Bool BufferCommit(Buffer buffer, Addr p, Size size)
{
AVERT(Buffer, buffer);
AVER(size > 0);
AVER(SizeIsAligned(size, BufferPool(buffer)->alignment));
AVER(!BufferIsReady(buffer));
/* <design/collection#.flip>. */
/* .commit.before: If a flip occurs before this point, when the */
/* pool reads "initAtFlip" it will point below the object, so it */
/* will be trashed and the commit must fail when trip is called. */
AVER(p == buffer->ap_s.init);
AVER(AddrAdd(buffer->ap_s.init, size) == buffer->ap_s.alloc);
/* .commit.update: Atomically update the init pointer to declare */
/* that the object is initialized (though it may be invalid if a */
/* flip occurred). */
buffer->ap_s.init = buffer->ap_s.alloc;
/* .improve.memory-barrier: Memory barrier here on the DEC Alpha */
/* (and other relaxed memory order architectures). */
/* .commit.after: If a flip occurs at this point, the pool will */
/* see "initAtFlip" above the object, which is valid, so it will */
/* be collected. The commit must succeed when trip is called. */
/* The pointer "p" will have been fixed up. */
/* TODO: Check the above assertion and explain why it is so. */
/* .commit.trip: Trip the buffer if a flip has occurred. */
if (buffer->ap_s.limit == 0)
return BufferTrip(buffer, p, size);
/* No flip occurred, so succeed. */
return TRUE;
}
Res BufferFill(Addr *pReturn, Buffer buffer, Size size)
{
Res res;
Pool pool;
Addr base, limit, next;
AVER(pReturn != NULL);
AVERT(Buffer, buffer);
AVER(size > 0);
AVER(SizeIsAligned(size, BufferPool(buffer)->alignment));
AVER(BufferIsReady(buffer));
pool = BufferPool(buffer);
/* If we're here because the buffer was trapped, then we attempt */
/* the allocation here. */
if (!BufferIsReset(buffer) && buffer->ap_s.limit == (Addr)0) {
/* .fill.unflip: If the buffer is flipped then we unflip the buffer. */
if (buffer->mode & BufferModeFLIPPED) {
BufferSetUnflipped(buffer);
}
/* .fill.logged: If the buffer is logged then we leave it logged. */
next = AddrAdd(buffer->ap_s.alloc, size);
if (next > (Addr)buffer->ap_s.alloc &&
next <= (Addr)buffer->poolLimit) {
buffer->ap_s.alloc = next;
if (buffer->mode & BufferModeLOGGED) {
EVENT3(BufferReserve, buffer, buffer->ap_s.init, size);
}
*pReturn = buffer->ap_s.init;
return ResOK;
}
}
/* There really isn't enough room for the allocation now. */
AVER(AddrAdd(buffer->ap_s.alloc, size) > buffer->poolLimit ||
AddrAdd(buffer->ap_s.alloc, size) < (Addr)buffer->ap_s.alloc);
BufferDetach(buffer, pool);
/* Ask the pool for some memory. */
res = Method(Pool, pool, bufferFill)(&base, &limit, pool, buffer, size);
if (res != ResOK)
return res;
/* Set up the buffer to point at the memory given by the pool */
/* and do the allocation that was requested by the client. */
BufferAttach(buffer, base, limit, base, size);
if (buffer->mode & BufferModeLOGGED) {
EVENT3(BufferReserve, buffer, buffer->ap_s.init, size);
}
*pReturn = base;
return res;
}
void BufferFinish(Buffer buffer)
{
AVERT(Buffer, buffer);
AVER(BufferIsReady(buffer));
BufferDetach(buffer, BufferPool(buffer)); /* FIXME: Should be in BufferAbsFinish? */
Method(Inst, buffer, finish)(MustBeA(Inst, buffer));
}
static void NBufferEmpty(Pool pool, Buffer buffer,
Addr init, Addr limit)
{
AVERT(Pool, pool);
AVERT(Buffer, buffer);
AVER(BufferIsReady(buffer));
AVER(init <= limit);
NOTREACHED; /* can't create buffers, so they shouldn't trip */
}
void BufferSetAllocAddr(Buffer buffer, Addr addr)
{
AVERT(Buffer, buffer);
/* Can't check Addr */
AVER(BufferIsReady(buffer));
AVER(buffer->base <= addr);
AVER(buffer->poolLimit >= addr);
buffer->ap_s.init = addr;
buffer->ap_s.alloc = addr;
}
void BufferDetach(Buffer buffer, Pool pool)
{
AVERT(Buffer, buffer);
AVER(BufferIsReady(buffer));
if (!BufferIsReset(buffer)) {
Addr init, limit;
Size spare;
buffer->mode |= BufferModeTRANSITION;
/* Ask the owning pool to do whatever it needs to before the */
/* buffer is detached (e.g. copy buffer state into pool state). */
Method(Pool, pool, bufferEmpty)(pool, buffer);
/* run any class-specific detachment method */
Method(Buffer, buffer, detach)(buffer);
init = BufferGetInit(buffer);
limit = BufferLimit(buffer);
spare = AddrOffset(init, limit);
buffer->emptySize += spare;
if (buffer->isMutator) {
ArenaGlobals(buffer->arena)->emptyMutatorSize += spare;
ArenaGlobals(buffer->arena)->allocMutatorSize +=
AddrOffset(buffer->base, init);
} else {
ArenaGlobals(buffer->arena)->emptyInternalSize += spare;
}
/* Reset the buffer. */
buffer->base = (Addr)0;
buffer->initAtFlip = (Addr)0;
buffer->ap_s.init = (mps_addr_t)0;
buffer->ap_s.alloc = (mps_addr_t)0;
buffer->ap_s.limit = (mps_addr_t)0;
buffer->poolLimit = (Addr)0;
buffer->mode &=
~(BufferModeATTACHED|BufferModeFLIPPED|BufferModeTRANSITION);
EVENT2(BufferEmpty, buffer, spare);
}
}
static void MVFFBufferEmpty(Pool pool, Buffer buffer,
Addr base, Addr limit)
{
MVFF mvff;
AVERT(Pool, pool);
mvff = Pool2MVFF(pool);
AVERT(MVFF, mvff);
AVERT(Buffer, buffer);
AVER(BufferIsReady(buffer));
AVER(base <= limit);
if (base == limit)
return;
MVFFAddToFreeList(&base, &limit, mvff);
MVFFFreeSegs(mvff, base, limit);
return;
}
Res BufferReserve(Addr *pReturn, Buffer buffer, Size size)
{
Addr next;
AVER(pReturn != NULL);
AVERT(Buffer, buffer);
AVER(size > 0);
AVER(SizeIsAligned(size, BufferPool(buffer)->alignment));
AVER(BufferIsReady(buffer)); /* <design/check/#.common> */
/* Is there enough room in the unallocated portion of the buffer to */
/* satisfy the request? If so, just increase the alloc marker and */
/* return a pointer to the area below it. */
next = AddrAdd(buffer->ap_s.alloc, size);
if (next > (Addr)buffer->ap_s.alloc &&
next <= (Addr)buffer->ap_s.limit) {
buffer->ap_s.alloc = next;
*pReturn = buffer->ap_s.init;
return ResOK;
}
/* If the buffer can't accommodate the request, call "fill". */
return BufferFill(pReturn, buffer, size);
}
