unix, windows: add uv_fs_poll_getpath

include/uv.h

@@ -1932,6 +1932,13 @@ UV_EXTERN int uv_fs_poll_start(uv_fs_poll_t* handle,
 
 UV_EXTERN int uv_fs_poll_stop(uv_fs_poll_t* handle);
 
+/*
+ * Get the path befing monitored by the handle. The buffer must be preallocated
+ * by the user. Returns 0 on success or an error code < 0 in case of failure.
+ * On sucess, `buf` will contain the path and `len` its length.
+ */
+UV_EXTERN int uv_fs_poll_getpath(uv_fs_poll_t* handle, char* buf, size_t* len);
+
 
 /*
  * UNIX signal handling on a per-event loop basis. The implementation is not

src/fs-poll.c

@@ -118,6 +118,31 @@ int uv_fs_poll_stop(uv_fs_poll_t* handle) {
 }
 
 
+int uv_fs_poll_getpath(uv_fs_poll_t* handle, char* buf, size_t* len) {
+  struct poll_ctx* ctx;
+  size_t required_len;
+
+  if (!uv__is_active(handle)) {
+    *len = 0;
+    return UV_EINVAL;
+  }
+
+  ctx = handle->poll_ctx;
+  assert(ctx != NULL);
+
+  required_len = strlen(ctx->path) + 1;
+  if (required_len > *len) {
+    *len = 0;
+    return UV_ENOBUFS;
+  }
+
+  memcpy(buf, ctx->path, required_len);
+  *len = required_len;
+
+  return 0;
+}
+
+
 void uv__fs_poll_close(uv_fs_poll_t* handle) {
   uv_fs_poll_stop(handle);
 }

test/test-fs-poll.c

@@ -33,6 +33,11 @@ static void poll_cb(uv_fs_poll_t* handle,
                     const uv_stat_t* prev,
                     const uv_stat_t* curr);
 
+static void poll_cb_fail(uv_fs_poll_t* handle,
+                         int status,
+                         const uv_stat_t* prev,
+                         const uv_stat_t* curr);
+
 static uv_fs_poll_t poll_handle;
 static uv_timer_t timer_handle;
 static uv_loop_t* loop;
@@ -72,6 +77,14 @@ static void timer_cb(uv_timer_t* handle, int status) {
 }
 
 
+static void poll_cb_fail(uv_fs_poll_t* handle,
+                         int status,
+                         const uv_stat_t* prev,
+                         const uv_stat_t* curr) {
+  ASSERT(0 && "fail_cb called");
+}
+
+
 static void poll_cb(uv_fs_poll_t* handle,
                     int status,
                     const uv_stat_t* prev,
@@ -144,3 +157,29 @@ TEST_IMPL(fs_poll) {
   MAKE_VALGRIND_HAPPY();
   return 0;
 }
+
+
+TEST_IMPL(fs_poll_getpath) {
+  char buf[1024];
+  size_t len;
+  loop = uv_default_loop();
+
+  remove(FIXTURE);
+
+  ASSERT(0 == uv_fs_poll_init(loop, &poll_handle));
+  len = sizeof buf;
+  ASSERT(UV_EINVAL == uv_fs_poll_getpath(&poll_handle, buf, &len));
+  ASSERT(0 == uv_fs_poll_start(&poll_handle, poll_cb_fail, FIXTURE, 100));
+  len = sizeof buf;
+  ASSERT(0 == uv_fs_poll_getpath(&poll_handle, buf, &len));
+  ASSERT(0 == memcmp(buf, FIXTURE, len));
+
+  uv_close((uv_handle_t*) &poll_handle, close_cb);
+
+  ASSERT(0 == uv_run(loop, UV_RUN_DEFAULT));
+
+  ASSERT(close_cb_called == 1);
+
+  MAKE_VALGRIND_HAPPY();
+  return 0;
+}

test/test-list.h

@@ -176,6 +176,7 @@ TEST_DECLARE   (spawn_stdout_to_file)
 TEST_DECLARE   (spawn_stdout_and_stderr_to_file)
 TEST_DECLARE   (spawn_auto_unref)
 TEST_DECLARE   (fs_poll)
+TEST_DECLARE   (fs_poll_getpath)
 TEST_DECLARE   (kill)
 TEST_DECLARE   (fs_file_noent)
 TEST_DECLARE   (fs_file_nametoolong)
@@ -475,6 +476,7 @@ TASK_LIST_START
   TEST_ENTRY  (spawn_stdout_and_stderr_to_file)
   TEST_ENTRY  (spawn_auto_unref)
   TEST_ENTRY  (fs_poll)
+  TEST_ENTRY  (fs_poll_getpath)
   TEST_ENTRY  (kill)
 
 #ifdef _WIN32