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annotate src/c/driver.c @ 498:cbeb1683dc6a

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Extend prose about server .exes
author Adam Chlipala <adamc@hcoop.net>
date Tue, 18 Nov 2008 13:47:23 -0500
parents 667c0e54632a
children 581554f8e642
rev   line source
adamc@116 1 #include <stdio.h>
adamc@116 2
adamc@116 3 #include <string.h>
adamc@116 4 #include <sys/types.h>
adamc@116 5 #include <sys/socket.h>
adamc@116 6 #include <netinet/in.h>
adamc@472 7 #include <unistd.h>
adamc@116 8
adamc@138 9 #include <pthread.h>
adamc@138 10
adamc@244 11 #include "urweb.h"
adamc@117 12
adamc@311 13 int uw_backlog = 10;
adamc@311 14 int uw_bufsize = 1024;
adamc@116 15
adamc@138 16 typedef struct node {
adamc@138 17 int fd;
adamc@138 18 struct node *next;
adamc@138 19 } *node;
adamc@138 20
adamc@138 21 static node front = NULL, back = NULL;
adamc@138 22
adamc@138 23 static int empty() {
adamc@138 24 return front == NULL;
adamc@138 25 }
adamc@138 26
adamc@138 27 static void enqueue(int fd) {
adamc@138 28 node n = malloc(sizeof(struct node));
adamc@138 29
adamc@138 30 n->fd = fd;
adamc@138 31 n->next = NULL;
adamc@138 32 if (back)
adamc@138 33 back->next = n;
adamc@138 34 else
adamc@138 35 front = n;
adamc@138 36 back = n;
adamc@138 37 }
adamc@138 38
adamc@138 39 static int dequeue() {
adamc@138 40 int ret = front->fd;
adamc@138 41
adamc@138 42 front = front->next;
adamc@138 43 if (!front)
adamc@138 44 back = NULL;
adamc@138 45
adamc@138 46 return ret;
adamc@138 47 }
adamc@138 48
adamc@138 49 static pthread_mutex_t queue_mutex = PTHREAD_MUTEX_INITIALIZER;
adamc@138 50 static pthread_cond_t queue_cond = PTHREAD_COND_INITIALIZER;
adamc@138 51
adamc@167 52 #define MAX_RETRIES 5
adamc@167 53
adamc@424 54 int uw_db_begin(uw_context);
adamc@424 55 int uw_db_commit(uw_context);
adamc@424 56 int uw_db_rollback(uw_context);
adamc@424 57
adamc@424 58 static int try_rollback(uw_context ctx) {
adamc@424 59 int r = uw_db_rollback(ctx);
adamc@424 60
adamc@424 61 if (r) {
adamc@424 62 printf("Error running SQL ROLLBACK\n");
adamc@424 63 uw_reset(ctx);
adamc@424 64 uw_write(ctx, "HTTP/1.1 500 Internal Server Error\n\r");
adamc@424 65 uw_write(ctx, "Content-type: text/plain\r\n\r\n");
adamc@424 66 uw_write(ctx, "Error running SQL ROLLBACK\n");
adamc@424 67 }
adamc@424 68
adamc@424 69 return r;
adamc@424 70 }
adamc@424 71
adamc@138 72 static void *worker(void *data) {
adamc@324 73 int me = *(int *)data, retries_left = MAX_RETRIES;
adamc@466 74 uw_context ctx = uw_init(0, 1024, 0);
adamc@272 75
adamc@272 76 while (1) {
adamc@311 77 failure_kind fk = uw_begin_init(ctx);
adamc@272 78
adamc@272 79 if (fk == SUCCESS) {
adamc@311 80 uw_db_init(ctx);
adamc@272 81 printf("Database connection initialized.\n");
adamc@272 82 break;
adamc@272 83 } else if (fk == BOUNDED_RETRY) {
adamc@272 84 if (retries_left) {
adamc@311 85 printf("Initialization error triggers bounded retry: %s\n", uw_error_message(ctx));
adamc@272 86 --retries_left;
adamc@272 87 } else {
adamc@311 88 printf("Fatal initialization error (out of retries): %s\n", uw_error_message(ctx));
adamc@311 89 uw_free(ctx);
adamc@272 90 return NULL;
adamc@272 91 }
adamc@272 92 } else if (fk == UNLIMITED_RETRY)
adamc@311 93 printf("Initialization error triggers unlimited retry: %s\n", uw_error_message(ctx));
adamc@272 94 else if (fk == FATAL) {
adamc@311 95 printf("Fatal initialization error: %s\n", uw_error_message(ctx));
