diff options
| -rw-r--r-- | backend.c | 81 | ||||
| -rw-r--r-- | midimonster.h | 54 |
2 files changed, 74 insertions, 61 deletions
@@ -16,9 +16,21 @@ static struct { .n = 0 }; -//TODO move channel store into registry -static size_t nchannels = 0; -static channel** channels = NULL; +//the global channel store was converted from a naive list to a hashmap of lists for performance reasons +static struct { + //channelstore hash is set up for 256 buckets + size_t n[256]; + channel** entry[256]; +} channels = { + .n = { + 0 + } +}; + +static size_t channelstore_hash(instance* inst, uint64_t ident){ + uint64_t repr = ((uint64_t) inst) ^ ident; + return (repr ^ (repr >> 8) ^ (repr >> 16) ^ (repr >> 24) ^ (repr >> 32)) & 0xFF; +} int backends_handle(size_t nfds, managed_fd* fds){ size_t u, p, n; @@ -81,11 +93,12 @@ int backends_notify(size_t nev, channel** c, channel_value* v){ } MM_API channel* mm_channel(instance* inst, uint64_t ident, uint8_t create){ - size_t u; - for(u = 0; u < nchannels; u++){ - if(channels[u]->instance == inst && channels[u]->ident == ident){ - DBGPF("Requested channel %" PRIu64 " on instance %s already exists, reusing\n", ident, inst->name); - return channels[u]; + size_t u, bucket = channelstore_hash(inst, ident); + for(u = 0; u < channels.n[bucket]; u++){ + if(channels.entry[bucket][u]->instance == inst + && channels.entry[bucket][u]->ident == ident){ + DBGPF("Requested channel %" PRIu64 " on instance %s already exists, reusing (%" PRIsize_t " search steps)\n", ident, inst->name, u); + return channels.entry[bucket][u]; } } @@ -94,24 +107,23 @@ MM_API channel* mm_channel(instance* inst, uint64_t ident, uint8_t create){ return NULL; } - DBGPF("Creating previously unknown channel %" PRIu64 " on instance %s\n", ident, inst->name); - channel** new_chan = realloc(channels, (nchannels + 1) * sizeof(channel*)); - if(!new_chan){ + DBGPF("Creating previously unknown channel %" PRIu64 " on instance %s, bucket %" PRIsize_t "\n", ident, inst->name, bucket); + channels.entry[bucket] = realloc(channels.entry[bucket], (channels.n[bucket] + 1) * sizeof(channel*)); + if(!channels.entry[bucket]){ fprintf(stderr, "Failed to allocate memory\n"); - nchannels = 0; + channels.n[bucket] = 0; return NULL; } - channels = new_chan; - channels[nchannels] = calloc(1, sizeof(channel)); - if(!channels[nchannels]){ + channels.entry[bucket][channels.n[bucket]] = calloc(1, sizeof(channel)); + if(!channels.entry[bucket][channels.n[bucket]]){ fprintf(stderr, "Failed to allocate memory\n"); return NULL; } - channels[nchannels]->instance = inst; - channels[nchannels]->ident = ident; - return channels[nchannels++]; + channels.entry[bucket][channels.n[bucket]]->instance = inst; + channels.entry[bucket][channels.n[bucket]]->ident = ident; + return channels.entry[bucket][(channels.n[bucket]++)]; } instance* mm_instance(backend* b){ @@ -191,21 +203,6 @@ MM_API int mm_backend_instances(char* name, size_t* ninst, instance*** inst){ return 1; } -void channels_free(){ - size_t u; - for(u = 0; u < nchannels; u++){ - DBGPF("Destroying channel %" PRIu64 " on instance %s\n", channels[u]->ident, channels[u]->instance->name); - if(channels[u]->impl && channels[u]->instance->backend->channel_free){ - channels[u]->instance->backend->channel_free(channels[u]); - } - free(channels[u]); - channels[u] = NULL; - } - free(channels); - nchannels = 0; -} - - backend* backend_match(char* name){ size_t u; for(u = 0; u < registry.n; u++){ @@ -306,6 +303,24 @@ int backends_start(){ return rv; } +static void channels_free(){ + size_t u, p; + for(u = 0; u < sizeof(channels.n) / sizeof(channels.n[0]); u++){ + DBGPF("Cleaning up channel registry bucket %" PRIsize_t " with %" PRIsize_t " channels", u, channels.n[u]); + for(p = 0; p < channels.n[u]; p++){ + DBGPF("Destroying channel %" PRIu64 " on instance %s\n", channels.entry[u][p]->ident, channels.entry[u][p]->instance->name); + //call the channel_free function if the backend supports it + if(channels.entry[u][p]->impl && channels.entry[u][p]->instance->backend->channel_free){ + channels.entry[u][p]->instance->backend->channel_free(channels.entry[u][p]); + } + free(channels.entry[u][p]); + } + free(channels.entry[u]); + channels.entry[u] = NULL; + channels.n[u] = 0; + } +} + int backends_stop(){ size_t u, n; instance** inst = NULL; diff --git a/midimonster.h b/midimonster.h index 61467c1..75eb30a 100644 --- a/midimonster.h +++ b/midimonster.h @@ -192,8 +192,8 @@ typedef struct _backend_instance { /* * Instance channel structure - * Backends may either manage their own channel registry - * or use the memory returned by mm_channel() + * Backends may either manage their own channel registry or use the global + * channel store via the mm_channel() API */ typedef struct _backend_channel { instance* instance; @@ -218,25 +218,24 @@ MM_API int mm_backend_register(backend b); /* * Finds an instance matching the specified backend and identifier. - * Since setting an identifier for an instance is optional, - * this may not work depending on the backend. - * Instance identifiers may for example be set in the backends - * mmbackend_start call. + * Since setting an identifier for an instance is optional, this may not work + * depending on the backend. Instance identifiers may for example be set in the + * backends mmbackend_start call. */ MM_API instance* mm_instance_find(char* backend, uint64_t ident); /* - * Provides a pointer to a channel structure, pre-filled with - * the provided instance reference and identifier. - * The `create` parameter is a boolean flag indicating whether - * a channel matching the `ident` parameter should be created if - * none exists. If the instance already registered a channel - * matching `ident`, a pointer to it is returned. - * This API is just a convenience function. The array of channels is - * only used for mapping internally, creating and managing your own - * channel store is possible. When returning pointers from a - * backend-local channel store, the returned pointers must stay - * valid over the lifetime of the instance. + * Provides a pointer to a channel structure, pre-filled with the provided + * instance reference and identifier. + * The `create` parameter is a boolean flag indicating whether a channel + * matching the `ident` parameter should be created in the global channel store + * if none exists yet. If the instance already registered a channel matching + * `ident`, a pointer to the existing channel is returned. + * This API is just a convenience function. Creating and managing a + * backend-internal channel store is possible (and encouraged for performance + * reasons). When returning pointers from a backend-local channel store, the + * returned pointers must stay valid over the lifetime of the instance and + * provide valid `instance` members, as they are used for callbacks. * For each channel with a non-NULL `impl` field registered using * this function, the backend will receive a call to its channel_free * function (if it exists). @@ -244,17 +243,16 @@ MM_API instance* mm_instance_find(char* backend, uint64_t ident); MM_API channel* mm_channel(instance* i, uint64_t ident, uint8_t create); /* - * Register (manage = 1) or unregister (manage = 0) a file descriptor - * to be selected on. The backend will be notified when the descriptor - * becomes ready to read via its registered mmbackend_process_fd call. - * The `impl` argument will be provided within the corresponding - * managed_fd structure upon callback. + * Register (manage = 1) or unregister (manage = 0) a file descriptor to be + * selected on. The backend will be notified when the descriptor becomes ready + * to read via its registered mmbackend_process_fd call. The `impl` argument + * will be provided within the corresponding managed_fd structure upon callback. */ MM_API int mm_manage_fd(int fd, char* backend, int manage, void* impl); /* - * Notifies the core of a channel event. Called by backends to - * inject events gathered from their backing implementation. + * Notifies the core of a channel event. Called by backends to inject events + * gathered from their backing implementation. */ MM_API int mm_channel_event(channel* c, channel_value v); @@ -266,14 +264,14 @@ MM_API int mm_backend_instances(char* backend, size_t* n, instance*** i); /* * Query an internal timestamp, which is updated every core iteration. - * This timestamp should not be used as a performance counter, but can be - * used for timeouting. Resolution is milliseconds. + * This timestamp should not be used as a performance counter, but can be used + * for timeouting. Resolution is milliseconds. */ MM_API uint64_t mm_timestamp(); /* - * Create a channel-to-channel mapping. This API should not - * be used by backends. It is only exported for core modules. + * Create a channel-to-channel mapping. This API should not be used by backends. + * It is only exported for core modules. */ int mm_map_channel(channel* from, channel* to); #endif |