1/* Copyright Joyent, Inc. and other Node contributors. All rights reserved. 2 * 3 * Permission is hereby granted, free of charge, to any person obtaining a copy 4 * of this software and associated documentation files (the "Software"), to 5 * deal in the Software without restriction, including without limitation the 6 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or 7 * sell copies of the Software, and to permit persons to whom the Software is 8 * furnished to do so, subject to the following conditions: 9 * 10 * The above copyright notice and this permission notice shall be included in 11 * all copies or substantial portions of the Software. 12 * 13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 16 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 18 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 19 * IN THE SOFTWARE. 20 */ 21 22#include "uv.h" 23#include "uv-common.h" 24 25#ifdef _WIN32 26#include "win/internal.h" 27#include "win/handle-inl.h" 28#define uv__make_close_pending(h) uv__want_endgame((h)->loop, (h)) 29#else 30#include "unix/internal.h" 31#endif 32 33#include <assert.h> 34#include <stdlib.h> 35#include <string.h> 36 37struct poll_ctx { 38 uv_fs_poll_t* parent_handle; 39 int busy_polling; 40 unsigned int interval; 41 uint64_t start_time; 42 uv_loop_t* loop; 43 uv_fs_poll_cb poll_cb; 44 uv_timer_t timer_handle; 45 uv_fs_t fs_req; /* TODO(bnoordhuis) mark fs_req internal */ 46 uv_stat_t statbuf; 47 struct poll_ctx* previous; /* context from previous start()..stop() period */ 48 char path[1]; /* variable length */ 49}; 50 51static int statbuf_eq(const uv_stat_t* a, const uv_stat_t* b); 52static void poll_cb(uv_fs_t* req); 53static void timer_cb(uv_timer_t* timer); 54static void timer_close_cb(uv_handle_t* handle); 55 56static uv_stat_t zero_statbuf; 57 58 59int uv_fs_poll_init(uv_loop_t* loop, uv_fs_poll_t* handle) { 60 uv__handle_init(loop, (uv_handle_t*)handle, UV_FS_POLL); 61 handle->poll_ctx = NULL; 62 return 0; 63} 64 65 66int uv_fs_poll_start(uv_fs_poll_t* handle, 67 uv_fs_poll_cb cb, 68 const char* path, 69 unsigned int interval) { 70 struct poll_ctx* ctx; 71 uv_loop_t* loop; 72 size_t len; 73 int err; 74 75 if (uv_is_active((uv_handle_t*)handle)) 76 return 0; 77 78 loop = handle->loop; 79 len = strlen(path); 80 ctx = uv__calloc(1, sizeof(*ctx) + len); 81 82 if (ctx == NULL) 83 return UV_ENOMEM; 84 85 ctx->loop = loop; 86 ctx->poll_cb = cb; 87 ctx->interval = interval ? interval : 1; 88 ctx->start_time = uv_now(loop); 89 ctx->parent_handle = handle; 90 memcpy(ctx->path, path, len + 1); 91 92 err = uv_timer_init(loop, &ctx->timer_handle); 93 if (err < 0) 94 goto error; 95 96 ctx->timer_handle.flags |= UV_HANDLE_INTERNAL; 97 uv__handle_unref(&ctx->timer_handle); 98 99 err = uv_fs_stat(loop, &ctx->fs_req, ctx->path, poll_cb); 100 if (err < 0) 101 goto error; 102 103 if (handle->poll_ctx != NULL) 104 ctx->previous = handle->poll_ctx; 105 handle->poll_ctx = ctx; 106 uv__handle_start(handle); 107 108 return 0; 109 110error: 111 uv__free(ctx); 112 return err; 113} 114 115 116int uv_fs_poll_stop(uv_fs_poll_t* handle) { 117 struct poll_ctx* ctx; 118 119 if (!uv_is_active((uv_handle_t*)handle)) 120 return 0; 121 122 ctx = handle->poll_ctx; 123 assert(ctx != NULL); 124 assert(ctx->parent_handle == handle); 125 126 /* Close the timer if it's active. If it's inactive, there's a stat request 127 * in progress and poll_cb will take care of the cleanup. 