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|
#include <string.h>
#include <signal.h>
#include <sys/select.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>
#include "midimonster.h"
#include "config.h"
#include "backend.h"
#include "plugin.h"
typedef struct /*_event_collection*/ {
size_t alloc;
size_t n;
channel** channel;
channel_value* value;
} event_collection;
static size_t mappings = 0;
static channel_mapping* map = NULL;
static size_t fds = 0;
static managed_fd* fd = NULL;
static volatile sig_atomic_t fd_set_dirty = 1;
static uint64_t global_timestamp = 0;
static event_collection event_pool[2] = {
{0},
{0}
};
static event_collection* primary = event_pool;
volatile static sig_atomic_t shutdown_requested = 0;
static void signal_handler(int signum){
shutdown_requested = 1;
}
uint64_t mm_timestamp(){
return global_timestamp;
}
static void update_timestamp(){
struct timespec current;
if(clock_gettime(CLOCK_MONOTONIC_COARSE, ¤t)){
fprintf(stderr, "Failed to update global timestamp, time-based processing for some backends may be impaired: %s\n", strerror(errno));
return;
}
global_timestamp = current.tv_sec * 1000 + current.tv_nsec / 1000000;
}
int mm_map_channel(channel* from, channel* to){
size_t u, m;
//find existing source mapping
for(u = 0; u < mappings; u++){
if(map[u].from == from){
break;
}
}
//create new entry
if(u == mappings){
map = realloc(map, (mappings + 1) * sizeof(channel_mapping));
if(!map){
fprintf(stderr, "Failed to allocate memory\n");
return 1;
}
memset(map + mappings, 0, sizeof(channel_mapping));
mappings++;
map[u].from = from;
}
//check whether the target is already mapped
for(m = 0; m < map[u].destinations; m++){
if(map[u].to[m] == to){
return 0;
}
}
map[u].to = realloc(map[u].to, (map[u].destinations + 1) * sizeof(channel*));
if(!map[u].to){
fprintf(stderr, "Failed to allocate memory\n");
map[u].destinations = 0;
return 1;
}
map[u].to[map[u].destinations] = to;
map[u].destinations++;
return 0;
}
void map_free(){
size_t u;
for(u = 0; u < mappings; u++){
free(map[u].to);
}
free(map);
mappings = 0;
map = NULL;
}
int mm_manage_fd(int new_fd, char* back, int manage, void* impl){
backend* b = backend_match(back);
size_t u;
if(!b){
fprintf(stderr, "Unknown backend %s registered for managed fd\n", back);
return 1;
}
//find exact match
for(u = 0; u < fds; u++){
if(fd[u].fd == new_fd && fd[u].backend == b){
if(!manage){
fd[u].fd = -1;
fd[u].backend = NULL;
fd[u].impl = NULL;
fd_set_dirty = 1;
}
return 0;
}
}
if(!manage){
return 0;
}
//find free slot
for(u = 0; u < fds; u++){
if(fd[u].fd < 0){
break;
}
}
//if necessary expand
if(u == fds){
fd = realloc(fd, (fds + 1) * sizeof(managed_fd));
if(!fd){
fprintf(stderr, "Failed to allocate memory\n");
return 1;
}
fds++;
}
//store new fd
fd[u].fd = new_fd;
fd[u].backend = b;
fd[u].impl = impl;
fd_set_dirty = 1;
return 0;
}
void fds_free(){
size_t u;
for(u = 0; u < fds; u++){
//TODO free impl
if(fd[u].fd >= 0){
close(fd[u].fd);
fd[u].fd = -1;
}
}
free(fd);
fds = 0;
fd = NULL;
}
int mm_channel_event(channel* c, channel_value v){
size_t u, p;
//find mapped channels
for(u = 0; u < mappings; u++){
if(map[u].from == c){
break;
}
}
if(u == mappings){
//target-only channel
return 0;
}
//resize event structures to fit additional events
if(primary->n + map[u].destinations >= primary->alloc){
primary->channel = realloc(primary->channel, (primary->alloc + map[u].destinations) * sizeof(channel*));
primary->value = realloc(primary->value, (primary->alloc + map[u].destinations) * sizeof(channel_value));
