X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fpoll-loop.c;h=e47cccc392763f53c3e68ecfd987ca8894e99d1b;hb=8368c090cab;hp=aff2c335c732b88a0afa9152422d038c25b06039;hpb=a14bc59fb8f27db193d74662dc9c5cb8237177ef;p=sliver-openvswitch.git diff --git a/lib/poll-loop.c b/lib/poll-loop.c index aff2c335c..e47cccc39 100644 --- a/lib/poll-loop.c +++ b/lib/poll-loop.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2008, 2009 Nicira Networks. + * Copyright (c) 2008, 2009, 2010 Nicira Networks. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -18,31 +18,33 @@ #include "poll-loop.h" #include #include +#include #include #include #include #include "backtrace.h" #include "coverage.h" #include "dynamic-string.h" +#include "fatal-signal.h" #include "list.h" #include "timeval.h" - -#define THIS_MODULE VLM_poll_loop #include "vlog.h" +VLOG_DEFINE_THIS_MODULE(poll_loop); + +COVERAGE_DEFINE(poll_fd_wait); +COVERAGE_DEFINE(poll_zero_timeout); + /* An event that will wake the following call to poll_block(). */ struct poll_waiter { /* Set when the waiter is created. */ struct list node; /* Element in global waiters list. */ int fd; /* File descriptor. */ short int events; /* Events to wait for (POLLIN, POLLOUT). */ - poll_fd_func *function; /* Callback function, if any, or null. */ - void *aux; /* Argument to callback function. */ struct backtrace *backtrace; /* Optionally, event that created waiter. */ /* Set only when poll_block() is called. */ - struct pollfd *pollfd; /* Pointer to element of the pollfds array - (null if added from a callback). */ + struct pollfd *pollfd; /* Pointer to element of the pollfds array. */ }; /* All active poll waiters. */ @@ -58,12 +60,6 @@ static int timeout = -1; /* Backtrace of 'timeout''s registration, if debugging is enabled. */ static struct backtrace timeout_backtrace; -/* Callback currently running, to allow verifying that poll_cancel() is not - * being called on a running callback. */ -#ifndef NDEBUG -static struct poll_waiter *running_cb; -#endif - static struct poll_waiter *new_waiter(int fd, short int events); /* Registers 'fd' as waiting for the specified 'events' (which should be POLLIN @@ -80,6 +76,18 @@ poll_fd_wait(int fd, short int events) return new_waiter(fd, events); } +/* The caller must ensure that 'msec' is not negative. */ +static void +poll_timer_wait__(int msec) +{ + if (timeout < 0 || msec < timeout) { + timeout = msec; + if (VLOG_IS_DBG_ENABLED()) { + backtrace_capture(&timeout_backtrace); + } + } +} + /* Causes the following call to poll_block() to block for no more than 'msec' * milliseconds. If 'msec' is nonpositive, the following call to poll_block() * will not block at all. @@ -88,14 +96,28 @@ poll_fd_wait(int fd, short int events) * is affected. The timer will need to be re-registered after poll_block() is * called if it is to persist. */ void -poll_timer_wait(int msec) +poll_timer_wait(long long int msec) { - if (timeout < 0 || msec < timeout) { - timeout = MAX(0, msec); - if (VLOG_IS_DBG_ENABLED()) { - backtrace_capture(&timeout_backtrace); - } - } + poll_timer_wait__(msec < 0 ? 0 + : msec > INT_MAX ? INT_MAX + : msec); +} + +/* Causes the following call to poll_block() to wake up when the current time, + * as returned by time_msec(), reaches 'msec' or later. If 'msec' is earlier + * than the current time, the following call to poll_block() will not block at + * all. + * + * The timer registration is one-shot: only the following call to poll_block() + * is affected. The timer will need to be re-registered after poll_block() is + * called if it is to persist. */ +void +poll_timer_wait_until(long long int msec) +{ + long long int now = time_msec(); + poll_timer_wait__(msec <= now ? 0 + : msec < now + INT_MAX ? msec - now + : INT_MAX); } /* Causes the following call to poll_block() to wake up immediately, without @@ -122,7 +144,7 @@ log_wakeup(const struct backtrace *backtrace, const char *format, ...) ds_put_char(&ds, ':'); for (i = 0; i < backtrace->n_frames; i++) { - ds_put_format(&ds, " 0x%x", backtrace->frames[i]); + ds_put_format(&ds, " 0x%"PRIxPTR, backtrace->frames[i]); } } VLOG_DBG("%s", ds_cstr(&ds)); @@ -131,29 +153,28 @@ log_wakeup(const struct backtrace *backtrace, const char *format, ...) /* Blocks until one or more of the events registered with poll_fd_wait() * occurs, or until the minimum duration registered with poll_timer_wait() - * elapses, or