Enable SDL2 threads (emscripten-core#8301)

Closes emscripten-core#8300

Author: jakogut

embuilder.py

@@ -80,6 +80,7 @@
     'ogg',
     'regal',
     'sdl2',
+    'sdl2-mt',
     'sdl2-gfx',
     'sdl2-image',
     'sdl2-image-png',
@@ -326,6 +327,8 @@ def is_flag(arg):
       build_port('libpng', libname('libpng'), ['-s', 'USE_ZLIB=1', '-s', 'USE_LIBPNG=1'])
     elif what == 'sdl2':
       build_port('sdl2', libname('libSDL2'), ['-s', 'USE_SDL=2'])
+    elif what == 'sdl2-mt':
+      build_port('sdl2', libname('libSDL2-mt'), ['-s', 'USE_SDL=2', '-s', 'USE_PTHREADS=1'])
     elif what == 'sdl2-gfx':
       build_port('sdl2-gfx', libname('libSDL2_gfx'), ['-s', 'USE_SDL=2', '-s', 'USE_SDL_IMAGE=2', '-s', 'USE_SDL_GFX=2'])
     elif what == 'sdl2-image':

tests/sdl2_threads.c

@@ -0,0 +1,30 @@
+#include <SDL.h>
+#include <assert.h>
+
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+#endif
+
+static int test_thread(void *data)
+{
+	return 2 + 2;
+}
+
+int main()
+{
+	SDL_Thread *thread;
+	int result;
+
+	thread = SDL_CreateThread(test_thread, "Test Thread", (void *)NULL);
+
+	if (NULL == thread) {
+		return 1;
+	} else {
+		SDL_WaitThread(thread, &result);
+	}
+
+#ifdef REPORT_RESULT
+	REPORT_RESULT(result);
+#endif
+	return 0;
+}

tests/test_browser.py

@@ -2984,6 +2984,10 @@ def test_sdl2_mouse_offsets(self):
     run_process([PYTHON, EMCC, 'sdl2_mouse.c', '-DTEST_SDL_MOUSE_OFFSETS=1', '-O2', '--minify', '0', '-o', 'sdl2_mouse.js', '--pre-js', 'pre.js', '-s', 'USE_SDL=2'])
     self.run_browser('page.html', '', '/report_result?1')
 
+  @requires_threads
+  def test_sdl2_threads(self):
+      self.btest('sdl2_threads.c', expected='4', args=['-s', 'USE_PTHREADS=1', '-s', 'USE_SDL=2', '-s', 'PROXY_TO_PTHREAD=1'])
+
   @requires_graphics_hardware
   def test_sdl2glshader(self):
     self.btest('sdl2glshader.c', reference='sdlglshader.png', args=['-s', 'USE_SDL=2', '-O2', '--closure', '1', '-g1', '-s', 'LEGACY_GL_EMULATION=1'])

tools/ports/sdl2.py

@@ -16,7 +16,7 @@ def get(ports, settings, shared):
 
   # get the port
   ports.fetch_project('sdl2', 'https://github.com/emscripten-ports/SDL2/archive/' + TAG + '.zip', SUBDIR)
-  libname = ports.get_lib_name('libSDL2')
+  libname = ports.get_lib_name('libSDL2' + ('-mt' if settings.USE_PTHREADS else ''))
 
