Commit 61e8d2fc authored by Greg Tatum's avatar Greg Tatum
Browse files

Bug 1582741 - Create a test for balanced native allocation; r=canaltinova 

This file adds coverage for the balanced native allocations feature from the
previous commit. It asserts that a de-allocation will have a matching allocation.

Differential Revision: https://phabricator.services.mozilla.com/D51936

--HG--
extra : moz-landing-system : lando
parent bcab6046

tools/profiler/tests/xpcshell/test_feature_nativeallocations.js

+83 −10
Original line number Diff line number Diff line
@@ -31,19 +31,14 @@ add_task(async () => { 
    );

    doWork();



    info(

      "Go ahead and wait for a periodic sample as well, in order to make sure that " +

        "the native allocations play nicely with the rest of the profiler machinery."

    );

    await Services.profiler.waitOnePeriodicSampling();



    info("Get the profile data and analyze it.");

    const profile = await stopAndGetProfile();



    const allocationPayloads = getPayloadsOfType(

      profile.threads[0],

      "Native allocation"

    );

    const {

      allocationPayloads,

      unmatchedAllocations,

      logAllocationsAndDeallocations,

    } = getAllocationInformation(profile);



    Assert.greater(

      allocationPayloads.length,
@@ -51,6 +46,23 @@ add_task(async () => { 
      "Native allocation payloads were recorded for the parent process' main thread when " +

        "the Native Allocation feature was turned on."

    );



    if (unmatchedAllocations.length !== 0) {

      info(

        "There were unmatched allocations. Log all of the allocations and " +

          "deallocations in order to aid debugging."

      );

      logAllocationsAndDeallocations();

      ok(

        false,

        "Found a deallocation that did not have a matching allocation site. " +

          "This could happen if balanced allocations is broken, or if the the " +

          "buffer size of this test was too small, and some markers ended up " +

          "rolling off."

      );

    }



    ok(true, "All deallocation sites had matching allocations.");

  }



  info("Restart the profiler, to ensure that we get no more allocations.");
@@ -81,3 +93,64 @@ function doWork() { 
    this.n += Math.random();

  }

}



/**

 * Extract the allocation payloads, and find the unmatched allocations.

 */

function getAllocationInformation(profile) {

  // Get all of the allocation payloads.

  const allocationPayloads = getPayloadsOfType(

    profile.threads[0],

    "Native allocation"

  );



  // Decide what is an allocation and deallocation.

  const allocations = allocationPayloads.filter(

    payload => ensureIsNumber(payload.size) >= 0

  );

  const deallocations = allocationPayloads.filter(

    payload => ensureIsNumber(payload.size) < 0

  );



  // Now determine the unmatched allocations by building a set

  const allocationSites = new Set(

    allocations.map(({ memoryAddress }) => memoryAddress)

  );



  const unmatchedAllocations = deallocations.filter(

    ({ memoryAddress }) => !allocationSites.has(memoryAddress)

  );



  // Provide a helper to log out the allocations and deallocations on failure.

  function logAllocationsAndDeallocations() {

    for (const { memoryAddress } of allocations) {

      console.log("Allocations", formatHex(memoryAddress));

      allocationSites.add(memoryAddress);

    }



    for (const { memoryAddress } of deallocations) {

      console.log("Deallocations", formatHex(memoryAddress));

    }



    for (const { memoryAddress } of unmatchedAllocations) {

      console.log("Deallocation with no allocation", formatHex(memoryAddress));

    }

  }



  return {

    allocationPayloads,

    unmatchedAllocations,

    logAllocationsAndDeallocations,

  };

}



function ensureIsNumber(value) {

  if (typeof value !== "number") {

    throw new Error(`Expected a number: ${value}`);

  }

  return value;

}



function formatHex(number) {

  return `0x${number.toString(16)}`;

}