This source file includes following definitions.
- KeyEqual
- table_
- AddTrace
- ReadStackTracesAndClear
#include <config.h>
#include "stack_trace_table.h"
#include <string.h>
#include "base/spinlock.h"
#include "common.h"
#include "internal_logging.h"
#include "page_heap_allocator.h"
#include "static_vars.h"
namespace tcmalloc {
bool StackTraceTable::Bucket::KeyEqual(uintptr_t h,
const StackTrace& t) const {
const bool eq = (this->hash == h && this->trace.depth == t.depth);
for (int i = 0; eq && i < t.depth; ++i) {
if (this->trace.stack[i] != t.stack[i]) {
return false;
}
}
return eq;
}
StackTraceTable::StackTraceTable()
: error_(false),
depth_total_(0),
bucket_total_(0),
table_(new Bucket*[kHashTableSize]()) {
memset(table_, 0, kHashTableSize * sizeof(Bucket*));
}
StackTraceTable::~StackTraceTable() {
delete[] table_;
}
void StackTraceTable::AddTrace(const StackTrace& t) {
if (error_) {
return;
}
uintptr_t h = 0;
for (int i = 0; i < t.depth; ++i) {
h += reinterpret_cast<uintptr_t>(t.stack[i]);
h += h << 10;
h ^= h >> 6;
}
h += h << 3;
h ^= h >> 11;
const int idx = h % kHashTableSize;
Bucket* b = table_[idx];
while (b != NULL && !b->KeyEqual(h, t)) {
b = b->next;
}
if (b != NULL) {
b->count++;
b->trace.size += t.size;
} else {
depth_total_ += t.depth;
bucket_total_++;
b = Static::bucket_allocator()->New();
if (b == NULL) {
Log(kLog, __FILE__, __LINE__,
"tcmalloc: could not allocate bucket", sizeof(*b));
error_ = true;
} else {
b->hash = h;
b->trace = t;
b->count = 1;
b->next = table_[idx];
table_[idx] = b;
}
}
}
void** StackTraceTable::ReadStackTracesAndClear() {
if (error_) {
return NULL;
}
const int out_len = bucket_total_ * 3 + depth_total_ + 1;
void** out = new void*[out_len];
if (out == NULL) {
Log(kLog, __FILE__, __LINE__,
"tcmalloc: allocation failed for stack traces",
out_len * sizeof(*out));
return NULL;
}
int idx = 0;
for (int i = 0; i < kHashTableSize; ++i) {
Bucket* b = table_[i];
while (b != NULL) {
out[idx++] = reinterpret_cast<void*>(static_cast<uintptr_t>(b->count));
out[idx++] = reinterpret_cast<void*>(b->trace.size);
out[idx++] = reinterpret_cast<void*>(b->trace.depth);
for (int d = 0; d < b->trace.depth; ++d) {
out[idx++] = b->trace.stack[d];
}
b = b->next;
}
}
out[idx++] = NULL;
ASSERT(idx == out_len);
error_ = false;
depth_total_ = 0;
bucket_total_ = 0;
SpinLockHolder h(Static::pageheap_lock());
for (int i = 0; i < kHashTableSize; ++i) {
Bucket* b = table_[i];
while (b != NULL) {
Bucket* next = b->next;
Static::bucket_allocator()->Delete(b);
b = next;
}
table_[i] = NULL;
}
return out;
}
}