missing enable syscalls in create session
[lttngtop.git] / lib / mmap-packet-seek.c
CommitLineData
b1acd2b3
JD
1#include "babeltrace/ctf/types.h"
2#include "babeltrace/ctf/metadata.h"
3
4void ctf_move_mmap_pos_slow(struct ctf_stream_pos *pos, size_t offset, int whence)
5{
6 struct ctf_file_stream *file_stream =
7 container_of(pos, struct ctf_file_stream, pos);
8 int ret, err, i;
9 off_t off;
10 struct packet_index *index;
11 int len_index;
12 struct mmap_stream *iter, *tmp;
13 struct mmap_stream tmp_snapshot;
14
15 /* first time we have to mmap the region */
16 if (pos->mmap_len == 0) {
17 /* get the len of the mmap region */
18 ret = kernctl_get_mmap_len(pos->fd, &pos->mmap_len);
19 if (ret != 0) {
20 ret = errno;
21 perror("kernctl_get_mmap_len");
22 goto end;
23 }
24 pos->mmap_real_base = mmap(NULL, pos->mmap_len, PROT_READ, MAP_PRIVATE, pos->fd, 0);
25 if (pos->mmap_real_base == MAP_FAILED) {
26 perror("Error mmaping");
27 ret = -1;
28 }
29 }
30
31 if (pos->base) {
32 /* FIXME : put_subbuf should work but fails after nb_subbuf get + put */
33 ret = kernctl_put_next_subbuf(pos->fd);
34 if (ret != 0) {
35 ret = errno;
36 perror("kernctl_put_subbuf");
37 }
38 pos->base = NULL;
39 }
40
41next_snapshot:
42 tmp_snapshot.kconsumerd_fd = 0;
43 for (i = 0; i < available_snapshots->len; i++) {
44 tmp = g_ptr_array_index(available_snapshots, 0);
45 if (tmp->kconsumerd_fd->wait_fd == pos->fd) {
46 tmp_snapshot.last_pos = tmp->last_pos;
47 tmp_snapshot.kconsumerd_fd = tmp->kconsumerd_fd;
48 g_ptr_array_remove_index(available_snapshots, i);
49 free(tmp);
50 break;
51 }
52 }
53 if (tmp_snapshot.kconsumerd_fd == 0) {
54 pos->offset = EOF;
55 return;
56 }
57// fprintf(stderr,"READING FROM SNAPSHOT ON FD %d at %lu\n",
58// tmp_snapshot.kconsumerd_fd->wait_fd, tmp_snapshot.last_pos);
59 ret = kernctl_get_subbuf(tmp_snapshot.kconsumerd_fd->wait_fd, &tmp_snapshot.last_pos);
60 if (ret != 0) {
61 ret = errno;
62 perror("kernctl_get_subbuf");
63 goto next_snapshot;
64 }
65
66 ret = kernctl_get_mmap_read_offset(pos->fd, &(pos->mmap_offset));
67 if (ret != 0) {
68 ret = errno;
69 perror("kernctl_get_mmap_read_offset");
70 goto end;
71 }
72
73 /* read only the data in the subbuffer */
74 err = kernctl_get_subbuf_size(pos->fd, &pos->content_size);
75 if (err != 0) {
76 ret = errno;
77 perror("Getting sub-buffer len failed.");
78 goto end;
79 }
80 /* bits vs bytes */
81 pos->content_size *= CHAR_BIT;
82 /* read the whole subbuffer */
83 err = kernctl_get_padded_subbuf_size(pos->fd, &pos->packet_size);
84 if (err != 0) {
85 ret = errno;
86 perror("Getting sub-buffer len failed.");
87 goto end;
88 }
89 /* bits vs bytes */
90 pos->packet_size *= CHAR_BIT;
91
92 pos->offset = 0; /* will read headers */
93
94 /* map new base. Need mapping length from header. */
95 pos->base = pos->mmap_real_base + pos->mmap_offset;
96
97 /* update trace_packet_header and stream_packet_context */
98 if (pos->prot != PROT_WRITE && file_stream->parent.trace_packet_header) {
99 /* Read packet header */
100 ret = generic_rw(&pos->parent, &file_stream->parent.trace_packet_header->p);
101 assert(!ret);
102 }
103 if (pos->prot != PROT_WRITE && file_stream->parent.stream_packet_context) {
104 /* Read packet context */
105 ret = generic_rw(&pos->parent, &file_stream->parent.stream_packet_context->p);
106 assert(!ret);
107 }
108
109 /* read timestamp begin from header */
110 len_index = struct_declaration_lookup_field_index(
111 file_stream->parent.stream_packet_context->declaration,
112 g_quark_from_static_string("timestamp_begin"));
113 if (len_index >= 0) {
114 struct definition_integer *defint;
115 struct definition *field;
116
117 field = struct_definition_get_field_from_index(
118 file_stream->parent.stream_packet_context, len_index);
119 assert(field->declaration->id == CTF_TYPE_INTEGER);
120 defint = container_of(field, struct definition_integer, p);
121 assert(defint->declaration->signedness == FALSE);
122 file_stream->parent.timestamp = defint->value._unsigned;
123// fprintf(stderr, "READ TIMESTAMP : %lu\n", file_stream->parent.timestamp);
124 }
125
126
127end:
128 return;
129}
130
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