Is it safe to cast the osThreadId pointer to a 32-bit integer for a unique thread ID across platform

Hey friends, Porting a product to a CMSIS RTOS. We need a 32-bit integer representing the thread ID. While

osThreadId

osThreadId

is opaque, comments suggest it's a pointer. Is it safe to cast the

osThreadId

osThreadId

pointer to a 32-bit integer for a unique thread ID across platforms? Why or why not? @Middleware & OS

Solution:

Hi @Dtynin , Casting a osThreadId pointer to a 32-bit integer is generally not safe and should be avoided, instead you can try maintain a mapping or using a 64-bit Integer. this is how your code should look like for maintaining a map 👇 ```c...

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Solution

Enthernet Code•2w ago

#include <stdint.h>
#include <stdlib.h>

#define MAX_THREADS 128

typedef struct {
    osThreadId threadId;
    uint32_t uniqueId;
} ThreadMapping;

ThreadMapping threadMappings[MAX_THREADS];
uint32_t nextUniqueId = 1;

uint32_t getThreadUniqueId(osThreadId threadId) {
    for (int i = 0; i < MAX_THREADS; i++) {
        if (threadMappings[i].threadId == threadId) {
            return threadMappings[i].uniqueId;
        }
    }

    // If thread ID not found, add new mapping
    for (int i = 0; i < MAX_THREADS; i++) {
        if (threadMappings[i].threadId == NULL) {
            threadMappings[i].threadId = threadId;
            threadMappings[i].uniqueId = nextUniqueId++;
            return threadMappings[i].uniqueId;
        }
    }

    // Handle case where no space is left for new threads
    // This can be expanded based on your application's requirements
    return 0;
}

#include <stdint.h>
#include <stdlib.h>

#define MAX_THREADS 128

typedef struct {
    osThreadId threadId;
    uint32_t uniqueId;
} ThreadMapping;

ThreadMapping threadMappings[MAX_THREADS];
uint32_t nextUniqueId = 1;

uint32_t getThreadUniqueId(osThreadId threadId) {
    for (int i = 0; i < MAX_THREADS; i++) {
        if (threadMappings[i].threadId == threadId) {
            return threadMappings[i].uniqueId;
        }
    }

    // If thread ID not found, add new mapping
    for (int i = 0; i < MAX_THREADS; i++) {
        if (threadMappings[i].threadId == NULL) {
            threadMappings[i].threadId = threadId;
            threadMappings[i].uniqueId = nextUniqueId++;
            return threadMappings[i].uniqueId;
        }
    }

    // Handle case where no space is left for new threads
    // This can be expanded based on your application's requirements
    return 0;
}

Joseph Ogbonna•2w ago

This might be helpful https://developer.arm.com/documentation/ka003944/latest/

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Is it safe to cast the osThreadId pointer to a 32-bit integer for a unique thread ID across platform