adamc@311 96 uw_free(ctx);
adamc@272 97 return NULL;
adamc@272 98 } else {
adamc@311 99 printf("Unknown uw_handle return code!\n");
adamc@311 100 uw_free(ctx);
adamc@272 101 return NULL;
adamc@272 102 }
adamc@272 103 }
adamc@116 104
adamc@116 105 while (1) {
adamc@311 106 char buf[uw_bufsize+1], *back = buf, *s;
adamc@138 107 int sock;
adamc@116 108
adamc@138 109 pthread_mutex_lock(&queue_mutex);
adamc@138 110 while (empty())
adamc@138 111 pthread_cond_wait(&queue_cond, &queue_mutex);
adamc@138 112 sock = dequeue();
adamc@138 113 pthread_mutex_unlock(&queue_mutex);
adamc@138 114
adamc@138 115 printf("Handling connection with thread #%d.\n", me);
adamc@138 116
adamc@138 117 while (1) {
adamc@167 118 unsigned retries_left = MAX_RETRIES;
adamc@311 119 int r = recv(sock, back, uw_bufsize - (back - buf), 0);
adamc@138 120
adamc@138 121 if (r < 0) {
adamc@138 122 fprintf(stderr, "Recv failed\n");
adamc@138 123 break;
adamc@138 124 }
adamc@138 125
adamc@138 126 if (r == 0) {
adamc@138 127 printf("Connection closed.\n");
adamc@138 128 break;
adamc@138 129 }
adamc@138 130
adamc@138 131 printf("Received %d bytes.\n", r);
adamc@138 132
adamc@138 133 back += r;
adamc@138 134 *back = 0;
adamc@138 135
adamc@138 136 if (s = strstr(buf, "\r\n\r\n")) {
adamc@424 137 failure_kind fk;
adamc@457 138 char *cmd, *path, *headers, path_copy[uw_bufsize+1], *inputs;
adamc@138 139
adamc@475 140 s[2] = 0;
adamc@144 141
adamc@138 142 if (!(s = strstr(buf, "\r\n"))) {
adamc@138 143 fprintf(stderr, "No newline in buf\n");
adamc@138 144 break;
adamc@138 145 }
adamc@138 146
adamc@138 147 *s = 0;
adamc@457 148 headers = s + 2;
adamc@138 149 cmd = s = buf;
adamc@401 150
adamc@401 151 printf("Read: %s\n", buf);
adamc@138 152
adamc@138 153 if (!strsep(&s, " ")) {
adamc@138 154 fprintf(stderr, "No first space in HTTP command\n");
adamc@138 155 break;
adamc@138 156 }
adamc@138 157
adamc@138 158 if (strcmp(cmd, "GET")) {
adamc@138 159 fprintf(stderr, "Not ready for non-get command: %s\n", cmd);
adamc@138 160 break;
adamc@138 161 }
adamc@138 162
adamc@138 163 path = s;
adamc@138 164 if (!strsep(&s, " ")) {
adamc@138 165 fprintf(stderr, "No second space in HTTP command\n");
adamc@138 166 break;
adamc@138 167 }
adamc@138 168
adamc@144 169 if (inputs = strchr(path, '?')) {
adamc@144 170 char *name, *value;
adamc@144 171 *inputs++ = 0;
adamc@144 172
adamc@144 173 while (*inputs) {
adamc@144 174 name = inputs;
adamc@145 175 if (inputs = strchr(inputs, '&'))
adamc@145 176 *inputs++ = 0;
adamc@145 177 else
adamc@145 178 inputs = strchr(name, 0);
adamc@145 179
adamc@145 180 if (value = strchr(name, '=')) {
adamc@144 181 *value++ = 0;
adamc@311 182 uw_set_input(ctx, name, value);
adamc@144 183 }
adamc@145 184 else
adamc@311 185 uw_set_input(ctx, name, "");
adamc@144 186 }
adamc@144 187 }
adamc@144 188
adamc@138 189 printf("Serving URI %s....\n", path);
adamc@138 190
adamc@458 191 uw_set_headers(ctx, headers);
adamc@464 192 uw_write(ctx, "<html>");
adamc@458 193
adamc@167 194 while (1) {
adamc@424 195 if (uw_db_begin(ctx)) {
adamc@424 196 printf("Error running SQL BEGIN\n");
adamc@424 197 if (retries_left)
adamc@424 198 --retries_left;
adamc@424 199 else {
adamc@424 200 fk = FATAL;
adamc@424 201 uw_reset(ctx);
adamc@464 202 uw_write_header(ctx, "HTTP/1.1 500 Internal Server Error\n\r");
adamc@464 203 uw_write_header(ctx, "Content-type: text/plain\r\n\r\n");
adamc@424 204 uw_write(ctx, "Error running SQL BEGIN\n");
