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annotate src/c/driver.c @ 425:7009b0ac1501

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Properly freeing libpq results on errors
author Adam Chlipala <adamc@hcoop.net>
date Fri, 24 Oct 2008 17:30:07 -0400
parents b10132434adc
children 360cbc202756
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@116 7
adamc@138 8 #include <pthread.h>
adamc@138 9
adamc@244 10 #include "urweb.h"
adamc@117 11
adamc@311 12 int uw_port = 8080;
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@324 74 uw_context ctx = uw_init(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@400 138 char *cmd, *path, path_copy[uw_bufsize+1], *inputs;
adamc@138 139
adamc@138 140 *s = 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@138 148 cmd = s = buf;
adamc@401 149
adamc@401 150 printf("Read: %s\n", buf);
adamc@138 151
adamc@138 152 if (!strsep(&s, " ")) {
adamc@138 153 fprintf(stderr, "No first space in HTTP command\n");
adamc@138 154 break;
adamc@138 155 }
adamc@138 156
adamc@138 157 if (strcmp(cmd, "GET")) {
adamc@138 158 fprintf(stderr, "Not ready for non-get command: %s\n", cmd);
adamc@138 159 break;
adamc@138 160 }
adamc@138 161
adamc@138 162 path = s;
adamc@138 163 if (!strsep(&s, " ")) {
adamc@138 164 fprintf(stderr, "No second space in HTTP command\n");
adamc@138 165 break;
adamc@138 166 }
adamc@138 167
adamc@144 168 if (inputs = strchr(path, '?')) {
adamc@144 169 char *name, *value;
adamc@144 170 *inputs++ = 0;
adamc@144 171
adamc@144 172 while (*inputs) {
adamc@144 173 name = inputs;
adamc@145 174 if (inputs = strchr(inputs, '&'))
adamc@145 175 *inputs++ = 0;
adamc@145 176 else
adamc@145 177 inputs = strchr(name, 0);
adamc@145 178
adamc@145 179 if (value = strchr(name, '=')) {
adamc@144 180 *value++ = 0;
adamc@311 181 uw_set_input(ctx, name, value);
adamc@144 182 }
adamc@145 183 else
adamc@311 184 uw_set_input(ctx, name, "");
adamc@144 185 }
adamc@144 186 }
adamc@144 187
adamc@138 188 printf("Serving URI %s....\n", path);
adamc@138 189
adamc@167 190 while (1) {
adamc@424 191 if (uw_db_begin(ctx)) {
adamc@424 192 printf("Error running SQL BEGIN\n");
adamc@424 193 if (retries_left)
adamc@424 194 --retries_left;
adamc@424 195 else {
adamc@424 196 fk = FATAL;
adamc@424 197 uw_reset(ctx);
adamc@424 198 uw_write(ctx, "HTTP/1.1 500 Internal Server Error\n\r");
adamc@424 199 uw_write(ctx, "Content-type: text/plain\r\n\r\n");
adamc@424 200 uw_write(ctx, "Error running SQL BEGIN\n");
adamc@424 201
adamc@424 202 break;
adamc@424 203 }
adamc@424 204 }
adamc@167 205
adamc@311 206 uw_write(ctx, "HTTP/1.1 200 OK\r\n");
adamc@311 207 uw_write(ctx, "Content-type: text/html\r\n\r\n");
adamc@311 208 uw_write(ctx, "<html>");
adamc@167 209
adamc@400 210 strcpy(path_copy, path);
adamc@400 211 fk = uw_begin(ctx, path_copy);
adamc@167 212 if (fk == SUCCESS) {
adamc@311 213 uw_write(ctx, "</html>");
adamc@424 214
adamc@424 215 if (uw_db_commit(ctx)) {
adamc@424 216 fk = FATAL;
adamc@424 217
adamc@424 218 printf("Error running SQL COMMIT\n");
adamc@424 219 uw_reset(ctx);
adamc@424 220 uw_write(ctx, "HTTP/1.1 500 Internal Server Error\n\r");
adamc@424 221 uw_write(ctx, "Content-type: text/plain\r\n\r\n");
adamc@424 222 uw_write(ctx, "Error running SQL COMMIT\n");
adamc@424 223 }
adamc@424 224
adamc@167 225 break;
adamc@167 226 } else if (fk == BOUNDED_RETRY) {
adamc@167 227 if (retries_left) {
adamc@311 228 printf("Error triggers bounded retry: %s\n", uw_error_message(ctx));
adamc@167 229 --retries_left;
adamc@167 230 }
adamc@167 231 else {
adamc@311 232 printf("Fatal error (out of retries): %s\n", uw_error_message(ctx));
adamc@167 233
adamc@311 234 uw_reset_keep_error_message(ctx);
adamc@311 235 uw_write(ctx, "HTTP/1.1 500 Internal Server Error\n\r");
adamc@311 236 uw_write(ctx, "Content-type: text/plain\r\n\r\n");
adamc@311 237 uw_write(ctx, "Fatal error (out of retries): ");
adamc@311 238 uw_write(ctx, uw_error_message(ctx));
adamc@311 239 uw_write(ctx, "\n");
adamc@424 240
adamc@424 241 try_rollback(ctx);
adamc@424 242
adamc@424 243 break;
adamc@167 244 }
adamc@167 245 } else if (fk == UNLIMITED_RETRY)
adamc@311 246 printf("Error triggers unlimited retry: %s\n", uw_error_message(ctx));
adamc@167 247 else if (fk == FATAL) {