   def create():
     # we are rebuilding SDL, clear dependant projects so they copy in their includes to ours properly
@@ -31,7 +31,12 @@ def create():
     open(os.path.join(dest_include_path, 'SDL_config.h'), 'w').write(sdl_config_h)
     open(os.path.join(dest_include_path, 'SDL2', 'SDL_config.h'), 'w').write(sdl_config_h)
     # build
-    srcs = 'SDL.c SDL_assert.c SDL_dataqueue.c SDL_error.c SDL_hints.c SDL_log.c atomic/SDL_atomic.c atomic/SDL_spinlock.c audio/SDL_audio.c audio/SDL_audiocvt.c audio/SDL_audiodev.c audio/SDL_audiotypecvt.c audio/SDL_mixer.c audio/SDL_wave.c cpuinfo/SDL_cpuinfo.c dynapi/SDL_dynapi.c events/SDL_clipboardevents.c events/SDL_dropevents.c events/SDL_events.c events/SDL_gesture.c events/SDL_keyboard.c events/SDL_mouse.c events/SDL_quit.c events/SDL_touch.c events/SDL_windowevents.c file/SDL_rwops.c haptic/SDL_haptic.c joystick/SDL_gamecontroller.c joystick/SDL_joystick.c libm/e_atan2.c libm/e_log.c libm/e_pow.c libm/e_rem_pio2.c libm/e_sqrt.c libm/k_cos.c libm/k_rem_pio2.c libm/k_sin.c libm/k_tan.c libm/s_atan.c libm/s_copysign.c libm/s_cos.c libm/s_fabs.c libm/s_floor.c libm/s_scalbn.c libm/s_sin.c libm/s_tan.c power/SDL_power.c render/SDL_d3dmath.c render/SDL_render.c render/SDL_yuv_mmx.c render/SDL_yuv_sw.c render/direct3d/SDL_render_d3d.c render/direct3d11/SDL_render_d3d11.c render/opengl/SDL_render_gl.c render/opengl/SDL_shaders_gl.c render/opengles/SDL_render_gles.c render/opengles2/SDL_render_gles2.c render/opengles2/SDL_shaders_gles2.c render/psp/SDL_render_psp.c render/software/SDL_blendfillrect.c render/software/SDL_blendline.c render/software/SDL_blendpoint.c render/software/SDL_drawline.c render/software/SDL_drawpoint.c render/software/SDL_render_sw.c render/software/SDL_rotate.c stdlib/SDL_getenv.c stdlib/SDL_iconv.c stdlib/SDL_malloc.c stdlib/SDL_qsort.c stdlib/SDL_stdlib.c stdlib/SDL_string.c thread/SDL_thread.c timer/SDL_timer.c video/SDL_RLEaccel.c video/SDL_blit.c video/SDL_blit_0.c video/SDL_blit_1.c video/SDL_blit_A.c video/SDL_blit_N.c video/SDL_blit_auto.c video/SDL_blit_copy.c video/SDL_blit_slow.c video/SDL_bmp.c video/SDL_clipboard.c video/SDL_egl.c video/SDL_fillrect.c video/SDL_pixels.c video/SDL_rect.c video/SDL_shape.c video/SDL_stretch.c video/SDL_surface.c video/SDL_video.c video/emscripten/SDL_emscriptenevents.c video/emscripten/SDL_emscriptenframebuffer.c video/emscripten/SDL_emscriptenmouse.c video/emscripten/SDL_emscriptenopengles.c video/emscripten/SDL_emscriptenvideo.c audio/emscripten/SDL_emscriptenaudio.c video/dummy/SDL_nullevents.c video/dummy/SDL_nullframebuffer.c video/dummy/SDL_nullvideo.c audio/disk/SDL_diskaudio.c audio/dummy/SDL_dummyaudio.c loadso/dlopen/SDL_sysloadso.c power/emscripten/SDL_syspower.c joystick/emscripten/SDL_sysjoystick.c filesystem/emscripten/SDL_sysfilesystem.c timer/unix/SDL_systimer.c haptic/dummy/SDL_syshaptic.c thread/generic/SDL_syscond.c thread/generic/SDL_sysmutex.c thread/generic/SDL_syssem.c thread/generic/SDL_systhread.c thread/generic/SDL_systls.c main/dummy/SDL_dummy_main.c'.split(' ')