adamc@424 205
adamc@424 206 break;
adamc@424 207 }
adamc@424 208 }
adamc@167 209
adamc@462 210 uw_write_header(ctx, "HTTP/1.1 200 OK\r\n");
adamc@462 211 uw_write_header(ctx, "Content-type: text/html\r\n");
adamc@167 212
adamc@400 213 strcpy(path_copy, path);
adamc@458 214 fk = uw_begin(ctx, path_copy);
adamc@167 215 if (fk == SUCCESS) {
adamc@464 216 uw_write(ctx, "</html>");
adamc@464 217
adamc@424 218 if (uw_db_commit(ctx)) {
adamc@424 219 fk = FATAL;
adamc@424 220
adamc@424 221 printf("Error running SQL COMMIT\n");
adamc@424 222 uw_reset(ctx);
adamc@464 223 uw_write_header(ctx, "HTTP/1.1 500 Internal Server Error\n\r");
adamc@464 224 uw_write_header(ctx, "Content-type: text/plain\r\n");
adamc@424 225 uw_write(ctx, "Error running SQL COMMIT\n");
adamc@424 226 }
adamc@424 227
adamc@167 228 break;
adamc@167 229 } else if (fk == BOUNDED_RETRY) {
adamc@167 230 if (retries_left) {
adamc@311 231 printf("Error triggers bounded retry: %s\n", uw_error_message(ctx));
adamc@167 232 --retries_left;
adamc@167 233 }
adamc@167 234 else {
adamc@311 235 printf("Fatal error (out of retries): %s\n", uw_error_message(ctx));
adamc@167 236
adamc@311 237 uw_reset_keep_error_message(ctx);
adamc@464 238 uw_write_header(ctx, "HTTP/1.1 500 Internal Server Error\n\r");
adamc@464 239 uw_write_header(ctx, "Content-type: text/plain\r\n");
adamc@311 240 uw_write(ctx, "Fatal error (out of retries): ");
adamc@311 241 uw_write(ctx, uw_error_message(ctx));
adamc@311 242 uw_write(ctx, "\n");
adamc@424 243
adamc@424 244 try_rollback(ctx);
adamc@424 245
adamc@424 246 break;
adamc@167 247 }
adamc@167 248 } else if (fk == UNLIMITED_RETRY)
adamc@311 249 printf("Error triggers unlimited retry: %s\n", uw_error_message(ctx));
adamc@167 250 else if (fk == FATAL) {
adamc@311 251 printf("Fatal error: %s\n", uw_error_message(ctx));
adamc@167 252
adamc@311 253 uw_reset_keep_error_message(ctx);
adamc@464 254 uw_write_header(ctx, "HTTP/1.1 500 Internal Server Error\r\n");
adamc@464 255 uw_write_header(ctx, "Content-type: text/plain\r\n");
adamc@311 256 uw_write(ctx, "Fatal error: ");
adamc@311 257 uw_write(ctx, uw_error_message(ctx));
adamc@311 258 uw_write(ctx, "\n");
adamc@167 259
adamc@424 260 try_rollback(ctx);
adamc@424 261
adamc@167 262 break;
adamc@167 263 } else {
adamc@311 264 printf("Unknown uw_handle return code!\n");
adamc@167 265
adamc@311 266 uw_reset_keep_request(ctx);
adamc@464 267 uw_write_header(ctx, "HTTP/1.1 500 Internal Server Error\n\r");
adamc@464 268 uw_write_header(ctx, "Content-type: text/plain\r\n");
adamc@311 269 uw_write(ctx, "Unknown uw_handle return code!\n");
adamc@167 270
adamc@424 271 try_rollback(ctx);
adamc@424 272
adamc@167 273 break;
adamc@167 274 }
adamc@167 275
adamc@311 276 uw_reset_keep_request(ctx);
adamc@424 277
adamc@424 278 if (try_rollback(ctx))
adamc@424 279 break;
adamc@167 280 }
adamc@138 281
adamc@311 282 uw_send(ctx, sock);
adamc@138 283
adamc@138 284 printf("Done with client.\n\n");
adamc@324 285 uw_memstats(ctx);
adamc@138 286 break;
adamc@138 287 }
adamc@116 288 }
adamc@116 289
adamc@138 290 close(sock);
adamc@311 291 uw_reset(ctx);
adamc@116 292 }
adamc@116 293 }
adamc@102 294
adamc@477 295 static void help(char *cmd) {
adamc@477 296 printf("Usage: %s [-p <port>] [-t <thread-count>]\n", cmd);
adamc@477 297 }
adamc@477 298
adamc@138 299 int main(int argc, char *argv[]) {
adamc@116 300 // The skeleton for this function comes from Beej's sockets tutorial.
