From 3b134cc43965c1c196734be7a162da7cddeeafc8 Mon Sep 17 00:00:00 2001 From: cbdev Date: Thu, 1 Jul 2021 22:34:24 +0200 Subject: Factor out explicit frontend API --- core/core.c | 257 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 257 insertions(+) create mode 100644 core/core.c (limited to 'core/core.c') diff --git a/core/core.c b/core/core.c new file mode 100644 index 0000000..cd097f8 --- /dev/null +++ b/core/core.c @@ -0,0 +1,257 @@ +#include +#include +#include +#include +#include +#ifndef _WIN32 + #include + #define MM_API __attribute__((visibility ("default"))) +#else + #define MM_API __attribute__((dllexport)) +#endif + +#define BACKEND_NAME "core" +#include "midimonster.h" +#include "core.h" +#include "backend.h" +#include "routing.h" +#include "plugin.h" +#include "config.h" + +static size_t fds = 0; +static int max_fd = -1; +static managed_fd* fd = NULL; +static managed_fd* signaled_fds = NULL; +static volatile sig_atomic_t fd_set_dirty = 1; +static uint64_t global_timestamp = 0; + +static fd_set all_fds; + +MM_API uint64_t mm_timestamp(){ + return global_timestamp; +} + +static void core_timestamp(){ + #ifdef _WIN32 + global_timestamp = GetTickCount(); + #else + 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; + #endif +} + +static fd_set core_collect(int* max_fd){ + size_t u = 0; + fd_set rv_fds; + + if(max_fd){ + *max_fd = -1; + } + + DBGPF("Building selector set from %" PRIsize_t " FDs registered to core", 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; +} + +MM_API 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){ + fd[u].impl = impl; + 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; + } + + signaled_fds = realloc(signaled_fds, (fds + 1) * sizeof(managed_fd)); + if(!signaled_fds){ + 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; +} + +int core_initialize(){ + FD_ZERO(&all_fds); + + //load initial timestamp + core_timestamp(); + + #ifdef _WIN32 + WSADATA wsa; + WORD version = MAKEWORD(2, 2); + if(WSAStartup(version, &wsa)){ + return 1; + } + _fmode = _O_BINARY; + #endif + + //attach plugins + if(plugins_load(PLUGINS)){ + LOG("Failed to initialize a backend"); + return 1; + } + + return 0; +} + +int core_start(){ + if(backends_start()){ + return 1; + } + + routing_stats(); + + if(!fds){ + LOG("No descriptors registered for multiplexing"); + } + + return 0; +} + +int core_iteration(){ + fd_set read_fds; + struct timeval tv; + int error; + size_t n, u; + #ifdef _WIN32 + char* error_message = NULL; + #else + struct timespec ts; + #endif + + //rebuild fd set if necessary + if(fd_set_dirty || !signaled_fds){ + all_fds = core_collect(&max_fd); + 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(max_fd >= 0){ + error = select(max_fd + 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 + 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; + nanosleep(&ts, NULL); + #endif + } + + //update this iteration's timestamp + core_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++; + } + } + + //run backend processing to collect events + DBGPF("%" PRIsize_t " backend FDs signaled", nfds); + if(backends_handle(n, signaled_fds)){ + return 1; + } + + //route generated events + return routing_iteration(); +} + +static void fds_free(){ + size_t u; + for(u = 0; u < fds; u++){ + if(fd[u].fd >= 0){ + close(fd[u].fd); + fd[u].fd = -1; + } + } + free(fd); + fds = 0; + fd = NULL; +} + +void core_shutdown(){ + backends_stop(); + routing_cleanup(); + free(signaled_fds); + signaled_fds = NULL; + fds_free(); + plugins_close(); + config_free(); + fd_set_dirty = 1; +} -- cgit v1.2.3