Move kernelcompat.h to include/ust/ and share.h, usterr.h to include/
[ust.git] / ustd / ustd.c
index a054554db07bc465a8d86cf90b1fdde366602287..0026c3b12a88816392df29447289d48404656d16 100644 (file)
@@ -33,7 +33,7 @@
 #include <getopt.h>
 
 #include "ustd.h"
-#include "localerr.h"
+#include "usterr.h"
 #include "ustcomm.h"
 
 /* return value: 0 = subbuffer is finished, it won't produce data anymore
@@ -51,6 +51,8 @@
 
 char *sock_path=NULL;
 char *trace_path=NULL;
+int daemon_mode = 0;
+char *pidfile = NULL;
 
 /* Number of active buffers and the mutex to protect it. */
 int active_buffers = 0;
@@ -58,68 +60,32 @@ pthread_mutex_t active_buffers_mutex = PTHREAD_MUTEX_INITIALIZER;
 /* Whether a request to end the program was received. */
 sig_atomic_t terminate_req = 0;
 
-int test_sigpipe(void)
-{
-       sigset_t sigset;
-       int result;
-
-       result = sigemptyset(&sigset);
-       if(result == -1) {
-               PERROR("sigemptyset");
-               return -1;
-       }
-       result = sigaddset(&sigset, SIGPIPE);
-       if(result == -1) {
-               PERROR("sigaddset");
-               return -1;
-       }
-
-       result = sigtimedwait(&sigset, NULL, &(struct timespec){0,0});
-       if(result == -1 && errno == EAGAIN) {
-               /* no signal received */
-               return 0;
-       }
-       else if(result == -1) {
-               PERROR("sigtimedwait");
-               return -1;
-       }
-       else if(result == SIGPIPE) {
-               /* received sigpipe */
-               return 1;
-       }
-       else {
-               assert(0);
-       }
-}
-
 int get_subbuffer(struct buffer_info *buf)
 {
-       char *send_msg;
-       char *received_msg;
-       char *rep_code;
+       char *send_msg=NULL;
+       char *received_msg=NULL;
+       char *rep_code=NULL;
        int retval;
        int result;
 
        asprintf(&send_msg, "get_subbuffer %s", buf->name);
        result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
-       free(send_msg);
-       if(test_sigpipe()) {
-               WARN("process %d destroyed before we could connect to it", buf->pid);
-               return GET_SUBBUF_DONE;
+       if((result == -1 && errno == EPIPE) || result == 0) {
+               DBG("app died while being traced");
+               retval = GET_SUBBUF_DIED;
+               goto end;
        }
        else if(result < 0) {
                ERR("get_subbuffer: ustcomm_send_request failed");
-               return -1;
-       }
-       else if(result == 0) {
-               DBG("app died while being traced");
-               return GET_SUBBUF_DIED;
+               retval = -1;
+               goto end;
        }
 
        result = sscanf(received_msg, "%as %ld", &rep_code, &buf->consumed_old);
        if(result != 2 && result != 1) {
                ERR("unable to parse response to get_subbuffer");
-               return -1;
+               retval = -1;
+               goto end_rep;
        }
 
        DBG("received msg is %s", received_msg);
@@ -129,7 +95,8 @@ int get_subbuffer(struct buffer_info *buf)
                retval = GET_SUBBUF_OK;
        }
        else if(nth_token_is(received_msg, "END", 0) == 1) {
-               return GET_SUBBUF_DONE;
+               retval = GET_SUBBUF_DONE;
+               goto end_rep;
        }
        else {
                DBG("error getting subbuffer %s", buf->name);
@@ -137,33 +104,44 @@ int get_subbuffer(struct buffer_info *buf)
        }
 
        /* FIMXE: free correctly the stuff */
-       free(received_msg);
-       free(rep_code);
+end_rep:
+       if(rep_code)
+               free(rep_code);
+end:
+       if(send_msg)
+               free(send_msg);
+       if(received_msg)
+               free(received_msg);
+
        return retval;
 }
 
 int put_subbuffer(struct buffer_info *buf)
 {
-       char *send_msg;
-       char *received_msg;
-       char *rep_code;
+       char *send_msg=NULL;
+       char *received_msg=NULL;
+       char *rep_code=NULL;
        int retval;
        int result;
 
        asprintf(&send_msg, "put_subbuffer %s %ld", buf->name, buf->consumed_old);
        result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
+       if(result < 0 && errno == ECONNRESET) {
+               retval = PUT_SUBBUF_DIED;
+               goto end;
+       }
        if(result < 0) {
                ERR("put_subbuffer: send_message failed");
-               return -1;
+               retval = -1;
+               goto end;
        }
-       free(send_msg);
 
