Add a safepoint-based mechanism to avoid SIGALRM for the TIMER facility

[sbcl.git] / src / runtime / bsd-os.c

diff --git a/src/runtime/bsd-os.c b/src/runtime/bsd-os.c
index c2829b3..4c08b97 100644 (file)
--- a/src/runtime/bsd-os.c
+++ b/src/runtime/bsd-os.c
@@ -45,6 +45,11 @@
 #if defined LISP_FEATURE_GENCGC
 #include "gencgc-internal.h"
 #endif
+
+#if defined(LISP_FEATURE_SB_WTIMER) && !defined(LISP_FEATURE_DARWIN)
+# include <sys/event.h>
+#endif
+
 \f
 os_vm_size_t os_vm_page_size;
 
@@ -567,3 +572,60 @@ os_dlsym(void *handle, const char *symbol)
 }
 
 #endif
+
+#if defined(LISP_FEATURE_SB_WTIMER) && !defined(LISP_FEATURE_DARWIN)
+/*
+ * Waitable timer implementation for the safepoint-based (SIGALRM-free)
+ * timer facility using kqueue.
+ */
+int
+os_create_wtimer()
+{
+    int kq = kqueue();
+    if (kq == -1)
+        lose("os_create_wtimer: kqueue");
+    return kq;
+}
+
+int
+os_wait_for_wtimer(int kq)
+{
+    struct kevent ev;
+    int n;
+    if ( (n = kevent(kq, 0, 0, &ev, 1, 0)) == -1) {
+        if (errno != EINTR)
+            lose("os_wtimer_listen failed");
+        n = 0;
+    }
+    return n != 1;
+}
+
+void
+os_close_wtimer(int kq)
+{
+    if (close(kq) == -1)
+        lose("os_close_wtimer failed");
+}
+
+void
+os_set_wtimer(int kq, int sec, int nsec)
+{
+    long long msec
+        = ((long long) sec) * 1000 + (long long) (nsec+999999) / 1000000;
+    if (msec > INT_MAX) msec = INT_MAX;
+
+    struct kevent ev;
+    EV_SET(&ev, 1, EVFILT_TIMER, EV_ADD|EV_ENABLE|EV_ONESHOT, 0, (int)msec, 0);
+    if (kevent(kq, &ev, 1, 0, 0, 0) == -1)
+        perror("os_set_wtimer: kevent");
+}
+
+void
+os_cancel_wtimer(int kq)
+{
+    struct kevent ev;
+    EV_SET(&ev, 1, EVFILT_TIMER, EV_DISABLE, 0, 0, 0);
+    if (kevent(kq, &ev, 1, 0, 0, 0) == -1 && errno != ENOENT)
+        perror("os_cancel_wtimer: kevent");
+}
+#endif