Added cache line size info in SDL_cpuinfo.h

I also added an implementation to dynamically query it, but didn't expose it since most x86 CPUs have an L1 cache line size of 64 bytes.
This commit is contained in:
Sam Lantinga 2011-01-27 16:46:15 -08:00
parent 1d518f0d73
commit fb824f9a04
4 changed files with 121 additions and 67 deletions

View file

@ -243,9 +243,6 @@ void RunEpicTest()
#define NUM_WRITERS 4
#define EVENTS_PER_WRITER 1000000
/* A decent guess for the size of a cache line on this architecture */
#define CACHELINE 64
/* The number of entries must be a power of 2 */
#define MAX_ENTRIES 256
#define WRAP_MASK (MAX_ENTRIES-1)
@ -260,22 +257,22 @@ typedef struct
{
SDL_EventQueueEntry entries[MAX_ENTRIES];
char cache_pad1[CACHELINE-((sizeof(SDL_EventQueueEntry)*MAX_ENTRIES)%CACHELINE)];
char cache_pad1[SDL_CACHELINE_SIZE-((sizeof(SDL_EventQueueEntry)*MAX_ENTRIES)%SDL_CACHELINE_SIZE)];
SDL_atomic_t enqueue_pos;
char cache_pad2[CACHELINE-sizeof(SDL_atomic_t)];
char cache_pad2[SDL_CACHELINE_SIZE-sizeof(SDL_atomic_t)];
SDL_atomic_t dequeue_pos;
char cache_pad3[CACHELINE-sizeof(SDL_atomic_t)];
char cache_pad3[SDL_CACHELINE_SIZE-sizeof(SDL_atomic_t)];
#ifdef TEST_SPINLOCK_FIFO
SDL_SpinLock lock;
SDL_atomic_t rwcount;
SDL_atomic_t watcher;
char cache_pad4[CACHELINE-sizeof(SDL_SpinLock)-2*sizeof(SDL_atomic_t)];
char cache_pad4[SDL_CACHELINE_SIZE-sizeof(SDL_SpinLock)-2*sizeof(SDL_atomic_t)];
#endif
volatile SDL_bool active;
@ -470,10 +467,10 @@ typedef struct
{
SDL_EventQueue *queue;
int index;
char padding1[CACHELINE-(sizeof(SDL_EventQueue*)+sizeof(int))%CACHELINE];
char padding1[SDL_CACHELINE_SIZE-(sizeof(SDL_EventQueue*)+sizeof(int))%SDL_CACHELINE_SIZE];
int waits;
SDL_bool lock_free;
char padding2[CACHELINE-sizeof(int)-sizeof(SDL_bool)];
char padding2[SDL_CACHELINE_SIZE-sizeof(int)-sizeof(SDL_bool)];
} WriterData;
typedef struct
@ -482,7 +479,7 @@ typedef struct
int counters[NUM_WRITERS];
int waits;
SDL_bool lock_free;
char padding[CACHELINE-(sizeof(SDL_EventQueue*)+sizeof(int)*NUM_WRITERS+sizeof(int)+sizeof(SDL_bool))%CACHELINE];
char padding[SDL_CACHELINE_SIZE-(sizeof(SDL_EventQueue*)+sizeof(int)*NUM_WRITERS+sizeof(int)+sizeof(SDL_bool))%SDL_CACHELINE_SIZE];
} ReaderData;
static int FIFO_Writer(void* _data)