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write parts of types/static frames/strings incrementally
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so in case the program crashes before it can finish up, we can
still recover everything we need.
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@timo
timo committed Sep 6, 2017
1 parent bc75679 commit c3c1926
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Showing 2 changed files with 54 additions and 12 deletions.
61 changes: 49 additions & 12 deletions src/profiler/heapsnapshot.c
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Expand Up @@ -671,10 +671,12 @@ void string_heap_to_filehandle(MVMThreadContext *tc, MVMHeapSnapshotCollection *
/* Write out the number of strings we have and record the "header" size
* in the index. */

fwrite(&col->num_strings, sizeof(MVMuint64), 1, fh);
i = col->num_strings - col->strings_written;

fwrite(&i, sizeof(MVMuint64), 1, fh);
index->stringheap_size = sizeof(MVMuint64) + 4;

for (i = 0; i < col->num_strings; i++) {
for (i = col->strings_written; i < col->num_strings; i++) {
char *str = col->strings[i];
MVMuint64 output_size = strlen(str);

Expand All @@ -688,53 +690,68 @@ void string_heap_to_filehandle(MVMThreadContext *tc, MVMHeapSnapshotCollection *

index->stringheap_size += sizeof(MVMuint64) + sizeof(MVMuint8) * output_size;
}

col->strings_written = col->num_strings;
}

/* The following functions all act the exact same way:
*
* Write a little introductory text of 4 bytes for the parser to ensure
* the index is correct, write the number of entries and the size of each entry
* as 64bit integers, calculate the complete size for the index, and then
* just write out each entry */
* just write out each entry
*
* We also write a partial table after every snapshot so that if the process
* crashes we still have a usable file.
*/
void types_to_filehandle(MVMThreadContext *tc, MVMHeapSnapshotCollection *col) {
MVMuint64 i;
MVMHeapDumpIndex *index = col->index;
FILE *fh = col->fh;

fputs("type", fh);

fwrite(&col->num_types, sizeof(MVMuint64), 1, fh);
i = col->num_types - col->types_written;

fwrite(&i, sizeof(MVMuint64), 1, fh);
i = sizeof(MVMuint64) * 2;
fwrite(&i, sizeof(MVMuint64), 1, fh);

index->types_size = sizeof(MVMuint64) * 2 + 4 + sizeof(MVMuint64) * 2 * col->num_types;
index->types_size = sizeof(MVMuint64) * 2 + 4 + sizeof(MVMuint64) * 2 * (col->num_types - col->types_written);

for (i = 0; i < col->num_types; i++) {
for (i = col->types_written; i < col->num_types; i++) {
MVMHeapSnapshotType *t = &col->types[i];

fwrite(&t->repr_name, sizeof(MVMuint64), 1, fh);
fwrite(&t->type_name, sizeof(MVMuint64), 1, fh);
}

col->types_written = col->num_types;
}
void static_frames_to_filehandle(MVMThreadContext *tc, MVMHeapSnapshotCollection *col) {
MVMuint64 i;
MVMHeapDumpIndex *index = col->index;
FILE *fh = col->fh;

fputs("fram", fh);
fwrite(&col->num_static_frames, sizeof(MVMuint64), 1, fh);

i = col->num_static_frames - col->static_frames_written;

fwrite(&i, sizeof(MVMuint64), 1, fh);
i = sizeof(MVMuint64) * 4;
fwrite(&i, sizeof(MVMuint64), 1, fh);
index->staticframes_size = sizeof(MVMuint64) * 2 + 4 + sizeof(MVMuint64) * 4 * col->num_static_frames;
index->staticframes_size = sizeof(MVMuint64) * 2 + 4 + sizeof(MVMuint64) * 4 * (col->num_static_frames - col->static_frames_written);

for (i = 0; i < col->num_static_frames; i++) {
for (i = col->static_frames_written; i < col->num_static_frames; i++) {
MVMHeapSnapshotStaticFrame *sf = &col->static_frames[i];

fwrite(&sf->name, sizeof(MVMuint64), 1, fh);
fwrite(&sf->cuid, sizeof(MVMuint64), 1, fh);
fwrite(&sf->line, sizeof(MVMuint64), 1, fh);
fwrite(&sf->file, sizeof(MVMuint64), 1, fh);
}

col->static_frames_written = col->num_static_frames;
}

/* The collectables table gets an entry in the additional "snapshot sizes
Expand All @@ -749,12 +766,15 @@ void collectables_to_filehandle(MVMThreadContext *tc, MVMHeapSnapshotCollection
MVMHeapSnapshot *s = col->snapshot;

fputs("coll", fh);

fwrite(&s->num_collectables, sizeof(MVMuint64), 1, fh);
i = sizeof(MVMuint16) * 2 + sizeof(MVMuint32) * 2 + sizeof(MVMuint64) * 2;
fwrite(&i, sizeof(MVMuint64), 1, fh);

