Added mutex.h and thread.h

src/cor/flags.h

@@ -26,15 +26,18 @@ static struct
     int RANGE;     // Index out of range
     int DUPLICATE; // Duplicate key or value
     int ERROR;     // Generic error, usually caused by algorithm error
-} cmc_flags = { 0, 1, 2, 3, 4, 5, 6, 7 };
+    int THREAD;    // Generic error regarding threads
+    int MUTEX;     // Generic error regarding mutexes
+} cmc_flags = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
 
 /**
  * cmc_flags_to_str
  *
  * Maps the error codes to their character representation.
  */
-const char *cmc_flags_to_str[8] = { "OK",        "ALLOC",   "EMPTY",
+const char *cmc_flags_to_str[10] = { "OK",        "ALLOC",   "EMPTY",
-                                    "NOT_FOUND", "INVALID", "RANGE",
+                                     "NOT_FOUND", "INVALID", "RANGE",
-                                    "DUPLICATE", "ERROR" };
+                                     "DUPLICATE", "ERROR",   "THREAD",
+                                     "MUTEX" };
 
 #endif /* CMC_FLAGS_H */

src/utl/mutex.h

@@ -0,0 +1,212 @@
+/**
+ * mutex.h
+ *
+ * Creation Date: 14/05/2020
+ *
+ * Authors:
+ * Leonardo Vencovsky (https://github.com/LeoVen)
+ *
+ */
+
+/**
+ * A very simple, header-only and minimalistic cross-platform mutex
+ *
+ * Types
+ *  - cmc_mutex
+ *
+ * Functions
+ *  - cmc_mtx_init
+ *  - cmc_mtx_destroy
+ *  - cmc_mtx_lock
+ *  - cmc_mtx_unlock
+ *  - cmc_mtx_trylock
+ */
+
+#include <stdbool.h>
+
+#include "../cor/flags.h"
+
+#if defined(_WIN32)
+#define CMC_MUTEX_WINDOWS
+#elif defined(__unix__)
+#define CMC_MUTEX_UNIX
+#else
+#error "Unknown platform for CMC Mutex"
+#endif
+
+/* Platform specific includes */
+#if defined(CMC_MUTEX_WINDOWS)
+#include <windows.h>
+#elif defined(CMC_MUTEX_UNIX)
+#include <errno.h>
+#include <pthread.h>
+#endif
+
+/**
+ * struct cmc_mutex
+ *
+ * A mutex wrapper.
+ */
+struct cmc_mutex
+{
+#if defined(CMC_MUTEX_WINDOWS)
+    HANDLE mutex;
+#elif defined(CMC_MUTEX_UNIX)
+    pthread_mutex_t mutex;
+#endif
+    int flag;
+};
+
+/**
+ * Acquire resources for a mutex.
+ *
+ * \param mtx An uninitialized mutex wrapper.
+ * \return True or false if the mutex was successfully initialized.
+ */
+static inline bool cmc_mtx_init(struct cmc_mutex *mtx)
+{
+#if defined(CMC_MUTEX_WINDOWS)
+    mtx->mutex = CreateMutex(NULL, FALSE, NULL);
+
+    if (mtx->mutex == NULL)
+        mtx->flag = cmc_flags.MUTEX;
+    else
+        mtx->flag = cmc_flags.OK;
+
+    return mtx->mutex != NULL;
+
+#elif defined(CMC_MUTEX_UNIX)
+    int err = pthread_mutex_init(&(mtx->mutex), NULL);
+
+    if (err != 0)
+        mtx->flag = cmc_flags.MUTEX;
+    else
+        mtx->flag = cmc_flags.OK;
+
+    return err == 0;
+#endif
+}
+
+/**
+ * Release all resources from a mutex. Calling this function on a locked mutex
+ * causes undefined behavior.
+ *
+ * \param mtx A mutex to be destroyed.
