[NaCl SDK] nacl_io: big refactor to return error value (errno).

native_client_sdk/src/libraries/nacl_io/mount_dev.cc

 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #if defined(WIN32)
 #define _CRT_RAND_S
 #endif
 
 #include <errno.h>
 #include <fcntl.h>
 #include <string.h>
 #include "nacl_io/kernel_wrap_real.h"
 #include "nacl_io/mount_dev.h"
 #include "nacl_io/mount_node.h"
 #include "nacl_io/mount_node_dir.h"
 #include "nacl_io/pepper_interface.h"
 #include "utils/auto_lock.h"
 
 #if defined(__native_client__)
-#  include <irt.h>
+#include <irt.h>
 #elif defined(WIN32)
-#  include <stdlib.h>
+#include <stdlib.h>
 #endif
 
-
 namespace {
 
-void ReleaseAndNullNode(MountNode** node) {
-  if (*node)
-    (*node)->Release();
-  *node = NULL;
-}
-
-
 class RealNode : public MountNode {
  public:
   RealNode(Mount* mount, int fd);
 
-  virtual int Read(size_t offs, void* buf, size_t count);
-  virtual int Write(size_t offs, const void* buf, size_t count);
-  virtual int GetStat(struct stat* stat);
+  virtual Error Read(size_t offs, void* buf, size_t count, int* out_bytes);
+  virtual Error Write(size_t offs,
+                      const void* buf,
+                      size_t count,
+                      int* out_bytes);
+  virtual Error GetStat(struct stat* stat);
 
  protected:
   int fd_;
 };
 
 class NullNode : public MountNode {
  public:
   explicit NullNode(Mount* mount);
 
-  virtual int Read(size_t offs, void* buf, size_t count);
-  virtual int Write(size_t offs, const void* buf, size_t count);
+  virtual Error Read(size_t offs, void* buf, size_t count, int* out_bytes);
+  virtual Error Write(size_t offs,
+                      const void* buf,
+                      size_t count,
+                      int* out_bytes);
 };
 
 class ConsoleNode : public NullNode {
  public:
   ConsoleNode(Mount* mount, PP_LogLevel level);
 
-  virtual int Write(size_t offs, const void* buf, size_t count);
+  virtual Error Write(size_t offs,
+                      const void* buf,
+                      size_t count,
+                      int* out_bytes);
 
-private:
+ private:
   PP_LogLevel level_;
 };
 
-
 class TtyNode : public NullNode {
  public:
   explicit TtyNode(Mount* mount);
 
-  virtual int Write(size_t offs, const void* buf, size_t count);
+  virtual Error Write(size_t offs,
+                      const void* buf,
+                      size_t count,
+                      int* out_bytes);
 };
 
-
 class ZeroNode : public MountNode {
  public:
   explicit ZeroNode(Mount* mount);
 
-  virtual int Read(size_t offs, void* buf, size_t count);
-  virtual int Write(size_t offs, const void* buf, size_t count);
+  virtual Error Read(size_t offs, void* buf, size_t count, int* out_bytes);
+  virtual Error Write(size_t offs,
+                      const void* buf,
+                      size_t count,
+                      int* out_bytes);
 };
 
 class UrandomNode : public MountNode {
  public:
   explicit UrandomNode(Mount* mount);
 
-  virtual int Read(size_t offs, void* buf, size_t count);
-  virtual int Write(size_t offs, const void* buf, size_t count);
+  virtual Error Read(size_t offs, void* buf, size_t count, int* out_bytes);
+  virtual Error Write(size_t offs,
+                      const void* buf,
+                      size_t count,
+                      int* out_bytes);
 
  private:
 #if defined(__native_client__)
   nacl_irt_random random_interface_;
   bool interface_ok_;
 #endif
 };
 
-RealNode::RealNode(Mount* mount, int fd)
-    : MountNode(mount),
-      fd_(fd) {
+RealNode::RealNode(Mount* mount, int fd) : MountNode(mount), fd_(fd) {
   stat_.st_mode = S_IFCHR;
 }
 
-int RealNode::Read(size_t offs, void* buf, size_t count) {
+Error RealNode::Read(size_t offs, void* buf, size_t count, int* out_bytes) {
+  *out_bytes = 0;
+
   size_t readcnt;
   int err = _real_read(fd_, buf, count, &readcnt);
-  if (err) {
-    errno = err;
-    return -1;
-  }
-  return static_cast<int>(readcnt);
-}
+  if (err)
+    return err;
 
