this repo has no description
Fix tryPush/tryPop semantics and DRY queue ops
authored by
john xu
and committed by
Tim Culverhouse
75035b16
90cfa3c9
+26
-28
+26
-28
src/queue.zig
+26
-28
src/queue.zig
···
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self.not_empty.wait(&self.mutex);
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}
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std.debug.assert(!self.isEmptyLH());
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-
if (self.isFullLH()) {
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-
// If we are full, wake up a push that might be
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// waiting here.
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self.not_full.signal();
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}
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-
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return self.popLH();
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+
return self.popAndSignalLH();
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}
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/// Push an item into the queue. Blocks until an item has been
···
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self.not_full.wait(&self.mutex);
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}
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std.debug.assert(!self.isFullLH());
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-
const was_empty = self.isEmptyLH();
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-
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self.buf[self.mask(self.write_index)] = item;
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-
self.write_index = self.mask2(self.write_index + 1);
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-
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// If we were empty, wake up a pop if it was waiting.
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if (was_empty) {
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self.not_empty.signal();
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}
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+
self.pushAndSignalLH(item);
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}
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/// Push an item into the queue. Returns true when the item
···
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/// was full.
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pub fn tryPush(self: *Self, item: T) bool {
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self.mutex.lock();
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if (self.isFullLH()) {
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self.mutex.unlock();
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return false;
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}
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self.mutex.unlock();
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self.push(item);
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defer self.mutex.unlock();
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if (self.isFullLH()) return false;
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self.pushAndSignalLH(item);
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return true;
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}
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···
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/// available.
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pub fn tryPop(self: *Self) ?T {
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self.mutex.lock();
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if (self.isEmptyLH()) {
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self.mutex.unlock();
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return null;
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}
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self.mutex.unlock();
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return self.pop();
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defer self.mutex.unlock();
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if (self.isEmptyLH()) return null;
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return self.popAndSignalLH();
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}
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/// Poll the queue. This call blocks until events are in the queue
···
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/// Returns `index` modulo twice the length of the backing slice.
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fn mask2(self: Self, index: usize) usize {
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return index % (2 * self.buf.len);
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}
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+
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fn pushAndSignalLH(self: *Self, item: T) void {
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const was_empty = self.isEmptyLH();
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self.buf[self.mask(self.write_index)] = item;
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self.write_index = self.mask2(self.write_index + 1);
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if (was_empty) {
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self.not_empty.signal();
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}
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}
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+
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fn popAndSignalLH(self: *Self) T {
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const was_full = self.isFullLH();
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const result = self.popLH();
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if (was_full) {
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self.not_full.signal();
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}
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return result;
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}
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fn popLH(self: *Self) T {