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2013-08-20Use "error-checking" mutexes in place of other kinds wherever possible.Ben Pfaff
We've seen a number of deadlocks in the tree since thread safety was introduced. So far, all of these are self-deadlocks, that is, a single thread acquiring a lock and then attempting to re-acquire the same lock recursively. When this has happened, the process simply hung, and it was somewhat difficult to find the cause. POSIX "error-checking" mutexes check for this specific problem (and others). This commit switches from other types of mutexes to error-checking mutexes everywhere that we can, that is, everywhere that we're not using recursive mutexes. This ought to help find problems more quickly in the future. There might be performance advantages to other kinds of mutexes in some cases. However, the existing mutex type choices were just guesses, so I'd rather go for easy detection of errors until we know that other mutex types actually perform better in specific cases. Also, I did a quick microbenchmark of glibc mutex types on my host and found that the error checking mutexes weren't any slower than the other types, at least when the mutex is uncontended. Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Ethan Jackson <ethan@nicira.com>
2013-07-30clang: Add annotations for thread safety check.Ethan Jackson
This commit adds annotations for thread safety check. And the check can be conducted by using -Wthread-safety flag in clang. Co-authored-by: Alex Wang <alexw@nicira.com> Signed-off-by: Alex Wang <alexw@nicira.com> Signed-off-by: Ethan Jackson <ethan@nicira.com> Signed-off-by: Ben Pfaff <blp@nicira.com>
2013-07-23fatal-signal: Make thread-safe.Ben Pfaff
Signed-off-by: Ben Pfaff <blp@nicira.com>
2013-07-11fatal-signal: Remove write-only variable fatal_signal_set.Ben Pfaff
Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Ed Maste <emaste@freebsd.org>
2013-06-28Replace all uses of strerror() by ovs_strerror(), for thread safety.Ben Pfaff
Signed-off-by: Ben Pfaff <blp@nicira.com>
2013-06-05signals: Make signal_name() thread-safe.Ben Pfaff
Signed-off-by: Ben Pfaff <blp@nicira.com>
2013-01-16Replace most uses of assert by ovs_assert.Ben Pfaff
This is a straight search-and-replace, except that I also removed #include <assert.h> from each file where there were no assert calls left. Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Ethan Jackson <ethan@nicira.com>
2012-09-28lib: Add xpipe_nonblocking helperEd Maste
Signed-off-by: Ed Maste <emaste@adaranet.com> Signed-off-by: Ben Pfaff <blp@nicira.com>
2012-07-18socket-util: New function xset_nonblocking().Ben Pfaff
Signed-off-by: Ben Pfaff <blp@nicira.com>
2012-06-26lib: Do not assume sig_atomic_t is int.Ed Maste
On FreeBSD sig_atomic_t is long, which causes the comparison in fatal_signal_run to be true when no signal has been reported. Signed-off-by: Ed Maste <emaste@freebsd.org> Signed-off-by: Ben Pfaff <blp@nicira.com>
2012-05-14fatal-signal: Log when terminating due to a fatal signal.Ben Pfaff
This makes it easier to diagnose why and when a daemon exited. Signed-off-by: Ben Pfaff <blp@nicira.com>
2012-05-02Global replace of Nicira Networks.Raju Subramanian
Replaced all instances of Nicira Networks(, Inc) to Nicira, Inc. Feature #10593 Signed-off-by: Raju Subramanian <rsubramanian@nicira.com> Signed-off-by: Ben Pfaff <blp@nicira.com>
2011-09-22Add fallback definition of SIG_ATOMIC_MAXSimon Horman
Android appears to lack SIG_ATOMIC_MAX which is only used in fatal-signal.c. Observed when compiling using the Android NDK r6b (Android API level 13). Patch based on a suggestion by Ben Pfaff
2011-04-04Log anything that could prevent a daemon from starting.Ben Pfaff
If a daemon doesn't start, we need to know why. Being able to consistently consult the log to find out is helpful.
2011-03-31Convert shash users that don't use the 'data' value to sset instead.Ben Pfaff
In each of the cases converted here, an shash was used simply to maintain a set of strings, with the shash_nodes' 'data' values set to NULL. This commit converts them to use sset instead.