-int RealNode::Write(size_t offs, const void* buf, size_t count) {
-  size_t writecnt;
-  int err = _real_write(fd_, buf, count, &writecnt);
-  if (err) {
-    errno = err;
-    return -1;
-  }
-  return static_cast<int>(writecnt);
-}
-
-int RealNode::GetStat(struct stat* stat) {
-  int err =  _real_fstat(fd_, stat);
-  if (err) {
-    errno = err;
-    return -1;
-  }
+  *out_bytes = static_cast<int>(readcnt);
   return 0;
 }
 
-NullNode::NullNode(Mount* mount)
-    : MountNode(mount) {
+Error RealNode::Write(size_t offs,
+                      const void* buf,
+                      size_t count,
+                      int* out_bytes) {
+  *out_bytes = 0;
+
+  size_t writecnt;
+  int err = _real_write(fd_, buf, count, &writecnt);
+  if (err)
+    return err;
+
+  *out_bytes = static_cast<int>(writecnt);
+  return 0;
+}
+
+Error RealNode::GetStat(struct stat* stat) { return _real_fstat(fd_, stat); }
+
+NullNode::NullNode(Mount* mount) : MountNode(mount) { stat_.st_mode = S_IFCHR; }
+
+Error NullNode::Read(size_t offs, void* buf, size_t count, int* out_bytes) {
+  *out_bytes = 0;
+  return 0;
+}
+
+Error NullNode::Write(size_t offs,
+                      const void* buf,
+                      size_t count,
+                      int* out_bytes) {
+  *out_bytes = count;
+  return 0;
+}
+
+ConsoleNode::ConsoleNode(Mount* mount, PP_LogLevel level)
+    : NullNode(mount), level_(level) {
   stat_.st_mode = S_IFCHR;
 }
 
-int NullNode::Read(size_t offs, void* buf, size_t count) {
+Error ConsoleNode::Write(size_t offs,
+                         const void* buf,
+                         size_t count,
+                         int* out_bytes) {
+  *out_bytes = 0;
+
+  ConsoleInterface* con_intr = mount_->ppapi()->GetConsoleInterface();
+  VarInterface* var_intr = mount_->ppapi()->GetVarInterface();
+
+  if (!(var_intr && con_intr))
+    return ENOSYS;
+
+  const char* data = static_cast<const char*>(buf);
+  uint32_t len = static_cast<uint32_t>(count);
+  struct PP_Var val = var_intr->VarFromUtf8(data, len);
+  con_intr->Log(mount_->ppapi()->GetInstance(), level_, val);
+
+  *out_bytes = count;
   return 0;
 }
 
-int NullNode::Write(size_t offs, const void* buf, size_t count) {
-  return count;
-}
+TtyNode::TtyNode(Mount* mount) : NullNode(mount) {}
 
-ConsoleNode::ConsoleNode(Mount* mount, PP_LogLevel level)
-    : NullNode(mount),
-    level_(level) {
-  stat_.st_mode = S_IFCHR;
-}
+Error TtyNode::Write(size_t offs,
+                     const void* buf,
+                     size_t count,
+                     int* out_bytes) {
+  *out_bytes = 0;
 
-int ConsoleNode::Write(size_t offs, const void* buf, size_t count) {
-  ConsoleInterface* con_intr = mount_->ppapi()->GetConsoleInterface();
+  MessagingInterface* msg_intr = mount_->ppapi()->GetMessagingInterface();
   VarInterface* var_intr = mount_->ppapi()->GetVarInterface();
 
-  if (var_intr && con_intr) {
-    const char* data = static_cast<const char *>(buf);
-    uint32_t len = static_cast<uint32_t>(count);
-    struct PP_Var val = var_intr->VarFromUtf8(data, len);
-    con_intr->Log(mount_->ppapi()->GetInstance(), level_, val);
-    return count;
-  }
+  if (!(var_intr && msg_intr))
+    return ENOSYS;
+
+  const char* data = static_cast<const char*>(buf);
+  uint32_t len = static_cast<uint32_t>(count);
+  struct PP_Var val = var_intr->VarFromUtf8(data, len);
+  msg_intr->PostMessage(mount_->ppapi()->GetInstance(), val);
+
+  *out_bytes = count;
   return 0;
 }
 
+ZeroNode::ZeroNode(Mount* mount) : MountNode(mount) { stat_.st_mode = S_IFCHR; }
 
-TtyNode::TtyNode(Mount* mount)
-    : NullNode(mount) {
-}
-
-int TtyNode::Write(size_t offs, const void* buf, size_t count) {
-  MessagingInterface* msg_intr = mount_->ppapi()->GetMessagingInterface();
-  VarInterface* var_intr = mount_->ppapi()->GetVarInterface();
-
-  if (var_intr && msg_intr) {
-    const char* data = static_cast<const char *>(buf);
-    uint32_t len = static_cast<uint32_t>(count);
-    struct PP_Var val = var_intr->VarFromUtf8(data, len);
-    msg_intr->PostMessage(mount_->ppapi()->GetInstance(), val);
-    return count;
-  }
+Error ZeroNode::Read(size_t offs, void* buf, size_t count, int* out_bytes) {
+  memset(buf, 0, count);
+  *out_bytes = count;
   return 0;
 }
 
