David Sehr | 4c16ac0 | 2016-03-17 13:51:42 -0700 | [diff] [blame] | 1 | //===- subzero/src/LinuxMallocProfiling.cpp - malloc/new tracing ---------===// |
| 2 | // |
| 3 | // The Subzero Code Generator |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | /// |
| 10 | /// \file |
| 11 | /// \brief malloc/new/...caller tracing. |
| 12 | /// |
| 13 | //===----------------------------------------------------------------------===// |
| 14 | |
| 15 | #include "LinuxMallocProfiling.h" |
| 16 | |
| 17 | #ifdef ALLOW_LINUX_MALLOC_PROFILE |
| 18 | |
| 19 | #include <dlfcn.h> |
| 20 | #include <malloc.h> |
| 21 | #include <unordered_map> |
| 22 | |
| 23 | extern "C" void *__libc_malloc(size_t size); |
| 24 | |
| 25 | namespace { |
| 26 | // The Callers structure allocates memory, which would perturb the tracing. |
| 27 | // InAllocatorFunction is true when we are tracing a new/malloc/... |
| 28 | bool InAllocatorFunction = false; |
| 29 | |
| 30 | // Keep track of the number of times a particular call site address invoked an |
| 31 | // allocator. NOTE: this is not thread safe, so the user must invoke with |
| 32 | // --threads=0 to enable profiling. |
| 33 | using MallocMap = std::unordered_map<void *, uint64_t>; |
| 34 | MallocMap *Callers; |
| 35 | |
| 36 | void *internalAllocator(size_t size, void *caller) { |
| 37 | if (Callers != nullptr && !InAllocatorFunction) { |
| 38 | InAllocatorFunction = true; |
| 39 | ++(*Callers)[caller]; |
| 40 | InAllocatorFunction = false; |
| 41 | } |
| 42 | return __libc_malloc(size); |
| 43 | } |
| 44 | } // end of anonymous namespace |
| 45 | |
| 46 | // new, new[], and malloc are all defined as weak symbols to allow them to be |
| 47 | // overridden by user code. This gives us a convenient place to hook allocation |
| 48 | // tracking, to record the IP of the caller, which we get from the call to |
| 49 | // __builtin_return_address. |
| 50 | void *operator new(size_t size) { |
| 51 | void *caller = __builtin_return_address(0); |
| 52 | return internalAllocator(size, caller); |
| 53 | } |
| 54 | |
| 55 | void *operator new[](size_t size) { |
| 56 | void *caller = __builtin_return_address(0); |
| 57 | return internalAllocator(size, caller); |
| 58 | } |
| 59 | |
| 60 | extern "C" void *malloc(size_t size) { |
| 61 | void *caller = __builtin_return_address(0); |
| 62 | return internalAllocator(size, caller); |
| 63 | } |
| 64 | |
| 65 | namespace Ice { |
| 66 | |
| 67 | LinuxMallocProfiling::LinuxMallocProfiling(size_t NumThreads, Ostream *Ls) |
| 68 | : Ls(Ls) { |
| 69 | if (NumThreads != 0) { |
| 70 | *Ls << "NOTE: Malloc profiling is not thread safe. Use --threads=0 to " |
| 71 | "enable.\n"; |
| 72 | return; |
| 73 | } |
| 74 | Callers = new MallocMap(); |
| 75 | } |
| 76 | |
| 77 | LinuxMallocProfiling::~LinuxMallocProfiling() { |
| 78 | if (Callers == nullptr) { |
| 79 | return; |
| 80 | } |
| 81 | for (const auto &C : *Callers) { |
| 82 | Dl_info dli; |
| 83 | dladdr(C.first, &dli); |
| 84 | |
| 85 | *Ls << C.second << " "; |
| 86 | if (dli.dli_sname == NULL) { |
| 87 | *Ls << C.first; |
| 88 | } else { |
| 89 | *Ls << dli.dli_sname; |
| 90 | } |
| 91 | *Ls << "\n"; |
| 92 | } |
| 93 | delete Callers; |
| 94 | Callers = nullptr; |
| 95 | } |
| 96 | } // end of namespace Ice |
| 97 | |
| 98 | #else // !ALLOW_LINUX_MALLOC_PROFILE |
| 99 | |
| 100 | namespace Ice { |
| 101 | |
| 102 | LinuxMallocProfiling::LinuxMallocProfiling(size_t NumThreads, Ostream *Ls) { |
| 103 | (void)NumThreads; |
| 104 | (void)Ls; |
| 105 | } |
| 106 | |
| 107 | LinuxMallocProfiling::~LinuxMallocProfiling() {} |
| 108 | } // end of namespace Ice |
| 109 | |
| 110 | #endif // ALLOW_LINUX_MALLOC_PROFILE |