struct Window {
MMapCache *cache;
- bool keep_always;
+ unsigned keep_always;
bool in_unused;
+ int prot;
void *ptr;
uint64_t offset;
- int prot;
size_t size;
FileDescriptor *fd;
struct MMapCache {
int n_ref;
+ unsigned n_windows;
+
+ unsigned n_hit, n_missed;
+
Hashmap *fds;
Hashmap *contexts;
- unsigned n_windows;
-
LIST_HEAD(Window, unused);
Window *last_unused;
};
munmap(w->ptr, w->size);
if (w->fd)
- LIST_REMOVE(Window, by_fd, w->fd->windows, w);
+ LIST_REMOVE(by_fd, w->fd->windows, w);
if (w->in_unused) {
if (w->cache->last_unused == w)
w->cache->last_unused = w->unused_prev;
- LIST_REMOVE(Window, unused, w->cache->unused, w);
+ LIST_REMOVE(unused, w->cache->unused, w);
}
LIST_FOREACH(by_window, c, w->contexts) {
assert(w);
window_unlink(w);
+ w->cache->n_windows--;
free(w);
}
-static bool window_matches(Window *w, int fd, int prot, uint64_t offset, size_t size) {
+_pure_ static bool window_matches(Window *w, int fd, int prot, uint64_t offset, size_t size) {
assert(w);
assert(fd >= 0);
assert(size > 0);
w = new0(Window, 1);
if (!w)
return NULL;
+ m->n_windows++;
} else {
/* Reuse an existing one */
w = c->window;
c->window = NULL;
- LIST_REMOVE(Context, by_window, w->contexts, c);
+ LIST_REMOVE(by_window, w->contexts, c);
- if (!w->contexts) {
+ if (!w->contexts && w->keep_always == 0) {
/* Not used anymore? */
- LIST_PREPEND(Window, unused, c->cache->unused, w);
+ LIST_PREPEND(unused, c->cache->unused, w);
if (!c->cache->last_unused)
c->cache->last_unused = w;
context_detach_window(c);
- if (!w->contexts) {
+ if (w->in_unused) {
/* Used again? */
- LIST_REMOVE(Window, unused, c->cache->unused, w);
- if (!c->cache->last_unused)
- c->cache->last_unused = w;
+ LIST_REMOVE(unused, c->cache->unused, w);
+ if (c->cache->last_unused == w)
+ c->cache->last_unused = w->unused_prev;
w->in_unused = false;
}
c->window = w;
- LIST_PREPEND(Context, by_window, w->contexts, c);
+ LIST_PREPEND(by_window, w->contexts, c);
}
static Context *context_add(MMapCache *m, unsigned id) {
while ((c = hashmap_first(m->contexts)))
context_free(c);
+ hashmap_free(m->contexts);
+
while ((f = hashmap_first(m->fds)))
fd_free(f);
+ hashmap_free(m->fds);
+
while (m->unused)
window_free(m->unused);
assert(m->n_ref > 0);
assert(fd >= 0);
assert(size > 0);
- assert(ret);
c = hashmap_get(m->contexts, UINT_TO_PTR(context+1));
if (!c)
return 0;
}
- c->window->keep_always = c->window->keep_always || keep_always;
+ c->window->keep_always += keep_always;
- *ret = (uint8_t*) c->window->ptr + (offset - c->window->offset);
+ if (ret)
+ *ret = (uint8_t*) c->window->ptr + (offset - c->window->offset);
return 1;
}
assert(m->n_ref > 0);
assert(fd >= 0);
assert(size > 0);
- assert(ret);
f = hashmap_get(m->fds, INT_TO_PTR(fd + 1));
if (!f)
return -ENOMEM;
context_attach_window(c, w);
- w->keep_always = w->keep_always || keep_always;
+ w->keep_always += keep_always;
- *ret = (uint8_t*) w->ptr + (offset - w->offset);
+ if (ret)
+ *ret = (uint8_t*) w->ptr + (offset - w->offset);
return 1;
}
assert(m->n_ref > 0);
assert(fd >= 0);
assert(size > 0);
- assert(ret);
woffset = offset & ~((uint64_t) page_size() - 1ULL);
wsize = size + (offset - woffset);
w->size = wsize;
w->fd = f;
- LIST_PREPEND(Window, by_fd, f->windows, w);
+ LIST_PREPEND(by_fd, f->windows, w);
context_detach_window(c);
c->window = w;
- LIST_PREPEND(Context, by_window, w->contexts, c);
+ LIST_PREPEND(by_window, w->contexts, c);
- *ret = (uint8_t*) w->ptr + (offset - w->offset);
+ if (ret)
+ *ret = (uint8_t*) w->ptr + (offset - w->offset);
return 1;
}
assert(m->n_ref > 0);
assert(fd >= 0);
assert(size > 0);
- assert(ret);
/* Check whether the current context is the right one already */
r = try_context(m, fd, prot, context, keep_always, offset, size, ret);
- if (r != 0)
+ if (r != 0) {
+ m->n_hit ++;
return r;
+ }
/* Search for a matching mmap */
r = find_mmap(m, fd, prot, context, keep_always, offset, size, ret);
- if (r != 0)
+ if (r != 0) {
+ m->n_hit ++;
return r;
+ }
+
+ m->n_missed++;
/* Create a new mmap */
return add_mmap(m, fd, prot, context, keep_always, offset, size, st, ret);
}
+int mmap_cache_release(
+ MMapCache *m,
+ int fd,
+ int prot,
+ unsigned context,
+ uint64_t offset,
+ size_t size) {
+
+ FileDescriptor *f;
+ Window *w;
+
+ assert(m);
+ assert(m->n_ref > 0);
+ assert(fd >= 0);
+ assert(size > 0);
+
+ f = hashmap_get(m->fds, INT_TO_PTR(fd + 1));
+ if (!f)
+ return -EBADF;
+
+ assert(f->fd == fd);
+
+ LIST_FOREACH(by_fd, w, f->windows)
+ if (window_matches(w, fd, prot, offset, size))
+ break;
+
+ if (!w)
+ return -ENOENT;
+
+ if (w->keep_always == 0)
+ return -ENOLCK;
+
+ w->keep_always -= 1;
+ return 0;
+}
+
void mmap_cache_close_fd(MMapCache *m, int fd) {
FileDescriptor *f;
context_free(c);
}
+
+unsigned mmap_cache_get_hit(MMapCache *m) {
+ assert(m);
+
+ return m->n_hit;
+}
+
+unsigned mmap_cache_get_missed(MMapCache *m) {
+ assert(m);
+
+ return m->n_missed;
+}