tcmalloc 内存分析

　　　#启动程序的方式：
　　　HEAPCHECK=normal   HEAPPROFILE=prefix  ./test      //需要前台启动程序
     #第一个参数HEAPCHECK表示检查的严格程度    HEAPPROFILE参数表示生产的内存快照
     #默认生成的内存快照文件在/tmp  目录下。

使用HeapProFilerStart("prefix")  "prefix"是生成文件的前缀和 HeapProFilerStop 接口  
1.在头文件 <gperftools/heap-profiler.h> 中。
2.可以使用http接口或者telnet
  使用方式：程序可以前台，也可以后台，启动之后，发命令或者请求让其执行HeapProFilerStart  ，
           然后复现程序内存上涨的情况，接着在程序的当前目录可以看到 prefix_heap.0001.heap （prefix为start传入的前缀）,
          随着内存上涨，会持续的生很多的内存快照，差不多的时候stop。然后开始使用获得的内存快照分析。

执行命令： pprof --pdf  ./test  ./prefix_heap.0001.heap  > 1.pdf  

执行命令：pprof --pdf  --base=prefix_heap.0001.heap   ./test  ./prefix_heap.0002.heap  > 1.pdf 

HeapLeakChecker heap_checker("test_foo");
{
    code that exercises some foo functionality;
    this code should preserve memory allocation state;
}
if (!heap_checker.SameHeap()) assert(NULL == "heap memory leak");

 No Leaks found for check "test_foo" 

Leak check _main_ detected leaks of 1136 bytes in 2 objects The 2 largest leaks:
Leak of 568 bytes in 1 objects allocated from:
@ 7fa7f4197dd2
 
If the preceding stack traces are not enough to find the leaks, try running THIS shell command:
 
pprof ./bin/exe "/tmp/exe.7539._main_-end.heap" --inuse_objects --lines --heapcheck --edgefraction=1e-10 --nodefraction=1e-10 --pdf
 
If you are still puzzled about why the leaks are there, try rerunning this program with HEAP_CHECK_TEST_POINTER_ALIGNMENT=1 and/or with HEAP_CHECK_MAX_POINTER_OFFSET=-1 
If the leak report occurs in a small fraction of runs, try running with TCMALLOC_MAX_FREE_QUEUE_SIZE of few hundred MB or with TCMALLOC_RECLAIM_MEMORY=false, 
it mi Exiting with error code (instead of crashing) because of whole-program memory leaks