shared data and pass fps to main thread

src/shared.c

@@ -0,0 +1,51 @@
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "shared.h"
+#include "types.h"
+
+static void *open_shared(const char *key, size_t size, int *fd) {
+  *fd = shm_open(key, O_CREAT | O_RDWR, S_IRUSR | S_IWUSR);
+  ftruncate(*fd, size);
+
+  return mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, *fd, 0);
+}
+
+static void close_shared(void *shared, size_t size, int fd) {
+  munmap(shared, size);
+  close(fd);
+}
+
+SharedUint *shared_init_uint(const char *key, unsigned int initial_value) {
+  int shared_fd;
+  SharedUint *shared;
+
+  shared = open_shared(key, sizeof(SharedUint), &shared_fd);
+
+  shared->fd = shared_fd;
+  shared->value = initial_value;
+
+  return shared;
+}
+
+void shared_close_uint(SharedUint *shared) {
+  close_shared(shared, sizeof(SharedUint), shared->fd);
+}
+
+SharedBool *shared_init_bool(const char *key, bool initial_value) {
+  int shared_fd;
+  SharedBool *shared;
+
+  shared = open_shared(key, sizeof(SharedBool), &shared_fd);
+
+  shared->fd = shared_fd;
+  shared->value = initial_value;
+
+  return shared;
+}
+
+void shared_close_bool(SharedBool *shared) {
+  close_shared(shared, sizeof(SharedBool), shared->fd);
+}