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我正在编写一个与英特尔的DPDK接口的Rust程序，并且我遇到了一个我不太明白的问题。我目前可以从在锈病程序DPDK库执行的功能，但它在从写入C.DPDK函数具有不同的输出，当从Rust中调用时比从C中输出
锈病程序输出相同的程序的结果不同 -
~/Dev/rust_eal_init_test$ sudo target/debug/rust_eal_init_test
EAL: Detected 8 lcore(s)
EAL: No free hugepages reported in hugepages-2048kB
EAL: Probing VFIO support...
~/Dev/rust_eal_init_test$
C程序输出 -
~/Dev/c_eal_init_test$ sudo build/c_eal_init_test
EAL: Detected 8 lcore(s)
EAL: No free hugepages reported in hugepages-2048kB
EAL: Probing VFIO support...
PMD: bnxt_rte_pmd_init() called for (null)
EAL: PCI device 0000:00:19.0 on NUMA socket -1
EAL: probe driver: 8086:153a rte_em_pmd
EAL: PCI device 0000:04:00.0 on NUMA socket -1
EAL: probe driver: 8086:1533 rte_igb_pmd
~/Dev/c_eal_init_test$
DPDK已被编译为我在Rust中链接到的静态库。下面是Rust和C程序的代码。
锈main.rs -
extern crate libc;
use std::env;
use std::process::exit;
use std::ffi::CString;
use libc::{c_int, c_char,};
extern {
pub fn rte_eal_init(argc: c_int, argv: *mut *mut c_char) -> c_int;
}
// librte_eal
pub fn dpdk_rte_eal_init(argc: i32, argv: Vec<String>) -> i32 {
let mut args: Vec<*mut c_char> = argv.iter().map(|x| CString::new(x.clone()).unwrap().into_raw()).collect();
let retc: c_int = unsafe { rte_eal_init(argc as c_int, args.as_mut_ptr()) };
let ret: i32 = retc as i32;
ret
}
fn main() {
let args: Vec<String> = env::args().collect();
let ret: i32 = dpdk_rte_eal_init(args.len() as i32, args);
if ret < 0 {
exit(ret);
}
}
Ç的main.c -
#include <stdio.h>
#include <string.h>
#include <rte_eal.h>
#include <rte_debug.h>
int
main(int argc, char **argv)
{
int ret;
ret = rte_eal_init(argc, argv);
if (ret < 0)
rte_panic("Cannot init EAL\n");
return 0;
}
我已经做了由翻翻DPDK来源并添加打印语句，看看那里的东西不同一番调查。 rte_eal_init()函数位于eal.c中，并调用各种其他初始化函数。额外输出的触发来自rte_eal_dev_init()中的另一个函数eal_common_dev.c。
rte_eal_dev_init() -
int
rte_eal_dev_init(void)
{
struct rte_devargs *devargs;
struct rte_driver *driver;
/*
* Note that the dev_driver_list is populated here
* from calls made to rte_eal_driver_register from constructor functions
* embedded into PMD modules via the PMD_REGISTER_DRIVER macro
*/
/* call the init function for each virtual device */
TAILQ_FOREACH(devargs, &devargs_list, next) {
if (devargs->type != RTE_DEVTYPE_VIRTUAL)
continue;
if (rte_eal_vdev_init(devargs->virt.drv_name,
devargs->args)) {
RTE_LOG(ERR, EAL, "failed to initialize %s device\n",
devargs->virt.drv_name);
return -1;
}
}
/* Once the vdevs are initalized, start calling all the pdev drivers */
TAILQ_FOREACH(driver, &dev_driver_list, next) {
if (driver->type != PMD_PDEV)
continue;
/* PDEV drivers don't get passed any parameters */
driver->init(NULL, NULL);
}
return 0;
}
我发现是生锈程序进入rte_eal_dev_init()功能，但从未进入的TAILQ_FOREACH()宏循环。如果我要加正上方和像这样的宏观调控下打印语句 -
printf("Test before TAILQ_FOREACH\n");
TAILQ_FOREACH(driver, &dev_driver_list, next) {
printf("Test in TAILQ_FOREACH\n");
if (driver->type != PMD_PDEV)
continue;
/* PDEV drivers don't get passed any parameters */
driver->init(NULL, NULL);
}
这使我在锈下面的输出 -
~/Dev/rust_eal_init_test$ sudo target/debug/rust_eal_init_test
EAL: Detected 8 lcore(s)
EAL: No free hugepages reported in hugepages-2048kB
EAL: Probing VFIO support...
Test before TAILQ_FOREACH
~/Dev/rust_eal_init_test$
而下面的输出用C -
~/Dev/c_eal_init_test$ sudo build/c_eal_init_test
EAL: Detected 8 lcore(s)
EAL: No free hugepages reported in hugepages-2048kB
EAL: Probing VFIO support...
Test before TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
PMD: bnxt_rte_pmd_init() called for (null)
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
Test in TAILQ_FOREACH
EAL: PCI device 0000:00:19.0 on NUMA socket -1
EAL: probe driver: 8086:153a rte_em_pmd
EAL: PCI device 0000:04:00.0 on NUMA socket -1
EAL: probe driver: 8086:1533 rte_igb_pmd
~/Dev/c_eal_init_test$
我发现TAILQ_FOREACH()定义在sys/queue.h。据我了解，链接到一个静态库不应该导致与动态链接到其他库的问题。它是否正确？
这听起来像你可能没有将'TAIL_Q_FOREACH'，这可能是一个宏生成一个循环，转换成锈 - 但你没有显示任何代码，所以不能告诉。我不希望这是一个链接问题，如果你得到它运行。 –
正如目前所写，这个问题应该是封闭的，因为：*寻求调试的帮助（“为什么不是这个代码工作？”）必须包含所需的行为，特定的问题或错误以及重现它所需的最短代码质疑自己。没有明确问题陈述的问题对其他读者无用。* [编辑]您的问题以产生[MCVE]。 – Shepmaster
您的'printf' **完全改变循环**的行为。这就是为什么if语句应该是强制性的。 – Shepmaster