adamc@138 301 int sockfd; // listen on sock_fd
adamc@116 302 struct sockaddr_in my_addr;
adamc@116 303 struct sockaddr_in their_addr; // connector's address information
adamc@116 304 int sin_size, yes = 1;
adamc@472 305 int uw_port = 8080, nthreads = 1, i, *names, opt;
adamc@472 306
adamc@477 307 while ((opt = getopt(argc, argv, "hp:t:")) != -1) {
adamc@472 308 switch (opt) {
adamc@472 309 case '?':
adamc@472 310 fprintf(stderr, "Unknown command-line option");
adamc@477 311 help(argv[0]);
adamc@472 312 return 1;
adamc@138 313
adamc@477 314 case 'h':
adamc@477 315 help(argv[0]);
adamc@477 316 return 0;
adamc@477 317
adamc@472 318 case 'p':
adamc@472 319 uw_port = atoi(optarg);
adamc@472 320 if (uw_port <= 0) {
adamc@472 321 fprintf(stderr, "Invalid port number\n");
adamc@477 322 help(argv[0]);
adamc@472 323 return 1;
adamc@472 324 }
adamc@472 325 break;
adamc@472 326
adamc@472 327 case 't':
adamc@472 328 nthreads = atoi(optarg);
adamc@472 329 if (nthreads <= 0) {
adamc@472 330 fprintf(stderr, "Invalid thread count\n");
adamc@477 331 help(argv[0]);
adamc@472 332 return 1;
adamc@472 333 }
adamc@472 334 break;
adamc@472 335
adamc@472 336 default:
adamc@472 337 fprintf(stderr, "Unexpected getopt() behavior\n");
adamc@472 338 return 1;
adamc@472 339 }
adamc@138 340 }
adamc@138 341
adamc@138 342 names = calloc(nthreads, sizeof(int));
adamc@116 343
adamc@116 344 sockfd = socket(PF_INET, SOCK_STREAM, 0); // do some error checking!
adamc@116 345
adamc@116 346 if (sockfd < 0) {
adamc@116 347 fprintf(stderr, "Listener socket creation failed\n");
adamc@116 348 return 1;
adamc@116 349 }
adamc@116 350
adamc@116 351 if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int)) < 0) {
adamc@116 352 fprintf(stderr, "Listener socket option setting failed\n");
adamc@116 353 return 1;
adamc@116 354 }
adamc@116 355
adamc@116 356 my_addr.sin_family = AF_INET; // host byte order
adamc@311 357 my_addr.sin_port = htons(uw_port); // short, network byte order
adamc@116 358 my_addr.sin_addr.s_addr = INADDR_ANY; // auto-fill with my IP
adamc@116 359 memset(my_addr.sin_zero, '\0', sizeof my_addr.sin_zero);
adamc@116 360
adamc@116 361 if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof my_addr) < 0) {
adamc@116 362 fprintf(stderr, "Listener socket bind failed\n");
adamc@116 363 return 1;
adamc@116 364 }
adamc@116 365
adamc@311 366 if (listen(sockfd, uw_backlog) < 0) {
adamc@116 367 fprintf(stderr, "Socket listen failed\n");
adamc@116 368 return 1;
adamc@116 369 }
adamc@116 370
adamc@116 371 sin_size = sizeof their_addr;
adamc@116 372
adamc@311 373 printf("Listening on port %d....\n", uw_port);
adamc@116 374
adamc@138 375 for (i = 0; i < nthreads; ++i) {
adamc@138 376 pthread_t thread;
adamc@138 377 names[i] = i;
adamc@138 378 if (pthread_create(&thread, NULL, worker, &names[i])) {
adamc@138 379 fprintf(stderr, "Error creating worker thread #%d\n", i);
adamc@138 380 return 1;
adamc@138 381 }
adamc@138 382 }
adamc@138 383
adamc@116 384 while (1) {
adamc@138 385 int new_fd = accept(sockfd, (struct sockaddr *)&their_addr, &sin_size);
adamc@116 386
adamc@116 387 if (new_fd < 0) {
adamc@116 388 fprintf(stderr, "Socket accept failed\n");
adamc@116 389 return 1;
adamc@116 390 }
adamc@116 391
adamc@116 392 printf("Accepted connection.\n");
adamc@138 393
adamc@138 394 pthread_mutex_lock(&queue_mutex);
adamc@138 395 enqueue(new_fd);
adamc@139 396 pthread_cond_broadcast(&queue_cond);
adamc@138 397 pthread_mutex_unlock(&queue_mutex);
adamc@116 398 }
adamc@102 399 }