        result = sscanf(received_msg, "%as", &rep_code);
        if(result != 1) {
                ERR("unable to parse response to put_subbuffer");
-               return -1;
+               retval = -1;
+               goto end_rep;
        }
-       free(received_msg);
 
        if(!strcmp(rep_code, "OK")) {
                DBG("subbuffer put %s", buf->name);
@@ -171,35 +149,21 @@ int put_subbuffer(struct buffer_info *buf)
        }
        else {
                DBG("put_subbuffer: received error, we were pushed");
-               return PUT_SUBBUF_PUSHED;
+               retval = PUT_SUBBUF_PUSHED;
+               goto end_rep;
        }
 
-       free(rep_code);
-       return retval;
-}
-
-/* This write is patient because it restarts if it was incomplete.
- */
-
-ssize_t patient_write(int fd, const void *buf, size_t count)
-{
-       const char *bufc = (const char *) buf;
-       int result;
-
-       for(;;) {
-               result = write(fd, bufc, count);
-               if(result <= 0) {
-                       return result;
-               }
-               count -= result;
-               bufc += result;
+end_rep:
+       if(rep_code)
+               free(rep_code);
 
-               if(count == 0) {
-                       break;
-               }
-       }
+end:
+       if(send_msg)
+               free(send_msg);
+       if(received_msg)
+               free(received_msg);
 
-       return bufc-(const char *)buf;
+       return retval;
 }
 
 void decrement_active_buffers(void *arg)
@@ -209,64 +173,6 @@ void decrement_active_buffers(void *arg)
        pthread_mutex_unlock(&active_buffers_mutex);
 }
 
-void *consumer_thread(void *arg)
-{
-       struct buffer_info *buf = (struct buffer_info *) arg;
-       int result;
-
-       pthread_cleanup_push(decrement_active_buffers, NULL);
-
-       for(;;) {
-               /* get the subbuffer */
-               result = get_subbuffer(buf);
-               if(result == -1) {
-                       ERR("error getting subbuffer");
-                       continue;
-               }
-               else if(result == GET_SUBBUF_DONE) {
-                       /* this is done */
-                       break;
-               }
-               else if(result == GET_SUBBUF_DIED) {
-                       finish_consuming_dead_subbuffer(buf);
-                       break;
-               }
-
-               /* write data to file */
-               result = patient_write(buf->file_fd, buf->mem + (buf->consumed_old & (buf->n_subbufs * buf->subbuf_size-1)), buf->subbuf_size);
-               if(result == -1) {
-                       PERROR("write");
-                       /* FIXME: maybe drop this trace */
-               }
-
-               /* put the subbuffer */
-               result = put_subbuffer(buf);
-               if(result == -1) {
-                       ERR("unknown error putting subbuffer (channel=%s)", buf->name);
-                       break;
-               }
-               else if(result == PUT_SUBBUF_PUSHED) {
-                       ERR("Buffer overflow (channel=%s), reader pushed. This channel will not be usable passed this point.", buf->name);
-                       break;
-               }
-               else if(result == PUT_SUBBUF_DIED) {
-                       WARN("application died while putting subbuffer");
-                       /* FIXME: probably need to skip the first subbuffer in finish_consuming_dead_subbuffer */
-                       finish_consuming_dead_subbuffer(buf);
-               }
-               else if(result == PUT_SUBBUF_OK) {
-               }
-       }
-
-       DBG("thread for buffer %s is stopping", buf->name);
-
-       /* FIXME: destroy, unalloc... */
-
-       pthread_cleanup_pop(1);
-
-       return NULL;
-}
-
 int create_dir_if_needed(char *dir)
 {
        int result;
@@ -299,7 +205,7 @@ int is_directory(const char *dir)
        return 1;
 }
 
-int add_buffer(pid_t pid, char *bufname)
+struct buffer_info *connect_buffer(pid_t pid, const char *bufname)
 {
        struct buffer_info *buf;
        char *send_msg;
@@ -307,13 +213,12 @@ int add_buffer(pid_t pid, char *bufname)
        int result;
        char *tmp;
        int fd;
-       pthread_t thr;
        struct shmid_ds shmds;
 
        buf = (struct buffer_info *) malloc(sizeof(struct buffer_info));
        if(buf == NULL) {
                ERR("add_buffer: insufficient memory");
-               return -1;
+               return NULL;
        }
 
        buf->name = bufname;
@@ -323,7 +228,7 @@ int add_buffer(pid_t pid, char *bufname)
        result = ustcomm_connect_app(buf->pid, &buf->conn);
        if(result) {
                WARN("unable to connect to process, it probably died before we were able to connect");
-               return -1;
+               return NULL;
        }
 