128 */ 129 if (uv_is_active((uv_handle_t*)&ctx->timer_handle)) 130 uv_close((uv_handle_t*)&ctx->timer_handle, timer_close_cb); 131 132 uv__handle_stop(handle); 133 134 return 0; 135} 136 137 138int uv_fs_poll_getpath(uv_fs_poll_t* handle, char* buffer, size_t* size) { 139 struct poll_ctx* ctx; 140 size_t required_len; 141 142 if (!uv_is_active((uv_handle_t*)handle)) { 143 *size = 0; 144 return UV_EINVAL; 145 } 146 147 ctx = handle->poll_ctx; 148 assert(ctx != NULL); 149 150 required_len = strlen(ctx->path); 151 if (required_len >= *size) { 152 *size = required_len + 1; 153 return UV_ENOBUFS; 154 } 155 156 memcpy(buffer, ctx->path, required_len); 157 *size = required_len; 158 buffer[required_len] = '\0'; 159 160 return 0; 161} 162 163 164void uv__fs_poll_close(uv_fs_poll_t* handle) { 165 uv_fs_poll_stop(handle); 166 167 if (handle->poll_ctx == NULL) 168 uv__make_close_pending((uv_handle_t*)handle); 169} 170 171 172static void timer_cb(uv_timer_t* timer) { 173 struct poll_ctx* ctx; 174 175 ctx = container_of(timer, struct poll_ctx, timer_handle); 176 assert(ctx->parent_handle != NULL); 177 assert(ctx->parent_handle->poll_ctx == ctx); 178 ctx->start_time = uv_now(ctx->loop); 179 180 if (uv_fs_stat(ctx->loop, &ctx->fs_req, ctx->path, poll_cb)) 181 abort(); 182} 183 184 185static void poll_cb(uv_fs_t* req) { 186 uv_stat_t* statbuf; 187 struct poll_ctx* ctx; 188 uint64_t interval; 189 uv_fs_poll_t* handle; 190 191 ctx = container_of(req, struct poll_ctx, fs_req); 192 handle = ctx->parent_handle; 193 194 if (!uv_is_active((uv_handle_t*)handle) || uv__is_closing(handle)) 195 goto out; 196 197 if (req->result != 0) { 198 if (ctx->busy_polling != req->result) { 199 ctx->poll_cb(ctx->parent_handle, 200 req->result, 201 &ctx->statbuf, 202 &zero_statbuf); 203 ctx->busy_polling = req->result; 204 } 205 goto out; 206 } 207 208 statbuf = &req->statbuf; 209 210 if (ctx->busy_polling != 0) 211 if (ctx->busy_polling < 0 || !statbuf_eq(&ctx->statbuf, statbuf)) 212 ctx->poll_cb(ctx->parent_handle, 0, &ctx->statbuf, statbuf); 213 214 ctx->statbuf = *statbuf; 215 ctx->busy_polling = 1; 216 217out: 218 uv_fs_req_cleanup(req); 219 220 if (!uv_is_active((uv_handle_t*)handle) || uv__is_closing(handle)) { 221 uv_close((uv_handle_t*)&ctx->timer_handle, timer_close_cb); 222 return; 223 } 224 225 /* Reschedule timer, subtract the delay from doing the stat(). */ 226 interval = ctx->interval; 227 interval -= (uv_now(ctx->loop) - ctx->start_time) % interval; 228 229 if (uv_timer_start(&ctx->timer_handle, timer_cb, interval, 0)) 230 abort(); 231} 232 233 234static void timer_close_cb(uv_handle_t* timer) { 235 struct poll_ctx* ctx; 236 struct poll_ctx* it; 237 struct poll_ctx* last; 238 uv_fs_poll_t* handle; 239 240 ctx = container_of(timer, struct poll_ctx, timer_handle); 241 handle = ctx->parent_handle; 242 if (ctx == handle->poll_ctx) { 243 handle->poll_ctx = ctx->previous; 244 if (handle->poll_ctx == NULL && uv__is_closing(handle)) 245 uv__make_close_pending((uv_handle_t*)handle); 246 } else { 247 for (last = handle->poll_ctx, it = last->previous; 248 it != ctx; 249 last = it, it = it->previous) { 250 assert(last->previous != NULL); 251 } 252 last->previous = ctx->previous; 253 } 254 uv__free(ctx); 255} 256 257 258static int statbuf_eq(const uv_stat_t* a, const uv_stat_t* b) { 259 return a->st_ctim.tv_nsec == b->st_ctim.tv_nsec 260 && a->st_mtim.tv_nsec == b->st_mtim.tv_nsec 261 && a->st_birthtim.tv_nsec == b->st_birthtim.tv_nsec 262 && a->st_ctim.tv_sec == b->st_ctim.tv_sec 263 && a->st_mtim.tv_sec == b->st_mtim.tv_sec 264 && a->st_birthtim.tv_sec == b->st_birthtim.tv_sec 265 && a->st_size == b->st_size 266 && a->st_mode == b->st_mode 267 && a->st_uid == b->st_uid 268 && a->st_gid == b->st_gid 269 && a->st_ino == b->st_ino 270 && a->st_dev == b->st_dev 271 && a->st_flags == b->st_flags 272 && a->st_gen == b->st_gen; 273} 274 275 276#if defined(_WIN32) 277 278#include "win/internal.h" 279#include "win/handle-inl.h" 280 281void uv__fs_poll_endgame(uv_loop_t* loop, uv_fs_poll_t* handle) { 282 assert(handle->flags & UV_HANDLE_CLOSING); 283 assert(!(handle->flags & UV_HANDLE_CLOSED)); 284 uv__handle_close(handle); 285} 286 287#endif /* _WIN32 */ 288