__pctx
static void (*pctx_cpc_callback)(cpc_t *cpc, struct __pctx *pctx);
__pctx_cpc_register_callback(void (*arg)(struct __cpc *, struct __pctx *))
pctx_terminate(struct __pctx *pctx)
typedef struct __pctx pctx_t;
struct __pctx *));