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-rw-r--r--util-src/poll.c462
1 files changed, 462 insertions, 0 deletions
diff --git a/util-src/poll.c b/util-src/poll.c
new file mode 100644
index 00000000..7fd28524
--- /dev/null
+++ b/util-src/poll.c
@@ -0,0 +1,462 @@
+
+/*
+ * Lua polling library
+ * Copyright (C) 2017-2018 Kim Alvefur
+ *
+ * This project is MIT licensed. Please see the
+ * COPYING file in the source package for more information.
+ *
+ */
+
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+#ifdef __linux__
+#define USE_EPOLL
+#endif
+
+#ifdef USE_EPOLL
+#include <sys/epoll.h>
+#ifndef MAX_EVENTS
+#define MAX_EVENTS 64
+#endif
+#else
+#include <sys/select.h>
+#endif
+
+#include <lualib.h>
+#include <lauxlib.h>
+
+#ifdef USE_EPOLL
+#define STATE_MT "util.poll<epoll>"
+#else
+#define STATE_MT "util.poll<select>"
+#endif
+
+#if (LUA_VERSION_NUM == 501)
+#define luaL_setmetatable(L, tname) luaL_getmetatable(L, tname); lua_setmetatable(L, -2)
+#endif
+
+/*
+ * Structure to keep state for each type of API
+ */
+typedef struct Lpoll_state {
+ int processed;
+#ifdef USE_EPOLL
+ int epoll_fd;
+ struct epoll_event events[MAX_EVENTS];
+#else
+ fd_set wantread;
+ fd_set wantwrite;
+ fd_set readable;
+ fd_set writable;
+ fd_set all;
+ fd_set err;
+#endif
+} Lpoll_state;
+
+/*
+ * Add an FD to be watched
+ */
+int Ladd(lua_State *L) {
+ struct Lpoll_state *state = luaL_checkudata(L, 1, STATE_MT);
+ int fd = luaL_checkinteger(L, 2);
+
+ int wantread = lua_toboolean(L, 3);
+ int wantwrite = lua_toboolean(L, 4);
+
+ if(fd < 0) {
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(EBADF));
+ lua_pushinteger(L, EBADF);
+ return 3;
+ }
+
+#ifdef USE_EPOLL
+ struct epoll_event event;
+ event.data.fd = fd;
+ event.events = (wantread ? EPOLLIN : 0) | (wantwrite ? EPOLLOUT : 0);
+
+ event.events |= EPOLLERR | EPOLLHUP | EPOLLRDHUP;
+
+ int ret = epoll_ctl(state->epoll_fd, EPOLL_CTL_ADD, fd, &event);
+
+ if(ret < 0) {
+ ret = errno;
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(ret));
+ lua_pushinteger(L, ret);
+ return 3;
+ }
+
+ lua_pushboolean(L, 1);
+ return 1;
+
+#else
+
+ if(fd > FD_SETSIZE) {
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(EBADF));
+ lua_pushinteger(L, EBADF);
+ return 3;
+ }
+
+ if(FD_ISSET(fd, &state->all)) {
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(EEXIST));
+ lua_pushinteger(L, EEXIST);
+ return 3;
+ }
+
+ FD_CLR(fd, &state->readable);
+ FD_CLR(fd, &state->writable);
+ FD_CLR(fd, &state->err);
+
+ FD_SET(fd, &state->all);
+
+ if(wantread) {
+ FD_SET(fd, &state->wantread);
+ }
+ else {
+ FD_CLR(fd, &state->wantread);
+ }
+
+ if(wantwrite) {
+ FD_SET(fd, &state->wantwrite);
+ }
+ else {
+ FD_CLR(fd, &state->wantwrite);
+ }
+
+ lua_pushboolean(L, 1);
+ return 1;
+#endif
+}
+
+/*
+ * Set events to watch for, readable and/or writable
+ */
+int Lset(lua_State *L) {
+ struct Lpoll_state *state = luaL_checkudata(L, 1, STATE_MT);
+ int fd = luaL_checkinteger(L, 2);
+
+#ifdef USE_EPOLL
+
+ int wantread = lua_toboolean(L, 3);
+ int wantwrite = lua_toboolean(L, 4);
+
+ struct epoll_event event;
+ event.data.fd = fd;
+ event.events = (wantread ? EPOLLIN : 0) | (wantwrite ? EPOLLOUT : 0);
