Starter bug: SR-946 Unify mutexes in the Swift runtime.

gparker42 · 2016-03-15T02:59:01.000Z

github.com/apple/swift

[SR-946] Unify mutexes in the Swift runtime

opened 03:54AM - 15 Mar 16 UTC

closed 04:38AM - 27 Jul 19 UTC

3391d72f-a29f-4e23-ba0f-4b2ca3af6551

Improvement StarterBug Standard Library Runtime

| | | |------------------|-----------------|… |Previous ID | SR-946 | |Radar | rdar://25058486 | |Original Reporter | @gparker42 | |Type | Improvement | |Status | Resolved | |Resolution | Done | <details> <summary>Additional Detail from JIRA</summary> | | | |------------------|-----------------| |Votes | 0 | |Component/s | Standard Library | |Labels | Improvement, Runtime, StarterBug | |Assignee | None | |Priority | Medium | md5: af9f82a35d32e960d03bb405bb35fd8d </details> **Issue Description:** The Swift runtime uses two different mutexes internally. Neither one is good. We should write a new swift::mutex or adopt some LLVM mutex that solves these problems. Some code uses C++ std::mutex. This mutex throws exceptions when errors occur. Nobody can reasonably catch and respond to these errors. Backtraces are lost when these exceptions are caught and re-thrown before the process halts (such as rdar://25058486, probably). Some code uses pthread_mutex_t. This mutex returns non-zero when errors occur. Our code does not check these errors. The new mutex implementation should: - use pthread_mutex_t or some LLVM mutex if a suitable one is available - implement C++ STL's BasicLockable and Lockable - halt using swift::reportError when a failure occurs - not throw exceptions

"The Swift runtime uses two different mutexes internally. Neither one is good. We should write a new swift::mutex or adopt some LLVM mutex that solves these problems. ..."

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Greg Parker gparker@apple.com Runtime Wrangler