tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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futex.js (3328B)

      1 // |reftest| slow skip-if(!xulRuntime.shell)
      2 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
      3 /*
      4 * Any copyright is dedicated to the Public Domain.
      5 * http://creativecommons.org/licenses/publicdomain/
      6 */
      7 
      8 var DEBUG = false;
      9 
     10 function dprint(s) {
     11    if (DEBUG) print(s);
     12 }
     13 
     14 var hasSharedArrayBuffer = !!(this.SharedArrayBuffer &&
     15                              this.getSharedObject &&
     16                              this.setSharedObject);
     17 
     18 // Futex test
     19 
     20 // Only run if helper threads are available.
     21 if (hasSharedArrayBuffer && helperThreadCount() !== 0) {
     22 
     23 var mem = new Int32Array(new SharedArrayBuffer(1024));
     24 
     25 ////////////////////////////////////////////////////////////
     26 
     27 // wait() returns "not-equal" if the value is not the expected one.
     28 
     29 mem[0] = 42;
     30 
     31 assertEq(Atomics.wait(mem, 0, 33), "not-equal");
     32 
     33 // wait() returns "timed-out" if it times out
     34 
     35 assertEq(Atomics.wait(mem, 0, 42, 100), "timed-out");
     36 
     37 ////////////////////////////////////////////////////////////
     38 
     39 // Main is sharing the buffer with the worker; the worker is clearing
     40 // the buffer.
     41 
     42 mem[0] = 42;
     43 mem[1] = 37;
     44 mem[2] = DEBUG;
     45 
     46 setSharedObject(mem.buffer);
     47 
     48 evalInWorker(`
     49 var mem = new Int32Array(getSharedObject());
     50 function dprint(s) {
     51    if (mem[2]) print(s);
     52 }
     53 assertEq(mem[0], 42);		// what was written in the main thread
     54 assertEq(mem[1], 37);		//   is read in the worker
     55 mem[1] = 1337;
     56 dprint("Sleeping for 2 seconds");
     57 sleep(2);
     58 dprint("Waking the main thread now");
     59 setSharedObject(null);
     60 assertEq(Atomics.notify(mem, 0, 1), 1); // Can fail spuriously but very unlikely
     61 `);
     62 
     63 var then = Date.now();
     64 assertEq(Atomics.wait(mem, 0, 42), "ok");
     65 dprint("Woke up as I should have in " + (Date.now() - then)/1000 + "s");
     66 assertEq(mem[1], 1337); // what was written in the worker is read in the main thread
     67 assertEq(getSharedObject(), null); // The worker's clearing of the mbx is visible
     68 
     69 ////////////////////////////////////////////////////////////
     70 
     71 // Test the default argument to Atomics.notify()
     72 
     73 setSharedObject(mem.buffer);
     74 
     75 evalInWorker(`
     76 var mem = new Int32Array(getSharedObject());
     77 sleep(2);				// Probably long enough to avoid a spurious error next
     78 assertEq(Atomics.notify(mem, 0), 1);	// Last argument to notify should default to +Infinity
     79 `);
     80 
     81 var then = Date.now();
     82 dprint("Main thread waiting on wakeup (2s)");
     83 assertEq(Atomics.wait(mem, 0, 42), "ok");
     84 dprint("Woke up as I should have in " + (Date.now() - then)/1000 + "s");
     85 
     86 ////////////////////////////////////////////////////////////
     87 
     88 // A tricky case: while in the wait there will be an interrupt, and in
     89 // the interrupt handler we will execute a wait.  This is
     90 // explicitly prohibited (for now), so there should be a catchable exception.
     91 
     92 var exn = false;
     93 timeout(2, function () {
     94    dprint("In the interrupt, starting inner wait with timeout 2s");
     95    try {
     96        Atomics.wait(mem, 0, 42); // Should throw
     97    } catch (e) {
     98        dprint("Got the interrupt exception!");
     99        exn = true;
    100    }
    101    return true;
    102 });
    103 try {
    104    dprint("Starting outer wait");
    105    assertEq(Atomics.wait(mem, 0, 42, 5000), "timed-out");
    106 }
    107 finally {
    108    timeout(-1);
    109 }
    110 assertEq(exn, true);
    111 
    112 ////////////////////////////////////////////////////////////
    113 
    114 } // if (hasSharedArrayBuffer && helperThreadCount() !== 0) { ... }
    115 
    116 dprint("Done");
    117 reportCompare(true,true);