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-rw-r--r--librt/timer_create.c70
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