1 files changed, 45 insertions, 0 deletions
diff --git a/src/user/knob/ipc.c b/src/user/knob/ipc.c
new file mode 100644
index 0000000..dbf1a22
--- /dev/null
+++ b/src/user/knob/ipc.c
@@ -0,0 +1,45 @@
+#include <pland/syscall.h>
+
+//blocking, returns early if other process is dead.
+//return value is number of bytes written.
+uint32_t try_send_ipc(_task_handle_t to, void *buffer, uint32_t size) {
+  const uint32_t size_backup = size;
+  while (size) {
+    uint32_t res = _ipc_send(to, size, buffer);
+    if (!res) {
+      _wait_ipc_read(to);
+      _yield_task();
+    }
+    else if (res == -1)
+      return size_backup - size;
+    else {
+      size -= res;
+      buffer += res;
+    }
+  }
+}
+
+//blocking, returns early if other process is dead.
+//return value is number of bytes read.
+uint32_t read_ipc(_task_handle_t from, void *buffer, uint32_t size) {
+  const uint32_t size_backup = size;
+  while (size) {
+    uint32_t res = _ipc_read(from, size, buffer);
+    if (!res) {
+      _wait_ipc_send(from);
+      _yield_task();
+    }
+    else if (res == -1)
+      return size_backup - size;
+    else {
+      size -= res;
+      buffer += res;
+    }
+  }
+}
+
+void flush_ipc(_task_handle_t from) {
+  uint8_t buf[4096];
+  while (_ipc_read(from, 4096, buf))
+    ;
+}
+\ No newline at end of file