if(!primary->channel || !primary->value){
fprintf(stderr, "Failed to allocate memory\n");
primary->alloc = 0;
primary->n = 0;
return 1;
}
primary->alloc += map[u].destinations;
}
//enqueue channel events
//FIXME this might lead to one channel being mentioned multiple times in an apply call
for(p = 0; p < map[u].destinations; p++){
primary->channel[primary->n + p] = map[u].to[p];
primary->value[primary->n + p] = v;
}
primary->n += map[u].destinations;
return 0;
}
void event_free(){
size_t u;
for(u = 0; u < sizeof(event_pool) / sizeof(event_collection); u++){
free(event_pool[u].channel);
free(event_pool[u].value);
event_pool[u].alloc = 0;
}
}
int usage(char* fn){
fprintf(stderr, "MIDIMonster v0.1\n");
fprintf(stderr, "Usage:\n");
fprintf(stderr, "\t%s <configfile>\n", fn);
return EXIT_FAILURE;
}
static fd_set fds_collect(int* max_fd){
size_t u = 0;
fd_set rv_fds;
if(max_fd){
*max_fd = -1;
}
DBGPF("Building selector set from %zu FDs registered to core\n", fds);
FD_ZERO(&rv_fds);
for(u = 0; u < fds; u++){
if(fd[u].fd >= 0){
FD_SET(fd[u].fd, &rv_fds);
if(max_fd){
*max_fd = max(*max_fd, fd[u].fd);
}
}
}
return rv_fds;
}
int main(int argc, char** argv){
fd_set all_fds, read_fds;
event_collection* secondary = NULL;
struct timeval tv;
size_t u, n;
managed_fd* signaled_fds = NULL;
int rv = EXIT_FAILURE, error, maxfd = -1;
char* cfg_file = DEFAULT_CFG;
if(argc > 1){
cfg_file = argv[1];
}
//initialize backends
if(plugins_load(PLUGINS)){
fprintf(stderr, "Failed to initialize a backend\n");
goto bail;
}
//read config
if(config_read(cfg_file)){
fprintf(stderr, "Failed to read configuration file %s\n", cfg_file);
backends_stop();
channels_free();
instances_free();
map_free();
fds_free();
plugins_close();
return usage(argv[0]);
}
//start backends
if(backends_start()){
goto bail;
}
signal(SIGINT, signal_handler);
//allocate data buffers
signaled_fds = calloc(fds, sizeof(managed_fd));
if(!signaled_fds){
fprintf(stderr, "Failed to allocate memory\n");
goto bail;
}
//process events
while(!shutdown_requested){
//build fd set if necessary
if(fd_set_dirty){
all_fds = fds_collect(&maxfd);
fd_set_dirty = 0;
}
//wait for & translate events
read_fds = all_fds;
tv = backend_timeout();
error = select(maxfd + 1, &read_fds, NULL, NULL, &tv);
if(error < 0){
fprintf(stderr, "select failed: %s\n", strerror(errno));
break;
}
//find all signaled fds
n = 0;
for(u = 0; u < fds; u++){
if(fd[u].fd >= 0 && FD_ISSET(fd[u].fd, &read_fds)){
signaled_fds[n] = fd[u];
n++;
}
}
//update this iteration's timestamp
update_timestamp();
//run backend processing, collect events
DBGPF("%zu backend FDs signaled\n", n);
if(backends_handle(n, signaled_fds)){
goto bail;
}
while(primary->n){
//swap primary and secondary event collectors
DBGPF("Swapping event collectors, %zu events in primary\n", primary->n);
for(u = 0; u < sizeof(event_pool)/sizeof(event_collection); u++){
if(primary != event_pool + u){
secondary = primary;
primary = event_pool + u;
break;
}
}
//push collected events to target backends
if(secondary->n && backends_notify(secondary->n, secondary->channel, secondary->value)){
fprintf(stderr, "Backends failed to handle output\n");
goto bail;
}
//reset the event count
secondary->n = 0;
}
}
rv = EXIT_SUCCESS;
bail:
//free all data
free(signaled_fds);
backends_stop();
channels_free();
instances_free();
map_free();
fds_free();
event_free();
plugins_close();
return rv;
}
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