From d757a9c63371fcf5f9aa832d58ed4b8bdf634909 Mon Sep 17 00:00:00 2001 From: cbdev Date: Tue, 10 Mar 2020 20:42:55 +0100 Subject: Restructure core loop, add check for zero-descriptor case --- midimonster.c | 197 ++++++++++++++++++++++++++++++++++++---------------------- 1 file changed, 121 insertions(+), 76 deletions(-) (limited to 'midimonster.c') diff --git a/midimonster.c b/midimonster.c index b8594b4..3212f7f 100644 --- a/midimonster.c +++ b/midimonster.c @@ -9,6 +9,7 @@ #else #define MM_API __attribute__((dllexport)) #endif +#define BACKEND_NAME "core" #include "midimonster.h" #include "config.h" #include "backend.h" @@ -325,18 +326,126 @@ static int args_parse(int argc, char** argv, char** cfg_file){ return 0; } -int main(int argc, char** argv){ - fd_set all_fds, read_fds; +static int core_process(size_t nfds, managed_fd* signaled_fds){ event_collection* secondary = NULL; - struct timeval tv; - size_t u, n; + size_t u; + + //run backend processing, collect events + DBGPF("%lu backend FDs signaled\n", nfds); + if(backends_handle(nfds, signaled_fds)){ + return 1; + } + + while(primary->n){ + //swap primary and secondary event collectors + DBGPF("Swapping event collectors, %lu 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"); + return 1; + } + + //reset the event count + secondary->n = 0; + } + + return 0; +} + +static int core_loop(){ + fd_set all_fds, read_fds; managed_fd* signaled_fds = NULL; - int rv = EXIT_FAILURE, error, maxfd = -1; - char* cfg_file = DEFAULT_CFG; + struct timeval tv; + int error, maxfd = -1; + size_t n, u; #ifdef _WIN32 char* error_message = NULL; + #else + struct timespec ts; #endif + FD_ZERO(&all_fds); + + //process events + while(!shutdown_requested){ + //rebuild fd set if necessary + if(fd_set_dirty){ + all_fds = fds_collect(&maxfd); + signaled_fds = realloc(signaled_fds, fds * sizeof(managed_fd)); + if(!signaled_fds){ + fprintf(stderr, "Failed to allocate memory\n"); + return 1; + } + fd_set_dirty = 0; + } + + //wait for & translate events + read_fds = all_fds; + tv = backend_timeout(); + + //check whether there are any fds active, windows does not like select() without descriptors + if(maxfd >= 0){ + error = select(maxfd + 1, &read_fds, NULL, NULL, &tv); + if(error < 0){ + #ifndef _WIN32 + fprintf(stderr, "select failed: %s\n", strerror(errno)); + #else + FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, + NULL, WSAGetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) &error_message, 0, NULL); + fprintf(stderr, "select failed: %s\n", error_message); + LocalFree(error_message); + error_message = NULL; + #endif + free(signaled_fds); + return 1; + } + } + else{ + DBGPF("No descriptors, sleeping for %zu msec", tv.tv_sec * 1000 + tv.tv_usec / 1000); + #ifdef _WIN32 + Sleep(tv.tv_sec * 1000 + tv.tv_usec / 1000); + #else + ts.tv_sec = tv.tv_sec; + ts.tv_nsec = tv.tv_usec * 1000; + error = nanosleep(&ts, NULL); + #endif + } + + //update this iteration's timestamp + update_timestamp(); + + //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++; + } + } + + //fetch and process events + if(core_process(n, signaled_fds)){ + free(signaled_fds); + return 1; + } + } + + free(signaled_fds); + return 0; +} + +int main(int argc, char** argv){ + int rv = EXIT_FAILURE; + char* cfg_file = DEFAULT_CFG; + //parse commandline arguments if(args_parse(argc, argv, &cfg_file)){ return EXIT_FAILURE; @@ -347,7 +456,6 @@ int main(int argc, char** argv){ return EXIT_FAILURE; } - FD_ZERO(&all_fds); //initialize backends if(plugins_load(PLUGINS)){ fprintf(stderr, "Failed to initialize a backend\n"); @@ -377,80 +485,17 @@ int main(int argc, char** argv){ signal(SIGINT, signal_handler); - //process events - while(!shutdown_requested){ - //rebuild fd set if necessary - if(fd_set_dirty){ - all_fds = fds_collect(&maxfd); - signaled_fds = realloc(signaled_fds, fds * sizeof(managed_fd)); - if(!signaled_fds){ - fprintf(stderr, "Failed to allocate memory\n"); - goto bail; - } - 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){ - #ifndef _WIN32 - fprintf(stderr, "select failed: %s\n", strerror(errno)); - #else - FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, - NULL, WSAGetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) &error_message, 0, NULL); - fprintf(stderr, "select failed: %s\n", error_message); - LocalFree(error_message); - error_message = NULL; - #endif - 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("%lu 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, %lu 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; - } + if(!fds){ + fprintf(stderr, "No descriptors registered for multiplexing\n"); + } - //reset the event count - secondary->n = 0; - } + //run the core loop + if(!core_loop()){ + rv = EXIT_SUCCESS; } - rv = EXIT_SUCCESS; bail: //free all data - free(signaled_fds); backends_stop(); channels_free(); instances_free(); -- cgit v1.2.3