libgcm can be used add Google Cloud Messaging (GCM) to an application. It currently supports a simple send function to one or more clients.
Default timeouts can be changed at compile time:
./configure CPPFLAGS="-DGCM_TIMEOUT_MS=2000 -DGCM_CONNECTTIMEOUT_MS=800"
Changing CPPFLAGS this way will not trigger recompilation the next time
make is run; make clean before make is necessary when changing these
flags.