c - brk 和 sbrk 的区别

Question

我是新手，任何人都可以通过一个简短的例子说出 brk 和 sbrk 之间的确切区别吗？有没有效率因素可以从两者中选择任何一个？malloc 和 new 内部调用 brk 或 sbrk。

Answer 1

int brk(void *addr);

brk() sets the end of the data segment to the value specified by addr, when that value is reasonable, the system has enough memory, and the process does not exceed its maximum data size.

On success, brk() returns zero. On error, -1 is returned, and errno is set to ENOMEM.

void *sbrk(intptr_t increment);

sbrk() increments the program's data space by increment bytes. Calling sbrk() with an increment of 0 can be used to find the current location of the program break.

On success, sbrk() returns the previous program break. (If the break was increased, then this value is a pointer to the start of the newly allocated memory). On error, (void *) -1 is returned, and errno is set to ENOMEM.

From linux manual page