+
+ event.events |= EPOLLERR | EPOLLHUP | EPOLLRDHUP;
+
+ int ret = epoll_ctl(state->epoll_fd, EPOLL_CTL_MOD, fd, &event);
+
+ if(ret == 0) {
+ lua_pushboolean(L, 1);
+ return 1;
+ }
+ else {
+ ret = errno;
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(ret));
+ lua_pushinteger(L, ret);
+ return 3;
+ }
+
+#else
+
+ if(!FD_ISSET(fd, &state->all)) {
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(ENOENT));
+ lua_pushinteger(L, ENOENT);
+ }
+
+ if(!lua_isnoneornil(L, 3)) {
+ if(lua_toboolean(L, 3)) {
+ FD_SET(fd, &state->wantread);
+ }
+ else {
+ FD_CLR(fd, &state->wantread);
+ }
+ }
+
+ if(!lua_isnoneornil(L, 4)) {
+ if(lua_toboolean(L, 4)) {
+ FD_SET(fd, &state->wantwrite);
+ }
+ else {
+ FD_CLR(fd, &state->wantwrite);
+ }
+ }
+
+ lua_pushboolean(L, 1);
+ return 1;
+#endif
+}
+
+/*
+ * Remove FDs
+ */
+int Ldel(lua_State *L) {
+ struct Lpoll_state *state = luaL_checkudata(L, 1, STATE_MT);
+ int fd = luaL_checkinteger(L, 2);
+
+#ifdef USE_EPOLL
+
+ struct epoll_event event;
+ event.data.fd = fd;
+
+ int ret = epoll_ctl(state->epoll_fd, EPOLL_CTL_DEL, fd, &event);
+
+ if(ret == 0) {
+ lua_pushboolean(L, 1);
+ return 1;
+ }
+ else {
+ ret = errno;
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(ret));
+ lua_pushinteger(L, ret);
+ return 3;
+ }
+
+#else
+
+ if(!FD_ISSET(fd, &state->all)) {
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(ENOENT));
+ lua_pushinteger(L, ENOENT);
+ }
+
+ FD_CLR(fd, &state->wantread);
+ FD_CLR(fd, &state->wantwrite);
+ FD_CLR(fd, &state->readable);
+ FD_CLR(fd, &state->writable);
+ FD_CLR(fd, &state->all);
+ FD_CLR(fd, &state->err);
+
+ lua_pushboolean(L, 1);
+ return 1;
+#endif
+}
+
+
+/*
+ * Check previously manipulated event state for FDs ready for reading or writing
+ */
+int Lpushevent(lua_State *L, struct Lpoll_state *state) {
+#ifdef USE_EPOLL
+
+ if(state->processed > 0) {
+ state->processed--;
+ struct epoll_event event = state->events[state->processed];
+ lua_pushinteger(L, event.data.fd);
+ lua_pushboolean(L, event.events & (EPOLLIN | EPOLLHUP | EPOLLRDHUP | EPOLLERR));
+ lua_pushboolean(L, event.events & EPOLLOUT);
+ return 3;
+ }
+
+#else
+
+ for(int fd = state->processed + 1; fd < FD_SETSIZE; fd++) {
+ if(FD_ISSET(fd, &state->readable) || FD_ISSET(fd, &state->writable) || FD_ISSET(fd, &state->err)) {
+ lua_pushinteger(L, fd);
+ lua_pushboolean(L, FD_ISSET(fd, &state->readable) | FD_ISSET(fd, &state->err));
+ lua_pushboolean(L, FD_ISSET(fd, &state->writable));
+ FD_CLR(fd, &state->readable);
+ FD_CLR(fd, &state->writable);
+ FD_CLR(fd, &state->err);
+ state->processed = fd;
+ return 3;
+ }
+ }
+
+#endif
+ return 0;
+}
+
+/*
+ * Wait for event
+ */
+int Lwait(lua_State *L) {
+ struct Lpoll_state *state = luaL_checkudata(L, 1, STATE_MT);
+
+ int ret = Lpushevent(L, state);
+
+ if(ret != 0) {
+ return ret;
+ }
+
+ lua_Number timeout = luaL_checknumber(L, 2);
+ luaL_argcheck(L, timeout >= 0, 1, "positive number expected");
+
+#ifdef USE_EPOLL
+ ret = epoll_wait(state->epoll_fd, state->events, MAX_EVENTS, timeout * 1000);
+#else
+ /*
+ * select(2) mutates the fd_sets passed to it so in order to not
+ * have to recreate it manually every time a copy is made.