+    srcs = 'SDL.c SDL_assert.c SDL_dataqueue.c SDL_error.c SDL_hints.c SDL_log.c atomic/SDL_atomic.c atomic/SDL_spinlock.c audio/SDL_audio.c audio/SDL_audiocvt.c audio/SDL_audiodev.c audio/SDL_audiotypecvt.c audio/SDL_mixer.c audio/SDL_wave.c cpuinfo/SDL_cpuinfo.c dynapi/SDL_dynapi.c events/SDL_clipboardevents.c events/SDL_dropevents.c events/SDL_events.c events/SDL_gesture.c events/SDL_keyboard.c events/SDL_mouse.c events/SDL_quit.c events/SDL_touch.c events/SDL_windowevents.c file/SDL_rwops.c haptic/SDL_haptic.c joystick/SDL_gamecontroller.c joystick/SDL_joystick.c libm/e_atan2.c libm/e_log.c libm/e_pow.c libm/e_rem_pio2.c libm/e_sqrt.c libm/k_cos.c libm/k_rem_pio2.c libm/k_sin.c libm/k_tan.c libm/s_atan.c libm/s_copysign.c libm/s_cos.c libm/s_fabs.c libm/s_floor.c libm/s_scalbn.c libm/s_sin.c libm/s_tan.c power/SDL_power.c render/SDL_d3dmath.c render/SDL_render.c render/SDL_yuv_mmx.c render/SDL_yuv_sw.c render/direct3d/SDL_render_d3d.c render/direct3d11/SDL_render_d3d11.c render/opengl/SDL_render_gl.c render/opengl/SDL_shaders_gl.c render/opengles/SDL_render_gles.c render/opengles2/SDL_render_gles2.c render/opengles2/SDL_shaders_gles2.c render/psp/SDL_render_psp.c render/software/SDL_blendfillrect.c render/software/SDL_blendline.c render/software/SDL_blendpoint.c render/software/SDL_drawline.c render/software/SDL_drawpoint.c render/software/SDL_render_sw.c render/software/SDL_rotate.c stdlib/SDL_getenv.c stdlib/SDL_iconv.c stdlib/SDL_malloc.c stdlib/SDL_qsort.c stdlib/SDL_stdlib.c stdlib/SDL_string.c thread/SDL_thread.c timer/SDL_timer.c video/SDL_RLEaccel.c video/SDL_blit.c video/SDL_blit_0.c video/SDL_blit_1.c video/SDL_blit_A.c video/SDL_blit_N.c video/SDL_blit_auto.c video/SDL_blit_copy.c video/SDL_blit_slow.c video/SDL_bmp.c video/SDL_clipboard.c video/SDL_egl.c video/SDL_fillrect.c video/SDL_pixels.c video/SDL_rect.c video/SDL_shape.c video/SDL_stretch.c video/SDL_surface.c video/SDL_video.c video/emscripten/SDL_emscriptenevents.c video/emscripten/SDL_emscriptenframebuffer.c video/emscripten/SDL_emscriptenmouse.c video/emscripten/SDL_emscriptenopengles.c video/emscripten/SDL_emscriptenvideo.c audio/emscripten/SDL_emscriptenaudio.c video/dummy/SDL_nullevents.c video/dummy/SDL_nullframebuffer.c video/dummy/SDL_nullvideo.c audio/disk/SDL_diskaudio.c audio/dummy/SDL_dummyaudio.c loadso/dlopen/SDL_sysloadso.c power/emscripten/SDL_syspower.c joystick/emscripten/SDL_sysjoystick.c filesystem/emscripten/SDL_sysfilesystem.c timer/unix/SDL_systimer.c haptic/dummy/SDL_syshaptic.c main/dummy/SDL_dummy_main.c'.split()
+
+    thread_srcs = ['SDL_syscond.c', 'SDL_sysmutex.c', 'SDL_syssem.c', 'SDL_systhread.c', 'SDL_systls.c']
+    thread_backend = 'generic' if not settings.USE_PTHREADS else 'pthread'
+    srcs += ['thread/%s/%s' % (thread_backend, s) for s in thread_srcs]
+
     commands = []
     o_s = []
     for src in srcs:
@@ -416,3 +421,7 @@ def show():
 
 #endif /* _SDL_config_h */
 '''
+
+sdl_config_mt_h = sdl_config_h
+sdl_config_mt_h.replace('/* #undef SDL_THREAD_PTHREAD */', '#define SDL_THREAD_PTHREAD 1')
+sdl_config_mt_h.replace('#define SDL_THREADS_DISABLED 1', '/* #undef SDL_THREADS_DISABLED */')