PPAPI: Implement PPB_FileMapping on POSIX

BUG=83774
R=bbudge@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=247473

Review URL: https://codereview.chromium.org/69663002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247546 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 375 insertions, 1 deletions

diff --git a/ppapi/proxy/file_io_resource.h b/ppapi/proxy/file_io_resource.h
index d6465fd..5d58035 100644
--- a/ppapi/proxy/file_io_resource.h
+++ b/ppapi/proxy/file_io_resource.h
@@ -69,7 +69,6 @@ class PPAPI_PROXY_EXPORT FileIOResource
       PP_FileHandle* handle,
       scoped_refptr<TrackedCallback> callback) OVERRIDE;
 
- private:
   // FileHandleHolder is used to guarantee that file operations will have a
   // valid FD to operate on, even if they're in a different thread.
   // If instead we just passed the raw FD, the FD could be closed before the
@@ -102,7 +101,11 @@ class PPAPI_PROXY_EXPORT FileIOResource
     ~FileHandleHolder();
     PP_FileHandle raw_handle_;
   };
+  scoped_refptr<FileHandleHolder> file_handle() {
+    return file_handle_;
+  }
 
+ private:
   // Class to perform file query operations across multiple threads.
   class QueryOp : public base::RefCountedThreadSafe<QueryOp> {
    public:
diff --git a/ppapi/proxy/file_mapping_resource.cc b/ppapi/proxy/file_mapping_resource.cc
new file mode 100644
index 0000000..5b18dbb
--- /dev/null
+++ b/ppapi/proxy/file_mapping_resource.cc
@@ -0,0 +1,160 @@
+// Copyright 2014 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.
+
+#include "ppapi/proxy/file_mapping_resource.h"
+
+#include "base/bind.h"
+#include "base/numerics/safe_conversions.h"
+#include "base/task_runner_util.h"
+#include "ppapi/c/pp_errors.h"
+#include "ppapi/shared_impl/tracked_callback.h"
+#include "ppapi/shared_impl/var.h"
+#include "ppapi/thunk/enter.h"
+#include "ppapi/thunk/ppb_file_io_api.h"
+
+namespace ppapi {
+namespace proxy {
+
+FileMappingResource::FileMappingResource(Connection connection,
+                                         PP_Instance instance)
+    : PluginResource(connection, instance) {
+}
+
+FileMappingResource::~FileMappingResource() {
+}
+
+thunk::PPB_FileMapping_API* FileMappingResource::AsPPB_FileMapping_API() {
+  return this;
+}
+
+int32_t FileMappingResource::Map(PP_Instance /* instance */,
+                                 PP_Resource file_io,
+                                 int64_t length,
+                                 uint32_t protection,
+                                 uint32_t flags,
+                                 int64_t offset,
+                                 void** address,
+                                 scoped_refptr<TrackedCallback> callback) {
+  thunk::EnterResourceNoLock<thunk::PPB_FileIO_API> enter(file_io, true);
+  if (enter.failed())
+    return PP_ERROR_BADARGUMENT;
+  FileIOResource* file_io_resource =
+      static_cast<FileIOResource*>(enter.object());
+  scoped_refptr<FileIOResource::FileHandleHolder> file_handle =
+      file_io_resource->file_handle();
+  if (!FileIOResource::FileHandleHolder::IsValid(file_handle))
+    return PP_ERROR_FAILED;
+  if (length < 0 || offset < 0 ||
+      !base::IsValueInRangeForNumericType<off_t>(offset)) {
+    return PP_ERROR_BADARGUMENT;
+  }
+  if (!base::IsValueInRangeForNumericType<size_t>(length)) {
+    return PP_ERROR_NOMEMORY;
+  }
+
+  // Ensure any bits we don't recognize are zero.
+  if (protection &
+      ~(PP_FILEMAPPROTECTION_READ | PP_FILEMAPPROTECTION_WRITE)) {
+    return PP_ERROR_BADARGUMENT;
+  }
+  if (flags &
+      ~(PP_FILEMAPFLAG_SHARED | PP_FILEMAPFLAG_PRIVATE |
+        PP_FILEMAPFLAG_FIXED)) {
+    return PP_ERROR_BADARGUMENT;
+  }
+  // Ensure at least one of SHARED and PRIVATE is set.
+  if (!(flags & (PP_FILEMAPFLAG_SHARED | PP_FILEMAPFLAG_PRIVATE)))
+    return PP_ERROR_BADARGUMENT;
+  // Ensure at most one of SHARED and PRIVATE is set.
