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| author | Lennart Poettering <lennart@poettering.net> | 2020-08-28 21:18:14 +0200 |
|---|---|---|
| committer | Daan De Meyer <daan.j.demeyer@gmail.com> | 2020-08-30 18:09:39 +0100 |
| commit | e2b40db616b4e723036f72a726e2f2f31d35ffe1 (patch) | |
| tree | 8b57d9179f15a67622b5fec14476127d129de6a4 /man/sd_bus_message_read_basic.xml | |
| parent | a667ddf1327f55a5af5abef006b60fc42e998beb (diff) | |
| download | systemd-e2b40db616b4e723036f72a726e2f2f31d35ffe1.tar.gz | |
man: document fd ownership for sd-bus fd marshalling
Fixes: #8003
Diffstat (limited to 'man/sd_bus_message_read_basic.xml')
| -rw-r--r-- | man/sd_bus_message_read_basic.xml | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/man/sd_bus_message_read_basic.xml b/man/sd_bus_message_read_basic.xml index e1e993434a..dc9f960618 100644 --- a/man/sd_bus_message_read_basic.xml +++ b/man/sd_bus_message_read_basic.xml @@ -52,17 +52,19 @@ </para> <para> - If <parameter>p</parameter> is not <constant>NULL</constant>, it should contain - a pointer to an appropriate object. For example, if <parameter>type</parameter> - is <constant>'y'</constant>, the object passed in <parameter>p</parameter> - should have type <type>uint8_t *</type>. If <parameter>type</parameter> is - <constant>'s'</constant>, the object passed in <parameter>p</parameter> should - have type <type>const char **</type>. Note that, if the basic type is a pointer - (e.g., <type>const char *</type> in the case of a string), the pointer is only - borrowed and the contents must be copied if they are to be used after the end - of the messages lifetime. Similarly, during the lifetime of such a pointer, the - message must not be modified. See the table below for a complete list of allowed - types. + If <parameter>p</parameter> is not <constant>NULL</constant>, it should contain a pointer to an + appropriate object. For example, if <parameter>type</parameter> is <constant>'y'</constant>, the object + passed in <parameter>p</parameter> should have type <type>uint8_t *</type>. If + <parameter>type</parameter> is <constant>'s'</constant>, the object passed in <parameter>p</parameter> + should have type <type>const char **</type>. Note that, if the basic type is a pointer (e.g., + <type>const char *</type> in the case of a string), the pointer is only borrowed and the contents must + be copied if they are to be used after the end of the messages lifetime. Similarly, during the lifetime + of such a pointer, the message must not be modified. If <parameter>type</parameter> is + <constant>'h'</constant> (UNIX file descriptor), the descriptor is not duplicated by this call and the + returned descriptor remains in possession of the message object, and needs to be duplicated by the caller + in order to keep an open reference to it after the message object is freed (for example by calling + <literal>fcntl(fd, FD_DUPFD_CLOEXEC, 3)</literal>). See the table below for a complete list of + allowed types. </para> <table id='format-specifiers'> |