        /* get pidunique */
@@ -332,13 +237,13 @@ int add_buffer(pid_t pid, char *bufname)
        free(send_msg);
        if(result == -1) {
                ERR("problem in ustcomm_send_request(get_pidunique)");
-               return -1;
+               return NULL;
        }
 
        result = sscanf(received_msg, "%lld", &buf->pidunique);
        if(result != 1) {
                ERR("unable to parse response to get_pidunique");
-               return -1;
+               return NULL;
        }
        free(received_msg);
        DBG("got pidunique %lld", buf->pidunique);
@@ -349,13 +254,13 @@ int add_buffer(pid_t pid, char *bufname)
        free(send_msg);
        if(result == -1) {
                ERR("problem in ustcomm_send_request(get_shmid)");
-               return -1;
+               return NULL;
        }
 
        result = sscanf(received_msg, "%d %d", &buf->shmid, &buf->bufstruct_shmid);
        if(result != 2) {
                ERR("unable to parse response to get_shmid");
-               return -1;
+               return NULL;
        }
        free(received_msg);
        DBG("got shmids %d %d", buf->shmid, buf->bufstruct_shmid);
@@ -366,13 +271,13 @@ int add_buffer(pid_t pid, char *bufname)
        free(send_msg);
        if(result == -1) {
                ERR("problem in ustcomm_send_request(g_n_subbufs)");
-               return -1;
+               return NULL;
        }
 
        result = sscanf(received_msg, "%d", &buf->n_subbufs);
        if(result != 1) {
                ERR("unable to parse response to get_n_subbufs");
-               return -1;
+               return NULL;
        }
        free(received_msg);
        DBG("got n_subbufs %d", buf->n_subbufs);
@@ -385,7 +290,7 @@ int add_buffer(pid_t pid, char *bufname)
        result = sscanf(received_msg, "%d", &buf->subbuf_size);
        if(result != 1) {
                ERR("unable to parse response to get_subbuf_size");
-               return -1;
+               return NULL;
        }
        free(received_msg);
        DBG("got subbuf_size %d", buf->subbuf_size);
@@ -394,14 +299,14 @@ int add_buffer(pid_t pid, char *bufname)
        buf->mem = shmat(buf->shmid, NULL, 0);
        if(buf->mem == (void *) 0) {
                PERROR("shmat");
-               return -1;
+               return NULL;
        }
        DBG("successfully attached buffer memory");
 
        buf->bufstruct_mem = shmat(buf->bufstruct_shmid, NULL, 0);
        if(buf->bufstruct_mem == (void *) 0) {
                PERROR("shmat");
-               return -1;
+               return NULL;
        }
        DBG("successfully attached buffer bufstruct memory");
 
@@ -409,7 +314,7 @@ int add_buffer(pid_t pid, char *bufname)
        result = shmctl(buf->shmid, IPC_STAT, &shmds);
        if(result == -1) {
                PERROR("shmctl");
-               return -1;
+               return NULL;
        }
        buf->memlen = shmds.shm_segsz;
 
@@ -422,7 +327,7 @@ int add_buffer(pid_t pid, char *bufname)
                result = create_dir_if_needed(USTD_DEFAULT_TRACE_PATH);
                if(result == -1) {
                        ERR("could not create directory %s", USTD_DEFAULT_TRACE_PATH);
-                       return -1;
+                       return NULL;
                }
 
                trace_path = USTD_DEFAULT_TRACE_PATH;
@@ -433,7 +338,7 @@ int add_buffer(pid_t pid, char *bufname)
        if(result == -1) {
                ERR("could not create directory %s", tmp);
                free(tmp);
-               return -1;
+               return NULL;
        }
        free(tmp);
 
@@ -442,7 +347,7 @@ int add_buffer(pid_t pid, char *bufname)
        if(result == -1) {
                PERROR("open");
                ERR("failed opening trace file %s", tmp);
-               return -1;
+               return NULL;
        }
        buf->file_fd = fd;
        free(tmp);
@@ -451,7 +356,115 @@ int add_buffer(pid_t pid, char *bufname)
        active_buffers++;
        pthread_mutex_unlock(&active_buffers_mutex);
 