+  if ((flags & PP_FILEMAPFLAG_SHARED) &&
+      (flags & PP_FILEMAPFLAG_PRIVATE)) {
+    return PP_ERROR_BADARGUMENT;
+  }
+  if (!address)
+    return PP_ERROR_BADARGUMENT;
+
+  base::Callback<MapResult()> map_cb(
+      base::Bind(&FileMappingResource::DoMapBlocking, file_handle, *address,
+                 length, protection, flags, offset));
+  if (callback->is_blocking()) {
+    // The plugin could release its reference to this instance when we release
+    // the proxy lock below.
+    scoped_refptr<FileMappingResource> protect(this);
+    MapResult map_result;
+    {
+      // Release the proxy lock while making a potentially slow file call.
+      ProxyAutoUnlock unlock;
+      map_result = map_cb.Run();
+    }
+    OnMapCompleted(address, length, callback, map_result);
+    return map_result.result;
+  } else {
+    base::PostTaskAndReplyWithResult(
+      PpapiGlobals::Get()->GetFileTaskRunner(),
+      FROM_HERE,
+      map_cb,
+      RunWhileLocked(Bind(&FileMappingResource::OnMapCompleted,
+                          this,
+                          base::Unretained(address),
+                          length,
+                          callback)));
+    return PP_OK_COMPLETIONPENDING;
+  }
+}
+
+int32_t FileMappingResource::Unmap(PP_Instance /* instance */,
+                                   const void* address,
+                                   int64_t length,
+                                   scoped_refptr<TrackedCallback> callback) {
+  if (!address)
+    return PP_ERROR_BADARGUMENT;
+  if (!base::IsValueInRangeForNumericType<size_t>(length))
+    return PP_ERROR_BADARGUMENT;
+
+  base::Callback<int32_t()> unmap_cb(
+      base::Bind(&FileMappingResource::DoUnmapBlocking, address, length));
+  if (callback->is_blocking()) {
+    // Release the proxy lock while making a potentially slow file call.
+    ProxyAutoUnlock unlock;
+    return unmap_cb.Run();
+  } else {
+    base::PostTaskAndReplyWithResult(
+      PpapiGlobals::Get()->GetFileTaskRunner(),
+      FROM_HERE,
+      unmap_cb,
+      RunWhileLocked(Bind(&TrackedCallback::Run, callback)));
+    return PP_OK_COMPLETIONPENDING;
+  }
+}
+
+int64_t FileMappingResource::GetMapPageSize(PP_Instance /* instance */) {
+  return DoGetMapPageSize();
+}
+
+void FileMappingResource::OnMapCompleted(
+    void** mapped_address_out_param,
+    int64_t length,
+    scoped_refptr<TrackedCallback> callback,
+    const MapResult& map_result) {
+  if (callback->aborted()) {
+    if (map_result.result == PP_OK) {
+      // If the Map operation was successful, we need to Unmap to avoid leaks.
+      // The plugin won't get the address, so doesn't have a chance to do the
+      // Unmap.
+      PpapiGlobals::Get()->GetFileTaskRunner()->PostTask(
+          FROM_HERE,
+          base::Bind(base::IgnoreResult(&FileMappingResource::DoUnmapBlocking),
+                     map_result.address,
+                     length));
+    }
+    return;
+  }
+  if (map_result.result == PP_OK)
+    *mapped_address_out_param = map_result.address;
+  if (!callback->is_blocking())
+    callback->Run(map_result.result);
+}
+
+}  // namespace proxy
+}  // namespace ppapi
diff --git a/ppapi/proxy/file_mapping_resource.h b/ppapi/proxy/file_mapping_resource.h
new file mode 100644
index 0000000..240da21
--- /dev/null
+++ b/ppapi/proxy/file_mapping_resource.h
@@ -0,0 +1,77 @@
+// Copyright 2014 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.
+
+#ifndef PPAPI_PROXY_FILE_MAPPING_RESOURCE_H_
+#define PPAPI_PROXY_FILE_MAPPING_RESOURCE_H_
+
+#include "ppapi/proxy/file_io_resource.h"
+#include "ppapi/proxy/plugin_resource.h"
+#include "ppapi/proxy/ppapi_proxy_export.h"
+#include "ppapi/thunk/ppb_file_mapping_api.h"
+
+namespace ppapi {
+namespace proxy {
+
+// The proxy-side resource for PPB_FileMapping.
