Support `IO#pread` / `IO#pwrite` using fiber scheduler. (#7594)

* Skip test if non-blocking file IO is not supported.

2 files changed, 55 insertions, 25 deletions

diff --git a/include/ruby/fiber/scheduler.h b/include/ruby/fiber/scheduler.h
index 250b39b6df..ad3d2d7483 100644
--- a/include/ruby/fiber/scheduler.h
+++ b/include/ruby/fiber/scheduler.h
@@ -267,10 +267,10 @@ VALUE rb_fiber_scheduler_io_selectv(VALUE scheduler, int argc, VALUE *argv);
  * Non-blocking read from the passed IO.
  *
  * @param[in]   scheduler    Target scheduler.
- * @param[out]  io           An io object to read from.
- * @param[out]  buffer       Return buffer.
- * @param[in]   length       Requested number of bytes to read.
- * @param[in]   offset       The offset in the buffer to read to.
+ * @param[in]   io           An io object to read from.
+ * @param[in]   buffer       The buffer to read to.
+ * @param[in]   length       The minimum number of bytes to read.
+ * @param[in]   offset       The offset in the buffer to read from.
  * @retval      RUBY_Qundef  `scheduler` doesn't have `#io_read`.
  * @return      otherwise    What `scheduler.io_read` returns `[-errno, size]`.
  */
@@ -280,9 +280,9 @@ VALUE rb_fiber_scheduler_io_read(VALUE scheduler, VALUE io, VALUE buffer, size_t
  * Non-blocking write to the passed IO.
  *
  * @param[in]   scheduler    Target scheduler.
- * @param[out]  io           An io object to write to.
- * @param[in]   buffer       What to write.
- * @param[in]   length       Number of bytes to write.
+ * @param[in]   io           An io object to write to.
+ * @param[in]   buffer       The buffer to write from.
+ * @param[in]   length       The minimum number of bytes to write.
  * @param[in]   offset       The offset in the buffer to write from.
  * @retval      RUBY_Qundef  `scheduler` doesn't have `#io_write`.
  * @return      otherwise    What `scheduler.io_write` returns `[-errno, size]`.
@@ -293,10 +293,10 @@ VALUE rb_fiber_scheduler_io_write(VALUE scheduler, VALUE io, VALUE buffer, size_
  * Non-blocking read from the passed IO at the specified offset.
  *
  * @param[in]   scheduler    Target scheduler.
- * @param[out]  io           An io object to read from.
- * @param[in]   from         The offset in the given IO to read the data from.
- * @param[out]  buffer       The buffer to read the data to.
- * @param[in]   length       Requested number of bytes to read.
+ * @param[in]   io           An io object to read from.
+ * @param[in]   from         The offset to read from.
+ * @param[in]   buffer       The buffer to read to.
+ * @param[in]   length       The minimum number of bytes to read.
  * @param[in]   offset       The offset in the buffer to read to.
  * @retval      RUBY_Qundef  `scheduler` doesn't have `#io_read`.
  * @return      otherwise    What `scheduler.io_read` returns.
@@ -307,10 +307,10 @@ VALUE rb_fiber_scheduler_io_pread(VALUE scheduler, VALUE io, rb_off_t from, VALU
  * Non-blocking write to the passed IO at the specified offset.
  *
  * @param[in]   scheduler    Target scheduler.
- * @param[out]  io           An io object to write to.
- * @param[in]   from         The offset in the given IO to write the data to.
- * @param[in]   buffer       The buffer to write the data from.
- * @param[in]   length       Number of bytes to write.
+ * @param[in]   io           An io object to write to.
+ * @param[in]   from         The offset to write to.
+ * @param[in]   buffer       The buffer to write from.
+ * @param[in]   length       The minimum number of bytes to write.
  * @param[in]   offset       The offset in the buffer to write from.
  * @retval      RUBY_Qundef  `scheduler` doesn't have `#io_write`.
  * @return      otherwise    What `scheduler.io_write` returns.
@@ -321,27 +321,55 @@ VALUE rb_fiber_scheduler_io_pwrite(VALUE scheduler, VALUE io, rb_off_t from, VAL
  * Non-blocking read from the passed IO using a native buffer.
  *
  * @param[in]   scheduler    Target scheduler.
- * @param[out]  io           An io object to read from.
- * @param[out]  buffer       Return buffer.
- * @param[in]   size         Size of the return buffer.
- * @param[in]   length       Requested number of bytes to read.
+ * @param[in]   io           An io object to read from.
+ * @param[in]   base         The memory to read to.
+ * @param[in]   size         Size of the memory.
+ * @param[in]   length       The minimum number of bytes to read.
  * @retval      RUBY_Qundef  `scheduler` doesn't have `#io_read`.
  * @return      otherwise    What `scheduler.io_read` returns.
  */
-VALUE rb_fiber_scheduler_io_read_memory(VALUE scheduler, VALUE io, void *buffer, size_t size, size_t length);
+VALUE rb_fiber_scheduler_io_read_memory(VALUE scheduler, VALUE io, void *base, size_t size, size_t length);
 
