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/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* Fluent Bit
* ==========
* Copyright (C) 2015-2022 The Fluent Bit Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef FLB_TAIL_SIGNAL_H
#define FLB_TAIL_SIGNAL_H
#include "tail_config.h"
static inline int tail_signal_manager(struct flb_tail_config *ctx)
{
int n;
uint64_t val = 0xc001;
/*
* The number of signal reads might be less than the written signals, this
* means that some event is still pending in the queue. On that case we
* don't need to signal it again.
*/
if (ctx->ch_reads < ctx->ch_writes) {
return 1;
}
/* Reset counters: prevent an overflow, unlikely..but let's keep safe */
if (ctx->ch_reads == ctx->ch_writes) {
ctx->ch_reads = 0;
ctx->ch_writes = 0;
}
/* Insert a dummy event into the channel manager */
n = flb_pipe_w(ctx->ch_manager[1], (const char *) &val, sizeof(val));
if (n == -1) {
flb_errno();
return -1;
}
else {
ctx->ch_writes++;
}
return n;
}
static inline int tail_signal_pending(struct flb_tail_config *ctx)
{
int n;
uint64_t val = 0xc002;
/* Insert a dummy event into the 'pending' channel */
n = flb_pipe_w(ctx->ch_pending[1], (const char *) &val, sizeof(val));
/*
* If we get EAGAIN, it simply means pending channel is full. As
* notification is already pending, it's safe to ignore.
*/
if (n == -1 && !FLB_PIPE_WOULDBLOCK()) {
flb_errno();
return -1;
}
return n;
}
static inline int tail_consume_pending(struct flb_tail_config *ctx)
{
int ret;
uint64_t val;
/*
* We need to consume the pending bytes. Loop until we would have
* blocked (pipe is empty).
*/
do {
ret = flb_pipe_r(ctx->ch_pending[0], (char *) &val, sizeof(val));
if (ret <= 0 && !FLB_PIPE_WOULDBLOCK()) {
flb_errno();
return -1;
}
} while (!FLB_PIPE_WOULDBLOCK());
return 0;
}
#endif
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