one because signals are not
* queued. For example during a period when the SIGCHLD signal is
* blocked several child processes can terminate and only one call
* to the SIGCHLD handler will occur when the SIGCHLD signal is
* unblocked. For this reason we must call waitpid in a loop, until
* the last call indicates that no other child process is available.
*/

for (;;)
{
int status;
___device *head;
pid_t pid = ___waitpid_no_EINTR (-1, &status, WNOHANG);

if (pid <= 0)
break;

/*
* Find the process device structure for the process which
* terminated, and save the exit status with the process device.
*/

head = ___global_device_group ()->list;

if (head != NULL)
{
___device *d = head->prev;

do
{
if (___device_kind (d) == ___PROCESS_DEVICE_KIND)
{
___device_process *dev = ___CAST(___device_process*,d);

if (dev->pid == pid)
{
if (WIFEXITED(status) || WIFSIGNALED(status))
___device_process_status_set (dev, status); /* ignore error */
break;
}
}
d = d->prev;
} while (d != head);
}
}
errno = save_errno;
}

#endif


/* - - - - - - - - - - - - - - - - - - */

/* Opening a TCP client. */
Expand Down Expand Up @@ -10752,11 +10799,7 @@ ___HIDDEN ___SCMOBJ io_module_setup ___PVOID

if ((e = ___device_group_setup (&___io_mod.dgroup)) == ___FIX(___NO_ERR))
{
#ifdef USE_POSIX

___set_signal_handler (SIGCHLD, sigchld_signal_handler);

#endif
___setup_child_interrupt_handling (); /* ignore error */

#ifdef USE_WIN32

Expand Down Expand Up @@ -10786,11 +10829,7 @@ ___HIDDEN ___SCMOBJ io_module_setup ___PVOID

___HIDDEN void io_module_cleanup ___PVOID
{
#ifdef USE_POSIX

___set_signal_handler (SIGCHLD, SIG_DFL);

#endif
___cleanup_child_interrupt_handling ();

#ifdef USE_WIN32

Expand Down
2 changes: 2 additions & 0 deletions lib/os_io.h
View file
Expand Up @@ -743,6 +743,8 @@ extern ___SCMOBJ ___os_device_process_status
___P((___SCMOBJ dev),
());

extern void ___cleanup_child_interrupt_handling ___PVOID;

/* - - - - - - - - - - - - - - - - - - */

/* Opening a TCP client. */
Expand Down

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