23 lines
1.1 KiB
Plaintext
23 lines
1.1 KiB
Plaintext
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[Not yet complete]
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Cygwin has recently adopted something called the "cygwin heap". This is
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an internal heap that is inherited by forked/execed children. It
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consists of process specific information that should be inherited. So
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things like the file descriptor table, the current working directory,
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and the chroot value live there.
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The cygheap is also used to pass argv information to a child process.
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There is a problem here, though. If you allocate space for argv on the
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heap and then exec a process the child process (1) will happily use the
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space in the heap. But what happens when that process execs another
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process (2)? The space used by child process (1) still is being used in
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child process (2) but it is basically just a memory leak.
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To rectify this problem, memory used by child process 1 is tagged in
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such a way that child process 2 will know to delete it. This is in
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cygheap_fixup_in_child.
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The cygheap memory allocation functions are adapted from memory
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allocators developed by DJ Delorie. They are similar to early BSD
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malloc and are intended to be relatively lightweight and relatively
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fast.
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