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Add invariant checks to Limiter in Env implementations.

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PiperOrigin-RevId: 417853172
This commit is contained in:
Victor Costan 2021-12-22 19:12:56 +00:00 committed by Victor Costan
parent e426c83e88
commit 335876a133
2 changed files with 52 additions and 5 deletions
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33
util/env_posix.cc
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@ -73,7 +73,14 @@ Status PosixError(const std::string& context, int error_number) {
class Limiter {
public:
// Limit maximum number of resources to |max_acquires|.
Limiter(int max_acquires) : acquires_allowed_(max_acquires) {}
Limiter(int max_acquires)
:
#if !defined(NDEBUG)
max_acquires_(max_acquires),
#endif // !defined(NDEBUG)
acquires_allowed_(max_acquires) {
assert(max_acquires >= 0);
}
Limiter(const Limiter&) = delete;
Limiter operator=(const Limiter&) = delete;
@ -86,15 +93,35 @@ class Limiter {
if (old_acquires_allowed > 0) return true;
acquires_allowed_.fetch_add(1, std::memory_order_relaxed);
int pre_increment_acquires_allowed =
acquires_allowed_.fetch_add(1, std::memory_order_relaxed);
// Silence compiler warnings about unused arguments when NDEBUG is defined.
(void)pre_increment_acquires_allowed;
// If the check below fails, Release() was called more times than acquire.
assert(pre_increment_acquires_allowed < max_acquires_);
return false;
}
// Release a resource acquired by a previous call to Acquire() that returned
// true.
void Release() { acquires_allowed_.fetch_add(1, std::memory_order_relaxed); }
void Release() {
int old_acquires_allowed =
acquires_allowed_.fetch_add(1, std::memory_order_relaxed);
// Silence compiler warnings about unused arguments when NDEBUG is defined.
(void)old_acquires_allowed;
// If the check below fails, Release() was called more times than acquire.
assert(old_acquires_allowed < max_acquires_);
}
private:
#if !defined(NDEBUG)
// Catches an excessive number of Release() calls.
const int max_acquires_;
#endif // !defined(NDEBUG)
// The number of available resources.
//
// This is a counter and is not tied to the invariants of any other class, so

24
util/env_windows.cc
View File

@ -114,7 +114,14 @@ class ScopedHandle {
class Limiter {
public:
// Limit maximum number of resources to |max_acquires|.
Limiter(int max_acquires) : acquires_allowed_(max_acquires) {}
Limiter(int max_acquires)
:
#if !defined(NDEBUG)
max_acquires_(max_acquires),
#endif // !defined(NDEBUG)
acquires_allowed_(max_acquires) {
assert(max_acquires >= 0);
}
Limiter(const Limiter&) = delete;
Limiter operator=(const Limiter&) = delete;
@ -133,9 +140,22 @@ class Limiter {
// Release a resource acquired by a previous call to Acquire() that returned
// true.
void Release() { acquires_allowed_.fetch_add(1, std::memory_order_relaxed); }
void Release() {
int old_acquires_allowed =
acquires_allowed_.fetch_add(1, std::memory_order_relaxed);
// Silence compiler warnings about unused arguments when NDEBUG is defined.
(void)old_acquires_allowed;
// If the check below fails, Release() was called more times than acquire.
assert(old_acquires_allowed < max_acquires_);
}
private:
#if !defined(NDEBUG)
// Catches an excessive number of Release() calls.
const int max_acquires_;
#endif // !defined(NDEBUG)
// The number of available resources.
//
// This is a counter and is not tied to the invariants of any other class, so