adamc@311 248 printf("Fatal error: %s\n", uw_error_message(ctx));
adamc@167 249
adamc@311 250 uw_reset_keep_error_message(ctx);
adamc@311 251 uw_write(ctx, "HTTP/1.1 500 Internal Server Error\n\r");
adamc@311 252 uw_write(ctx, "Content-type: text/plain\r\n\r\n");
adamc@311 253 uw_write(ctx, "Fatal error: ");
adamc@311 254 uw_write(ctx, uw_error_message(ctx));
adamc@311 255 uw_write(ctx, "\n");
adamc@167 256
adamc@424 257 try_rollback(ctx);
adamc@424 258
adamc@167 259 break;
adamc@167 260 } else {
adamc@311 261 printf("Unknown uw_handle return code!\n");
adamc@167 262
adamc@311 263 uw_reset_keep_request(ctx);
adamc@311 264 uw_write(ctx, "HTTP/1.1 500 Internal Server Error\n\r");
adamc@311 265 uw_write(ctx, "Content-type: text/plain\r\n\r\n");
adamc@311 266 uw_write(ctx, "Unknown uw_handle return code!\n");
adamc@167 267
adamc@424 268 try_rollback(ctx);
adamc@424 269
adamc@167 270 break;
adamc@167 271 }
adamc@167 272
adamc@311 273 uw_reset_keep_request(ctx);
adamc@424 274
adamc@424 275 if (try_rollback(ctx))
adamc@424 276 break;
adamc@167 277 }
adamc@138 278
adamc@311 279 uw_send(ctx, sock);
adamc@138 280
adamc@138 281 printf("Done with client.\n\n");
adamc@324 282 uw_memstats(ctx);
adamc@138 283 break;
adamc@138 284 }
adamc@116 285 }
adamc@116 286
adamc@138 287 close(sock);
adamc@311 288 uw_reset(ctx);
adamc@116 289 }
adamc@116 290 }
adamc@102 291
adamc@138 292 int main(int argc, char *argv[]) {
adamc@116 293 // The skeleton for this function comes from Beej's sockets tutorial.
adamc@138 294 int sockfd; // listen on sock_fd
adamc@116 295 struct sockaddr_in my_addr;
adamc@116 296 struct sockaddr_in their_addr; // connector's address information
adamc@116 297 int sin_size, yes = 1;
adamc@138 298 int nthreads, i, *names;
adamc@138 299
adamc@138 300 if (argc < 2) {
adamc@138 301 fprintf(stderr, "No thread count specified\n");
adamc@138 302 return 1;
adamc@138 303 }
adamc@138 304
adamc@138 305 nthreads = atoi(argv[1]);
adamc@138 306 if (nthreads <= 0) {
adamc@138 307 fprintf(stderr, "Invalid thread count\n");
adamc@138 308 return 1;
adamc@138 309 }
adamc@138 310 names = calloc(nthreads, sizeof(int));
adamc@116 311
adamc@116 312 sockfd = socket(PF_INET, SOCK_STREAM, 0); // do some error checking!
adamc@116 313
adamc@116 314 if (sockfd < 0) {
adamc@116 315 fprintf(stderr, "Listener socket creation failed\n");
adamc@116 316 return 1;
adamc@116 317 }
adamc@116 318
adamc@116 319 if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int)) < 0) {
adamc@116 320 fprintf(stderr, "Listener socket option setting failed\n");
adamc@116 321 return 1;
adamc@116 322 }
adamc@116 323
adamc@116 324 my_addr.sin_family = AF_INET; // host byte order
adamc@311 325 my_addr.sin_port = htons(uw_port); // short, network byte order
adamc@116 326 my_addr.sin_addr.s_addr = INADDR_ANY; // auto-fill with my IP
adamc@116 327 memset(my_addr.sin_zero, '\0', sizeof my_addr.sin_zero);
adamc@116 328
adamc@116 329 if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof my_addr) < 0) {
adamc@116 330 fprintf(stderr, "Listener socket bind failed\n");
adamc@116 331 return 1;
adamc@116 332 }
adamc@116 333
adamc@311 334 if (listen(sockfd, uw_backlog) < 0) {
adamc@116 335 fprintf(stderr, "Socket listen failed\n");
adamc@116 336 return 1;
adamc@116 337 }
adamc@116 338
adamc@116 339 sin_size = sizeof their_addr;
adamc@116 340
adamc@311 341 printf("Listening on port %d....\n", uw_port);
adamc@116 342
adamc@138 343 for (i = 0; i < nthreads; ++i) {
adamc@138 344 pthread_t thread;
adamc@138 345 names[i] = i;
adamc@138 346 if (pthread_create(&thread, NULL, worker, &names[i])) {
adamc@138 347 fprintf(stderr, "Error creating worker thread #%d\n", i);
adamc@138 348 return 1;
adamc@138 349 }
adamc@138 350 }
adamc@138 351
adamc@116 352 while (1) {
adamc@138 353 int new_fd = accept(sockfd, (struct sockaddr *)&their_addr, &sin_size);
adamc@116 354
adamc@116 355 if (new_fd < 0) {
adamc@116 356 fprintf(stderr, "Socket accept failed\n");
adamc@116 357 return 1;
adamc@116 358 }
adamc@116 359
adamc@116 360 printf("Accepted connection.\n");
adamc@138 361
adamc@138 362 pthread_mutex_lock(&queue_mutex);
adamc@138 363 enqueue(new_fd);
adamc@139 364 pthread_cond_broadcast(&queue_cond);
adamc@138 365 pthread_mutex_unlock(&queue_mutex);
adamc@116 366 }
adamc@102 367 }