-
-ZeroNode::ZeroNode(Mount* mount)
-    : MountNode(mount) {
-  stat_.st_mode = S_IFCHR;
+Error ZeroNode::Write(size_t offs,
+                      const void* buf,
+                      size_t count,
+                      int* out_bytes) {
+  *out_bytes = count;
+  return 0;
 }
 
-int ZeroNode::Read(size_t offs, void* buf, size_t count) {
-  memset(buf, 0, count);
-  return count;
-}
-
-int ZeroNode::Write(size_t offs, const void* buf, size_t count) {
-  return count;
-}
-
-UrandomNode::UrandomNode(Mount* mount)
-    : MountNode(mount) {
+UrandomNode::UrandomNode(Mount* mount) : MountNode(mount) {
   stat_.st_mode = S_IFCHR;
 #if defined(__native_client__)
-  size_t result = nacl_interface_query(NACL_IRT_RANDOM_v0_1, &random_interface_,
-                                       sizeof(random_interface_));
+  size_t result = nacl_interface_query(
+      NACL_IRT_RANDOM_v0_1, &random_interface_, sizeof(random_interface_));
   interface_ok_ = result != 0;
 #endif
 }
 
-int UrandomNode::Read(size_t offs, void* buf, size_t count) {
+Error UrandomNode::Read(size_t offs, void* buf, size_t count, int* out_bytes) {
+  *out_bytes = 0;
+
 #if defined(__native_client__)
-  if (interface_ok_) {
-    size_t nread;
-    int result = (*random_interface_.get_random_bytes)(buf, count, &nread);
-    if (result != 0) {
-      errno = result;
-      return 0;
-    }
+  if (!interface_ok_)
+    return EBADF;
 
-    return count;
-  }
+  size_t nread;
+  int error = (*random_interface_.get_random_bytes)(buf, count, &nread);
+  if (error)
+    return error;
 
-  errno = EBADF;
+  *out_bytes = count;
   return 0;
 #elif defined(WIN32)
   char* out = static_cast<char*>(buf);
   size_t bytes_left = count;
   while (bytes_left) {
     unsigned int random_int;
     errno_t err = rand_s(&random_int);
     if (err) {
-      errno = err;
-      return count - bytes_left;
+      *out_bytes = count - bytes_left;
+      return err;
     }
 
     int bytes_to_copy = std::min(bytes_left, sizeof(random_int));
     memcpy(out, &random_int, bytes_to_copy);
     out += bytes_to_copy;
     bytes_left -= bytes_to_copy;
   }
 
-  return count;
+  *out_bytes = count;
+  return 0;
 #endif
 }
 
-int UrandomNode::Write(size_t offs, const void* buf, size_t count) {
-  return count;
+Error UrandomNode::Write(size_t offs,
+                         const void* buf,
+                         size_t count,
+                         int* out_bytes) {
+  *out_bytes = count;
+  return 0;
 }
 
-
-
 }  // namespace
 
-MountNode *MountDev::Open(const Path& path, int mode) {
+Error MountDev::Open(const Path& path, int mode, MountNode** out_node) {
+  *out_node = NULL;
+
   AutoLock lock(&lock_);
 
   // Don't allow creating any files.
   if (mode & O_CREAT)
-    return NULL;
+    return EINVAL;
 
-  MountNode* node = root_->FindChild(path.Join());
-  if (node)
-    node->Acquire();
-  return node;
+  MountNode* node = NULL;
+  int error = root_->FindChild(path.Join(), &node);
+  if (error)
+    return error;
+
+  node->Acquire();
+  *out_node = node;
+  return 0;
 }
 
-int MountDev::Unlink(const Path& path) {
-  errno = EINVAL;
-  return -1;
-}
+Error MountDev::Unlink(const Path& path) { return EINVAL; }
 
-int MountDev::Mkdir(const Path& path, int permissions) {
-  errno = EINVAL;
-  return -1;
-}
+Error MountDev::Mkdir(const Path& path, int permissions) { return EINVAL; }
 
-int MountDev::Rmdir(const Path& path) {
-  errno = EINVAL;
-  return -1;
-}
+Error MountDev::Rmdir(const Path& path) { return EINVAL; }
 
-int MountDev::Remove(const Path& path) {
-  errno = EINVAL;
-  return -1;
-}
+Error MountDev::Remove(const Path& path) { return EINVAL; }
 