-       pthread_create(&thr, NULL, consumer_thread, buf);
+       return buf;
+}
+
+int consumer_loop(struct buffer_info *buf)
+{
+       int result;
+
+       pthread_cleanup_push(decrement_active_buffers, NULL);
+
+       for(;;) {
+               /* get the subbuffer */
+               result = get_subbuffer(buf);
+               if(result == -1) {
+                       ERR("error getting subbuffer");
+                       continue;
+               }
+               else if(result == GET_SUBBUF_DONE) {
+                       /* this is done */
+                       break;
+               }
+               else if(result == GET_SUBBUF_DIED) {
+                       finish_consuming_dead_subbuffer(buf);
+                       break;
+               }
+
+               /* write data to file */
+               result = patient_write(buf->file_fd, buf->mem + (buf->consumed_old & (buf->n_subbufs * buf->subbuf_size-1)), buf->subbuf_size);
+               if(result == -1) {
+                       PERROR("write");
+                       /* FIXME: maybe drop this trace */
+               }
+
+               /* put the subbuffer */
+               /* FIXME: we actually should unput the buffer before consuming... */
+               result = put_subbuffer(buf);
+               if(result == -1) {
+                       ERR("unknown error putting subbuffer (channel=%s)", buf->name);
+                       break;
+               }
+               else if(result == PUT_SUBBUF_PUSHED) {
+                       ERR("Buffer overflow (channel=%s), reader pushed. This channel will not be usable passed this point.", buf->name);
+                       break;
+               }
+               else if(result == PUT_SUBBUF_DIED) {
+                       WARN("application died while putting subbuffer");
+                       /* FIXME: probably need to skip the first subbuffer in finish_consuming_dead_subbuffer */
+                       finish_consuming_dead_subbuffer(buf);
+                       break;
+               }
+               else if(result == PUT_SUBBUF_OK) {
+               }
+       }
+
+       DBG("thread for buffer %s is stopping", buf->name);
+
+       /* FIXME: destroy, unalloc... */
+
+       pthread_cleanup_pop(1);
+
+       return 0;
+}
+
+void free_buffer(struct buffer_info *buf)
+{
+}
+
+struct consumer_thread_args {
+       pid_t pid;
+       const char *bufname;
+};
+
+void *consumer_thread(void *arg)
+{
+       struct buffer_info *buf = (struct buffer_info *) arg;
+       struct consumer_thread_args *args = (struct consumer_thread_args *) arg;
+
+       DBG("GOT ARGS: pid %d bufname %s", args->pid, args->bufname);
+
+       buf = connect_buffer(args->pid, args->bufname);
+       if(buf == NULL) {
+               ERR("failed to connect to buffer");
+               goto end;
+       }
+
+       consumer_loop(buf);
+
+       free_buffer(buf);
+
+       end:
+       /* bufname is free'd in free_buffer() */
+       free(args);
+       return NULL;
+}
+
+int start_consuming_buffer(pid_t pid, const char *bufname)
+{
+       pthread_t thr;
+       struct consumer_thread_args *args;
+
+       DBG("beginning of start_consuming_buffer: args: pid %d bufname %s", pid, bufname);
+
+       args = (struct consumer_thread_args *) malloc(sizeof(struct consumer_thread_args));
+
+       args->pid = pid;
+       args->bufname = strdup(bufname);
+       DBG("beginning2 of start_consuming_buffer: args: pid %d bufname %s", args->pid, args->bufname);
+
+       pthread_create(&thr, NULL, consumer_thread, args);
+       DBG("end of start_consuming_buffer: args: pid %d bufname %s", args->pid, args->bufname);
 
        return 0;
 }
@@ -461,7 +474,9 @@ void usage(void)
        fprintf(stderr, "Usage:\nustd OPTIONS\n\nOptions:\n"
                        "\t-h\t\tDisplay this usage.\n"
                        "\t-o DIR\t\tSpecify the directory where to output the traces.\n"
-                       "\t-s PATH\t\tSpecify the path to use for the daemon socket.\n");
+                       "\t-s PATH\t\tSpecify the path to use for the daemon socket.\n"
+                       "\t-d\t\tStart as a daemon.\n"
+                       "\t--pidfile FILE\tWrite the PID in this file (when using -d).\n");
 }
 
 int parse_args(int argc, char **argv)
@@ -471,12 +486,13 @@ int parse_args(int argc, char **argv)
        while (1) {
                int option_index = 0;
                static struct option long_options[] = {
+                       {"pidfile", 1, 0, 'p'},
                        {"help", 0, 0, 'h'},
                        {"version", 0, 0, 'V'},
                        {0, 0, 0, 0}
                };
 
-               c = getopt_long(argc, argv, "hs:o:", long_options, &option_index);
+               c = getopt_long(argc, argv, "hs:o:d", long_options, &option_index);
                if (c == -1)
                        break;
 
