Patch from Paul Mundt (lethal) adding an initial librt implementation.

I then reworked the syscall handling and made minor cleanups.  With luck
I've not completely broken his patch...

1 files changed, 70 insertions, 0 deletions

diff --git a/librt/timer_create.c b/librt/timer_create.c
new file mode 100644
index 000000000..a49572792
--- /dev/null
+++ b/librt/timer_create.c
@@ -0,0 +1,70 @@
+/*
+ * timer_create.c - create a per-process timer.
+ */
+
+#include <errno.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <sys/syscall.h>
+
+#include "kernel-posix-timers.h"
+
+#ifdef __NR_timer_create
+
+#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
+
+#define __NR___syscall_timer_create __NR_timer_create
+static inline _syscall3(int, __syscall_timer_create, clockid_t, clock_id,
+	struct sigevent *, evp, kernel_timer_t *, ktimerid);
+
+/* Create a per-process timer */
+int timer_create(clockid_t clock_id, struct sigevent *evp, timer_t *timerid)
+{
+    int retval;
+    kernel_timer_t ktimerid;
+    struct sigevent local_evp;
+    struct timer *newp;
+
+    /* Notification via a thread is not supported yet */
+    if (__builtin_expect(evp->sigev_notify == SIGEV_THREAD, 1))
+	return -1;
+
+    /*
+     * We avoid allocating too much memory by basically using
+     * struct timer as a derived class with the first two elements
+     * being in the superclass. We only need these two elements here.
+     */
+    newp = (struct timer *) malloc(offsetof(struct timer, thrfunc));
+    if (newp == NULL)
+	return -1;	/* No memory */
+
+    if (evp == NULL) {
+	/*
+	 * The kernel has to pass up the timer ID which is a userlevel object.
+	 * Therefore we cannot leave it up to the kernel to determine it.
+	 */
+	local_evp.sigev_notify = SIGEV_SIGNAL;
+	local_evp.sigev_signo = SIGALRM;
+	local_evp.sigev_value.sival_ptr = newp;
+
+	evp = &local_evp;
+    }
+
+    retval = __syscall_timer_create(clock_id, evp, &ktimerid);
+    if (retval != -1) {
+	newp->sigev_notify = (evp != NULL ? evp->sigev_notify : SIGEV_SIGNAL);
+	newp->ktimerid = ktimerid;
+
+	*timerid = (timer_t) newp;
+    } else {
+	/* Cannot allocate the timer, fail */
+	free(newp);
+	retval = -1;
+    }
+
+    return retval;
+}
+
+#endif