* Define THREAD_POOL_PARAM_T such that we can avoid a compiler
 * warning when we use the dispatch_*() functions below
#define THREAD_POOL_PARAM_T dispatch_context_t

#include <sys/iofunc.h>
#include <sys/dispatch.h>

The THREAD_POOL_PARAM_T manifest tells the compiler what type of parameter is passed between the various blocking/handling functions that the threads will be using. This parameter should be the context structure used for passing context information between the functions. By default it's defined as a resmgr_context_t, but since this sample is using the dispatch layer, we need it to be a dispatch_context_t. We define it prior to the include directives above, since the header files refer to it.