Files
zoneminder/tests/zm_monitorstream.cpp

70 lines
2.7 KiB
C++

/*
* This file is part of the ZoneMinder Project. See AUTHORS file for contributors.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "zm_catch2.h"
#include "zm_monitorstream.h"
TEST_CASE("MonitorStreamBufferLevel") {
SECTION("zero buffer count does not divide by zero") {
// Regression for zoneminder/zoneminder#4936: processCommand() could run on
// the command thread before runStream() assigned temp_image_buffer_count,
// leaving it 0 while playback_buffer was already > 0, causing a SIGFPE.
REQUIRE(MonitorStreamBufferLevel(0, 0, 0) == 0);
REQUIRE(MonitorStreamBufferLevel(5, 2, 0) == 0);
REQUIRE(MonitorStreamBufferLevel(0, 5, 0) == 0);
}
SECTION("negative buffer count is treated as empty") {
REQUIRE(MonitorStreamBufferLevel(3, 1, -10) == 0);
}
SECTION("empty buffer reports 0%") {
REQUIRE(MonitorStreamBufferLevel(0, 0, 100) == 0);
}
SECTION("full buffer reports nearly 100%") {
// write wraps around to one behind read => count-1 of count slots used
REQUIRE(MonitorStreamBufferLevel(99, 0, 100) == 99);
}
SECTION("half full buffer reports ~50%") {
REQUIRE(MonitorStreamBufferLevel(50, 0, 100) == 50);
}
SECTION("wrap-around (write behind read) is handled modularly") {
// write_index - read_index is negative; modular arithmetic keeps it in range
REQUIRE(MonitorStreamBufferLevel(2, 7, 10) == 50);
}
SECTION("a read that straddles an update still reports in range") {
// zoneminder/zoneminder#4939: the command thread reads the three values as
// separate atomics, so it can pick up a write index from one moment and a
// read index from another. That stays harmless for this percentage as long
// as each index is individually within [0, count): the +count before the
// modulo covers the whole (-count, count) span the difference can take.
const int count = 64;
for (int write_index = 0; write_index < count; write_index++) {
for (int read_index = 0; read_index < count; read_index++) {
const int level = MonitorStreamBufferLevel(write_index, read_index, count);
REQUIRE(level >= 0);
REQUIRE(level <= 100);
}
}
}
}