Add preload_provider app

[deliverable/lttng-ivc.git] / lttng_ivc / apps / preload_provider / app.c

diff --git a/lttng_ivc/apps/preload_provider/app.c b/lttng_ivc/apps/preload_provider/app.c
new file mode 100644 (file)
index 0000000..7da44d8
--- /dev/null
+++ b/lttng_ivc/apps/preload_provider/app.c
@@ -0,0 +1,190 @@
+/*
+ * Copyright (C) - 2012 David Goulet <dgoulet@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#include <arpa/inet.h>
+#include <assert.h>
+#include <time.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#define TRACEPOINT_DEFINE
+#define TRACEPOINT_PROBE_DYNAMIC_LINKAGE
+#include "tp.h"
+
+#define NSEC_PER_USEC 1000
+#define NSEC_PER_SEC 1000000000
+
+static inline
+int64_t elapsed_time_ns(struct timespec *t1, struct timespec *t2)
+{
+       struct timespec delta;
+
+       assert(t1 && t2);
+       delta.tv_sec = t2->tv_sec - t1->tv_sec;
+       delta.tv_nsec = t2->tv_nsec - t1->tv_nsec;
+       return ((int64_t) NSEC_PER_SEC * (int64_t) delta.tv_sec) +
+                       (int64_t) delta.tv_nsec;
+}
+
+static inline
+int usleep_safe(useconds_t usec)
+{
+       int ret = 0;
+       struct timespec t1, t2;
+       int64_t time_remaining_ns = (int64_t) usec * (int64_t) NSEC_PER_USEC;
+
+       ret = clock_gettime(CLOCK_MONOTONIC, &t1);
+       if (ret) {
+               ret = -1;
+               perror("clock_gettime");
+               goto end;
+       }
+
+       while (time_remaining_ns > 0) {
+               ret = usleep(time_remaining_ns / (int64_t) NSEC_PER_USEC);
+               if (ret && errno != EINTR) {
+                       perror("usleep");
+                       goto end;
+               }
+
+               ret = clock_gettime(CLOCK_MONOTONIC, &t2);
+               if (ret) {
+                       perror("clock_gettime");
+                       goto end;
+               }
+
+               time_remaining_ns -= elapsed_time_ns(&t1, &t2);
+       }
+end:
+       return ret;
+}
+
+void create_file(const char *path)
+{
+       static bool file_created = false;
+       int ret;
+
+       if (!path || file_created) {
+               return;
+       }
+
+       ret = creat(path, S_IRWXU);
+       if (ret < 0) {
+               fprintf(stderr, "Failed to create file %s\n", path);
+               return;
+       }
+
+       (void) close(ret);
+       file_created = true;
+}
+
+static
+void wait_on_file(const char *path)
+{
+       if (!path) {
+               return;
+       }
+       for (;;) {
+               int ret;
+               struct stat buf;
+
+               ret = stat(path, &buf);
+               if (ret == -1 && errno == ENOENT) {
+                       (void) poll(NULL, 0, 10);       /* 10 ms delay */
+                       continue;                       /* retry */
+               }
+               if (ret) {
+                       perror("stat");
+                       exit(EXIT_FAILURE);
+               }
+               break;  /* found */
+       }
+}
+
+int main(int argc, char **argv)
+{
+       unsigned int i, netint;
+       long values[] = { 1, 2, 3 };
+       char text[10] = "test";
+       double dbl = 2.0;
+       float flt = 2222.0;
+       int nr_iter = 100, ret = 0;
+       useconds_t nr_usec = 0;
+       char *after_first_event_file_path = NULL;
+       char *before_last_event_file_path = NULL;
+
+       if (argc >= 2) {
+               /*
+                * If nr_iter is negative, do an infinite tracing loop.
+                */
+               nr_iter = atoi(argv[1]);
+       }
+
+       if (argc >= 3) {
+               /* By default, don't wait unless user specifies. */
+               nr_usec = atoi(argv[2]);
+       }
+
+       if (argc >= 4) {
+               after_first_event_file_path = argv[3];
+       }
+
+       if (argc >= 5) {
+               before_last_event_file_path = argv[4];
+       }
+
+       for (i = 0; nr_iter < 0 || i < nr_iter; i++) {
+               if (nr_iter >= 0 && i == nr_iter - 1) {
+                       /*
+                        * Wait on synchronization before writing last
+                        * event.
+                        */
+                       wait_on_file(before_last_event_file_path);
+               }
+               netint = htonl(i);
+               tracepoint(tp, tptest, i, netint, values, text,
+                       strlen(text), dbl, flt);
+               tracepoint(tp, tpenum, 1);
+
+               /*
+                * First loop we create the file if asked to indicate
+                * that at least one tracepoint has been hit.
+                */
+               create_file(after_first_event_file_path);
+               if (nr_usec) {
+                       if (usleep_safe(nr_usec)) {
+                               ret = -1;
+                               goto end;
+                       }
+               }
+       }
+
+end:
+       exit(!ret ? EXIT_SUCCESS : EXIT_FAILURE);
+}