+class PPAPI_PROXY_EXPORT FileMappingResource
+      : public PluginResource,
+        public thunk::PPB_FileMapping_API {
+ public:
+  FileMappingResource(Connection connection, PP_Instance instance);
+
+ private:
+  virtual ~FileMappingResource();
+
+  // Resource implementation.
+  virtual thunk::PPB_FileMapping_API* AsPPB_FileMapping_API() OVERRIDE;
+
+  // PPB_FileMapping_API implementation.
+  virtual int32_t Map(PP_Instance instance,
+                      PP_Resource file_io,
+                      int64_t length,
+                      uint32_t protection,
+                      uint32_t flags,
+                      int64_t offset,
+                      void** address,
+                      scoped_refptr<TrackedCallback> callback) OVERRIDE;
+  virtual int32_t Unmap(PP_Instance instance,
+                        const void* address,
+                        int64_t length,
+                        scoped_refptr<TrackedCallback> callback) OVERRIDE;
+  virtual int64_t GetMapPageSize(PP_Instance instance) OVERRIDE;
+
+  struct MapResult {
+    MapResult() : result(PP_ERROR_FAILED), address(NULL) {
+    }
+    int32_t result;
+    void* address;
+  };
+  void OnMapCompleted(void** mapped_address_out_param,
+                      int64_t length,
+                      scoped_refptr<TrackedCallback> callback,
+                      const MapResult& map_result);
+
+  // These functions perform potentially blocking operations so they should not
+  // be called on the main thread or while we hold the proxy lock. Their
+  // implementation is platform specific. See file_mapping_resource_posix.cc and
+  // file_mapping_resource_win.cc.
+  static MapResult DoMapBlocking(
+      scoped_refptr<FileIOResource::FileHandleHolder> handle,
+      void* address_hint,
+      int64_t length,
+      uint32_t protection,
+      uint32_t flags,
+      int64_t offset);
+  static int32_t DoUnmapBlocking(const void* address, int64_t length);
+  // DoGetMapPageSize is platform-specific, but fast enough that we can call it
+  // on the main thread with the lock.
+  static int64_t DoGetMapPageSize();
+
+  DISALLOW_COPY_AND_ASSIGN(FileMappingResource);
+};
+
+}  // namespace proxy
+}  // namespace ppapi
+
+#endif  // PPAPI_PROXY_FILE_MAPPING_RESOURCE_H_
diff --git a/ppapi/proxy/file_mapping_resource_posix.cc b/ppapi/proxy/file_mapping_resource_posix.cc
new file mode 100644
index 0000000..b1aff77
--- /dev/null
+++ b/ppapi/proxy/file_mapping_resource_posix.cc
@@ -0,0 +1,89 @@
+// Copyright 2014 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.
+
+#include "ppapi/proxy/file_mapping_resource.h"
+
+#include <stdio.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include "ppapi/c/pp_errors.h"
+
+namespace ppapi {
+namespace proxy {
+
+namespace {
+
+int32_t ErrnoToPPError(int error_code) {
+  switch (error_code) {
+    case EACCES:
+      return PP_ERROR_NOACCESS;
+    case EAGAIN:
+      return PP_ERROR_NOMEMORY;
+    case EINVAL:
+      return PP_ERROR_BADARGUMENT;
+    case ENFILE:
+    case ENOMEM:
+      return PP_ERROR_NOMEMORY;
+    default:
+      return PP_ERROR_FAILED;
+  }
+}
+
+}  // namespace
+
+// static
+FileMappingResource::MapResult FileMappingResource::DoMapBlocking(
+    scoped_refptr<FileIOResource::FileHandleHolder> handle,
+    void* address_hint,
+    int64_t length,
+    uint32_t map_protection,
+    uint32_t map_flags,
+    int64_t offset) {
+  int prot_for_mmap = 0;
+  if (map_protection & PP_FILEMAPPROTECTION_READ)
+    prot_for_mmap |= PROT_READ;
+  if (map_protection & PP_FILEMAPPROTECTION_WRITE)
+    prot_for_mmap |= PROT_WRITE;
+  if (prot_for_mmap == 0)
+    prot_for_mmap = PROT_NONE;
+
+  int flags_for_mmap = 0;
+  if (map_flags & PP_FILEMAPFLAG_SHARED)
+    flags_for_mmap |= MAP_SHARED;
+  if (map_flags & PP_FILEMAPFLAG_PRIVATE)
+    flags_for_mmap |= MAP_PRIVATE;
+  if (map_flags & PP_FILEMAPFLAG_FIXED)
+    flags_for_mmap |= MAP_FIXED;
+
+  MapResult map_result;
+  map_result.address =
+      mmap(address_hint,
+           static_cast<size_t>(length),
+           prot_for_mmap,
+           flags_for_mmap,
+           handle->raw_handle(),
+           static_cast<off_t>(offset));
+  if (map_result.address != MAP_FAILED)
+    map_result.result = PP_OK;
+  else
+    map_result.result = ErrnoToPPError(errno);
+  return map_result;
+}
+
+// static
+int32_t FileMappingResource::DoUnmapBlocking(const void* address,
+                                             int64_t length) {
+  if (munmap(const_cast<void*>(address), static_cast<size_t>(length)))
+    return ErrnoToPPError(errno);
+  return PP_OK;
+}
+
+// static
+int64_t FileMappingResource::DoGetMapPageSize() {
+  return getpagesize();
+}
+
+}  // namespace proxy
+}  // namespace ppapi
diff --git a/ppapi/proxy/file_mapping_resource_win.cc b/ppapi/proxy/file_mapping_resource_win.cc
new file mode 100644
index 0000000..70c3d20
--- /dev/null
+++ b/ppapi/proxy/file_mapping_resource_win.cc
@@ -0,0 +1,40 @@
+// Copyright 2014 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.
