c++ - boost 共享内存 : the volume of a file has been externally altered and open file is not longer valid

Question

我正在使用 Boost shared memory 在不同进程之间共享 vector 。然而，在某些情况下，共享内存的消费者会抛出这个异常:

Unexpected exception: The volume for a file has been externally altered so that the opened file is no longer valid.

我设置了适当的同步机制。此错误可能表明什么？

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已解决其中一个进程在创建时未正确分配内存大小。

When a shared memory object is created, its size is 0. To set the size of the shared memory, the user must use the truncate function call, in a shared memory that has been opened with read-write attributes

来源 - Boost shared memory

Answer 1

这意味着文件的体积已被外部更改。查找写入文件的其他进程。

换句话说，这意味着您没有适当的同步。

你用bip::managed_mapped_file::grow吗？在任何情况下？文档说明它只允许离线增长。