| /* Code fragment of how to get a buffer from the heap that has a specific |
| * alignment. The typical alignment is to a "page" whose size is often |
| * 4096 bytes. */ |
| |
| uint8_t * wrkBuff; /* will get pointer to heap allocation */ |
| uint8_t * wrkPos; /* will get aligned pointer within wrkBuff */ |
| uint32_t sz_of_aligned = 1234; /* number of aligned bytes required */ |
| |
| int psz; |
| |
| #if defined(HAVE_SYSCONF) && defined(_SC_PAGESIZE) |
| psz = sysconf(_SC_PAGESIZE); /* POSIX.1 (was getpagesize()) */ |
| #else |
| psz = 4096; /* give up, pick likely figure */ |
| #endif |
| |
| |
| /* perhaps use posix_memalign() instead. Yes but not always available */ |
| wrkBuff = (uint8_t *)malloc(sz_of_aligned + psz); |
| wrkPos = (uint8_t *)(((sg_uintptr_t)wrkBuff + psz - 1) & (~(psz - 1))); |
| |
| /* The disadvantage of this approach is that it needs both wrkBuff and wrkPos |
| * to be held by the application. The wrkBuff is only needed for the |
| * corresponding free(), all other uses should be via wrkPos. */ |
