X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fpoll-loop.c;h=c944477dcead6f3d461325980a7721418f405bce;hb=9ac3fce4d5aea7e963439eb97f7c2d157aef4dfc;hp=29931f7855ae53f0d4e2651443a6dba9b382ab01;hpb=8bf4bbe390af3f370e7e95d9237572ff750047a8;p=openvswitch diff --git a/lib/poll-loop.c b/lib/poll-loop.c index 29931f78..c944477d 100644 --- a/lib/poll-loop.c +++ b/lib/poll-loop.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2008, 2009, 2010 Nicira Networks. + * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -22,23 +22,31 @@ #include #include #include -#include "backtrace.h" #include "coverage.h" #include "dynamic-string.h" #include "fatal-signal.h" #include "list.h" +#include "socket-util.h" #include "timeval.h" - -#define THIS_MODULE VLM_poll_loop #include "vlog.h" +#undef poll_fd_wait +#undef poll_timer_wait +#undef poll_timer_wait_until +#undef poll_immediate_wake + +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). */ - struct backtrace *backtrace; /* Optionally, event that created waiter. */ + const char *where; /* Where the waiter was created. */ /* Set only when poll_block() is called. */ struct pollfd *pollfd; /* Pointer to element of the pollfds array. */ @@ -54,10 +62,11 @@ static size_t n_waiters; * wait forever. */ static int timeout = -1; -/* Backtrace of 'timeout''s registration, if debugging is enabled. */ -static struct backtrace timeout_backtrace; +/* Location where waiter created. */ +static const char *timeout_where; -static struct poll_waiter *new_waiter(int fd, short int events); +static struct poll_waiter *new_waiter(int fd, short int events, + const char *where); /* Registers 'fd' as waiting for the specified 'events' (which should be POLLIN * or POLLOUT or POLLIN | POLLOUT). The following call to poll_block() will @@ -65,23 +74,24 @@ static struct poll_waiter *new_waiter(int fd, short int events); * * The event registration is one-shot: only the following call to poll_block() * is affected. The event will need to be re-registered after poll_block() is - * called if it is to persist. */ + * called if it is to persist. + * + * Ordinarily the 'where' argument is supplied automatically; see poll-loop.h + * for more information. */ struct poll_waiter * -poll_fd_wait(int fd, short int events) +poll_fd_wait(int fd, short int events, const char *where) { COVERAGE_INC(poll_fd_wait); - return new_waiter(fd, events); + return new_waiter(fd, events, where); } /* The caller must ensure that 'msec' is not negative. */ static void -poll_timer_wait__(int msec) +poll_timer_wait__(int msec, const char *where) { if (timeout < 0 || msec < timeout) { timeout = msec; - if (VLOG_IS_DBG_ENABLED()) { - backtrace_capture(&timeout_backtrace); - } + timeout_where = where; } } @@ -91,25 +101,53 @@ poll_timer_wait__(int msec) * * 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. */ + * called if it is to persist. + * + * Ordinarily the 'where' argument is supplied automatically; see poll-loop.h + * for more information. */ +void +poll_timer_wait(long long int msec, const char *where) +{ + poll_timer_wait__((msec < 0 ? 0 + : msec > INT_MAX ? INT_MAX + : msec), + where); +} + +/* 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. + * + * Ordinarily the 'where' argument is supplied automatically; see poll-loop.h + * for more information. */ void -poll_timer_wait(long long int msec) +poll_timer_wait_until(long long int msec, const char *where) { - poll_timer_wait__(msec < 0 ? 0 - : msec > INT_MAX ? INT_MAX - : msec); + long long int now = time_msec(); + poll_timer_wait__((msec <= now ? 0 + : msec < now + INT_MAX ? msec - now + : INT_MAX), + where); } /* Causes the following call to poll_block() to wake up immediately, without - * blocking. */ + * blocking. + * + * Ordinarily the 'where' argument is supplied automatically; see poll-loop.h + * for more information. */ void -poll_immediate_wake(void) +poll_immediate_wake(const char *where) { - poll_timer_wait(0); + poll_timer_wait(0, where); } static void PRINTF_FORMAT(2, 3) -log_wakeup(const struct backtrace *backtrace, const char *format, ...) +log_wakeup(const char *where, const char *format, ...) { struct ds ds; va_list args; @@ -119,14 +157,10 @@ log_wakeup(const struct backtrace *backtrace, const char *format, ...) ds_put_format_valist(&ds, format, args); va_end(args); - if (backtrace) { - int i; - - ds_put_char(&ds, ':'); - for (i = 0; i < backtrace->n_frames; i++) { - ds_put_format(&ds, " 0x%"PRIxPTR, backtrace->frames[i]); - } + if (where) { + ds_put_format(&ds, " at %s", where); } + VLOG_DBG("%s", ds_cstr(&ds)); ds_destroy(&ds); } @@ -154,7 +188,7 @@ poll_block(void) } 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; @@ -170,24 +204,26 @@ poll_block(void) static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5); VLOG_ERR_RL(&rl, "poll: %s", strerror(-retval)); } else if (!retval && VLOG_IS_DBG_ENABLED()) { - log_wakeup(&timeout_backtrace, "%d-ms timeout", timeout); + log_wakeup(timeout_where, "%d-ms timeout", timeout); } - LIST_FOR_EACH_SAFE (pw, next, struct poll_waiter, node, &waiters) { + 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", + char *description = describe_fd(pw->fd); + log_wakeup(pw->where, "%s%s%s%s%s on fd %d (%s)", 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); + pw->fd, description); + free(description); } poll_cancel(pw); } timeout = -1; - timeout_backtrace.n_frames = 0; + timeout_where = NULL; /* Handle any pending signals before doing anything else. */ fatal_signal_run(); @@ -204,7 +240,6 @@ poll_cancel(struct poll_waiter *pw) { if (pw) { list_remove(&pw->node); - free(pw->backtrace); free(pw); n_waiters--; } @@ -212,16 +247,13 @@ poll_cancel(struct poll_waiter *pw) /* Creates and returns a new poll_waiter for 'fd' and 'events'. */ static struct poll_waiter * -new_waiter(int fd, short int events) +new_waiter(int fd, short int events, const char *where) { struct poll_waiter *waiter = xzalloc(sizeof *waiter); assert(fd >= 0); waiter->fd = fd; waiter->events = events; - if (VLOG_IS_DBG_ENABLED()) { - waiter->backtrace = xmalloc(sizeof *waiter->backtrace); - backtrace_capture(waiter->backtrace); - } + waiter->where = where; list_push_back(&waiters, &waiter->node); n_waiters++; return waiter;