2010-10-29vlog: Make client supply semicolon for VLOG_DEFINE_THIS_MODULE.Ben Pfaff
It's kind of odd for VLOG_DEFINE_THIS_MODULE to supply its own semicolon, so this commit switches to the more common form.
2010-08-30treewide: Remove trailing whitespaceJoe Perches
Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Simon Horman <horms@verge.net.au> Signed-off-by: Jesse Gross <jesse@nicira.com>
2010-07-21vlog: Introduce VLOG_DEFINE_THIS_MODULE for declaring vlog module in use.Ben Pfaff
Adding a macro to define the vlog module in use adds a level of indirection, which makes it easier to change how the vlog module must be defined. A followup commit needs to do that, so getting these widespread changes out of the way first should make that commit easier to review.
2010-06-30Simplify shash_find() followed by shash_add() into shash_add_once().Ben Pfaff
This is just a cleanup.
2010-04-13Make fatal signals cause an exit more promptly in special cases.Ben Pfaff
The fatal-signal library notices and records fatal signals (e.g. SIGTERM) and terminates the process on the next trip through poll_block(). But some special utilities do not always invoke poll_block() promptly, e.g. "ovs-ofctl monitor" does not call poll_block() as long as OpenFlow messages are available. But these special cases seem like they are all likely to call into functions that themselves block (those with "_block" in their names). So make a new rule that such functions should always call fatal_signal_run(), either directly or through poll_block(). This commit implements and documents that rule. Bug #2625.
2010-03-24fatal-signal: Initialize library upon any call to public function.Ben Pfaff
Not calling fatal_signal_init() means that the signal handlers don't get registered, so the process won't clean up on fatal signals. Furthermore, signal_fds[0] is then 0, which means that fatal-signal_wait() waits on stdin, so if you are testing a program interactively and accidentally type something on stdin then that program's CPU usage jumps to 100%. Since poll_block() calls fatal_signal_wait() this seems like the most reliable solution.
2010-02-11Merge "master" into "next".Ben Pfaff
The main change here is the need to update all of the uses of UNUSED in the next branch to OVS_UNUSED as it is now spelled on "master".
2010-02-11Rename UNUSED macro to OVS_UNUSED to avoid naming conflict.Ben Pfaff
Requested by Jean Tourrilhes <jt@hpl.hp.com>.
2010-01-15fatal-signal: After fork, clear hooks instead of disabling them.Ben Pfaff
Until now, fatal_signal_fork() has simply disabled all the fatal signal callback hooks. This worked fine, because a daemon process forked only once and the parent didn't do much before it exited. But upcoming commits will introduce a --monitor option, which requires processes to fork multiple times. Sometimes the parent process will fork, then run for a while, then fork again. It's not good to disable the hooks in the child process in such a case, because that prevents e.g. pidfiles from being removed at the child's exit. So this commit changes the semantics of fatal_signal_fork() to just clearing out hooks. After hooks are cleared, new hooks can be added and will be executed on process termination in the usual way. This commit also introduces a cancellation callback function so that a canceled hook can free resources.
2010-01-06fatal-signal: Run signal hooks outside of actual signal handlers.Jesse Gross
Rather than running signal hooks directly from the actual signal handler, simply record the fact that the signal occured and run the hook next time around the poll loop. This allows significantly more freedom as to what can actually be done in the signal hooks.
2009-09-21fatal-signal: Add clarifying comments.Ben Pfaff
Suggested by Justin Pettit.
2009-09-21fatal-signal: New function fatal_signal_unlink_file_now().Ben Pfaff
This is a helper function that combines two actions that callers commonly wanted. It will have an additional user in an upcoming commit.
2009-09-21fatal-signal: Clean up code by using shash.Ben Pfaff
This simplifies the code here and should speed it up, too, when there are lots of files to unlink on a fatal signal.
2009-06-15Update primary code license to Apache 2.0.Ben Pfaff
2009-07-08Import from old repository commit 61ef2b42a9c4ba8e1600f15bb0236765edc2ad45.v0.90.0Ben Pfaff
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