libgomp_lithe_sched_t *libgomp_lithe_sched_alloc()
{
/* Allocate all the scheduler data together. */
struct sched_data {
libgomp_lithe_sched_t sched;
libgomp_lithe_context_t main_context;
struct lithe_fork_join_vc_mgmt vc_mgmt[];
};
/* Use a zombie list to reuse old schedulers if available, otherwise, create
* a new one. */
struct sched_data *s = wfl_remove(&sched_zombie_list);
if (!s) {
s = parlib_aligned_alloc(PGSIZE,
sizeof(*s) + sizeof(struct lithe_fork_join_vc_mgmt) * max_vcores());
s->sched.sched.vc_mgmt = &s->vc_mgmt[0];
s->sched.sched.sched.funcs = &libgomp_lithe_sched_funcs;
}
/* Initialize some libgomp specific fields before initializing the generic
* underlying fjs. */
s->sched.refcnt = 1;
s->main_context.completed = false;
lithe_fork_join_sched_init(&s->sched.sched, &s->main_context.context);
return &s->sched;
}
/* This function allocates a sigdata struct for use when running signal
* handlers inside a 2LS. The sigdata struct returned is pre-initialized with
* the 'stack' field pointing to a valid stack. Space is allocated for both
* the sigdata struct and the stack in a single mmap call. The sigdata struct
* just sits at the bottom of the stack, and its 'stack' field points just
* above it. */
struct sigdata *alloc_sigdata()
{
struct sigdata *data = wfl_remove(&sigdata_list);
if (data == NULL) {
void *stack = mmap(0, SIGNAL_STACK_SIZE,
PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_POPULATE|MAP_ANONYMOUS, -1, 0);
assert(stack != MAP_FAILED);
data = stack + SIGNAL_STACK_SIZE - sizeof(struct sigdata);
data->stack = data;
}
return data;
}
static libgomp_lithe_context_t *__ctx_alloc(size_t stacksize)
{
libgomp_lithe_context_t *ctx = wfl_remove(&context_zombie_list);
if (!ctx) {
int offset = ROUNDUP(sizeof(libgomp_lithe_context_t), ARCH_CL_SIZE);
offset += rand_r(&rseed(0)) % max_vcores() * ARCH_CL_SIZE;
stacksize = ROUNDUP(stacksize + offset, PGSIZE);
void *stackbot = mmap(
0, stacksize, PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0
);
if (stackbot == MAP_FAILED)
abort();
ctx = stackbot + stacksize - offset;
ctx->context.stack_offset = offset;
ctx->context.context.stack.bottom = stackbot;
ctx->context.context.stack.size = stacksize - offset;
}
return ctx;
}