+ * \return True or false if the mutex was successfully destroyed.
+ */
+static inline bool cmc_mtx_destroy(struct cmc_mutex *mtx)
+{
+#if defined(CMC_MUTEX_WINDOWS)
+    if (!CloseHandle(mtx->mutex))
+    {
+        mtx->flag = cmc_flags.MUTEX;
+        return false;
+    }
+
+    mtx->flag = cmc_flags.OK;
+    return true;
+
+#elif defined(CMC_MUTEX_UNIX)
+    if (pthread_mutex_destroy(&(mtx->mutex)) != 0)
+    {
+        mtx->flag = cmc_flags.MUTEX;
+        return false;
+    }
+
+    mtx->flag = cmc_flags.OK;
+    return true;
+#endif
+}
+
+/**
+ * Locks a mutex. If the mutex is already locked, the thread is blocked until
+ * the mutex can be acquired.
+ *
+ * \param mtx A mutex to be locked.
+ * \return True or false if the lock on the mutex was successfully acquired.
+ */
+static inline bool cmc_mtx_lock(struct cmc_mutex *mtx)
+{
+#if defined(CMC_MUTEX_WINDOWS)
+    DWORD result = WaitForSingleObject(mtx->mutex, INFINITE);
+
+    if (result == WAIT_FAILED || result == WAIT_ABANDONED)
+    {
+        mtx->flag = cmc_flags.MUTEX;
+        return false;
+    }
+
+    mtx->flag = cmc_flags.OK;
+    return true;
+
+#elif defined(CMC_MUTEX_UNIX)
+    if (pthread_mutex_lock(&mtx->mutex) != 0)
+    {
+        mtx->flag = cmc_flags.MUTEX;
+        return false;
+    }
+
+    mtx->flag = cmc_flags.OK;
+    return true;
+#endif
+}
+
+/**
+ * Unlocks a mutex. If the mutex is already locked, the thread is blocked until
+ * the mutex can be acquired.
+ *
+ * \param mtx A mutex to be unlocked.
+ * \return True or false if the mutex was successfully unlocked.
+ */
+static inline bool cmc_mtx_unlock(struct cmc_mutex *mtx)
+{
+#if defined(CMC_MUTEX_WINDOWS)
+    if (!ReleaseMutex(mtx->mutex))
+        mtx->flag = cmc_flags.MUTEX;
+    else
+        mtx->flag = cmc_flags.OK;
+
+    return mtx->flag == cmc_flags.OK;
+
+#elif defined(CMC_MUTEX_UNIX)
+    if (pthread_mutex_unlock(&mtx->mutex) != 0)
+        mtx->flag = cmc_flags.MUTEX;
+    else
+        mtx->flag = cmc_flags.OK;
+
+    return mtx->flag == cmc_flags.OK;
+#endif
+}
+
+/**
+ * Tries to lock a mutex. If the mutex is already locked, the thread is not
+ * blocked and the function returns false.
+ *
+ * \param mtx A mutex to try to lock.
+ * \return True or false if the lock on the mutex was successfully acquired.
+ */
+static inline bool cmc_mtx_trylock(struct cmc_mutex *mtx)
+{
+#if defined(CMC_MUTEX_WINDOWS)
+    DWORD result = WaitForSingleObject(mtx->mutex, 0);
+
+    if (result == WAIT_FAILED || result == WAIT_ABANDONED)
+    {
+        mtx->flag = cmc_flags.MUTEX;
+        return false;
+    }
+
+    mtx->flag = cmc_flags.OK;
+    return result != WAIT_TIMEOUT;
+
+#elif defined(CMC_MUTEX_UNIX)
+    int err = pthread_mutex_trylock(&mtx->mutex);
+
+    if (err == EINVAL || err == EFAULT)
+        mtx->flag = cmc_flags.MUTEX;
+    else
+        mtx->flag = cmc_flags.OK;
+
+    return err == 0;
+#endif
+}