not at all if poll_immediate_wake() has been called. - * - * Also executes any autonomous subroutines registered with poll_fd_callback(), - * if their file descriptors have become ready. */ + * elapses, or not at all if poll_immediate_wake() has been called. */ void poll_block(void) { static struct pollfd *pollfds; static size_t max_pollfds; - struct poll_waiter *pw; - struct list *node; + struct poll_waiter *pw, *next; int n_pollfds; int retval; - assert(!running_cb); + /* Register fatal signal events before actually doing any real work for + * poll_block. */ + fatal_signal_wait(); + if (max_pollfds < n_waiters) { max_pollfds = n_waiters; pollfds = xrealloc(pollfds, max_pollfds * sizeof *pollfds); } n_pollfds = 0; - LIST_FOR_EACH (pw, struct poll_waiter, node, &waiters) { + LIST_FOR_EACH (pw, node, &waiters) { pw->pollfd = &pollfds[n_pollfds]; pollfds[n_pollfds].fd = pw->fd; pollfds[n_pollfds].events = pw->events; @@ -172,76 +193,36 @@ poll_block(void) log_wakeup(&timeout_backtrace, "%d-ms timeout", timeout); } - for (node = waiters.next; node != &waiters; ) { - pw = CONTAINER_OF(node, struct poll_waiter, node); - if (!pw->pollfd || !pw->pollfd->revents) { - if (pw->function) { - node = node->next; - continue; - } - } else { - if (VLOG_IS_DBG_ENABLED()) { - log_wakeup(pw->backtrace, "%s%s%s%s%s on fd %d", - pw->pollfd->revents & POLLIN ? "[POLLIN]" : "", - pw->pollfd->revents & POLLOUT ? "[POLLOUT]" : "", - pw->pollfd->revents & POLLERR ? "[POLLERR]" : "", - pw->pollfd->revents & POLLHUP ? "[POLLHUP]" : "", - pw->pollfd->revents & POLLNVAL ? "[POLLNVAL]" : "", - pw->fd); - } - - if (pw->function) { -#ifndef NDEBUG - running_cb = pw; -#endif - pw->function(pw->fd, pw->pollfd->revents, pw->aux); -#ifndef NDEBUG - running_cb = NULL; -#endif - } + LIST_FOR_EACH_SAFE (pw, next, node, &waiters) { + if (pw->pollfd->revents && VLOG_IS_DBG_ENABLED()) { + log_wakeup(pw->backtrace, "%s%s%s%s%s on fd %d", + pw->pollfd->revents & POLLIN ? "[POLLIN]" : "", + pw->pollfd->revents & POLLOUT ? "[POLLOUT]" : "", + pw->pollfd->revents & POLLERR ? "[POLLERR]" : "", + pw->pollfd->revents & POLLHUP ? "[POLLHUP]" : "", + pw->pollfd->revents & POLLNVAL ? "[POLLNVAL]" : "", + pw->fd); } - node = node->next; poll_cancel(pw); } timeout = -1; timeout_backtrace.n_frames = 0; -} -/* Registers 'function' to be called with argument 'aux' by poll_block() when - * 'fd' becomes ready for one of the events in 'events', which should be POLLIN - * or POLLOUT or POLLIN | POLLOUT. - * - * The callback registration persists until the event actually occurs. At that - * point, it is automatically de-registered. The callback function must - * re-register the event by calling poll_fd_callback() again within the - * callback, if it wants to be called back again later. */ -struct poll_waiter * -poll_fd_callback(int fd, short int events, poll_fd_func *function, void *aux) -{ - struct poll_waiter *pw = new_waiter(fd, events); - pw->function = function; - pw->aux = aux; - return pw; + /* Handle any pending signals before doing anything else. */ + fatal_signal_run(); } -/* Cancels the file descriptor event registered with poll_fd_wait() or - * poll_fd_callback(). 'pw' must be the struct poll_waiter returned by one of - * those functions. +/* Cancels the file descriptor event registered with poll_fd_wait() using 'pw', + * the struct poll_waiter returned by that function. * * An event registered with poll_fd_wait() may be canceled from its time of * registration until the next call to poll_block(). At that point, the event - * is automatically canceled by the system and its poll_waiter is freed. - * - * An event registered with poll_fd_callback() may be canceled from its time of - * registration until its callback is actually called. At that point, the - * event is automatically canceled by the system and its poll_waiter is - * freed. */ + * is automatically canceled by the system and its poll_waiter is freed. */ void poll_cancel(struct poll_waiter *pw) { if (pw) { - assert(pw != running_cb); list_remove(&pw->node); free(pw->backtrace); free(pw); @@ -253,7 +234,7 @@ poll_cancel(struct poll_waiter *pw) static struct poll_waiter * new_waiter(int fd, short int events) { - struct poll_waiter *waiter = xcalloc(1, sizeof *waiter); + struct poll_waiter *waiter = xzalloc(sizeof *waiter); assert(fd >= 0); waiter->fd = fd; waiter->events = events;