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/*
* <signal.h> wrapper functions.
*
* Authors:
* Jonathan Pryor (jonpryor@vt.edu)
* Jonathan Pryor (jpryor@novell.com)
* Tim Jenks (tim.jenks@realtimeworlds.com)
*
* Copyright (C) 2004-2005 Jonathan Pryor
* Copyright (C) 2008 Novell, Inc.
*/
#include <signal.h>
#include "map.h"
#include "mph.h"
#ifndef HOST_WIN32
#include <sys/time.h>
#include <sys/types.h>
#if defined(__APPLE__)
#include "fakepoll.h"
#else
#include <poll.h>
#endif
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <mono/io-layer/atomic.h>
#include <mono/metadata/appdomain.h>
#endif
G_BEGIN_DECLS
typedef void (*mph_sighandler_t)(int);
typedef struct Mono_Unix_UnixSignal_SignalInfo signal_info;
#ifndef HOST_WIN32
static int count_handlers (int signum);
#endif
void*
Mono_Posix_Stdlib_SIG_DFL (void)
{
return SIG_DFL;
}
void*
Mono_Posix_Stdlib_SIG_ERR (void)
{
return SIG_ERR;
}
void*
Mono_Posix_Stdlib_SIG_IGN (void)
{
return SIG_IGN;
}
void
Mono_Posix_Stdlib_InvokeSignalHandler (int signum, void *handler)
{
mph_sighandler_t _h = (mph_sighandler_t) handler;
_h (signum);
}
int Mono_Posix_SIGRTMIN (void)
{
#ifdef SIGRTMIN
return SIGRTMIN;
#else /* def SIGRTMIN */
return -1;
#endif /* ndef SIGRTMIN */
}
int Mono_Posix_SIGRTMAX (void)
{
#ifdef SIGRTMAX
return SIGRTMAX;
#else /* def SIGRTMAX */
return -1;
#endif /* ndef SIGRTMAX */
}
int Mono_Posix_FromRealTimeSignum (int offset, int *r)
{
if (NULL == r) {
errno = EINVAL;
return -1;
}
*r = 0;
#if defined (SIGRTMIN) && defined (SIGRTMAX)
if ((offset < 0) || (SIGRTMIN > SIGRTMAX - offset)) {
errno = EINVAL;
return -1;
}
*r = SIGRTMIN+offset;
return 0;
#else /* defined (SIGRTMIN) && defined (SIGRTMAX) */
# ifdef ENOSYS
errno = ENOSYS;
# endif /* ENOSYS */
return -1;
#endif /* defined (SIGRTMIN) && defined (SIGRTMAX) */
}
#ifndef HOST_WIN32
#ifdef WAPI_ATOMIC_ASM
#define mph_int_get(p) InterlockedExchangeAdd ((p), 0)
#define mph_int_inc(p) InterlockedIncrement ((p))
#define mph_int_dec_test(p) (InterlockedDecrement ((p)) == 0)
#define mph_int_set(p,o,n) InterlockedExchange ((p), (n))
#elif GLIB_CHECK_VERSION(2,4,0)
#define mph_int_get(p) g_atomic_int_get ((p))
#define mph_int_inc(p) do {g_atomic_int_inc ((p));} while (0)
#define mph_int_dec_test(p) g_atomic_int_dec_and_test ((p))
#define mph_int_set(p,o,n) do { \
while (!g_atomic_int_compare_and_exchange ((p), (o), (n))) {} \
} while (0)
#else
#define mph_int_get(p) (*(p))
#define mph_int_inc(p) do { (*(p))++; } while (0)
#define mph_int_dec_test(p) (--(*(p)) == 0)
#define mph_int_set(p,o,n) do { *(p) = n; } while (0)
#endif
#if HAVE_PSIGNAL
int
Mono_Posix_Syscall_psignal (int sig, const char* s)
{
errno = 0;
psignal (sig, s);
return errno == 0 ? 0 : -1;
}
#endif /* def HAVE_PSIGNAL */
#define NUM_SIGNALS 64
static signal_info signals[NUM_SIGNALS];
static int acquire_mutex (pthread_mutex_t *mutex)
{
int mr;
while ((mr = pthread_mutex_lock (mutex)) == EAGAIN) {
/* try to acquire again */
}
if ((mr != 0) && (mr != EDEADLK)) {
errno = mr;
return -1;
}
return 0;
}
static void release_mutex (pthread_mutex_t *mutex)
{
int mr;
while ((mr = pthread_mutex_unlock (mutex)) == EAGAIN) {
/* try to release mutex again */
}
}
static inline int
keep_trying (int r)
{
return r == -1 && errno == EINTR;
}
static void
default_handler (int signum)
{
int i;
for (i = 0; i < NUM_SIGNALS; ++i) {
int fd;
signal_info* h = &signals [i];
if (mph_int_get (&h->signum) != signum)
continue;
mph_int_inc (&h->count);
fd = mph_int_get (&h->write_fd);
if (fd > 0) {
int j,pipecounter;
char c = signum;
pipecounter = mph_int_get (&h->pipecnt);
for (j = 0; j < pipecounter; ++j) {
int r;
do { r = write (fd, &c, 1); } while (keep_trying (r));
fsync (fd); /* force */
}
}
}
}
static pthread_mutex_t signals_mutex = PTHREAD_MUTEX_INITIALIZER;
void*
Mono_Unix_UnixSignal_install (int sig)
{
int i;
signal_info* h = NULL;
int have_handler = 0;
void* handler = NULL;
if (acquire_mutex (&signals_mutex) == -1)
return NULL;
#if defined (SIGRTMIN) && defined (SIGRTMAX)
/*The runtime uses some rt signals for itself so it's important to not override them.*/
