diff options
Diffstat (limited to 'src/core/objhash.c')
| -rw-r--r-- | src/core/objhash.c | 119 |
1 files changed, 99 insertions, 20 deletions
diff --git a/src/core/objhash.c b/src/core/objhash.c index ccc57c39..9529ac30 100644 --- a/src/core/objhash.c +++ b/src/core/objhash.c @@ -23,6 +23,7 @@ struct nni_objhash { uint32_t oh_maxval; uint32_t oh_dynval; nni_mtx oh_lock; + nni_cv oh_cv; nni_objhash_node * oh_nodes; nni_objhash_ctor oh_ctor; nni_objhash_dtor oh_dtor; @@ -55,6 +56,12 @@ nni_objhash_init(nni_objhash **ohp, nni_objhash_ctor ctor, return (rv); } + if ((rv = nni_cv_init(&oh->oh_cv, &oh->oh_lock)) != 0) { + nni_mtx_fini(&oh->oh_lock); + NNI_FREE_STRUCT(oh); + return (rv); + } + oh->oh_nodes = NULL; oh->oh_count = 0; oh->oh_load = 0; @@ -64,6 +71,8 @@ nni_objhash_init(nni_objhash **ohp, nni_objhash_ctor ctor, oh->oh_minval = 1; oh->oh_maxval = 0x7fffffff; oh->oh_dynval = nni_random(); + oh->oh_ctor = ctor; + oh->oh_dtor = dtor; *ohp = oh; return (0); @@ -79,27 +88,12 @@ nni_objhash_fini(nni_objhash *oh) oh->oh_cap = oh->oh_count = 0; oh->oh_load = oh->oh_minload = oh->oh_maxload = 0; } + nni_cv_fini(&oh->oh_cv); nni_mtx_fini(&oh->oh_lock); NNI_FREE_STRUCT(oh); } -void -nni_objhash_reclaim(nni_objhash *oh) -{ - nni_mtx_lock(&oh->oh_lock); - // Reclaim the buffer if we want, but preserve the limits. - if ((oh->oh_count == 0) && (oh->oh_cap != 0)) { - nni_free(oh->oh_nodes, oh->oh_cap * sizeof (nni_objhash_node)); - oh->oh_cap = 0; - oh->oh_nodes = NULL; - oh->oh_minload = 0; - oh->oh_maxload = 0; - } - nni_mtx_unlock(&oh->oh_lock); -} - - // Inspired by Python dict implementation. This probe will visit every // cell. We always hash consecutively assigned IDs. #define NNI_OBJHASH_NEXTPROBE(h, j) \ @@ -159,9 +153,10 @@ nni_objhash_find(nni_objhash *oh, uint32_t id, void **valp) // Resize the object hash. This is called internally with the lock -// for the object hash held. +// for the object hash held. Grow indicates that this is being called +// from a function that intends to add data, so extra space is needed. static int -nni_objhash_resize(nni_objhash *oh) +nni_objhash_resize(nni_objhash *oh, int grow) { size_t newsize; size_t oldsize; @@ -169,6 +164,20 @@ nni_objhash_resize(nni_objhash *oh) nni_objhash_node *oldnodes; uint32_t i; + if ((!grow) && (oh->oh_count == 0) && (oh->oh_cap != 0)) { + // Table is empty, and we are unrefing. Lets reclaim the + // space. Note that this means that allocations which + // fluctuate between one and zero are going to bang on the + // allocator a bit. Since such cases should not be very + // performance sensitive, this is probably okay. + nni_free(oh->oh_nodes, oh->oh_cap * sizeof (nni_objhash_node)); + oh->oh_cap = 0; + oh->oh_nodes = NULL; + oh->oh_minload = 0; + oh->oh_maxload = 0; + return (0); + } + if ((oh->oh_load < oh->oh_maxload) && (oh->oh_load >= oh->oh_minload)) { // No resize needed. return (0); @@ -241,6 +250,9 @@ nni_objhash_unref(nni_objhash *oh, uint32_t id) node->on_refcnt--; if (node->on_refcnt != 0) { + if (node->on_refcnt == 1) { + nni_cv_wake(&oh->oh_cv); + } // Still busy/referenced? nni_mtx_unlock(&oh->oh_lock); return; @@ -270,8 +282,72 @@ nni_objhash_unref(nni_objhash *oh, uint32_t id) if (node->on_skips == 0) { oh->oh_load--; } + // Reclaim the buffer if we want, but preserve the limits. + nni_objhash_resize(oh, 0); + + nni_mtx_unlock(&oh->oh_lock); + + // Now run the destructor. + dtor(val); +} + + +void +nni_objhash_unref_wait(nni_objhash *oh, uint32_t id) +{ + int rv; + void *val; + uint32_t index; + nni_objhash_node *node; + nni_objhash_dtor dtor; + + nni_mtx_lock(&oh->oh_lock); + + dtor = oh->oh_dtor; + + node = nni_objhash_find_node(oh, id); + NNI_ASSERT(node != NULL); + val = node->on_val; + + while (node->on_refcnt != 1) { + nni_cv_wait(&oh->oh_cv); + } + node->on_refcnt--; + if (node->on_refcnt != 0) { + if (node->on_refcnt == 1) { + nni_cv_wake(&oh->oh_cv); + } + // Still busy/referenced? + nni_mtx_unlock(&oh->oh_lock); + return; + } - nni_objhash_resize(oh); + index = id & (oh->oh_cap - 1); + for (;;) { + node = &oh->oh_nodes[index]; + if (node->on_id == id) { + break; + } + + NNI_ASSERT(node->on_skips != 0); + node->on_skips--; + if ((node->on_val == NULL) && (node->on_skips == 0)) { + oh->oh_load--; + } + index = NNI_OBJHASH_NEXTPROBE(oh, index); + } + + NNI_ASSERT(node->on_val != NULL); + NNI_ASSERT(node->on_refcnt == 0); + NNI_ASSERT(node->on_id == id); + + node->on_val = NULL; + oh->oh_count--; + if (node->on_skips == 0) { + oh->oh_load--; + } + // Reclaim the buffer if we want, but preserve the limits. + nni_objhash_resize(oh, 0); nni_mtx_unlock(&oh->oh_lock); @@ -299,6 +375,8 @@ nni_objhash_alloc(nni_objhash *oh, uint32_t *idp, void **valp) return (NNG_ENOMEM); } + nni_objhash_resize(oh, 1); + for (;;) { id = oh->oh_dynval; oh->oh_dynval++; @@ -349,9 +427,10 @@ nni_objhash_alloc(nni_objhash *oh, uint32_t *idp, void **valp) } nni_mtx_unlock(&oh->oh_lock); - return (NNG_ENOMEM); // no other return from ctor + return (NNG_ENOMEM); // no other return from ctor } + oh->oh_count++; if (node->on_skips == 0) { oh->oh_load++; } |