[wiring] Thread: fixes memory leakage due to mutex not being destroyed.

[XuGuohui]

Problem

Memory leakage if using wiring Mutex or RecursiveMutex class.

Solution

Add destructor which destroys the mutex if valid.

Example App

#include "Particle.h"

SYSTEM_MODE(MANUAL);
SerialLogHandler log(LOG_LEVEL_ALL);

void setup() {
}

void loop() {
    while(!Serial.isConnected());
    delay(1000);

    static runtime_info_t heapInfo;
    if (heapInfo.size == 0) {
        heapInfo.size = sizeof(heapInfo);
    }
    HAL_Core_Runtime_Info(&heapInfo, nullptr);
    Serial.printlnf("\n\n\n=======TP21============");
    Serial.printlnf("Heapinfo: size :%d, largest_free_block_heap :%lu", heapInfo.size, heapInfo.largest_free_block_heap);
    Serial.printlnf("===================\n\n\n");
    Mutex _buffer_mutex;
    HAL_Core_Runtime_Info(&heapInfo, nullptr);
    Serial.printlnf("\n\n\n=======TP22============");
    Serial.printlnf("Heapinfo: size :%d, largest_free_block_heap :%lu", heapInfo.size, heapInfo.largest_free_block_heap);
    Serial.printlnf("===================\n\n\n");
}

References

N/A

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Completeness

• User is totes amazing for contributing!
• Contributor has signed CLA (Info here)
• Problem and Solution clearly stated
• Run unit/integration/application tests on device
• Added documentation
• Added to CHANGELOG.md after merging (add links to docs and issues)

[eberseth]

Reviewed