if (sig >= SIGRTMIN && sig <= SIGRTMAX && count_handlers (sig) == 0) {
struct sigaction sinfo;
sigaction (sig, NULL, &sinfo);
if (sinfo.sa_handler != SIG_DFL || (void*)sinfo.sa_sigaction != (void*)SIG_DFL) {
pthread_mutex_unlock (&signals_mutex);
errno = EADDRINUSE;
return NULL;
}
}
#endif /*defined (SIGRTMIN) && defined (SIGRTMAX)*/
for (i = 0; i < NUM_SIGNALS; ++i) {
if (h == NULL && signals [i].signum == 0) {
h = &signals [i];
h->handler = signal (sig, default_handler);
if (h->handler == SIG_ERR) {
h->handler = NULL;
h = NULL;
break;
}
else {
h->have_handler = 1;
}
}
if (!have_handler && signals [i].signum == sig &&
signals [i].handler != default_handler) {
have_handler = 1;
handler = signals [i].handler;
}
if (h && have_handler)
break;
}
if (h && have_handler) {
h->have_handler = 1;
h->handler = handler;
}
if (h) {
mph_int_set (&h->count, h->count, 0);
mph_int_set (&h->signum, h->signum, sig);
mph_int_set (&h->pipecnt, h->pipecnt, 0);
}
release_mutex (&signals_mutex);
return h;
}
static int
count_handlers (int signum)
{
int i;
int count = 0;
for (i = 0; i < NUM_SIGNALS; ++i) {
if (signals [i].signum == signum)
++count;
}
return count;
}
int
Mono_Unix_UnixSignal_uninstall (void* info)
{
signal_info* h;
int r = -1;
if (acquire_mutex (&signals_mutex) == -1)
return -1;
h = info;
if (h == NULL || h < signals || h > &signals [NUM_SIGNALS])
errno = EINVAL;
else {
/* last UnixSignal -- we can unregister */
if (h->have_handler && count_handlers (h->signum) == 1) {
mph_sighandler_t p = signal (h->signum, h->handler);
if (p != SIG_ERR)
r = 0;
h->handler = NULL;
h->have_handler = 0;
}
h->signum = 0;
}
release_mutex (&signals_mutex);
return r;
}
static int
setup_pipes (signal_info** signals, int count, struct pollfd *fd_structs, int *currfd)
{
int i;
int r = 0;
for (i = 0; i < count; ++i) {
signal_info* h;
int filedes[2];
h = signals [i];
if (mph_int_get (&h->pipecnt) == 0) {
if ((r = pipe (filedes)) != 0) {
break;
}
h->read_fd = filedes [0];
h->write_fd = filedes [1];
}
mph_int_inc (&h->pipecnt);
fd_structs[*currfd].fd = h->read_fd;
fd_structs[*currfd].events = POLLIN;
++(*currfd);
}
return r;
}
static void
teardown_pipes (signal_info** signals, int count)
{
int i;
for (i = 0; i < count; ++i) {
signal_info* h = signals [i];
if (mph_int_dec_test (&h->pipecnt)) {
if (h->read_fd != 0)
close (h->read_fd);
if (h->write_fd != 0)
close (h->write_fd);
h->read_fd = 0;
h->write_fd = 0;
}
}
}
static int
wait_for_any (signal_info** signals, int count, int *currfd, struct pollfd* fd_structs, int timeout, Mono_Posix_RuntimeIsShuttingDown shutting_down)
{
int r, idx;
do {
struct timeval tv;
struct timeval *ptv = NULL;
if (timeout != -1) {
tv.tv_sec = timeout / 1000;
tv.tv_usec = (timeout % 1000)*1000;
ptv = &tv;
}
r = poll (fd_structs, count, timeout);
} while (keep_trying (r) && !shutting_down ());
idx = -1;
if (r == 0)
idx = timeout;
else if (r > 0) {
int i;
for (i = 0; i < count; ++i) {
signal_info* h = signals [i];
if (fd_structs[i].revents & POLLIN) {
int r;
char c;
do {
r = read (h->read_fd, &c, 1);
} while (keep_trying (r) && !shutting_down ());
if (idx == -1)
idx = i;
}
}
}
return idx;
}
/*
* returns: -1 on error:
* timeout on timeout
* index into _signals array of signal that was generated on success
*/
int
Mono_Unix_UnixSignal_WaitAny (void** _signals, int count, int timeout /* milliseconds */, Mono_Posix_RuntimeIsShuttingDown shutting_down)
{
int r;
int currfd = 0;
struct pollfd fd_structs[NUM_SIGNALS];
signal_info** signals = (signal_info**) _signals;
if (count > NUM_SIGNALS)
return -1;
if (acquire_mutex (&signals_mutex) == -1)
return -1;
r = setup_pipes (signals, count, &fd_structs[0], &currfd);
release_mutex (&signals_mutex);
if (r == 0) {
r = wait_for_any (signals, count, &currfd, &fd_structs[0], timeout, shutting_down);
}
if (acquire_mutex (&signals_mutex) == -1)
return -1;
teardown_pipes (signals, count);
release_mutex (&signals_mutex);
return r;
}
#endif /* ndef HOST_WIN32 */
G_END_DECLS
/*
* vim: noexpandtab
*/
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