@@ -497,6 +513,12 @@ int parse_args(int argc, char **argv)
                                return -1;
                        }
                        break;
+               case 'd':
+                       daemon_mode = 1;
+                       break;
+               case 'p':
+                       pidfile = strdup(optarg);
+                       break;
                case 'h':
                        usage();
                        exit(0);
@@ -519,7 +541,7 @@ void sigterm_handler(int sig)
        terminate_req = 1;
 }
 
-int main(int argc, char **argv)
+int start_ustd(int fd)
 {
        struct ustcomm_ustd ustd;
        int result;
@@ -540,11 +562,6 @@ int main(int argc, char **argv)
                return 1;
        }
 
-       result = parse_args(argc, argv);
-       if(result == -1) {
-               exit(1);
-       }
-
        result = ustcomm_init_ustd(&ustd, sock_path);
        if(result == -1) {
                ERR("failed to initialize socket");
@@ -568,6 +585,24 @@ int main(int argc, char **argv)
                return 1;
        }
 
+       /* Notify parent that we are successfully started. */
+       if(fd != -1) {
+               /* write any one character */
+               result = write(fd, "!", 1);
+               if(result == -1) {
+                       PERROR("write");
+                       return -1;
+               }
+               if(result != 1) {
+                       ERR("Problem sending confirmation of daemon start to parent");
+                       return -1;
+               }
+               result = close(fd);
+               if(result == -1) {
+                       PERROR("close");
+               }
+       }
+
        /* app loop */
        for(;;) {
                char *recvbuf;
@@ -576,7 +611,7 @@ int main(int argc, char **argv)
                result = ustcomm_ustd_recv_message(&ustd, &recvbuf, NULL, 100);
                if(result == -1) {
                        ERR("error in ustcomm_ustd_recv_message");
-                       continue;
+                       goto loop_end;
                }
                if(result > 0) {
                        if(!strncmp(recvbuf, "collect", 7)) {
@@ -586,19 +621,25 @@ int main(int argc, char **argv)
 
                                result = sscanf(recvbuf, "%*s %d %50as", &pid, &bufname);
                                if(result != 2) {
-                                       fprintf(stderr, "parsing error: %s\n", recvbuf);
+                                       ERR("parsing error: %s", recvbuf);
+                                       goto free_bufname;
                                }
 
-                               result = add_buffer(pid, bufname);
+                               result = start_consuming_buffer(pid, bufname);
                                if(result < 0) {
                                        ERR("error in add_buffer");
-                                       continue;
+                                       goto free_bufname;
                                }
+
+                               free_bufname:
+                               free(bufname);
                        }
 
                        free(recvbuf);
                }
 
+               loop_end:
+
                if(terminate_req) {
                        pthread_mutex_lock(&active_buffers_mutex);
                        if(active_buffers == 0) {
@@ -611,3 +652,86 @@ int main(int argc, char **argv)
 
        return 0;
 }
+
+int start_ustd_daemon()
+{
+       int result;
+       int fd[2];
+       pid_t child_pid;
+
+       result = pipe(fd);
+
+       result = child_pid = fork();
+       if(result == -1) {
+               PERROR("fork");
+               return -1;
+       }
+       else if(result == 0) {
+               return start_ustd(fd[1]);
+       }
+       else {
+               char buf;
+               FILE *pidfp;
+
+               /* It's important to write the file *before*
+                * the parent ends, because the file may be
+                * read as soon as the parent ends.
+                */
+               if(pidfile) {
+                       pidfp = fopen(pidfile, "w+");
+                       if(!pidfp) {
+                               PERROR("fopen (%s)", pidfile);
+                               WARN("killing child process");
+                               result = kill(child_pid, SIGTERM);
+                               if(result == -1) {
+                                       PERROR("kill");
+                               }
+                               return -1;
+                       }
+
+                       fprintf(pidfp, "%d\n", child_pid);
+                       fclose(pidfp);
+               }
+
+               result = read(fd[0], &buf, 1);
+               if(result == -1) {
+                       PERROR("read");
+                       return -1;
+               }
+               if(result != 1) {
+                       ERR("did not receive valid confirmation that the daemon is started");
+                       return -1;
+               }
+
+               result = close(fd[0]);
+               if(result == -1) {
+                       PERROR("close");
+               }
+
+               DBG("The daemon is now successfully started");
+       }
+
+       /* Wait for confirmation that the server is ready. */
+
+
+       return 0;
+}
+
+int main(int argc, char **argv)
+{
+       int result;
+
+       result = parse_args(argc, argv);
+       if(result == -1) {
+               exit(1);
+       }
+
+       if(daemon_mode) {
+               result = start_ustd_daemon();
+       }
+       else {
+               result = start_ustd(-1);
+       }
+
+       return result;
+}
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