git.ozlabs.org Git - ccan/blob - tools/ccanlint/async.c

   1 #include "ccanlint.h"
   2 #include "../tools.h"
   3 #include <sys/types.h>
   4 #include <sys/time.h>
   5 #include <sys/resource.h>
   6 #include <sys/wait.h>
   7 #include <sys/stat.h>
   8 #include <fcntl.h>
   9 #include <stdlib.h>
  10 #include <unistd.h>
  11 #include <err.h>
  12 #include <assert.h>
  13 #include <ccan/lbalance/lbalance.h>
  14 #include <ccan/tlist/tlist.h>
  15 #include <ccan/time/time.h>
  16 #include <ccan/talloc/talloc.h>
  17
  18 static struct lbalance *lb;
  19 TLIST_TYPE(command, struct command);
  20 static struct tlist_command pending = TLIST_INIT(pending);
  21 static struct tlist_command running = TLIST_INIT(running);
  22 static unsigned int num_running = 0;
  23 static struct tlist_command done = TLIST_INIT(done);
  24
  25 struct command {
  26         struct list_node list;
  27         char *command;
  28         pid_t pid;
  29         int output_fd;
  30         unsigned int time_ms;
  31         struct lbalance_task *task;
  32         int status;
  33         char *output;
  34         bool done;
  35         const void *ctx;
  36 };
  37
  38 static void killme(int sig)
  39 {
  40         kill(-getpid(), SIGKILL);
  41 }
  42
  43 static void run_more(void)
  44 {
  45         struct command *c;
  46
  47         while (num_running < lbalance_target(lb)) {
  48                 int p[2];
  49
  50                 c = tlist_top(&pending, list);
  51                 if (!c)
  52                         break;
  53
  54                 fflush(stdout);
  55                 if (pipe(p) != 0)
  56                         err(1, "Pipe failed");
  57                 c->pid = fork();
  58                 if (c->pid == -1)
  59                         err(1, "Fork failed");
  60                 if (c->pid == 0) {
  61                         struct itimerval itim;
  62
  63                         if (dup2(p[1], STDOUT_FILENO) != STDOUT_FILENO
  64                             || dup2(p[1], STDERR_FILENO) != STDERR_FILENO
  65                             || close(p[0]) != 0
  66                             || close(STDIN_FILENO) != 0
  67                             || open("/dev/null", O_RDONLY) != STDIN_FILENO)
  68                                 exit(128);
  69
  70                         signal(SIGALRM, killme);
  71                         itim.it_interval.tv_sec = itim.it_interval.tv_usec = 0;
  72                         itim.it_value = timespec_to_timeval(time_from_msec(c->time_ms));
  73                         setitimer(ITIMER_REAL, &itim, NULL);
  74
  75                         c->status = system(c->command);
  76                         if (WIFEXITED(c->status))
  77                                 exit(WEXITSTATUS(c->status));
  78                         /* Here's a hint... */
  79                         exit(128 + WTERMSIG(c->status));
  80                 }
  81
  82                 if (tools_verbose)
  83                         printf("Running async: %s => %i\n", c->command, c->pid);
  84
  85                 close(p[1]);
  86                 c->output_fd = p[0];
  87                 c->task = lbalance_task_new(lb);
  88                 tlist_del_from(&pending, c, list);
  89                 tlist_add_tail(&running, c, list);
  90                 num_running++;
  91         }
  92 }
  93
  94 static int destroy_command(struct command *command)
  95 {
  96         if (!command->done && command->pid) {
  97                 kill(-command->pid, SIGKILL);
  98                 close(command->output_fd);
  99                 num_running--;
 100         }
 101
 102         tlist_del(command, list);
 103         return 0;
 104 }
 105
 106 void run_command_async(const void *ctx, unsigned int time_ms,
 107                        const char *fmt, ...)
