在嵌入式环境中检测C++内存泄漏的好方法是什么?我尝试重载新操作符以记录每个数据分配,但是我一定做错了什么,该方法不起作用。还有其他人遇到过类似情况吗?
这是new和delete运算符重载的代码。
编辑:
完全公开:我正在寻找程序中的内存泄漏,并且正在使用别人编写的这段代码来使new和delete运算符过载。我的问题的部分原因是我不完全了解它的作用。我知道目标是记录调用方和上一个调用方的地址,分配的大小,如果要分配,则为1,如果是释放,则为2。加上正在运行的线程的名称。
感谢所有建议,我将尝试一种工作人员建议的不同方法。如果有效,我会在这里发布。
再次感谢所有一流的程序员花时间回答。
StackOverflow令人震惊!
结论
感谢所有的答案。不幸的是,我不得不继续处理另一个更加紧迫的问题。仅在极不可能的情况下才发生此泄漏。我只是丢下它而感到cr脚,如果我有更多的时间,我可能会再来。我选择了最有可能使用的答案。
#include <stdlib.h>
#include "stdio.h"
#include "nucleus.h"
#include "plus/inc/dm_defs.h"
#include "plus/inc/pm_defs.h"
#include "posix\inc\posix.h"
extern void* TCD_Current_Thread;
extern "C" void rd_write_text(char * text);
extern PM_PCB * PMD_Created_Pools_List;
typedef struct {
void* addr;
uint16_t size;
uint16_t flags;
} MemLogEntryNarrow_t;
typedef struct {
void* addr;
uint16_t size;
uint16_t flags;
void* caller;
void* prev_caller;
void* taskid;
uint32_t timestamp;
} MemLogEntryWide_t;
//size lookup table
unsigned char MEM_bitLookupTable[] = {
0,1,1,2,1,2,2,3,1,2,2,3,1,3,3,4
};
//#pragma CODE_SECTION ("section_ramset1_0")
void *::operator new(unsigned int size)
{
asm(" STR R14, [R13, #0xC]"); //save stack address temp[0]
asm(" STR R13, [R13, #0x10]"); //save pc return address temp[1]
if ( loggingEnabled )
{
uint32_t savedInterruptState;
uint32_t currentIndex;
// protect the thread unsafe section.
savedInterruptState = NU_Local_Control_Interrupts(NU_DISABLE_INTERRUPTS);
// Note that this code is FRAGILE. It peeks backwards on the stack to find the return
// address of the caller. The location of the return address on the stack can be easily changed
// as a result of other changes in this function (i.e. adding local variables, etc).
// The offsets may need to be adjusted if this function is touched.
volatile unsigned int temp[2];
unsigned int *addr = (unsigned int *)temp[0] - 1;
unsigned int count = 1 + (0x20/4); //current stack space ***
//Scan for previous store
while ((*addr & 0xFFFF0000) != 0xE92D0000)
{
if ((*addr & 0xFFFFF000) == 0xE24DD000)
{
//add offset in words
count += ((*addr & 0xFFF) >> 2);
}
addr--;
}
count += MEM_bitLookupTable[*addr & 0xF];
count += MEM_bitLookupTable[(*addr >>4) & 0xF];
count += MEM_bitLookupTable[(*addr >> 8) & 0xF];
count += MEM_bitLookupTable[(*addr >> 12) & 0xF];
addr = (unsigned int *)temp[1] + count;
// FRAGILE CODE ENDS HERE
currentIndex = currentMemLogWriteIndex;
currentMemLogWriteIndex++;
if ( memLogNarrow )
{
if (currentMemLogWriteIndex >= MEMLOG_SIZE/2 )
{
loggingEnabled = false;
rd_write_text( "Allocation Logging is complete and DISABLED!\r\n\r\n");
}
// advance the read index if necessary.
if ( currentMemLogReadIndex == currentMemLogWriteIndex )
{
currentMemLogReadIndex++;
if ( currentMemLogReadIndex == MEMLOG_SIZE/2 )
{
currentMemLogReadIndex = 0;
}
}
NU_Local_Control_Interrupts(savedInterruptState);
//Standard operator
//(For Partition Analysis we have to consider that if we alloc size of 0 always as size of 1 then are partitions must be optimized for this)
if (size == 0) size = 1;
((MemLogEntryNarrow_t*)memLog)[currentIndex].size = size;
((MemLogEntryNarrow_t*)memLog)[currentIndex].flags = 1; //allocated
//Standard operator
void * ptr;
ptr = malloc(size);
((MemLogEntryNarrow_t*)memLog)[currentIndex].addr = ptr;
return ptr;
}
else
{
if (currentMemLogWriteIndex >= MEMLOG_SIZE/6 )
{
loggingEnabled = false;
rd_write_text( "Allocation Logging is complete and DISABLED!\r\n\r\n");
}
// advance the read index if necessary.
