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The calling thread locks the recursive_mutex, blocking if necessary:
All lock and unlock operations on the recursive_mutex follow a single total order, with all visible effects synchronized between the lock operations and previous unlock operations on the same object.
Note that the order in which different concurrent locks are scheduled to return is unspecified, and not necessarily related to the order in which they are locked (depending on the system and library implementation).
If the call fails, a system_error exception is thrown:
Depending on the library implementation, this member function may also throw exceptions to report other situations.
Reference
C library:
- <cassert> (assert.h)
- <cctype> (ctype.h)
- <cerrno> (errno.h)
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<cfenv> (fenv.h)C++11
- <cfloat> (float.h)
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<cinttypes> (inttypes.h)C++11
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<cstdbool> (stdbool.h)C++11
- <cstddef> (stddef.h)
-
<cstdint> (stdint.h)C++11
- <cstdio> (stdio.h)
- <cstdlib> (stdlib.h)
- <cstring> (string.h)
-
<ctgmath> (tgmath.h)C++11
- <ctime> (time.h)
-
<cuchar> (uchar.h)C++11
- <cwchar> (wchar.h)
- <cwctype> (wctype.h)
Containers:
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<array>C++11
- <deque>
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<forward_list>C++11
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<unordered_map>C++11
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<unordered_set>C++11
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Input/Output:
Multi-threading:
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<atomic>C++11
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<condition_variable>C++11
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<future>C++11
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<mutex>C++11
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<thread>C++11
-
Other:
- <algorithm>
- <bitset>
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<chrono>C++11
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<codecvt>C++11
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<initializer_list>C++11
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<random>C++11
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<system_error>C++11
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<tuple>C++11
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<type_traits>C++11
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<typeindex>C++11
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<mutex>
classes
-
adopt_lock_tC++11
-
defer_lock_tC++11
-
lock_guardC++11
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mutexC++11
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once_flagC++11
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recursive_mutexC++11
-
recursive_timed_mutexC++11
-
timed_mutexC++11
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try_to_lock_tC++11
-
unique_lockC++11
-
functions
constants
-
adopt_lockC++11
-
defer_lockC++11
-
try_to_lockC++11
-
recursive_mutex
-
recursive_mutex::~recursive_mutexC++11
-
recursive_mutex::recursive_mutexC++11
member functions
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recursive_mutex::lockC++11
-
recursive_mutex::native_handleC++11
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recursive_mutex::try_lockC++11
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recursive_mutex::unlockC++11
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public member function
<mutex>
std::recursive_mutex::lock
void lock();
Lock recursive mutex
- If the recursive_mutex isn't currently locked by any thread, the calling thread locks it (from this point, and until its member unlock is called, the thread owns the mutex).
- If the recursive_mutex is currently locked by another thread, execution of the calling thread is blocked until completely unlocked by the other thread (other non-locked threads continue their execution).
- If the recursive_mutex is currently locked by the same thread calling this function, the thread acquires a new level of ownership over the recursive_mutex. Unlocking the recursive_mutex completely will require an additional call to member unlock.
All lock and unlock operations on the recursive_mutex follow a single total order, with all visible effects synchronized between the lock operations and previous unlock operations on the same object.
Note that the order in which different concurrent locks are scheduled to return is unspecified, and not necessarily related to the order in which they are locked (depending on the system and library implementation).
Parameters
noneReturn value
noneData races
The recursive_mutex object is modified as an atomic operation (causing no data races).Exception safety
Basic guarantee: if an exception is thrown by this member function, the recursive_mutex object is left in a valid state. Further, a lock is never acquired by the thread that made the throwing call.If the call fails, a system_error exception is thrown:
| exception type | error condition | description |
|---|---|---|
| system_error | errc::resource_deadlock_would_occur | A deadlock was detected (implementations may detect certain cases of deadlock). |
| system_error | errc::operation_not_permitted | The thread does not have privileges to perform the operation. |
| system_error | errc::device_or_resource_busy | The native handle type manipulated is already locked. |
See also
- recursive_mutex::try_lock
- Lock mutex if not locked by other threads (public member function)
- recursive_mutex::unlock
- Unlocks mutex (public member function)
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Spotted an error? contact us