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This closes patch: 

[ 960406 ] unblock signals in threads

although the changes do not correspond exactly to any patch attached to
that report.

Non-main threads no longer have all signals masked.

A different interface to readline is used.

The handling of signals inside calls to PyOS_Readline is now rather
different.

These changes are all a bit scary!  Review and cross-platform testing
much appreciated.
This commit is contained in:
Michael W. Hudson 2004-07-07 17:44:12 +00:00
parent e3c330b42a
commit 30ea2f223f
10 changed files with 1576 additions and 3095 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
Misc/ACKS
View File

@ -327,6 +327,7 @@ Hannu Krosing
Andrew Kuchling
Vladimir Kushnir
Cameron Laird
Andrew Langmead
Detlef Lannert
Soren Larsen
Piers Lauder

97
Modules/readline.c
View File

@ -656,6 +656,66 @@ setup_readline(void)
#endif
}
/* Wrapper around GNU readline that handles signals differently. */
#if defined(HAVE_RL_CALLBACK) && defined(HAVE_SELECT)
static char *completed_input_string;
static void
rlhandler(char *text)
{
completed_input_string = text;
rl_callback_handler_remove();
}
extern PyThreadState* _PyOS_ReadlineTState;
static char *
readline_until_enter_or_signal(char *prompt, int *signal)
{
char * not_done_reading = "";
fd_set selectset;
*signal = 0;
#ifdef HAVE_RL_CATCH_SIGNAL
rl_catch_signals = 0;
#endif
rl_callback_handler_install (prompt, rlhandler);
FD_ZERO(&selectset);
FD_SET(fileno(rl_instream), &selectset);
completed_input_string = not_done_reading;
while(completed_input_string == not_done_reading) {
int has_input;
has_input = select(fileno(rl_instream) + 1, &selectset,
NULL, NULL, NULL);
if(has_input > 0) {
rl_callback_read_char();
}
else if (errno == EINTR) {
int s;
PyEval_RestoreThread(_PyOS_ReadlineTState);
s = PyErr_CheckSignals();
PyThreadState_Swap(NULL);
if (s < 0) {
rl_free_line_state();
rl_cleanup_after_signal();
rl_callback_handler_remove();
*signal = 1;
completed_input_string = NULL;
}
}
}
return completed_input_string;
}
#else
/* Interrupt handler */
@ -669,14 +729,13 @@ onintr(int sig)
}
/* Wrapper around GNU readline that handles signals differently. */
static char *
call_readline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
readline_until_enter_or_signal(char *prompt, int *signal)
{
size_t n;
char *p, *q;
PyOS_sighandler_t old_inthandler;
char *p;
*signal = 0;
old_inthandler = PyOS_setsig(SIGINT, onintr);
if (setjmp(jbuf)) {
@ -685,8 +744,24 @@ call_readline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
sigrelse(SIGINT);
#endif
PyOS_setsig(SIGINT, old_inthandler);
*signal = 1;
return NULL;
}
p = readline(prompt);
PyOS_setsig(SIGINT, old_inthandler);
return p;
}
#endif /*defined(HAVE_RL_CALLBACK) && defined(HAVE_SELECT) */
static char *
call_readline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
{
size_t n;
char *p, *q;
int signal;
rl_event_hook = PyOS_InputHook;
if (sys_stdin != rl_instream || sys_stdout != rl_outstream) {
@ -697,16 +772,22 @@ call_readline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
#endif
}
p = readline(prompt);
PyOS_setsig(SIGINT, old_inthandler);
p = readline_until_enter_or_signal(prompt, &signal);
/* we got an interrupt signal */
if(signal) {
return NULL;
}
/* We must return a buffer allocated with PyMem_Malloc. */
/* We got an EOF, return a empty string. */
if (p == NULL) {
p = PyMem_Malloc(1);
if (p != NULL)
*p = '\0';
return p;
}
/* we have a valid line */
n = strlen(p);
if (n > 0) {
char *line;

41
Parser/myreadline.c
View File

@ -19,6 +19,14 @@
extern char* vms__StdioReadline(FILE *sys_stdin, FILE *sys_stdout, char *prompt);
#endif
PyThreadState* _PyOS_ReadlineTState;
#if WITH_THREAD
#include "pythread.h"
static PyThread_type_lock _PyOS_ReadlineLock = NULL;
#endif
int (*PyOS_InputHook)(void) = NULL;
#ifdef RISCOS
@ -73,10 +81,13 @@ my_fgets(char *buf, int len, FILE *fp)
}
#ifdef EINTR
if (errno == EINTR) {
if (PyOS_InterruptOccurred()) {
return 1; /* Interrupt */
int s;
PyEval_RestoreThread(_PyOS_ReadlineTState);
s = PyErr_CheckSignals();
PyThreadState_Swap(NULL);
if (s < 0) {
return 1;
}
continue;
}
#endif
if (PyOS_InterruptOccurred()) {
@ -155,6 +166,13 @@ PyOS_Readline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
{
char *rv;
if (_PyOS_ReadlineTState == PyThreadState_GET()) {
PyErr_SetString(PyExc_RuntimeError,
"can't re-enter readline");
return NULL;
}
if (PyOS_ReadlineFunctionPointer == NULL) {
#ifdef __VMS
PyOS_ReadlineFunctionPointer = vms__StdioReadline;
@ -162,8 +180,18 @@ PyOS_Readline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
PyOS_ReadlineFunctionPointer = PyOS_StdioReadline;
#endif
}
#if WITH_THREAD
if (_PyOS_ReadlineLock == NULL) {
_PyOS_ReadlineLock = PyThread_allocate_lock();
}
#endif
_PyOS_ReadlineTState = PyThreadState_GET();
Py_BEGIN_ALLOW_THREADS
#if WITH_THREAD
PyThread_acquire_lock(_PyOS_ReadlineLock, 1);
#endif
/* This is needed to handle the unlikely case that the
* interpreter is in interactive mode *and* stdin/out are not
@ -176,5 +204,12 @@ PyOS_Readline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
rv = (*PyOS_ReadlineFunctionPointer)(sys_stdin, sys_stdout,
prompt);
Py_END_ALLOW_THREADS
#if WITH_THREAD
PyThread_release_lock(_PyOS_ReadlineLock);
#endif
_PyOS_ReadlineTState = NULL;
return rv;
}