if ( currentMemLogReadIndex == currentMemLogWriteIndex )
{
currentMemLogReadIndex++;
if ( currentMemLogReadIndex == MEMLOG_SIZE/6 )
{
currentMemLogReadIndex = 0;
}
}
((MemLogEntryWide_t*)memLog)[currentIndex].caller = (void *)(temp[0] - 4);
((MemLogEntryWide_t*)memLog)[currentIndex].prev_caller = (void *)*addr;
NU_Local_Control_Interrupts(savedInterruptState);
((MemLogEntryWide_t*)memLog)[currentIndex].taskid = (void *)TCD_Current_Thread;
((MemLogEntryWide_t*)memLog)[currentIndex].size = size;
((MemLogEntryWide_t*)memLog)[currentIndex].flags = 1; //allocated
((MemLogEntryWide_t*)memLog)[currentIndex].timestamp = *(volatile uint32_t *)0xfffbc410; // for arm9
//Standard operator
if (size == 0) size = 1;
void * ptr;
ptr = malloc(size);
((MemLogEntryWide_t*)memLog)[currentIndex].addr = ptr;
return ptr;
}
}
else
{
//Standard operator
if (size == 0) size = 1;
void * ptr;
ptr = malloc(size);
return ptr;
}
}
//#pragma CODE_SECTION ("section_ramset1_0")
void ::operator delete(void *ptr)
{
uint32_t savedInterruptState;
uint32_t currentIndex;
asm(" STR R14, [R13, #0xC]"); //save stack address temp[0]
asm(" STR R13, [R13, #0x10]"); //save pc return address temp[1]
if ( loggingEnabled )
{
savedInterruptState = NU_Local_Control_Interrupts(NU_DISABLE_INTERRUPTS);
// Note that this code is FRAGILE. It peeks backwards on the stack to find the return
// address of the caller. The location of the return address on the stack can be easily changed
// as a result of other changes in this function (i.e. adding local variables, etc).
// The offsets may need to be adjusted if this function is touched.
volatile unsigned int temp[2];
unsigned int *addr = (unsigned int *)temp[0] - 1;
unsigned int count = 1 + (0x20/4); //current stack space ***
//Scan for previous store
while ((*addr & 0xFFFF0000) != 0xE92D0000)
{
if ((*addr & 0xFFFFF000) == 0xE24DD000)
{
//add offset in words
count += ((*addr & 0xFFF) >> 2);
}
addr--;
}
count += MEM_bitLookupTable[*addr & 0xF];
count += MEM_bitLookupTable[(*addr >>4) & 0xF];
count += MEM_bitLookupTable[(*addr >> 8) & 0xF];
count += MEM_bitLookupTable[(*addr >> 12) & 0xF];
addr = (unsigned int *)temp[1] + count;
// FRAGILE CODE ENDS HERE
currentIndex = currentMemLogWriteIndex;
currentMemLogWriteIndex++;
if ( memLogNarrow )
{
if ( currentMemLogWriteIndex >= MEMLOG_SIZE/2 )
{
loggingEnabled = false;
rd_write_text( "Allocation Logging is complete and DISABLED!\r\n\r\n");
}
// advance the read index if necessary.
if ( currentMemLogReadIndex == currentMemLogWriteIndex )
{
currentMemLogReadIndex++;
if ( currentMemLogReadIndex == MEMLOG_SIZE/2 )
{
currentMemLogReadIndex = 0;
}
}
NU_Local_Control_Interrupts(savedInterruptState);
// finish logging the fields. these are thread safe so they dont need to be inside the protected section.
((MemLogEntryNarrow_t*)memLog)[currentIndex].addr = ptr;
((MemLogEntryNarrow_t*)memLog)[currentIndex].size = 0;
((MemLogEntryNarrow_t*)memLog)[currentIndex].flags = 2; //unallocated
}
else
{
((MemLogEntryWide_t*)memLog)[currentIndex].caller = (void *)(temp[0] - 4);
((MemLogEntryWide_t*)memLog)[currentIndex].prev_caller = (void *)*addr;
if ( currentMemLogWriteIndex >= MEMLOG_SIZE/6 )
{
loggingEnabled = false;
rd_write_text( "Allocation Logging is complete and DISABLED!\r\n\r\n");
}
// advance the read index if necessary.
if ( currentMemLogReadIndex == currentMemLogWriteIndex )
{
currentMemLogReadIndex++;
if ( currentMemLogReadIndex == MEMLOG_SIZE/6 )
{
currentMemLogReadIndex = 0;
}
}
NU_Local_Control_Interrupts(savedInterruptState);
// finish logging the fields. these are thread safe so they dont need to be inside the protected section.
((MemLogEntryWide_t*)memLog)[currentIndex].addr = ptr;
((MemLogEntryWide_t*)memLog)[currentIndex].size = 0;
((MemLogEntryWide_t*)memLog)[currentIndex].flags = 2; //unallocated
((MemLogEntryWide_t*)memLog)[currentIndex].taskid = (void *)TCD_Current_Thread;
((MemLogEntryWide_t*)memLog)[currentIndex].timestamp = *(volatile uint32_t *)0xfffbc410; // for arm9
}
//Standard operator
if (ptr != NULL) {
free(ptr);
}
}
else
{
//Standard operator
if (ptr != NULL) {
free(ptr);
}
}
}
最佳答案
一种方法是将分配内存的模块的文件名和行号字符串(通过指针)插入分配的数据块中。文件和行号通过使用C++标准“__FILE__
”和“__LINE__
”宏进行处理。取消分配内存后,该信息将被删除。
我们的系统之一具有此功能,我们称其为“内存 pig 报告”。因此,随时可以从我们的CLI中打印出所有已分配的内存以及谁分配了内存的大量信息的 list 。该列表按分配最大内存的代码模块排序。很多时候,我们会随着时间的推移以这种方式监视内存使用情况,最终,内存消耗(泄漏)将上升到列表的顶部。
关于c++ - 如何在C++中查找内存泄漏,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/996498/