63bb0078f8
An initial patch for supporting automated root detection. The auto-detector is introduced subsequently, but this patch introduces a datastructure for capturing sampled stacks, per thread, in a trie, and inferring from such samples which functions are reasonable roots.
58 lines
2.0 KiB
C++
58 lines
2.0 KiB
C++
/*===- RootAutodetector.h- auto-detect roots for ctxprof -----------------===*\
|
|
|*
|
|
|* Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
|* See https://llvm.org/LICENSE.txt for license information.
|
|
|* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
|*
|
|
\*===----------------------------------------------------------------------===*/
|
|
|
|
#ifndef CTX_PROFILE_ROOTAUTODETECTOR_H_
|
|
#define CTX_PROFILE_ROOTAUTODETECTOR_H_
|
|
|
|
#include "sanitizer_common/sanitizer_dense_map.h"
|
|
#include "sanitizer_common/sanitizer_internal_defs.h"
|
|
#include "sanitizer_common/sanitizer_stacktrace.h"
|
|
#include <pthread.h>
|
|
#include <sanitizer/common_interface_defs.h>
|
|
|
|
using namespace __asan;
|
|
using namespace __sanitizer;
|
|
|
|
namespace __ctx_profile {
|
|
|
|
/// Capture all the stack traces observed for a specific thread. The "for a
|
|
/// specific thread" part is not enforced, but assumed in determineRoots.
|
|
class PerThreadCallsiteTrie {
|
|
protected:
|
|
/// A trie. A node is the address of a callsite in a function activation. A
|
|
/// child is a callsite in the activation made from the callsite
|
|
/// corresponding to the parent.
|
|
struct Trie final {
|
|
const uptr CallsiteAddress;
|
|
uint64_t Count = 0;
|
|
DenseMap<uptr, Trie> Children;
|
|
|
|
Trie(uptr CallsiteAddress = 0) : CallsiteAddress(CallsiteAddress) {}
|
|
};
|
|
Trie TheTrie;
|
|
|
|
/// Return the runtime start address of the function that contains the call at
|
|
/// the runtime address CallsiteAddress. May be overriden for easy testing.
|
|
virtual uptr getFctStartAddr(uptr CallsiteAddress) const;
|
|
|
|
public:
|
|
PerThreadCallsiteTrie(const PerThreadCallsiteTrie &) = delete;
|
|
PerThreadCallsiteTrie(PerThreadCallsiteTrie &&) = default;
|
|
PerThreadCallsiteTrie() = default;
|
|
|
|
virtual ~PerThreadCallsiteTrie() = default;
|
|
|
|
void insertStack(const StackTrace &ST);
|
|
|
|
/// Return the runtime address of root functions, as determined for this
|
|
/// thread, together with the number of samples that included them.
|
|
DenseMap<uptr, uint64_t> determineRoots() const;
|
|
};
|
|
} // namespace __ctx_profile
|
|
#endif
|