 108 {
 109         struct command *command;
 110         va_list ap;
 111
 112         assert(ctx);
 113
 114         if (!lb)
 115                 lb = lbalance_new();
 116
 117         command = talloc(ctx, struct command);
 118         command->ctx = ctx;
 119         command->time_ms = time_ms;
 120         command->pid = 0;
 121         command->output = talloc_strdup(command, "");
 122         va_start(ap, fmt);
 123         command->command = talloc_vasprintf(command, fmt, ap);
 124         va_end(ap);
 125         tlist_add_tail(&pending, command, list);
 126         command->done = false;
 127         talloc_set_destructor(command, destroy_command);
 128
 129         run_more();
 130 }
 131
 132 static void reap_output(void)
 133 {
 134         fd_set in;
 135         struct command *c, *next;
 136         int max_fd = 0;
 137
 138         FD_ZERO(&in);
 139
 140         tlist_for_each(&running, c, list) {
 141                 FD_SET(c->output_fd, &in);
 142                 if (c->output_fd > max_fd)
 143                         max_fd = c->output_fd;
 144         }
 145
 146         if (select(max_fd+1, &in, NULL, NULL, NULL) < 0)
 147                 err(1, "select failed");
 148
 149         tlist_for_each_safe(&running, c, next, list) {
 150                 if (FD_ISSET(c->output_fd, &in)) {
 151                         int old_len, len;
 152                         /* This length includes nul terminator! */
 153                         old_len = talloc_array_length(c->output);
 154                         c->output = talloc_realloc(c, c->output, char,
 155                                                    old_len + 1024);
 156                         len = read(c->output_fd, c->output + old_len - 1, 1024);
 157                         if (len < 0)
 158                                 err(1, "Reading from async command");
 159                         c->output = talloc_realloc(c, c->output, char,
 160                                                    old_len + len);
 161                         c->output[old_len + len - 1] = '\0';
 162                         if (len == 0) {
 163                                 struct rusage ru;
 164                                 wait4(c->pid, &c->status, 0, &ru);
 165                                 if (tools_verbose)
 166                                         printf("Finished async %i: %s %u\n",
 167                                                c->pid,
 168                                                WIFEXITED(c->status)
 169                                                ? "exit status"
 170                                                : "killed by signal",
 171                                                WIFEXITED(c->status)
 172                                                ? WEXITSTATUS(c->status)
 173                                                : WTERMSIG(c->status));
 174                                 lbalance_task_free(c->task, &ru);
 175                                 c->task = NULL;
 176                                 c->done = true;
 177                                 close(c->output_fd);
 178                                 tlist_del_from(&running, c, list);
 179                                 tlist_add_tail(&done, c, list);
 180                                 num_running--;
 181                         }
 182                 }
 183         }
 184 }
 185
 186 void *collect_command(bool *ok, char **output)
 187 {
 188         struct command *c;
 189         const void *ctx;
 190
 191         while ((c = tlist_top(&done, list)) == NULL) {
 192                 if (tlist_empty(&pending) && tlist_empty(&running))
 193                         return NULL;
 194                 reap_output();
 195                 run_more();
 196         }
 197
 198         *ok = (WIFEXITED(c->status) && WEXITSTATUS(c->status) == 0);
 199         ctx = c->ctx;
 200         *output = talloc_steal(ctx, c->output);
 201         talloc_free(c);
 202         return (void *)ctx;
 203 }
 204
 205 /* Compile and link single C file, with object files, async. */
 206 void compile_and_link_async(const void *ctx, unsigned int time_ms,
 207                             const char *cfile, const char *ccandir,
 208                             const char *objs, const char *compiler,
 209                             const char *cflags,
 210                             const char *libs, const char *outfile)
 211 {
 212         if (compile_verbose)
 213                 printf("Compiling and linking (async) %s\n", outfile);
 214         run_command_async(ctx, time_ms,
 215                           "%s %s -I%s -o %s %s %s %s",
 216                           compiler, cflags,
 217                           ccandir, outfile, cfile, objs, libs);
 218 }