-MountDev::MountDev()
-    : null_node_(NULL),
-      zero_node_(NULL),
-      random_node_(NULL),
-      console0_node_(NULL),
-      console1_node_(NULL),
-      console2_node_(NULL),
-      console3_node_(NULL),
-      tty_node_(NULL) {
-}
+MountDev::MountDev() {}
 
-bool MountDev::Init(int dev, StringMap_t& args, PepperInterface* ppapi) {
-  if (!Mount::Init(dev, args, ppapi))
+#define INITIALIZE_DEV_NODE(path, klass)          \
+  error = root_->AddChild(path, new klass(this)); \
+  if (error)                                      \
     return false;
 
+#define INITIALIZE_DEV_NODE_1(path, klass, arg)        \
+  error = root_->AddChild(path, new klass(this, arg)); \
+  if (error)                                           \
+    return false;
+
+Error MountDev::Init(int dev, StringMap_t& args, PepperInterface* ppapi) {
+  Error error = Mount::Init(dev, args, ppapi);
+  if (error)
+    return error;
+
   root_ = new MountNodeDir(this);
-  null_node_ = new NullNode(this);
-  root_->AddChild("/null", null_node_);
-  zero_node_ = new ZeroNode(this);
-  root_->AddChild("/zero", zero_node_);
-  random_node_ = new UrandomNode(this);
-  root_->AddChild("/urandom", random_node_);
 
-  console0_node_ = new ConsoleNode(this, PP_LOGLEVEL_TIP);
-  root_->AddChild("/console0", console0_node_);
-  console1_node_ = new ConsoleNode(this, PP_LOGLEVEL_LOG);
-  root_->AddChild("/console1", console1_node_);
-  console2_node_ = new ConsoleNode(this, PP_LOGLEVEL_WARNING);
-  root_->AddChild("/console2", console2_node_);
-  console3_node_ = new ConsoleNode(this, PP_LOGLEVEL_ERROR);
-  root_->AddChild("/console3", console3_node_);
+  INITIALIZE_DEV_NODE("/null", NullNode);
+  INITIALIZE_DEV_NODE("/zero", ZeroNode);
+  INITIALIZE_DEV_NODE("/urandom", UrandomNode);
+  INITIALIZE_DEV_NODE_1("/console0", ConsoleNode, PP_LOGLEVEL_TIP);
+  INITIALIZE_DEV_NODE_1("/console1", ConsoleNode, PP_LOGLEVEL_LOG);
+  INITIALIZE_DEV_NODE_1("/console2", ConsoleNode, PP_LOGLEVEL_WARNING);
+  INITIALIZE_DEV_NODE_1("/console3", ConsoleNode, PP_LOGLEVEL_ERROR);
+  INITIALIZE_DEV_NODE("/tty", TtyNode);
+  INITIALIZE_DEV_NODE_1("/stdin", RealNode, 0);
+  INITIALIZE_DEV_NODE_1("/stdout", RealNode, 1);
+  INITIALIZE_DEV_NODE_1("/stderr", RealNode, 2);
 
-  tty_node_ = new TtyNode(this);
-  root_->AddChild("/tty", tty_node_);
-
-  stdin_node_ = new RealNode(this, 0);
-  root_->AddChild("/stdin", stdin_node_);
-  stdout_node_ = new RealNode(this, 1);
-  root_->AddChild("/stdout", stdout_node_);
-  stderr_node_ = new RealNode(this, 2);
-  root_->AddChild("/stderr", stderr_node_);
-
-  return true;
+  return 0;

[noelallen1, 2013/06/07 21:48:43]

Error

[binji, 2013/06/07 23:23:11]

Done.

 }
 
 void MountDev::Destroy() {
-  ReleaseAndNullNode(&stdin_node_);
-  ReleaseAndNullNode(&stdout_node_);
-  ReleaseAndNullNode(&stderr_node_);
-  ReleaseAndNullNode(&tty_node_);
-  ReleaseAndNullNode(&console3_node_);
-  ReleaseAndNullNode(&console2_node_);
-  ReleaseAndNullNode(&console1_node_);
-  ReleaseAndNullNode(&console0_node_);
-  ReleaseAndNullNode(&random_node_);
-  ReleaseAndNullNode(&zero_node_);
-  ReleaseAndNullNode(&null_node_);
-  ReleaseAndNullNode(&root_);
+  if (root_)

[noelallen1, 2013/06/07 21:48:43]

This assumes derefing the root will defref the children which is currently not
true.  We should fix that in MountNodeDir.

[binji, 2013/06/07 23:23:11]

Done.

+    root_->Release();
+  root_ = NULL;
 }