1 files changed, 109 insertions, 0 deletions
diff --git a/rts/posix/Ticker.c b/rts/posix/Ticker.c
new file mode 100644
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--- /dev/null
+++ b/rts/posix/Ticker.c
@@ -0,0 +1,109 @@
+/* -----------------------------------------------------------------------------
+ *
+ * (c) The GHC Team, 1995-2007
+ *
+ * Interval timer for profiling and pre-emptive scheduling.
+ *
+ * ---------------------------------------------------------------------------*/
+
+/*
+ * The interval timer is used for profiling and for context switching in the
+ * threaded build.  Though POSIX 1003.1b includes a standard interface for
+ * such things, no one really seems to be implementing them yet.  Even
+ * Solaris 2.3 only seems to provide support for @CLOCK_REAL@, whereas we're
+ * keen on getting access to @CLOCK_VIRTUAL@.
+ *
+ * Hence, we often use the old-fashioned @setitimer@ that just about everyone
+ * seems to support.  So much for standards.
+ *
+ * If you are looking for Itimer.c then this is the right file. I renamed it
+ * Ticker.c for consistency.
+ */
+
+#include "PosixSource.h"
+
+/* We've defined _POSIX_SOURCE via "PosixSource.h", and yet still use
+   some non-POSIX features.  With _POSIX_SOURCE defined, visibility of
+   non-POSIX extension prototypes requires _DARWIN_C_SOURCE on Mac OS X,
+   __BSD_VISIBLE on FreeBSD and DragonflyBSD, and _NetBSD_SOURCE on
+   NetBSD.  Otherwise, for example, code using pthread_setname_np(3) and
+   variants will not compile.  We must therefore define the additional
+   macros that expose non-POSIX APIs early, before any of the relevant
+   system headers are included via "Rts.h".
+
+   An alternative approach could be to write portable wrappers or stubs for all
+   the non-posix functions in a C-module that does not include "PosixSource.h",
+   and then use only POSIX features and the portable wrapper functions in all
+   other C-modules. */
+#include "ghcconfig.h"
+#if defined(freebsd_HOST_OS) || defined(dragonfly_HOST_OS)
+#define __BSD_VISIBLE   1
+#endif
+#if defined(darwin_HOST_OS)
+#define _DARWIN_C_SOURCE 1
+#endif
+#if defined(netbsd_HOST_OS)
+#define _NETBSD_SOURCE 1
+#endif
+
+#include "Rts.h"
+
+/*
+ * It used to be that timer_create doesn't exist on iOS and setitimer doesn't fire on iOS
+ * during debugging. See #7723. Seems to be an issue with signals.
+ *
+ * We also want to avoid using alarm signals, as these can interrupt system calls (#10840)
+ * or can be overwritten by user code.
+ *
+ * So we are using the pthread based implementation.
+ */
+#if defined(ios_HOST_OS) || defined(darwin_HOST_OS)
+#define USE_PTHREAD_FOR_ITIMER
+#endif
+
+/*
+ * On Linux in the threaded RTS we can use timerfd_* (introduced in Linux
+ * 2.6.25) and a thread instead of alarm signals. It avoids the risk of
+ * interrupting syscalls (see #10840) and the risk of being accidentally
+ * modified in user code using signals.
+ */
+#if defined(linux_HOST_OS) && defined(THREADED_RTS) && HAVE_SYS_TIMERFD_H
+#define USE_PTHREAD_FOR_ITIMER
+#endif
+
+#if defined(freebsd_HOST_OS)
+#define USE_PTHREAD_FOR_ITIMER
+#endif
+
+#if defined(netbsd_HOST_OS)
+#define USE_PTHREAD_FOR_ITIMER
+#endif
+
+#if defined(solaris2_HOST_OS)
+/* USE_TIMER_CREATE is usually disabled for Solaris. In fact it is
+   supported well on this OS, but requires additional privilege. When
+   user does not have it, then the testing configure program fails
+   which results in USE_TIMER_CREATE not defined.
+   On the other hand when we cross-compile, then we optimistically
+   assume usage of timer_create function. The problem is that if we
+   cross compile for example from i386-solaris2 to x86_64-solaris2,
+   then the build fails with error like this:
+
+ghc-stage2: timer_create: Not owner
+
+   which happens on first ghc-stage2 invocation. So to support
+   cross-compilation to Solaris we manually undefine USE_TIMER_CREATE
+   here */
+#undef USE_TIMER_CREATE
+#endif /* solaris2_HOST_OS */
+
+// Select the variant to use
+#if defined(USE_PTHREAD_FOR_ITIMER)
+#include "ticker/Pthread.c"
+#elif defined(USE_TIMER_CREATE)
+ //#error TimerCreate
+#include "ticker/TimerCreate.c"
+#else
+ //#error Setitimer
+#include "ticker/Setitimer.c"
+#endif