entry->collectables_size += s->num_collectables * i + 4 + sizeof(MVMuint64) * 2;

fprintf(stderr, "writing collectables: %llx collectables of size %x each; collectables_size is %llx\n", s->num_collectables, i, entry->collectables_size);

for (i = 0; i < s->num_collectables; i++) {
MVMHeapSnapshotCollectable *coll = &s->collectables[i];
fwrite(&coll->kind, sizeof(MVMuint16), 1, fh);
Expand Down Expand Up @@ -787,7 +807,7 @@ void references_to_filehandle(MVMThreadContext *tc, MVMHeapSnapshotCollection *c

fputs("refs", fh);
fwrite(&s->num_references, sizeof(MVMuint64), 1, fh);
i = sizeof(MVMuint64) * 3;
i = sizeof(MVMuint64) * 2 + 1;
fwrite(&i, sizeof(MVMuint64), 1, fh);

entry->full_refs_size = 4 + sizeof(MVMuint64) * 2;
Expand Down Expand Up @@ -839,9 +859,12 @@ void references_to_filehandle(MVMThreadContext *tc, MVMHeapSnapshotCollection *c
fwrite(&index8, sizeof(MVMuint8), 1, fh);
entry->full_refs_size += sizeof(MVMuint8) * 3 + 1;
}
if (i == halfway)
if (i == halfway) {
fprintf(stderr, "refs: half-way point reached with %x entries at %llx\n", i, entry->full_refs_size);
entry->refs_middlepoint = entry->full_refs_size;
}
}
fprintf(stderr, "refs: done with %x entries at %llx\n", s->num_references, entry->full_refs_size);
}

void snapshot_to_filehandle(MVMThreadContext *tc, MVMHeapSnapshotCollection *col) {
Expand All @@ -859,9 +882,18 @@ void snapshot_to_filehandle(MVMThreadContext *tc, MVMHeapSnapshotCollection *col
entry->collectables_size = 0;
entry->full_refs_size = 0;
entry->refs_middlepoint = 0;
entry->incremental_data = 0;

collectables_to_filehandle(tc, col, entry);
references_to_filehandle(tc, col, entry);

string_heap_to_filehandle(tc, col);
types_to_filehandle(tc, col);
static_frames_to_filehandle(tc, col);

entry->incremental_data = index->stringheap_size + index->types_size + index->staticframes_size;

fprintf(stderr, "incremental data added, it was %llx big in total\n", entry->incremental_data);
}
void index_to_filehandle(MVMThreadContext *tc, MVMHeapSnapshotCollection *col) {
MVMHeapDumpIndex *index = col->index;
Expand All @@ -874,6 +906,10 @@ void index_to_filehandle(MVMThreadContext *tc, MVMHeapSnapshotCollection *col) {
fwrite(&index->snapshot_size_entries, sizeof(MVMuint64), 1, fh);
}
void finish_collection_to_filehandle(MVMThreadContext *tc, MVMHeapSnapshotCollection *col) {
col->strings_written = 0;
col->types_written = 0;
col->static_frames_written = 0;

string_heap_to_filehandle(tc, col);
types_to_filehandle(tc, col);
static_frames_to_filehandle(tc, col);
Expand All @@ -890,6 +926,7 @@ void MVM_profile_heap_take_snapshot(MVMThreadContext *tc) {
record_snapshot(tc, col, col->snapshot);

snapshot_to_filehandle(tc, col);
fflush(col->fh);

destroy_current_heap_snapshot(tc);
col->snapshot_idx++;
Expand All @@ -907,7 +944,7 @@ MVMObject * MVM_profile_heap_end(MVMThreadContext *tc) {
dataset = tc->instance->VMNull;

finish_collection_to_filehandle(tc, tc->instance->heap_snapshots);
destroy_heap_snapshot_collection(tc);
fclose(col->fh);
destroy_heap_snapshot_collection(tc);
return dataset;
}
5 changes: 5 additions & 0 deletions src/profiler/heapsnapshot.h
View file
Expand Up @@ -2,6 +2,7 @@ struct MVMHeapDumpIndexSnapshotEntry {
MVMuint64 collectables_size;
MVMuint64 full_refs_size;
MVMuint64 refs_middlepoint;
MVMuint64 incremental_data;
};

struct MVMHeapDumpIndex {
Expand Down Expand Up @@ -44,6 +45,10 @@ struct MVMHeapSnapshotCollection {
MVMuint64 num_strings_free;
MVMuint64 alloc_strings_free;

MVMuint64 types_written;
MVMuint64 static_frames_written;
MVMuint64 strings_written;

MVMHeapDumpIndex *index;

/* The file handle we are outputting to */
Expand Down

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