[PATCH 1/2] Support for setitimer() on platforms lacking it

["Joachim Schmitz" <jojo@schmitz-digital.de>]

Implementation includes getitimer(), but for now it is static.
Supports ITIMER_REAL only.

Signed-off-by: Joachim Schmitz <jojo@schmitz-digital.de>
---
May need a header file for ITIMER_*, struct itimerval and the prototypes,
But for now, and the HP NonStop platform this isn't needed, here
<sys/time> has ITIMER_* and struct timeval, and the prototypes can 
vo into git-compat-util.h for now (Patch 2/2) 

 compat/itimer.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 compat/itimer.c

diff --git a/compat/itimer.c b/compat/itimer.c
new file mode 100644
index 0000000..713f1ff
--- /dev/null
+++ b/compat/itimer.c
@@ -0,0 +1,50 @@
+#include "../git-compat-util.h"
+
+static int git_getitimer(int which, struct itimerval *value)
+{
+	int ret = 0;
+
+	switch (which) {
+		case ITIMER_REAL:
+			value->it_value.tv_usec = 0;
+			value->it_value.tv_sec = alarm(0);
+			ret = 0; /* if alarm() fails, we get a SIGLIMIT */
+			break;
+		case ITIMER_VIRTUAL: /* FALLTHRU */
+		case ITIMER_PROF: errno = ENOTSUP; ret = -1; break;
+		default: errno = EINVAL; ret = -1;
+	}
+	return ret;
+}
+
+int git_setitimer(int which, const struct itimerval *value,
+				struct itimerval *ovalue)
+{
+	int ret = 0;
+
+	if (!value
+		|| value->it_value.tv_usec < 0
+		|| value->it_value.tv_usec > 1000000
+		|| value->it_value.tv_sec < 0) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	else if (ovalue)
+		if (!git_getitimer(which, ovalue))
+			return -1; /* errno set in git_getitimer() */
+
+	else
+	switch (which) {
+		case ITIMER_REAL:
+			alarm(value->it_value.tv_sec +
+				(value->it_value.tv_usec > 0) ? 1 : 0);
+			ret = 0; /* if alarm() fails, we get a SIGLIMIT */
+			break;
+		case ITIMER_VIRTUAL: /* FALLTHRU */
+		case ITIMER_PROF: errno = ENOTSUP; ret = -1; break;
+		default: errno = EINVAL; ret = -1;
+	}
+
+	return ret;
+}
-- 
1.7.12