IPC例子工程全局变量共享问题

jian zong1

大家好，

我在论去中找到的IPC例子工程，仅仅在IPC.c 文件里加了一个变量 int g_flag = 3;在ISR里面让全局变量加1，然后打印出来。但是全局变量仅仅加一了次，打印出的结果全部都是4，请问这是为什么？打印的结果如下：

Set interrupt from Core 0 to Core 1, cycle = 1053673622
Interrupt Info 0
[TMS320C66x_1] Receive interrupt from Core 0 with info 0x0, cycle = 1057016594
g_flag = 4
Set interrupt from Core 1 to Core 2, cycle = 1057033058
Interrupt Info 8
[TMS320C66x_2] Receive interrupt from Core 1 with info 0x0, cycle = 1059235265
g_flag = 4
Set interrupt from Core 2 to Core 3, cycle = 1059251792
Interrupt Info 16
[TMS320C66x_3] Receive interrupt from Core 2 with info 0x10, cycle = 1057523984
g_flag = 4
Set interrupt from Core 3 to Core 4, cycle = 1057540624
Interrupt Info 24
[TMS320C66x_4] Receive interrupt from Core 3 with info 0x10, cycle = 1060312891
g_flag = 4
Set interrupt from Core 4 to Core 5, cycle = 1060329531
Interrupt Info 32
[TMS320C66x_5] Receive interrupt from Core 4 with info 0x20, cycle = 1060791800
g_flag = 4
Set interrupt from Core 5 to Core 6, cycle = 1060808440
Interrupt Info 40
[TMS320C66x_6] Receive interrupt from Core 5 with info 0x20, cycle = 1066910801
g_flag = 4
Set interrupt from Core 6 to Core 7, cycle = 1066927441
Interrupt Info 48
[TMS320C66x_7] Receive interrupt from Core 6 with info 0x30, cycle = 1070451703
g_flag = 4
Set interrupt from Core 7 to Core 0, cycle = 1070468343
Interrupt Info 56
[TMS320C66x_0] Receive interrupt from Core 7 with info 0x30, cycle = 1065998385
g_flag = 4
IPC test passed!

11 年多前

0 jian zong1 11 年多前

Expert 1110 points

没有DSP芯片，这个工程的运行是simulator下运行的。

0 Andy Yin 11 年多前

TI__Guru 61135 points

你这个变量应该是每个core上独有的变量，并非多核共享全局变量，所以每个core分别累加，互不影响。只产生一次中断是因为代码只触发一次。

0 jian zong1 11 年多前回复 Andy Yin

Expert 1110 points

那怎么才能让全局变量，被8个核都可以操作呢？？

0 yuanwen dong 11 年多前回复 jian zong1

Expert 1431 points

你好，教你一个方法。

（1）比如要共享变量share_variable，在每个核的代码中都声明：

///////////////////////////////////////////////////////////////////////////////////////////////

#pragma DATA_SECTION (share_variable, ".global_shared");
static unsigned int share_variable;

///////////////////////////////////////////////////////////////////////////////////////////////

（2）在link文件*.cmd中加入段定义

//////////////////////////////////////////////////////////////////////////////

MEMORY {

.....
VAR_SHARED_RAM: origin = 0x0C3E0000 length=0x00020000

.....
}

....

.global_shared: type=NOINIT > VAR_SHARED_RAM

///////////////////////////////////////////////////////////////////////////////////////////////

这样每个核上的变量share_variable，都对应与M3中的同一个内存，这就达到了类似全局变量的效果。

另外，记得在访问核间共享内存时，用spin_lock互斥（C6678有64个硬件信号量）。

BTW：Enea提供针对C66的商用平台软件，如果有兴趣可以联系。

William.dong@enea.com

0 jian zong1 11 年多前回复 yuanwen dong

Expert 1110 points

您好：

已经安装您的方法修改了CMD文件，但是还是打印出下面信息。
已经定义变量g_flag ，核0给核1 ，发中断，核1在中断里把g_flag加1.然后给核0发中断，核0在中断里把变量g_flag又加1。
g_flag 被加了两次，应该打印出4，为什么还是打印出3？附件是我的CCS工程，麻烦看哪里错了，谢谢。

[TMS320C66x_0] Set interrupt from Core 0 to Core 1, cycle = 15622 Interrupt Info 0
[TMS320C66x_1] Receive interrupt from Core 0 with info 0x0, cycle = 687498
Core1 output :g_flag = 3,address =c3e0000
Set interrupt from Core 1 to Core 0, cycle = 709011
Interrupt Info 8
[TMS320C66x_0] Receive interrupt from Core 1 with info 0x0, cycle = 1131531
core0:g_flag = 3, address =c3e0000
IPC test passed!

twoCoreExamp.rar

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IPC例子工程全局变量共享问题