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| author | Zac Medico <zmedico@gentoo.org> | 2013-01-15 12:09:21 -0800 |
|---|---|---|
| committer | Zac Medico <zmedico@gentoo.org> | 2013-01-15 12:09:21 -0800 |
| commit | dbe26095102cbdc6d5bef3509f05bc7b42c418cc (patch) | |
| tree | fbdc5d18ff9fa33dc7b69fdb6c173312cb4507a8 /pym/portage | |
| parent | 7c624515d0bb106c8a468addff5df153cebf31fc (diff) | |
| download | portage-dbe26095102cbdc6d5bef3509f05bc7b42c418cc.tar.gz portage-dbe26095102cbdc6d5bef3509f05bc7b42c418cc.tar.bz2 portage-dbe26095102cbdc6d5bef3509f05bc7b42c418cc.zip | |
SpawnProcess: improve dummy pipe allocation logic
By using allocated file descriptors for keys in fd_pipes, we naturally
avoid interference with callers such as FileDigester and MergeProcess.
See the _setup_pipes docstring for more benefits of this allocation
approach.
Diffstat (limited to 'pym/portage')
| -rw-r--r-- | pym/portage/package/ebuild/_config/special_env_vars.py | 4 | ||||
| -rw-r--r-- | pym/portage/process.py | 15 |
2 files changed, 17 insertions, 2 deletions
diff --git a/pym/portage/package/ebuild/_config/special_env_vars.py b/pym/portage/package/ebuild/_config/special_env_vars.py index 578e417f2..93bb98a42 100644 --- a/pym/portage/package/ebuild/_config/special_env_vars.py +++ b/pym/portage/package/ebuild/_config/special_env_vars.py @@ -22,7 +22,7 @@ env_blacklist = frozenset(( "PDEPEND", "PF", "PKGUSE", "PORTAGE_BACKGROUND", "PORTAGE_BACKGROUND_UNMERGE", "PORTAGE_BUILDDIR_LOCKED", "PORTAGE_BUILT_USE", "PORTAGE_CONFIGROOT", "PORTAGE_IUSE", - "PORTAGE_NONFATAL", "PORTAGE_REPO_NAME", + "PORTAGE_NONFATAL", "PORTAGE_PIPE_FD", "PORTAGE_REPO_NAME", "PORTAGE_USE", "PROPERTIES", "PROVIDE", "RDEPEND", "REPOSITORY", "RESTRICT", "ROOT", "SLOT", "SRC_URI" )) @@ -63,7 +63,7 @@ environ_whitelist += [ "PORTAGE_GID", "PORTAGE_GRPNAME", "PORTAGE_INST_GID", "PORTAGE_INST_UID", "PORTAGE_IPC_DAEMON", "PORTAGE_IUSE", - "PORTAGE_LOG_FILE", "PORTAGE_OVERRIDE_EPREFIX", + "PORTAGE_LOG_FILE", "PORTAGE_OVERRIDE_EPREFIX", "PORTAGE_PIPE_FD", "PORTAGE_PYM_PATH", "PORTAGE_PYTHON", "PORTAGE_QUIET", "PORTAGE_REPO_NAME", "PORTAGE_RESTRICT", "PORTAGE_SIGPIPE_STATUS", diff --git a/pym/portage/process.py b/pym/portage/process.py index 4cf1cec60..23a909466 100644 --- a/pym/portage/process.py +++ b/pym/portage/process.py @@ -429,6 +429,21 @@ def _setup_pipes(fd_pipes, close_fds=True): and also with CPython under some circumstances (as triggered by xmpppy in bug #374335). In order to close a safe subset of file descriptors, see portage.locks._close_fds(). + + NOTE: When not followed by exec, even when close_fds is False, + it's still possible for dup2() calls to cause interference in a + way that's similar to the way that close_fds interferes (since + dup2() has to close the target fd if it happens to be open). + It's possible to avoid such interference by using allocated + file descriptors as the keys in fd_pipes. For example: + + pr, pw = os.pipe() + fd_pipes[pw] = pw + + By using the allocated pw file descriptor as the key in fd_pipes, + it's not necessary for dup2() to close a file descriptor (it + actually does nothing in this case), which avoids possible + interference. """ my_fds = {} # To protect from cases where direct assignment could |