+ */
+ memcpy(&state->readable, &state->wantread, sizeof(fd_set));
+ memcpy(&state->writable, &state->wantwrite, sizeof(fd_set));
+ memcpy(&state->err, &state->all, sizeof(fd_set));
+
+ struct timeval tv;
+ tv.tv_sec = (time_t)timeout;
+ tv.tv_usec = ((suseconds_t)(timeout * 1000000)) % 1000000;
+
+ ret = select(FD_SETSIZE, &state->readable, &state->writable, &state->err, &tv);
+#endif
+
+ if(ret == 0) {
+ lua_pushnil(L);
+ lua_pushstring(L, "timeout");
+ return 2;
+ }
+ else if(ret < 0) {
+ ret = errno;
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(ret));
+ lua_pushinteger(L, ret);
+ return 3;
+ }
+
+ /*
+ * Search for the first ready FD and return it
+ */
+#ifdef USE_EPOLL
+ state->processed = ret;
+#else
+ state->processed = -1;
+#endif
+ return Lpushevent(L, state);
+}
+
+#ifdef USE_EPOLL
+/*
+ * Return Epoll FD
+ */
+int Lgetfd(lua_State *L) {
+ struct Lpoll_state *state = luaL_checkudata(L, 1, STATE_MT);
+ lua_pushinteger(L, state->epoll_fd);
+ return 1;
+}
+
+/*
+ * Close epoll FD
+ */
+int Lgc(lua_State *L) {
+ struct Lpoll_state *state = luaL_checkudata(L, 1, STATE_MT);
+
+ if(state->epoll_fd == -1) {
+ return 0;
+ }
+
+ if(close(state->epoll_fd) == 0) {
+ state->epoll_fd = -1;
+ }
+ else {
+ lua_pushstring(L, strerror(errno));
+ lua_error(L);
+ }
+
+ return 0;
+}
+#endif
+
+/*
+ * String representation
+ */
+int Ltos(lua_State *L) {
+ struct Lpoll_state *state = luaL_checkudata(L, 1, STATE_MT);
+ lua_pushfstring(L, "%s: %p", STATE_MT, state);
+ return 1;
+}
+
+/*
+ * Create a new context
+ */
+int Lnew(lua_State *L) {
+ /* Allocate state */
+ Lpoll_state *state = lua_newuserdata(L, sizeof(Lpoll_state));
+ luaL_setmetatable(L, STATE_MT);
+
+ /* Initialize state */
+#ifdef USE_EPOLL
+ state->epoll_fd = -1;
+ state->processed = 0;
+
+ int epoll_fd = epoll_create1(EPOLL_CLOEXEC);
+
+ if(epoll_fd <= 0) {
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(errno));
+ lua_pushinteger(L, errno);
+ return 3;
+ }
+
+ state->epoll_fd = epoll_fd;
+#else
+ FD_ZERO(&state->wantread);
+ FD_ZERO(&state->wantwrite);
+ FD_ZERO(&state->readable);
+ FD_ZERO(&state->writable);
+ FD_ZERO(&state->all);
+ FD_ZERO(&state->err);
+ state->processed = FD_SETSIZE;
+#endif
+
+ return 1;
+}
+
+/*
+ * Open library
+ */
+int luaopen_util_poll(lua_State *L) {
+#if (LUA_VERSION_NUM > 501)
+ luaL_checkversion(L);
+#endif
+
+ luaL_newmetatable(L, STATE_MT);
+ {
+
+ lua_pushliteral(L, STATE_MT);
+ lua_setfield(L, -2, "__name");
+
+ lua_pushcfunction(L, Ltos);
+ lua_setfield(L, -2, "__tostring");
+
+ lua_createtable(L, 0, 2);
+ {
+ lua_pushcfunction(L, Ladd);
+ lua_setfield(L, -2, "add");
+ lua_pushcfunction(L, Lset);
+ lua_setfield(L, -2, "set");
+ lua_pushcfunction(L, Ldel);
+ lua_setfield(L, -2, "del");
+ lua_pushcfunction(L, Lwait);
+ lua_setfield(L, -2, "wait");
+#ifdef USE_EPOLL
+ lua_pushcfunction(L, Lgetfd);
+ lua_setfield(L, -2, "getfd");
+#endif
+ }
+ lua_setfield(L, -2, "__index");
+
+#ifdef USE_EPOLL
+ lua_pushcfunction(L, Lgc);
+ lua_setfield(L, -2, "__gc");
+#endif
+ }
+
+ lua_createtable(L, 0, 1);
+ {
+ lua_pushcfunction(L, Lnew);
+ lua_setfield(L, -2, "new");
+ }
+ return 1;
+}
+
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