deadlock_detection.ipynb

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    "def is_safe_state(available, max_claim, allocation):\n",
    "    # Get the number of resources and processes\n",
    "    num_resources = len(available)\n",
    "    num_processes = len(max_claim)\n",
    "\n",
    "    # Create a copy of available resources (work) and initialize finish array\n",
    "    work = available.copy()\n",
    "    finish = [False] * num_processes\n",
    "\n",
    "    while True:\n",
    "        found = False\n",
    "        # Iterate through each process\n",
    "        for i in range(num_processes):\n",
    "            # Check if the process is not finished and if it can be executed\n",
    "            if not finish[i] and all(work[j] >= max_claim[i][j] - allocation[i][j] for j in range(num_resources)):\n",
    "                found = True\n",
    "                # Mark the process as finished\n",
    "                finish[i] = True\n",
    "                # Add the allocated resources to the work vector\n",
    "                work = [work[j] + allocation[i][j] for j in range(num_resources)]\n",
    "                break\n",
    "\n",
    "        # If no process can be executed, break out of the loop\n",
    "        if not found:\n",
    "            break\n",
    "\n",
    "    # Check if all processes have finished (i.e., system is in a safe state)\n",
    "    return all(finish)\n",
    "\n",
    "def deadlock_detection(available, max_claim, allocation):\n",
    "    # Check if the current state is safe or in a deadlock\n",
    "    if is_safe_state(available, max_claim, allocation):\n",
    "        print(\"The system is in a safe state. No deadlock detected.\")\n",
    "    else:\n",
    "        print(\"Deadlock detected. The system is in an unsafe state.\")\n",
    "\n",
    "if __name__ == \"__main__\":\n",
    "    # case 1\n",
    "    # Define the available resources, maximum claim of each process, and current allocation\n",
    "    available_resources = [3, 3, 2]\n",
    "    max_claim_per_process = [\n",
    "        [7, 5, 3],\n",
    "        [3, 2, 2],\n",
    "        [9, 0, 2],\n",
    "        [2, 2, 2],\n",
    "        [4, 3, 3]\n",
    "    ]\n",
    "    current_allocation = [\n",
    "        [0, 1, 0],\n",
    "        [2, 0, 0],\n",
    "        [3, 0, 2],\n",
    "        [2, 1, 1],\n",
    "        [0, 0, 2]\n",
    "    ]\n",
    "\n",
    "    # Perform deadlock detection\n",
    "    deadlock_detection(available_resources, max_claim_per_process, current_allocation)\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
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   "source": [
    "# case 2\n",
    "if __name__ == \"__main__\":\n",
    "    # Define the deadlock scenario\n",
    "    available_resources = [2, 2, 2]\n",
    "    max_claim_per_process = [\n",
    "        [3, 2, 2],\n",
    "        [1, 2, 4],\n",
    "        [4, 4, 3],\n",
    "        [2, 3, 2]\n",
    "    ]\n",
    "    current_allocation = [\n",
    "        [0, 1, 0],\n",
    "        [0, 0, 1],\n",
    "        [2, 1, 1],\n",
    "        [1, 0, 0]\n",
    "    ]\n",
    "\n",
    "    # Perform deadlock detection\n",
    "    deadlock_detection(available_resources, max_claim_per_process, current_allocation)\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Alternative 2\n",
    "With input"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "def input_data():\n",
    "    global n, r, max_claim, allocation, avail\n",
    "\n",
    "    n = int(input(\"Enter the number of processes: \"))\n",
    "    r = int(input(\"Enter the number of resources: \"))\n",
    "\n",
    "    print(\"Enter the Maximum Claim Matrix:\")\n",
    "    max_claim = []\n",
    "    for i in range(n):\n",
    "        row = list(map(int, input().split()))\n",
    "        max_claim.append(row)\n",
    "\n",
    "    print(\"Enter the Allocation Matrix:\")\n",
    "    allocation = []\n",
    "    for i in range(n):\n",
    "        row = list(map(int, input().split()))\n",
    "        allocation.append(row)\n",
    "\n",
    "    print(\"Enter the Available Resources:\")\n",
    "    avail = list(map(int, input().split()))\n",
    "\n",
    "\n",
    "def show_data():\n",
    "    global n, r, max_claim, allocation, avail\n",
    "\n",
    "    print(\"Process\\tAllocation\\tMax\\t\\tAvailable\")\n",
    "    for i in range(n):\n",
    "        print(f\"P{i + 1}\\t\\t{allocation[i]}\\t\\t{max_claim[i]}\\t\\t{avail}\")\n",
    "\n",
    "\n",
    "def is_safe_state():\n",
    "    global n, r, max_claim, allocation, avail\n",
    "\n",
    "    work = avail.copy()\n",
    "    finish = [False] * n\n",
    "\n",
    "    while True:\n",
    "        found = False\n",
    "        for i in range(n):\n",
    "            if not finish[i] and all(work[j] >= max_claim[i][j] - allocation[i][j] for j in range(r)):\n",
    "                found = True\n",
    "                finish[i] = True\n",
    "                work = [work[j] + allocation[i][j] for j in range(r)]\n",
    "                break\n",
    "\n",
    "        if not found:\n",
    "            break\n",
    "\n",
    "    return all(finish)\n",
    "\n",
    "\n",
    "def deadlock_detection():\n",
    "    if is_safe_state():\n",
    "        print(\"The system is in a safe state. No deadlock detected.\")\n",
    "    else:\n",
    "        print(\"Deadlock detected. The system is in an unsafe state.\")\n",
    "\n",
    "\n",
    "if __name__ == \"__main__\":\n",
    "    print(\"********** Deadlock Detection Algo ************\")\n",
    "    input_data()\n",
    "    show_data()\n",
    "    deadlock_detection()\n"
   ]
  }
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