This code is safe. If the data race fails, the result is that we take the
lock and recheck.
==================
WARNING: ThreadSanitizer: data race (pid=31401)
Read of size 1 at 0x00010f5d2500 by thread T11:
#0 wait_for_mieq_init darwinEvents.c:102 (X11.bin+0x00010003155a)
#1 -[X11Application(Private) sendX11NSEvent:] X11Application.m:1330 (X11.bin+0x00010001d652)
#2 __28-[X11Application sendEvent:]_block_invoke X11Application.m:476 (X11.bin+0x00010001887f)
#3 __tsan::invoke_and_release_block(void*) <null>:144 (libclang_rt.tsan_osx_dynamic.dylib+0x00000005d97b)
#4 _dispatch_client_callout <null>:33 (libdispatch.dylib+0x0000000020ef)
Previous write of size 1 at 0x00010f5d2500 by thread T8:
[failed to restore the stack]
Location is global 'mieqInitialized' at 0x00010f5d2500 (X11.bin+0x000100599500)
Thread T11 (tid=4367138, running) created by thread T-1
[failed to restore the stack]
Thread T8 (tid=4367130, running) created by main thread at:
#0 pthread_create <null>:144 (libclang_rt.tsan_osx_dynamic.dylib+0x000000024490)
#1 create_thread quartzStartup.c:78 (X11.bin+0x000100039d2d)
#2 QuartzInitServer quartzStartup.c:95 (X11.bin+0x000100039b96)
#3 X11ApplicationMain X11Application.m:1238 (X11.bin+0x00010001cd54)
#4 X11ControllerMain X11Controller.m:984 (X11.bin+0x00010002a5b2)
#5 server_main quartzStartup.c:136 (X11.bin+0x000100039fbb)
#6 do_start_x11_server bundle-main.c:436 (X11.bin+0x000100002e25)
#7 _Xstart_x11_server mach_startupServer.c:189 (X11.bin+0x000100004e09)
#8 mach_startup_server mach_startupServer.c:399 (X11.bin+0x0001000056a4)
#9 mach_msg_server mach_msg.c:563 (libsystem_kernel.dylib+0x000000012186)
#10 start <null>:29 (libdyld.dylib+0x000000005254)
SUMMARY: ThreadSanitizer: data race darwinEvents.c:102 in wait_for_mieq_init
==================
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
f72ff1f7ac