[xbuild] Add support for multi-targeting arbitrary frameworks.
[mono.git] / support / signal.c
index c6df230b1b7ebba017835d6f96378f9b3fa1978c..abd76382f0bc5646fdef31b4e1060f083f26a28d 100644 (file)
@@ -4,6 +4,7 @@
  * 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 "map.h"
 #include "mph.h"
 
-#ifndef PLATFORM_WIN32
+#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
@@ -96,24 +103,28 @@ int Mono_Posix_FromRealTimeSignum (int offset, int *r)
 #endif /* defined (SIGRTMIN) && defined (SIGRTMAX) */
 }
 
-#ifndef PLATFORM_WIN32
+#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)
 {
@@ -121,10 +132,38 @@ Mono_Posix_Syscall_psignal (int sig, const char* s)
        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)
 {
@@ -137,8 +176,14 @@ default_handler (int signum)
                mph_int_inc (&h->count);
                fd = mph_int_get (&h->write_fd);
                if (fd > 0) {
+                       int j,pipecounter;
                        char c = signum;
-                       write (fd, &c, 1);
+                       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 */
+                       }
                }
        }
 }
@@ -148,16 +193,13 @@ static pthread_mutex_t signals_mutex = PTHREAD_MUTEX_INITIALIZER;
 void*
 Mono_Unix_UnixSignal_install (int sig)
 {
-       int i, mr;
+       int i;
        signal_info* h = NULL; 
        int have_handler = 0;
        void* handler = NULL;
 
-       mr = pthread_mutex_lock (&signals_mutex);
-       if (mr != 0) {
-               errno = mr;
+       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.*/
@@ -202,9 +244,10 @@ Mono_Unix_UnixSignal_install (int sig)
        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);
        }
 
-       pthread_mutex_unlock (&signals_mutex);
+       release_mutex (&signals_mutex);
 
        return h;
 }
@@ -225,13 +268,10 @@ int
 Mono_Unix_UnixSignal_uninstall (void* info)
 {
        signal_info* h;
-       int mr, r = -1;
+       int r = -1;
 
-       mr = pthread_mutex_lock (&signals_mutex);
-       if (mr != 0) {
-               errno = mr;
+       if (acquire_mutex (&signals_mutex) == -1)
                return -1;
-       }
 
        h = info;
 
@@ -249,28 +289,33 @@ Mono_Unix_UnixSignal_uninstall (void* info)
                h->signum = 0;
        }
 
-       pthread_mutex_unlock (&signals_mutex);
+       release_mutex (&signals_mutex);
 
        return r;
 }
 
 static int
-setup_pipes (signal_info** signals, int count, fd_set *read_fds, int *max_fd)
+setup_pipes (signal_info** signals, int count, struct pollfd *fd_structs, int *currfd)
 {
-       int i, r;
+       int i;
+       int r = 0;
        for (i = 0; i < count; ++i) {
                signal_info* h;
                int filedes[2];
 
-               if ((r = pipe (filedes)) != 0) {
-                       break;
-               }
                h = signals [i];
-               h->read_fd  = filedes [0];
-               h->write_fd = filedes [1];
-               if (h->read_fd > *max_fd)
-                       *max_fd = h->read_fd;
-               FD_SET (h->read_fd, read_fds);
+
+               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;
 }
@@ -281,17 +326,20 @@ teardown_pipes (signal_info** signals, int count)
        int i;
        for (i = 0; i < count; ++i) {
                signal_info* h = signals [i];
-               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;
+
+               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 max_fd, fd_set* read_fds, int timeout)
+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 {
@@ -302,9 +350,8 @@ wait_for_any (signal_info** signals, int count, int max_fd, fd_set* read_fds, in
                        tv.tv_usec = (timeout % 1000)*1000;
                        ptv = &tv;
                }
-
-               r = select (max_fd + 1, read_fds, NULL, NULL, ptv);
-       } while (r == -1 && errno == EINTR);
+               r = poll (fd_structs, count, timeout);
+       } while (keep_trying (r) && !shutting_down ());
 
        idx = -1;
        if (r == 0)
@@ -313,9 +360,12 @@ wait_for_any (signal_info** signals, int count, int max_fd, fd_set* read_fds, in
                int i;
                for (i = 0; i < count; ++i) {
                        signal_info* h = signals [i];
-                       if (FD_ISSET (h->read_fd, read_fds)) {
+                       if (fd_structs[i].revents & POLLIN) {
+                               int r;
                                char c;
-                               read (h->read_fd, &c, 1); /* ignore any error */
+                               do {
+                                       r = read (h->read_fd, &c, 1);
+                               } while (keep_trying (r) && !shutting_down ());
                                if (idx == -1)
                                        idx = i;
                        }
@@ -331,34 +381,39 @@ wait_for_any (signal_info** signals, int count, int max_fd, fd_set* read_fds, in
  *          index into _signals array of signal that was generated on success
  */
 int
-Mono_Unix_UnixSignal_WaitAny (void** _signals, int count, int timeout /* milliseconds */)
+Mono_Unix_UnixSignal_WaitAny (void** _signals, int count, int timeout /* milliseconds */, Mono_Posix_RuntimeIsShuttingDown shutting_down)
 {
-       fd_set read_fds;
-       int mr, r;
-       int max_fd = 0;
+       int r;
+       int currfd = 0;
+       struct pollfd fd_structs[NUM_SIGNALS];
 
        signal_info** signals = (signal_info**) _signals;
 
-       mr = pthread_mutex_lock (&signals_mutex);
-       if (mr != 0) {
-               errno = mr;
+       if (count > NUM_SIGNALS)
                return -1;
-       }
 
-       FD_ZERO (&read_fds);
+       if (acquire_mutex (&signals_mutex) == -1)
+               return -1;
+
+       r = setup_pipes (signals, count, &fd_structs[0], &currfd);
+
+       release_mutex (&signals_mutex);
 
-       r = setup_pipes (signals, count, &read_fds, &max_fd);
        if (r == 0) {
-               r = wait_for_any (signals, count, max_fd, &read_fds, timeout);
+               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);
 
-       pthread_mutex_unlock (&signals_mutex);
+       release_mutex (&signals_mutex);
 
        return r;
 }
 
-#endif /* ndef PLATFORM_WIN32 */
+#endif /* ndef HOST_WIN32 */
 
 
 G_END_DECLS