 /**
  * Non-blocking write to the passed IO using a native buffer.
  *
  * @param[in]   scheduler    Target scheduler.
- * @param[out]  io           An io object to write to.
- * @param[in]   buffer       What to write.
- * @param[in]   size         Size of the buffer.
- * @param[in]   length       Number of bytes to write.
+ * @param[in]   io           An io object to write to.
+ * @param[in]   base         The memory to write from.
+ * @param[in]   size         Size of the memory.
+ * @param[in]   length       The minimum number of bytes to write.
+ * @retval      RUBY_Qundef  `scheduler` doesn't have `#io_write`.
+ * @return      otherwise    What `scheduler.io_write` returns.
+ */
+VALUE rb_fiber_scheduler_io_write_memory(VALUE scheduler, VALUE io, const void *base, size_t size, size_t length);
+
+/**
+ * Non-blocking pread from the passed IO using a native buffer.
+ *
+ * @param[in]   scheduler    Target scheduler.
+ * @param[in]   io           An io object to read from.
+ * @param[in]   from         The offset to read from.
+ * @param[in]   base         The memory to read to.
+ * @param[in]   size         Size of the memory.
+ * @param[in]   length       The minimum number of bytes to read.
+ * @retval      RUBY_Qundef  `scheduler` doesn't have `#io_read`.
+ * @return      otherwise    What `scheduler.io_read` returns.
+ */
+VALUE rb_fiber_scheduler_io_pread_memory(VALUE scheduler, VALUE io, rb_off_t from, void *base, size_t size, size_t length);
+
+/**
+ * Non-blocking pwrite to the passed IO using a native buffer.
+ *
+ * @param[in]   scheduler    Target scheduler.
+ * @param[in]   io           An io object to write to.
+ * @param[in]   from         The offset to write from.
+ * @param[in]   base         The memory to write from.
+ * @param[in]   size         Size of the memory.
+ * @param[in]   length       The minimum number of bytes to write.
  * @retval      RUBY_Qundef  `scheduler` doesn't have `#io_write`.
  * @return      otherwise    What `scheduler.io_write` returns.
  */
-VALUE rb_fiber_scheduler_io_write_memory(VALUE scheduler, VALUE io, const void *buffer, size_t size, size_t length);
+VALUE rb_fiber_scheduler_io_pwrite_memory(VALUE scheduler, VALUE io, rb_off_t from, const void *base, size_t size, size_t length);
 
 /**
  * Non-blocking close the given IO.
diff --git a/include/ruby/io/buffer.h b/include/ruby/io/buffer.h
index 88e5598066..737fafe518 100644
--- a/include/ruby/io/buffer.h
+++ b/include/ruby/io/buffer.h
@@ -75,7 +75,9 @@ VALUE rb_io_buffer_map(VALUE io, size_t size, rb_off_t offset, enum rb_io_buffer
 VALUE rb_io_buffer_lock(VALUE self);
 VALUE rb_io_buffer_unlock(VALUE self);
 int rb_io_buffer_try_unlock(VALUE self);
+
 VALUE rb_io_buffer_free(VALUE self);
+VALUE rb_io_buffer_free_locked(VALUE self);
 
 int rb_io_buffer_get_bytes(VALUE self, void **base, size_t *size);
 void rb_io_buffer_get_bytes_for_reading(VALUE self, const void **base, size_t *size);