Stack overflow exception when starting new threads

[dktapps]

Environment

• PHP: 7.2.1
• pthreads: 43ffd00
• OS: Windows 10 x64

Summary

Running the below test case on Windows with latest pthreads yields a stack overflow exception in pthreads_store_create().

This bug appears to occur when an interface constant is accessed via a class which implements the interface, and then a thread is started. Crucially, in the test case:

var_dump(MyClass::PIG);
var_dump(MyClass::COW);

produces the stack overflow, while:

var_dump(TestInterface::PIG);
var_dump(TestInterface::COW);

does not.

It is necessary to have the TestInterface class loaded by an autoloader, or the bug does not occur.

Reproducing Code

Test case: https://github.com/dktapps/pthreads-stack-overflow-test
Usage:

composer install
php run.php

Expected Output

int(1)
int(2)

and correct shutdown

Actual Output

int(1)
int(2)

followed by stackoverflow exception (debugged with Visual Studio).

Visual Studio debugging

Unhandled exception at 0x00007FFE5694FAE7 (php_pthreads.dll) in php.exe: 0xC00000FD: Stack overflow (parameters: 0x0000000000000001, 0x00000037BDE03FF8). occurred

Gigantic stack trace (be warned, it's about 6000 lines long): https://gist.github.com/dktapps/2cf08ea2b2fa93e01f9656fe303995fb

[dktapps]

Additional note: I'm currently using 1c9787e for production and this test case works fine there.

[sirsnyder]

Can you reproduce this bug on unix or is it windows only?

[dktapps]

@sirsnyder I quickly tested and it also crashes on linux, yes. Haven't done any debugging on linux but one would assume the cause is the same.

[sirsnyder]

At a first sight, the offending commit is 4c978ec.

[sirsnyder]

Could you please test this fix?

[dktapps]

looks like it's fixed, thanks!