+
+#include "ppapi/proxy/file_mapping_resource.h"
+
+#include "ppapi/c/pp_errors.h"
+
+namespace ppapi {
+namespace proxy {
+
+// static
+FileMappingResource::MapResult FileMappingResource::DoMapBlocking(
+    scoped_refptr<FileIOResource::FileHandleHolder> handle,
+    void* address_hint,
+    int64_t length,
+    uint32_t map_protection,
+    uint32_t map_flags,
+    int64_t offset) {
+  // TODO(dmichael): Implement for Windows (crbug.com/83774).
+  MapResult map_result;
+  map_result.result = PP_ERROR_NOTSUPPORTED;
+  return map_result;
+}
+
+// static
+int32_t FileMappingResource::DoUnmapBlocking(const void* address,
+                                             int64_t length) {
+  // TODO(dmichael): Implement for Windows (crbug.com/83774).
+  return PP_ERROR_NOTSUPPORTED;
+}
+
+// static
+int64_t FileMappingResource::DoGetMapPageSize() {
+  // TODO(dmichael): Implement for Windows (crbug.com/83774).
+  return 0;
+}
+
+}  // namespace proxy
+}  // namespace ppapi
diff --git a/ppapi/proxy/interface_list.cc b/ppapi/proxy/interface_list.cc
index 4044b27b..79789d7 100644
--- a/ppapi/proxy/interface_list.cc
+++ b/ppapi/proxy/interface_list.cc
@@ -35,6 +35,7 @@
 #include "ppapi/c/ppb_console.h"
 #include "ppapi/c/ppb_core.h"
 #include "ppapi/c/ppb_file_io.h"
+#include "ppapi/c/ppb_file_mapping.h"
 #include "ppapi/c/ppb_file_ref.h"
 #include "ppapi/c/ppb_file_system.h"
 #include "ppapi/c/ppb_fullscreen.h"
diff --git a/ppapi/proxy/ppb_instance_proxy.cc b/ppapi/proxy/ppb_instance_proxy.cc
index 6429f50..80715ad 100644
--- a/ppapi/proxy/ppb_instance_proxy.cc
+++ b/ppapi/proxy/ppb_instance_proxy.cc
@@ -19,6 +19,7 @@
 #include "ppapi/proxy/content_decryptor_private_serializer.h"
 #include "ppapi/proxy/enter_proxy.h"
 #include "ppapi/proxy/extensions_common_resource.h"
+#include "ppapi/proxy/file_mapping_resource.h"
 #include "ppapi/proxy/flash_clipboard_resource.h"
 #include "ppapi/proxy/flash_file_resource.h"
 #include "ppapi/proxy/flash_fullscreen_resource.h"
@@ -363,6 +364,9 @@ Resource* PPB_Instance_Proxy::GetSingletonResource(PP_Instance instance,
     case EXTENSIONS_COMMON_SINGLETON_ID:
       new_singleton = new ExtensionsCommonResource(connection, instance);
       break;
+    case FILE_MAPPING_SINGLETON_ID:
+      new_singleton = new FileMappingResource(connection, instance);
+      break;
     case GAMEPAD_SINGLETON_ID:
       new_singleton = new GamepadResource(connection, instance);
       break;