src/utl/thread.h

@@ -0,0 +1,173 @@
+/**
+ * thread.h
+ *
+ * Creation Date: 14/05/2020
+ *
+ * Authors:
+ * Leonardo Vencovsky (https://github.com/LeoVen)
+ *
+ */
+
+/**
+ * A very simple, header-only utility for spawning and joining threads
+ *
+ * Types
+ *  - cmc_thread
+ *  - cmc_thread_proc
+ *
+ * Functions
+ *  - cmc_thrd_create
+ *  - cmc_thrd_join
+ */
+
+#include <inttypes.h>
+#include <stdbool.h>
+
+#include "../cor/flags.h"
+
+#if defined(_WIN32)
+#define CMC_THREAD_WINDOWS
+#elif defined(__unix__)
+#define CMC_THREAD_UNIX
+#else
+#error "Unknown platform for CMC Threads"
+#endif
+
+#if defined(CMC_THREAD_WINDOWS)
+#include <windows.h>
+#elif defined(CMC_THREAD_UNIX)
+#include <pthread.h>
+#endif
+
+/* The type of a process run by a thread */
+typedef int (*cmc_thread_proc)(void *);
+
+/**
+ * struct cmc_thread
+ *
+ * A thread wrapper.
+ */
+struct cmc_thread
+{
+#if defined(CMC_THREAD_WINDOWS)
+    HANDLE thread;
+#elif defined(CMC_THREAD_UNIX)
+    pthread_t thread;
+#endif
+    int flag;
+    void *args;
+    cmc_thread_proc process;
+};
+
+/* A thread wrapper */
+#if defined(CMC_THREAD_WINDOWS)
+static DWORD cmc_thread_wrapper(void *arg)
+#elif defined(CMC_THREAD_UNIX)
+static void *cmc_thread_wrapper(void *arg)
+#endif
+{
+    struct cmc_thread *thr = (struct cmc_thread *)arg;
+
+    int result = thr->process(thr->args);
+
+#if defined(CMC_THREAD_WINDOWS)
+    return result;
+#elif defined(CMC_THREAD_UNIX)
+    return (void *)(intptr_t)result;
+#endif
+}
+
+/**
+ * Creates and spawns a new thread.
+ *
+ * \param thr  An uninitialized thread wrapper.
+ * \param proc Pointer to a function that will run in a new thread.
+ * \param args The arguments passed to the proc function.
+ * \return True or false if the thread creation was successfull.
+ */
+static inline bool cmc_thrd_create(struct cmc_thread *thr, cmc_thread_proc proc,
+                                   void *args)
+{
+#if defined(CMC_THREAD_WINDOWS)
+    thr->args = args;
+    thr->process = proc;
+    thr->thread = CreateThread(NULL, 0, cmc_thread_wrapper, thr, 0, NULL);
+
+    if (!thr->thread)
+        thr->flag = cmc_flags.THREAD;
+    else
+        thr->flag = cmc_flags.OK;
+
+    return thr->flag == cmc_flags.OK;
+
+#elif defined(CMC_THREAD_UNIX)
+    thr->args = args;
+    thr->process = proc;
+    if (pthread_create(&(thr->thread), NULL, cmc_thread_wrapper, thr) != 0)
+        thr->flag = cmc_flags.THREAD;
+    else
+        thr->flag = cmc_flags.OK;
+
+    return thr->flag == cmc_flags.OK;
+#endif
+}
+
+/**
+ * Blocks the current thread until the target thread terminates.
+ *
+ * \param thr    The target thread to wait on.
+ * \param result The value returned by the target thread. Optional.
+ * \return True or false if the join was successfull.
+ */
+static inline bool cmc_thrd_join(struct cmc_thread *thr, int *result)
+{
+#if defined(CMC_THREAD_WINDOWS)
+    if (WaitForSingleObject(thr->thread, INFINITE) == WAIT_FAILED)
+    {
+        thr->flag = cmc_flags.THREAD;
+        return false;
+    }
+
+    DWORD exit_code;
+
+    if (result)
+    {
+        if (GetExitCodeThread(thr->thread, &exit_code) == 0)
+        {
+            thr->flag = cmc_flags.THREAD;
+            return false;
+        }
+        else
+            *result = (int)exit_code;
+    }
+
+    thr->flag = cmc_flags.OK;
+
+    if (CloseHandle(thr->thread) == 0)
+    {
+        thr->flag = cmc_flags.THREAD;
+        return false;
+    }
+
+    thr->flag = cmc_flags.OK;
+    return true;
+
+#elif defined(CMC_THREAD_UNIX)
+    void *exit_value;
+
+    if (pthread_join(thr->thread, &exit_value) != 0)
+    {
+        thr->flag = cmc_flags.THREAD;
+        return false;
+    }
+
+    if (result)
+    {
+        *result = (int)(intptr_t)exit_value;
+    }
+
+    thr->flag = cmc_flags.OK;
+    return true;
+
+#endif
+}