freebsd with flexible iflib nic queues
635f917a9d
which does not know what is the state of interrupted system call, for example, open() system call opened a file and the thread is still cancelled, result is descriptor leak, there are other problems which can cause resource leak or undeterminable side effect when a thread is cancelled. However, this is no longer true in new implementation. In defering mode, a thread is canceled if cancellation request is pending and later the thread enters a cancellation point, otherwise, a later pthread_cancel() just causes SIGCANCEL to be sent to the target thread, and causes target thread to abort system call, userland code in libthr then checks cancellation state, and cancels the thread if needed. For example, the cancellation point open(), the thread may be canceled at start, but later, if it opened a file descriptor, it is not canceled, this avoids file handle leak. Another example is read(), a thread may be canceled at start of the function, but later, if it read some bytes from a socket, the thread is not canceled, the caller then can decide if it should still enable cancelling or disable it and continue reading data until it thinks it has read all bytes of a packet, and keeps a protocol stream in health state, if user ignores partly reading of a packet without disabling cancellation, then second iteration of read loop cause the thread to be cancelled. An exception is that the close() cancellation point always closes a file handle despite whether the thread is cancelled or not. The old mechanism is still kept, for a functions which is not so easily to fix a cancellation problem, the rough mechanism is used. Reviewed by: kib@ |
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| bin | ||
| cddl | ||
| contrib | ||
| crypto | ||
| etc | ||
| games | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| sys | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| Makefile.mips | ||
| ObsoleteFiles.inc | ||
| README | ||
| UPDATING | ||
This is the top level of the FreeBSD source directory. This file was last revised on: $FreeBSD$ For copyright information, please see the file COPYRIGHT in this directory (additional copyright information also exists for some sources in this tree - please see the specific source directories for more information). The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree, the most commonly used one being ``world'', which rebuilds and installs everything in the FreeBSD system from the source tree except the kernel, the kernel-modules and the contents of /etc. The ``world'' target should only be used in cases where the source tree has not changed from the currently running version. See: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html for more information, including setting make(1) variables. The ``buildkernel'' and ``installkernel'' targets build and install the kernel and the modules (see below). Please see the top of the Makefile in this directory for more information on the standard build targets and compile-time flags. Building a kernel is a somewhat more involved process, documentation for which can be found at: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html And in the config(8) man page. Note: If you want to build and install the kernel with the ``buildkernel'' and ``installkernel'' targets, you might need to build world before. More information is available in the handbook. The sample kernel configuration files reside in the sys/<arch>/conf sub-directory (assuming that you've installed the kernel sources), the file named GENERIC being the one used to build your initial installation kernel. The file NOTES contains entries and documentation for all possible devices, not just those commonly used. It is the successor of the ancient LINT file, but in contrast to LINT, it is not buildable as a kernel but a pure reference and documentation file. Source Roadmap: --------------- bin System/user commands. contrib Packages contributed by 3rd parties. crypto Cryptography stuff (see crypto/README). etc Template files for /etc. games Amusements. gnu Various commands and libraries under the GNU Public License. Please see gnu/COPYING* for more information. include System include files. kerberos5 Kerberos5 (Heimdal) package. lib System libraries. libexec System daemons. release Release building Makefile & associated tools. rescue Build system for statically linked /rescue utilities. sbin System commands. secure Cryptographic libraries and commands. share Shared resources. sys Kernel sources. tools Utilities for regression testing and miscellaneous tasks. usr.bin User commands. usr.sbin System administration commands. For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html