c154f7bc37
This checker should find the calls to blocking functions (for example: sleep, getc, fgets,read,recv etc.) inside a critical section. When sleep(x) is called while a mutex is held, other threads cannot lock the same mutex. This might take some time, leading to bad performance or even deadlock.
Example:
mutex_t m;
void f() {
sleep(1000); // Error: sleep() while m is locked! [f() is called from foobar() while m is locked]
// do some work
}
void foobar() {
lock(m);
f();
unlock(m);
}
A patch by zdtorok (Zoltán Dániel Török)!
Differential Revision: https://reviews.llvm.org/D21506
llvm-svn: 282011
51 lines
1.2 KiB
C++
51 lines
1.2 KiB
C++
// RUN: %clang_cc1 -analyze -analyzer-checker=alpha.unix.BlockInCriticalSection -std=c++11 -verify %s
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void sleep(int x) {}
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namespace std {
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struct mutex {
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void lock() {}
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void unlock() {}
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};
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}
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void testBlockInCriticalSection() {
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std::mutex m;
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m.lock();
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sleep(3); // expected-warning {{A blocking function %s is called inside a critical section}}
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m.unlock();
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}
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void testBlockInCriticalSectionWithNestedMutexes() {
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std::mutex m, n, k;
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m.lock();
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n.lock();
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k.lock();
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sleep(3); // expected-warning {{A blocking function %s is called inside a critical section}}
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k.unlock();
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sleep(5); // expected-warning {{A blocking function %s is called inside a critical section}}
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n.unlock();
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sleep(3); // expected-warning {{A blocking function %s is called inside a critical section}}
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m.unlock();
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sleep(3); // no-warning
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}
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void f() {
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sleep(1000); // expected-warning {{A blocking function %s is called inside a critical section}}
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}
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void testBlockInCriticalSectionInterProcedural() {
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std::mutex m;
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m.lock();
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f();
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m.unlock();
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}
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void testBlockInCriticalSectionUnexpectedUnlock() {
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std::mutex m;
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m.unlock();
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sleep(1); // no-warning
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m.lock();
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sleep(1); // expected-warning {{A blocking function %s is called inside a critical section}}
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}
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