Remove another potential stale CJS_Timer usage

Fix memory ownership model for PDFium timers.

The |app| class owns the CJS_Timer as part of its vector<unique_ptr>
to them.

The CJS_Timer "owns" its slot in the global ID to timer map, and
removes itself when it is destroyed. Nothing else deletes
from the global map. Deleting from the global map is
accompanied by a callback to the embedder to clear its

Next, the proper way to remove a CJS_Timer is by going
through the app, and having the app erase its unique ptr,
which then deletes the CJS_Timer, which in turn cleans up the
global map. Provide a CJS_Timer::Cancel static method to
do this conveniently.

There is a alternate path to the CJS_timer via JS and its
CJS_TimerObj. CJS_TimerObj owns a TimerObj that currently
points to the CJS_Timer. If the timer fires, and cleans
itself up, this can go stale.

Make the TimerObj maintain a weak reference via global
timer ID rather than a direct pointer to the CJS_Timer, so
that if the timer fires and is destroyed, future attempts
to cancel find nothing.

There is another path, where if the JS timer object is GC'd, then we
just clean up its CJS_TimerObj without touching
the actual CJS_Timers.  We could make this match the spec
by calling into the new cancel routine as described above,
but it seems weird to have a timer depend on whether a gc
happened or not.

A subsequent CL will rename these objects to more closely
match the conventions used by the other JS wrappers.


7 files changed
tree: dd86d4b10e658cef8bf5fea5d99baa1d15bda7ca
  1. build_gyp/
  2. build_overrides/
  3. core/
  4. docs/
  5. fpdfsdk/
  6. fxjs/
  7. infra/
  8. public/
  9. samples/
  10. skia/
  11. test/
  12. testing/
  13. third_party/
  14. tools/
  15. xfa/
  16. .clang-format
  17. .gitignore
  18. .gn
  21. codereview.settings
  22. DEPS
  25. OWNERS
  26. pdfium.gni
  27. pdfium.gyp
  30. xfa.gyp



As of 2016-05-04, GN is used to generate build files replacing GYP. GYP support will remain until it is disabled in Chromium and then will be removed from PDFium.

As of 2016-04-28, the Visual Studio toolchain from depot_tools is used as the default Windows toolchain for Googlers. Please set DEPOT_TOOLS_WIN_TOOLCHAIN=0 if you need to use the system toolchain. See Windows development subsection for details.


Get the chromium depot tools via the instructions at (this provides the gclient utility needed below).

Also install Python, Subversion, and Git and make sure they're in your path.

### Windows development

PDFium uses a similar Windows toolchain as Chromium:

Open source contributors

Visual Studio 2015 Update 2 or later is highly recommended.

Run set DEPOT_TOOLS_WIN_TOOLCHAIN=0, or set that variable in your global environment.

Compilation is done through ninja, not Visual Studio.

Google employees

Run: download_from_google_storage --config and follow the authentication instructions. Note that you must authenticate with your credentials. Enter “0” if asked for a project-id.

Once you've done this, the toolchain will be installed automatically for you in the step below.

The toolchain will be in depot_tools\win_toolchain\vs_files\<hash>, and windbg can be found in depot_tools\win_toolchain\vs_files\<hash>\win_sdk\Debuggers.

If you want the IDE for debugging and editing, you will need to install it separately, but this is optional and not needed for building PDFium.

Get the code

The name of the top-level directory does not matter. In our examples, we use “repo”. This directory must not have been used before by gclient config as each directory can only house a single gclient configuration.

mkdir repo
cd repo
gclient config --unmanaged
gclient sync
cd pdfium

## Generate the build files

We use GN to generate the build files and Ninja (also included with the depot_tools checkout) to execute the build files.

gn gen <directory>

If you want to set to out/Debug or out/Release you'll need to export GYP_PDFIUM_NO_ACTION=1 to stop gclient sync from executing GYP and overwriting your build files.

### Selecting build configuration

PDFium may be built either with or without JavaScript support, and with or without XFA forms support. Both of these features are enabled by default. Also note that the XFA feature requires JavaScript.

Configuration is done by executing gn args <directory> to configure the build. This will launch an editor in which you can set the following arguments.

use_goma = true  # Googlers only.
is_debug = true  # Enable debugging features.

pdf_use_skia = false  # Set true to enable experimental skia backend.

pdf_enable_xfa = true # Set false to remove XFA support (implies JS support).
pdf_enable_v8 = true  # Set false to remove Javascript support.
pdf_is_standalone = true  # Set for a non-embedded build.

Note, you must set pdf_is_standalone = true if you want the sample applications like pdfium_test to build.

When complete the arguments will be stored in <directory>/

Building the code

If you used Ninja, you can build the sample program by: ninja -C <directory>/pdfium_test You can build the entire product (which includes a few unit tests) by: ninja -C <directory>.

Running the sample program

The pdfium_test program supports reading, parsing, and rasterizing the pages of a .pdf file to .ppm or .png output image files (windows supports two other formats). For example: <directory>/pdfium_test --ppm path/to/myfile.pdf. Note that this will write output images to path/to/myfile.pdf.<n>.ppm.


There are currently several test suites that can be run:

  • pdfium_unittests
  • pdfium_embeddertests
  • testing/tools/
  • testing/tools/
  • testing/tools/

It is possible the tests in the testing directory can fail due to font differences on the various platforms. These tests are reliable on the bots. If you see failures, it can be a good idea to run the tests on the tip-of-tree checkout to see if the same failures appear.


The current health of the source tree can be found at


There are several mailing lists that are setup:

Note, the Reviews and Bugs lists are typically read-only.


We use this bug tracker, but for security bugs, please use [Chromium's security bug template] ( and add the “Cr-Internals-Plugins-PDF” label.

Contributing code

For contributing code, we will follow Chromium's process as much as possible. The main exceptions is:

  1. Code has to conform to the existing style and not Chromium/Google style.