diff options
Diffstat (limited to 'glibc')
| -rw-r--r-- | glibc/fork.mdwn | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/glibc/fork.mdwn b/glibc/fork.mdwn index c9efd1f4..e8556a91 100644 --- a/glibc/fork.mdwn +++ b/glibc/fork.mdwn @@ -8,7 +8,7 @@ Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled [[GNU Free Documentation License|/fdl]]."]]"""]] -On [[Unix]] systems, `fork` is a rather simple system call. +On [[Unix]] systems, `fork` is a rather simple [[system call]]. Our implementation in [[glibc]] is and needs to be rather bulky. @@ -22,12 +22,13 @@ which requires a small number of [[RPC]] for each of them. In sum, [[this affects performance|open_issues/performance/fork]] when new processes are continuously being spawned from the shell, for example. -Often, a `fork` call will eventually be followed by an `exec`, which will in -turn close (most of) the duplicated port rights. Unfortunately, this cannot be -known at the time the `fork` executing, so the code calling `fork` has to be -modified, and the `fork`, `exec` combo be replaced by a `posix_spawn` call, for -example, to avoid this work of duplicating each port right, then closing each -again. +Often, a `fork` call will eventually be followed by an `exec`, which [[may in +turn close|open_issues/secure_file_descriptor_handling]] (most of) the +duplicated port rights. Unfortunately, this cannot be known at the time the +`fork` executing, so in order to optimize this, the code calling `fork` has to +be modified instead, and the `fork`, `exec` combo be replaced by a +`posix_spawn` call, for example, to avoid this work of duplicating each port +right, then closing each again. As far as we know, Cygwin has the same problem of `fork` being a nontrivial operation. Perhaps we can learn from what they're been doing? Also, perhaps @@ -51,6 +52,11 @@ they have patches for software packages, to avoid using `fork` followed by ([[!taglink open_issue_glibc]]). +## Related + + * [[secure file descriptor handling]]. + + # External * [*How fork(2) ought to be*](http://www.greenend.org.uk/rjk/fork.html) by |