1 files changed, 68 insertions, 0 deletions
diff --git a/src/darwin/sem_darwin.c b/src/darwin/sem_darwin.c
new file mode 100644
index 0000000..0ace564
--- /dev/null
+++ b/src/darwin/sem_darwin.c
@@ -0,0 +1,68 @@
+// Copyright 2012-2022 David Robillard <d@drobilla.net>
+// SPDX-License-Identifier: ISC
+
+#include "zix/sem.h"
+
+#include "zix/status.h"
+
+#include <mach/mach.h>
+
+#include <stdint.h>
+#include <time.h>
+
+ZixStatus
+zix_sem_init(ZixSem* sem, unsigned val)
+{
+  return semaphore_create(
+           mach_task_self(), &sem->sem, SYNC_POLICY_FIFO, (int)val)
+           ? ZIX_STATUS_ERROR
+           : ZIX_STATUS_SUCCESS;
+}
+
+ZixStatus
+zix_sem_destroy(ZixSem* sem)
+{
+  return semaphore_destroy(mach_task_self(), sem->sem) ? ZIX_STATUS_ERROR
+                                                       : ZIX_STATUS_SUCCESS;
+}
+
+ZixStatus
+zix_sem_post(ZixSem* sem)
+{
+  return semaphore_signal(sem->sem) ? ZIX_STATUS_ERROR : ZIX_STATUS_SUCCESS;
+}
+
+ZixStatus
+zix_sem_wait(ZixSem* sem)
+{
+  kern_return_t r = 0;
+  while ((r = semaphore_wait(sem->sem)) && r == KERN_ABORTED) {
+    // Interrupted, try again
+  }
+
+  return r ? ZIX_STATUS_ERROR : ZIX_STATUS_SUCCESS;
+}
+
+ZixStatus
+zix_sem_try_wait(ZixSem* sem)
+{
+  const mach_timespec_t zero = {0, 0};
+  const kern_return_t   r    = semaphore_timedwait(sem->sem, zero);
+
+  return (r == KERN_SUCCESS)               ? ZIX_STATUS_SUCCESS
+         : (r == KERN_OPERATION_TIMED_OUT) ? ZIX_STATUS_UNAVAILABLE
+                                           : ZIX_STATUS_ERROR;
+}
+
+ZixStatus
+zix_sem_timed_wait(ZixSem*        sem,
+                   const uint32_t seconds,
+                   const uint32_t nanoseconds)
+{
+  const mach_timespec_t interval = {seconds, (clock_res_t)nanoseconds};
+  const kern_return_t   r        = semaphore_timedwait(sem->sem, interval);
+
+  return (r == KERN_SUCCESS)               ? ZIX_STATUS_SUCCESS
+         : (r == KERN_OPERATION_TIMED_OUT) ? ZIX_STATUS_TIMEOUT
+                                           : ZIX_STATUS_ERROR;
+}