-
Notifications
You must be signed in to change notification settings - Fork 32
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
1 parent
00d435f
commit 4ca1ad1
Showing
6 changed files
with
91 additions
and
7 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,86 @@ | ||
| #ifndef _JB_LIBRARIES_MINI_MUTEX_H_ | ||
| #define _JB_LIBRARIES_MINI_MUTEX_H_ | ||
|
|
||
| #include <util/atomic.h> | ||
| #include <tribool.h> | ||
|
|
||
| // Class contains Arduino implementation of very basic approach to mutex | ||
| // | ||
| // Created by https://github.com/jbanaszczyk | ||
|
|
||
| namespace jb { | ||
| namespace threads { | ||
| using namespace jb::logic; | ||
|
|
||
| template <typename T = uint8_t, T LOCKED = T{ 0xC3 }, T UNLOCKED = T{ 0x3C } > | ||
| class safe_mutex { | ||
|
|
||
| public: | ||
| safe_mutex(const safe_mutex&) = delete; | ||
| safe_mutex& operator = (const safe_mutex &) = delete; | ||
| safe_mutex() : state(UNLOCKED) {}; | ||
| ~safe_mutex() { | ||
| static_assert (mixer(LOCKED, UNLOCKED) != LOCKED, "Function mixer() in destructor should return something different from LOCKED and UNLOCKED value (LOCKED)"); | ||
| static_assert (mixer(LOCKED, UNLOCKED) != UNLOCKED, "Function mixer() in destructor should return something different from LOCKED and UNLOCKED value (UNLOCKED)"); | ||
| static_assert (LOCKED != UNLOCKED, "LOCKED and UNLOCKED parameters should be different"); | ||
| state = mixer(LOCKED, UNLOCKED); | ||
| } | ||
|
|
||
| tribool try_lock() { | ||
| tribool result = unknown; | ||
| ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { | ||
| if ((state == LOCKED) || (state == UNLOCKED)) { | ||
| result = state == UNLOCKED; | ||
| state = LOCKED; | ||
| } | ||
| } | ||
| return result; | ||
| } | ||
|
|
||
| void unlock() { | ||
| ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { | ||
| if (state == LOCKED) { | ||
| state = UNLOCKED; | ||
| } | ||
| } | ||
| } | ||
|
|
||
| protected: | ||
| volatile T state; | ||
|
|
||
| private: | ||
| static constexpr T mixer(T lhs, T rhs) { | ||
| return (!lhs) ^ (!rhs); | ||
| } | ||
| }; | ||
|
|
||
| class mutex { | ||
|
|
||
| public: | ||
| mutex(const mutex &) = delete; | ||
| mutex & operator = (const mutex &) = delete; | ||
| mutex() : unlocked(true) {}; | ||
|
|
||
| bool try_lock() { | ||
| static_assert (sizeof(unlocked) == 1, "locked : expected single byte"); | ||
| bool result; | ||
| ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { | ||
| result = unlocked; | ||
| unlocked = false; | ||
| } | ||
| return result; | ||
| } | ||
|
|
||
| void unlock() { | ||
| unlocked = true; | ||
| } | ||
|
|
||
|
|
||
| public: | ||
| volatile bool unlocked; | ||
| }; | ||
|
|
||
| } | ||
| } | ||
|
|
||
| #endif |