bindings: add spawn_sync bindings

This implements a nested event loop that makes it possible to control
a child process, while blocking the main loop until the process exits.

1 files changed, 247 insertions, 0 deletions

diff --git a/src/spawn_sync.h b/src/spawn_sync.h
new file mode 100644
index 0000000000..f0fcb464ed
--- /dev/null
+++ b/src/spawn_sync.h
@@ -0,0 +1,247 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+#ifndef SRC_SPAWN_SYNC_H_
+#define SRC_SPAWN_SYNC_H_
+
+#include "node.h"
+#include "node_buffer.h"
+
+namespace node {
+
+using v8::Array;
+using v8::Context;
+using v8::FunctionCallbackInfo;
+using v8::Handle;
+using v8::HandleScope;
+using v8::Integer;
+using v8::Isolate;
+using v8::Local;
+using v8::Null;
+using v8::Number;
+using v8::Object;
+using v8::String;
+using v8::Value;
+
+
+class SyncProcessOutputBuffer;
+class SyncProcessStdioPipe;
+class SyncProcessRunner;
+
+
+class SyncProcessOutputBuffer {
+  static const unsigned int kBufferSize = 65536;
+
+ public:
+  inline SyncProcessOutputBuffer();
+
+  inline void OnAlloc(size_t suggested_size, uv_buf_t* buf) const;
+  inline void OnRead(const uv_buf_t* buf, size_t nread);
+
+  inline size_t Copy(char* dest) const;
+
+  inline unsigned int available() const;
+  inline unsigned int used() const;
+
+  inline SyncProcessOutputBuffer* next() const;
+  inline void set_next(SyncProcessOutputBuffer* next);
+
+ private:
+  // Use unsigned int because that's what `uv_buf_init` takes.
+  mutable char data_[kBufferSize];
+  unsigned int used_;
+
+  SyncProcessOutputBuffer* next_;
+};
+
+
+class SyncProcessStdioPipe {
+  enum Lifecycle {
+    kUninitialized = 0,
+    kInitialized,
+    kStarted,
+    kClosing,
+    kClosed
+  };
+
+ public:
+  SyncProcessStdioPipe(SyncProcessRunner* process_handler,
+                       bool readable,
+                       bool writable,
+                       uv_buf_t input_buffer);
+  ~SyncProcessStdioPipe();
+
+  int Initialize(uv_loop_t* loop);
+  int Start();
+  void Close();
+
+  Local<Object> GetOutputAsBuffer() const;
+
+  inline bool readable() const;
+  inline bool writable() const;
+  inline uv_stdio_flags uv_flags() const;
+
+  inline uv_pipe_t* uv_pipe() const;
+  inline uv_stream_t* uv_stream() const;
+  inline uv_handle_t* uv_handle() const;
+
+ private:
+  inline size_t OutputLength() const;
+  inline void CopyOutput(char* dest) const;
+
+  inline void OnAlloc(size_t suggested_size, uv_buf_t* buf);
+  inline void OnRead(const uv_buf_t* buf, ssize_t nread);
+  inline void OnWriteDone(int result);
+  inline void OnShutdownDone(int result);
+  inline void OnClose();
+
+  inline void SetError(int error);
+
+  static void AllocCallback(uv_handle_t* handle,
+                            size_t suggested_size,
+                            uv_buf_t* buf);
+  static void ReadCallback(uv_stream_t* stream,
+                           ssize_t nread,
+                           const uv_buf_t* buf);
+  static void WriteCallback(uv_write_t* req, int result);
+  static void ShutdownCallback(uv_shutdown_t* req, int result);
+  static void CloseCallback(uv_handle_t* handle);
+
+  SyncProcessRunner* process_handler_;
+
+  bool readable_;
+  bool writable_;
+  uv_buf_t input_buffer_;
+
+  SyncProcessOutputBuffer* first_output_buffer_;
+  SyncProcessOutputBuffer* last_output_buffer_;
+
+  mutable uv_pipe_t uv_pipe_;
+  uv_write_t write_req_;
+  uv_shutdown_t shutdown_req_;
+
+  Lifecycle lifecycle_;
+};
+
+
+class SyncProcessRunner {
+  enum Lifecycle {
+    kUninitialized = 0,
+    kInitialized,
+    kHandlesClosed
+  };
+
+ public:
+  static void Initialize(Handle<Object> target,
+                         Handle<Value> unused,
+                         Handle<Context> context);
+  static void Spawn(const FunctionCallbackInfo<Value>& args);
+
+ private:
+  friend class SyncProcessStdioPipe;
+
+  explicit SyncProcessRunner(Environment* env_);
+  ~SyncProcessRunner();
+
+  inline Environment* env() const;
+
+  Local<Object> Run(Local<Value> options);
+  void TryInitializeAndRunLoop(Local<Value> options);
+  void CloseHandlesAndDeleteLoop();
+
+  void CloseStdioPipes();
+  void CloseKillTimer();
+
+  void Kill();
+  void IncrementBufferSizeAndCheckOverflow(ssize_t length);
+
+  void OnExit(int64_t exit_status, int term_signal);
+  void OnKillTimerTimeout(int status);
+
+  int GetError();
+  void SetError(int error);
+  void SetPipeError(int pipe_error);
+
+  Local<Object> BuildResultObject();
+  Local<Array> BuildOutputArray();
+
+  int ParseOptions(Local<Value> js_value);
+  int ParseStdioOptions(Local<Value> js_value);
+  int ParseStdioOption(int child_fd, Local<Object> js_stdio_option);
+
+  inline int AddStdioIgnore(uint32_t child_fd);
+  inline int AddStdioPipe(uint32_t child_fd,
+                          bool readable,
+                          bool writable,
+                          uv_buf_t input_buffer);
+  inline int AddStdioInheritFD(uint32_t child_fd, int inherit_fd);
+
+  static bool IsSet(Local<Value> value);
+  template <typename t> static bool CheckRange(Local<Value> js_value);
+  static int CopyJsString(Local<Value> js_value, const char** target);
+  static int CopyJsStringArray(Local<Value> js_value, char** target);
+
+  static void ExitCallback(uv_process_t* handle,
+                           int64_t exit_status,
+                           int term_signal);
+  static void KillTimerCallback(uv_timer_t* handle, int status);
+  static void KillTimerCloseCallback(uv_handle_t* handle);
+
+  size_t max_buffer_;
+  uint64_t timeout_;
+  int kill_signal_;
+
+  uv_loop_t* uv_loop_;
+
+  uint32_t stdio_count_;
+  uv_stdio_container_t* uv_stdio_containers_;
+  SyncProcessStdioPipe** stdio_pipes_;
+  bool stdio_pipes_initialized_;
+
+  uv_process_options_t uv_process_options_;
+  const char* file_buffer_;
+  char* args_buffer_;
+  char* env_buffer_;
+  const char* cwd_buffer_;
+
+  uv_process_t uv_process_;
+  bool killed_;
+
+  size_t buffered_output_size_;
+  int64_t exit_status_;
+  int term_signal_;
+
+  uv_timer_t uv_timer_;
+  bool kill_timer_initialized_;
+
+  // Errors that happen in one of the pipe handlers are stored in the
+  // `pipe_error` field. They are treated as "low-priority", only to be
+  // reported if no more serious errors happened.
+  int error_;
+  int pipe_error_;
+
+  Lifecycle lifecycle_;
+
+  Environment* env_;
+};
+}
+
+#endif  // SRC_SPAWN_SYNC_H_