3
Python/bltinmodule.c
View File

@ -1589,7 +1589,8 @@ builtin_raw_input(PyObject *self, PyObject *args)
prompt);
Py_XDECREF(po);
if (s == NULL) {
PyErr_SetNone(PyExc_KeyboardInterrupt);
if (!PyErr_Occurred())
PyErr_SetNone(PyExc_KeyboardInterrupt);
return NULL;
}
if (*s == '\0') {

2
Python/ceval.c
View File

@ -318,7 +318,7 @@ static volatile int things_to_do = 0;
int
Py_AddPendingCall(int (*func)(void *), void *arg)
{
static int busy = 0;
static volatile int busy = 0;
int i, j;
/* XXX Begin critical section */
/* XXX If you want this to be safe against nested

3
Python/pythonrun.c
View File

@ -1435,7 +1435,8 @@ err_input(perrdetail *err)
msg = "EOL while scanning single-quoted string";
break;
case E_INTR:
PyErr_SetNone(PyExc_KeyboardInterrupt);
if (!PyErr_Occurred())
PyErr_SetNone(PyExc_KeyboardInterrupt);
Py_XDECREF(v);
return;
case E_NOMEM:

11
Python/thread_pthread.h
View File

@ -119,7 +119,6 @@ PyThread_start_new_thread(void (*func)(void *), void *arg)
{
pthread_t th;
int status;
sigset_t oldmask, newmask;
#if defined(THREAD_STACK_SIZE) || defined(PTHREAD_SYSTEM_SCHED_SUPPORTED)
pthread_attr_t attrs;
#endif
@ -137,13 +136,6 @@ PyThread_start_new_thread(void (*func)(void *), void *arg)
pthread_attr_setscope(&attrs, PTHREAD_SCOPE_SYSTEM);
#endif
/* Mask all signals in the current thread before creating the new
* thread. This causes the new thread to start with all signals
* blocked.
*/
sigfillset(&newmask);
SET_THREAD_SIGMASK(SIG_BLOCK, &newmask, &oldmask);
status = pthread_create(&th,
#if defined(THREAD_STACK_SIZE) || defined(PTHREAD_SYSTEM_SCHED_SUPPORTED)
&attrs,
@ -154,9 +146,6 @@ PyThread_start_new_thread(void (*func)(void *), void *arg)
(void *)arg
);
/* Restore signal mask for original thread */
SET_THREAD_SIGMASK(SIG_SETMASK, &oldmask, NULL);
#if defined(THREAD_STACK_SIZE) || defined(PTHREAD_SYSTEM_SCHED_SUPPORTED)
pthread_attr_destroy(&attrs);
#endif

4491
configure vendored
View File

File diff suppressed because it is too large Load Diff

16
configure.in
View File

@ -2783,6 +2783,11 @@ then
[Define this if you have flockfile(), getc_unlocked(), and funlockfile()])
fi
# check for readline 2.1
AC_CHECK_LIB(readline, rl_callback_handler_install,
AC_DEFINE(HAVE_RL_CALLBACK, 1,
[Define if you have readline 2.1]), , -ltermcap)
# check for readline 2.2
AC_TRY_CPP([#include <readline/readline.h>],
have_readline=yes, have_readline=no)
@ -2804,6 +2809,17 @@ AC_CHECK_LIB(readline, rl_completion_matches,
AC_DEFINE(HAVE_RL_COMPLETION_MATCHES, 1,
[Define if you have readline 4.2]), , -ltermcap)
# also in readline 4.2
AC_TRY_CPP([#include <readline/readline.h>],
have_readline=yes, have_readline=no)
if test $have_readline = yes
then
AC_EGREP_HEADER([extern int rl_catch_signals;],
[readline/readline.h],
AC_DEFINE(HAVE_RL_CATCH_SIGNAL, 1,
[Define if you can turn off readline's signal handling.]), )
fi
AC_MSG_CHECKING(for broken nice())
AC_CACHE_VAL(ac_cv_broken_nice, [
AC_TRY_RUN([

6
pyconfig.h.in
View File

@ -359,6 +359,12 @@
/* Define to 1 if you have the `realpath' function. */
#undef HAVE_REALPATH
/* Define if you have readline 2.1 */
#undef HAVE_RL_CALLBACK
/* Define if you can turn off readline's signal handling. */
#undef HAVE_RL_CATCH_SIGNAL
/* Define if you have readline 2.2 */
#undef HAVE_RL_COMPLETION_APPEND_CHARACTER